cancer

Are NMN Supplements Safe?

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Where Do The Warnings Come From? 

Author: Dr. Stephen Chaney 

Where Do The Warnings Come From?

It’s no secret that the medical-pharmaceutical industry is biased against supplements. They view supplements as useless at best and dangerous at worst. They minimize the benefits and emphasize the potential dangers.

So, it is no surprise that whenever a supplement becomes popular, you start to hear about its dangers and are warned to check with your doctor before using them.

That’s great advice, but you need to think about where your doctor is getting their information. If it is from a medical society or pharmaceutical rep, the information is likely to be negative.

If they do an online search, you need to know that AI provides the most popular answer, not necessarily the most accurate answer.

AI is getting a little better in that it usually provides links to the sources of its information – and some of those links are to published scientific studies. But your doctor is overwhelmed. Unless they are highly motivated, they are unlikely to read and evaluate the studies behind the scary warnings that AI provides.

NMN supplements are no different. They have become very popular because of their clear benefits for an ageing population and their potential benefits for longevity. So, warnings of their dangers are proliferating.

If you believe in all the warnings, it sounds like almost no one should use them, and everyone should consult their doctor before using them. So, in this issue of “Health Tips From the Professor” I will evaluate the studies behind the warnings and help you evaluate the safety of NMN supplements.

My purpose is not to discourage you from consulting with your doctor where appropriate, but to give you enough information so you can have an informed discussion with your doctor.

NMN Supplements And Cancer 

You may have heard that NMN supplements may stimulate cancer cell growth, so you should not use them if you have or have had cancer. I covered this topic in detail in a previous issue of “Health Tips From the Professor”. Here is a “Cliff’s Notes” summary of that article: 

  • There are five studies utilizing cell culture and animal model systems, which are notoriously unreliable for predicting what happens in the human body
    • Two of those studies report that NMN may stimulate cancer cell growth. And one of those studies is an abstract from a presentation given at a scientific meeting. It has not yet gone through the peer review process required for publication.
    • Two of those studies report that NMN may inhibit cancer cell growth.
    • One study reported that NMN may reduce the side effects of chemotherapy.
  • There are currently no published human clinical studies on NMN supplementation and cancer risk.

In summary, we currently have no idea whether NMN supplements increase or decrease cancer risk. Based on currently published studies, both possibilities are equally probable. And the little published data we do have is based on cell culture and animal experiments which are notoriously unreliable.

Without clear guidance from clinical studies, I only have two thoughts to share with you:

  • If you currently have cancer or you have had cancer, you may wish to consult your health care provider before starting on an NMN supplement. Just understand that they have no reliable data on which to base their recommendation.
  • Until more definitive data are available, I recommend avoiding NMN supplementation while undergoing cancer treatment. I am basing my recommendation on a single animal study suggesting that NMN may interfere with chemotherapeutic agents that damage DNA. And the fact that NADH is involved in DNA repair provides a theoretical rationale for this observation.

It is not clear whether this applies to cancer drugs that do not damage DNA. And it is balanced by animal models suggesting that NMN may improve the results of chemotherapy by enhancing the immune response.

I wish I could provide you with a more definitive answer to your questions about NMN and cancer risk. But, like your health care provider, I don’t have reliable data on which to base my recommendations. And unlike most bloggers and social media influencers, I value accuracy more than clicks.

NMN And Blood Pressure Medications 

You have been warned that taking NAD+ precursors like NMN can significantly lower your blood pressure and increase your risk of developing dangerously low blood pressure. In this case we do have some clinical studies to guide us, but they are very small and should be considered preliminary.

One study with 24 subjects compared nicotinamide riboside (NR), another precursor to NAD+, to a placebo in a 6-week double blind study. It found:

  • NR improved blood vessel dilation and modestly decreased both systolic and diastolic blood pressure.
    • The decrease in blood pressure was greater in individuals with stage 1 hypertension (systolic blood pressure between 130 and 139 or diastolic blood pressure between 80 and 89).
    • None of these differences were statistically significant because of the small size of the study. The same authors have begun enrolling subjects into a larger phase-II clinical trial, but the results of this study are not yet available.

Another study of 19 subjects with stage 1 hypertension compared NMN supplementation with lifestyle change in a 6-week double blind study. It found:

  • NMN improved blood vessel dilation and modestly decreased both systolic and diastolic blood pressure in patients with mild hypertension.

A recent (2026) meta-analysis of data from 349 participants in 10 clinical studies reported:

  • NMN supplementation was associated with a statistically significant but modest reduction in diastolic blood pressure.
  • Overall, the reduction in systolic blood pressure was not statistically significant except for a modest reduction in participants over the age of 60.

In summary, the existing clinical studies are small and preliminary, but they all point toward the conclusion that NAD+ precursors like NR and NMN cause a modest reduction in blood pressure.

So, what does this mean for you?

  • For most users of NMN supplements this represents a side benefit, something that can be combined with diet and lifestyle modification to help you control your blood pressure.
  • The effect of NMN supplements on blood pressure is modest, so NMN supplements should not be considered an alternative to blood pressure medications.
  • If you are currently on blood pressure medications, there is a slight chance that combining NMN with your blood pressure medication might cause your blood pressure to become too low. I say slight chance because the effect of NMN supplements on blood pressure is so modest.

At this point I should reveal my bias, as if you haven’t already guessed. I try to avoid medications and their side effects as much as possible. When confronted with a health challenge I try diet, lifestyle change, and supplementation first, and only consider medication as a last resort. And so far, it is working. I am on zero medications.

But if I were on a medication and was faced with a possible supplement-medication interaction, my choice would be to modify the drug dose based on the supplement I was using rather than modify my supplement use based on the medication.

Finally, what does this mean in terms of your informed discussion with your doctor? Now that you know the facts, my recommendation is to discuss a plan with your doctor where you will monitor your blood pressure on a regular basis and report any changes to them so they can modify your medication dose if appropriate.

You might also want to watch for symptoms of low blood pressure such as dizziness or lightheadedness when standing up quickly, blurred vision, fatigue, or confusion. Monitoring symptoms should not be considered an alternative to blood pressure measurements. But if the symptoms are new and persistent, you should report them to your doctor.

NMN And Diabetes Medications 

You have been told that NAD+ precursors like NMN can interfere with blood-sugar lowering medications and reduce their effectiveness. Here the supporting data is very sketchy.

  • One animal study reported that high doses of niacinamide (vitamin B3) caused insulin resistance.
  • A clinical study with 8 subjects reported that a high dose (2 grams/day) of niacinamide for 2 weeks caused an increase in insulin resistance.
    • It should be noted that niacinamide is much less effective than NMN at increasing NAD+ levels and has metabolic effects that are different than NMN. It should also be noted that based on their molecular weights, this would be equivalent to a dose of 5.5 grams/day of NMN, which is considered an unsafe dose and greatly exceeds the dose found in NMN supplements.
  • Another clinical study with 11 subjects who took 250 mg/day of NMN (a more realistic dose) for 12 weeks reported:
    • NMN supplementation enhanced the increase in serum insulin levels following a meal.
    • The effect of NMN supplementation on insulin secretion following a meal varied widely among individuals.

Again, the question is what this means for you:

  • The studies are preliminary and conflicting. There is no good evidence on which to base recommendations.
  • However, the second clinical study is more convincing because it was conducted with NMN at a dosage similar to that found in most NMN supplements. If that finding is confirmed by future clinical studies, it would suggest that NMN supplements may enhance insulin sensitivity and improve blood sugar control.
  • For most users of NMN supplements that would represent a side benefit.
  • For people on blood-sugar lowering medications it raises the slight risk that the combination of NMN with your medication may cause your blood sugar levels to fall too far, causing hypoglycemia.

What does this mean in terms of your informed discussion with your doctor?

Most people on blood sugar medications are monitoring their blood sugar levels on a regular basis. If that is you, I would recommend continuing what you are doing. If your blood sugar levels go below your doctor’s recommendations after adding an NMN supplement, it would be time for an informed discussion with your doctor about lowering the dosage of your blood sugar medication.

If you aren’t currently monitoring your blood sugar levels, I would recommend an informed discussion with your doctor where you propose a plan to regularly monitor your blood sugar levels and inform your doctor of any changes.

NMN Supplements And Blood Thinners 

You may have been told that NAD+ precursors like NMN may affect the metabolism of blood thinners and alter your clotting time. In this case, the warnings are entirely theoretical. There are neither animal nor clinical studies that indicate this might be a problem with NMN. In short, we have no information about the effect of NMN on clotting time or whether NMN could alter the metabolism of blood thinning medications.

And we’ve seen this story before. We’ve been told that vitamin E, garlic, turmeric, and ginger should not be taken with blood thinners. In fact, the effect of each of these supplements on clotting time is insignificant at normal doses.

High-dose omega-3s represent the only supplement where the interaction with blood thinners is significant. And, as I mentioned above, if I were on a blood thinner, my preference would be to adjust the blood thinner dose based on my omega-3 intake rather than adjusting my omega-3 intake based on the blood thinner dose.

What does this mean in terms of your informed discussion with your doctor?

As I said above, there are no data that would suggest using NMN with blood thinners is a problem. However, if you are on blood thinning medication any effect on clotting time can have serious consequences.

So, if you wish to err on the side of caution, you might want to ask your doctor to test your clotting time before you start NMN supplementation and at an appropriate time after beginning NMN supplementation. That way, if there is a significant effect of NMN on your clotting time, you and your doctor can have an informed discussion about the best way to handle it.

Final Thoughts On NMN Safety 

A meta-analysis on the overall safety of NMN supplements has recently (July 2026) been published. It extracted safety data from 10 placebo-controlled NMN studies of 12-24 weeks with a total of 336 subjects. The study reported that NMN supplementation:

  • Did not cause any adverse side effects.
  • Did not increase ALT or AST, which means that there was no indication of liver damage.
  • Did not affect fasting blood glucose or HbA1C, and HOMA-IR, a measure of insulin resistance, showed a slight, non-significant decrease. In short, there was no evidence that NMN supplementation caused insulin resistance or had a significant effect on blood sugar control.
  • Did not affect lipid profiles.
  • Decreased diastolic blood pressure slightly but did not affect systolic blood pressure.

The authors concluded, “Short-term oral NMN or NMN-related supplementation showed favorable tolerability, with no clear increase in adverse events or hepatic biochemical abnormalities. Broad metabolic benefits [fasting blood glucose, HbA1c, and lipid levels] were not evident, but changes in diastolic blood pressure and HOMA-IE suggest preliminary [evidence of benefit], especially in older adults…Larger and longer trials should confirm efficacy and long-term safety.”

My comments:

  • This meta-analysis strengthens the data I described above for the effects of NMN supplements on blood pressure and blood sugar control.
  • Confirming these results with larger and longer clinical trials would be expensive. Food supplement companies don’t have the money for these kinds of studies, and pharmaceutical companies won’t touch them because they can’t patent NMN.
  • Larger, longer studies are not likely unless.
    • The medical community decides that the safety and efficacy of NMN supplements is an important enough issue to design such a study.
    • And the government decides to fund such a study.

The Bottom Line 

Whenever a supplement becomes popular and widely used, you start to hear about its dangers. NMN supplements are no different. They have become very popular because of their clear benefits for an ageing population and their potential benefits for longevity. So, warnings of their dangers are proliferating. 

In this issue of “Health Tips From the Professor” I list the top four warnings you may have heard about NMN supplements, evaluate the data supporting these warnings, and recommend how you can have an informed discussion with your doctor about each of warning.

For more information on the pros and cons of this study and what it means for you, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

___________________________________________________________________________________________

My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.

My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance

___________________________________________________________________________________

About The Author 

Dr. Chaney has a BS in Chemistry from Duke University and a PhD in Biochemistry from UCLA. He is Professor Emeritus from the University of North Carolina where he taught biochemistry and nutrition to medical and dental students for 40 years.  Dr. Chaney won numerous teaching awards at UNC, including the Academy of Educators “Excellence in Teaching Lifetime Achievement Award”.

Dr Chaney also ran an active cancer research program at UNC and published over 100 scientific articles and reviews in peer-reviewed scientific journals. In addition, he authored two chapters on nutrition in one of the leading biochemistry text books for medical students.

Since retiring from the University of North Carolina, he has been writing a weekly health blog called “Health Tips From the Professor”. He has also written two best-selling books, “Slaying the Food Myths” and “Slaying the Supplement Myths”. And most recently he has created an online lifestyle change course, “Create Your Personal Health Zone”. For more information visit https://chaneyhealth.com.

For the past 54 years Dr. Chaney and his wife Suzanne have been helping people improve their health holistically through a combination of good diet, exercise, weight control and appropriate supplementation.

Should Women Avoid Soy?

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Why Is There So Much Confusion About Soy?

Author: Dr. Stephen Chaney

soyMother’s Day was last Sunday. We love the women in our lives and want to keep them happy and healthy. But what should we tell them about soy? Should women avoid soy? Or is it good for them? Is it something they should be including in their diet?

Unfortunately, there is a lot of confusion about soy. The key issue is, “What is the truth about soy and breast cancer? Does it increase the risk of breast cancer, or is that just a myth?” If you are a woman, particularly a woman with breast cancer, it is an important question.

Some experts say soy should be avoided at all costs. They say that soy will increase your risk of breast cancer. Other experts say soy is perfectly safe and may even reduce your risk of breast cancer. Who is right?

If you are a breast cancer survivor, the question of whether soy increases or decreases your risk of disease recurrence is even more crucial. You have already endured surgery, chemotherapy, and/or radiation. You never want to go through that again.

Why Is There So Much Confusion About Soy?

soy confusionSoy isoflavones decrease estrogen production, strengthen the immune system, inhibit cell proliferation, and reduce the production of reactive oxygen species. These are all effects that might reduce breast cancer risk.

On the other hand, soy isoflavones also bind to estrogen receptors and exhibit weak estrogenic activity. This effect has the potential to increase breast cancer risk.

Cell culture and animal studies have only confused the issue. Soy isoflavones stimulate the growth of breast cancer cells in a petri dish. Soy isoflavones also stimulate breast cancer growth in a special strain of mice lacking an immune system. However, in studies in both mice and rats with a functioning immune system, soy isoflavones decrease breast cancer risk.

The confusion has been amplified by claims and counterclaims on the internet. There are bloggers who are more interested in the spectacular than they are in accuracy (Today we call this fake news). They have taken the very weak evidence that soy isoflavones could possibly increase breast cancer risk and have blown it all out of proportion.

Their blogs claim that soy definitely increases breast cancer risk and should be avoided at all costs. Their claims have been picked up by other web sites and blogs. Eventually, the claims have been repeated so many times that people started to believe them. A “myth” has been created. I call it a myth because it was never based on convincing scientific evidence.

In the meantime, scientists looked at the cell culture and animal studies and took a more responsible approach. They said “If this is true, it is an important public health issue. We need to do clinical trials in humans to test this hypothesis.”

What Have Previous Clinical Studies Shown?

breast cancerThe question of whether soy consumption increased the risk of developing breast cancer was settled a long time ago. Some studies have shown no effect of soy consumption on breast cancer risk. Others have reported that soy consumption decreased breast cancer risk. A meta-analysis of 18 previous clinical studies found that soy slightly decreased the risk of developing breast cancer (J Natl Cancer Inst, 98: 459-471, 2006). None of those studies found any evidence that soy increased the risk of breast cancer.

What about recurrence of breast cancer in women who are breast cancer survivors? There have been five major clinical studies looking at the effects of soy consumption on breast cancer recurrence in both Chinese and American populations. Once again, the studies have shown either no effect of soy on breast cancer recurrence or a protective effect. None of them have shown any detrimental effects of soy consumption for breast cancer survivors.

A meta-analysis of all 5 studies was published in 2013 (Chi et al, Asian Pac J Cancer Prev., 14: 2407-2412, 2013). This study combined the data from 11,206 breast cancer survivors in the US and China. Those with the highest soy consumption had a 23% decrease in recurrence and a 15% decrease in mortality from breast cancer.

What Did The Most Recent Study Show?

Clinical StudyIn earlier clinical studies the protective effect of soy has been greater in Asian populations than in North American populations. This could have been because Asians consume more soy. However, it could be due to other population differences as well.

To better evaluate the effect of soy consumption on breast cancer survivors in the North America, a group of investigators correlated soy consumption with all-cause mortality in breast cancer survivors in the US and Canada (Zhang et al, Cancer, DOI: 10.1002/cncr.30615, March 2017).

The data were collected from The Breast Cancer Family Registry, an international research infrastructure established in 1995. The women enrolled in this registry either have been recently diagnosed with breast cancer or have a family history of breast cancer.

This study included 6235 breast cancer survivors from the registry who lived in the San Francisco Bay area and the province of Ontario in Canada. The women represented an ethnically diverse population and had a median age of 51.8 at enrollment. Soy consumption was assessed either at the time of enrollment or immediately following breast cancer diagnosis. The women were followed for 9.4 years, during which time 1224 of them died.

The results were as follows:

  • There was a 21% decrease in all-cause mortality for women who had the highest soy consumption compared to those with the lowest soy consumption.
  • The protective effect of soy was strongest for those women who had receptor negative breast cancer. This is significant because receptor-negative breast cancer is associated with poorer survival rates than hormone receptor-positive cases.
  • The protective effect was also greatest (35% reduction in all-cause mortality) for women with the highest soy consumption following breast cancer diagnosis. This suggests that soy may play an important role in breast cancer survival.
  • The authors concluded “In this large, ethnically diverse cohort of women with breast cancer, higher dietary intake of [soy] was associated with reduced total mortality.”

In an accompanying editorial, Omer Kucuk, MD, of the Winship Cancer Institute of Emory University, noted that the United States is the number 1 soy producer in the world and is in a great position to initiate changes in health policy by encouraging soy intake.  He said “We now have evidence that soy foods not only prevent breast cancer but also benefit women who have had breast cancer. Therefore, we can recommend women to consume soy foods because of soy’s many health benefits.”

Should Women Avoid Soy?

soy breast cancer mythNow we can get back to the question I posed at the beginning of this article, “Should women avoid soy?”

The evidence from clinical studies says, “No”. But every clinical study has its limitations. If there were only one or two studies, the question of whether soy increases breast cancer risk might still be in doubt.

However, multiple clinical studies have come to the same conclusion. Either soy has no effect on breast cancer risk and breast cancer recurrence, or it has a protective effect.

Not a single clinical study has found any evidence that soy increases breast cancer risk. It is clear that consumption of soy foods is safe, and may be beneficial, for women with breast cancer. The myth that soy increases breast cancer risk needs to be put to rest.

With the breast cancer myth out of the way, we can focus on the many benefits of soy.

Soy is one of the very few plant proteins that is complete, meaning that is contains all the essential amino acids we need to build muscle and other important proteins like immunoglobulins. It is also high in fiber and is a good source of healthy polyunsaturated fatty acids and essential nutrients like folate, iron, and magnesium. When you include the phytoestrogens found in minimally processed soy products, soy consumption is associated with:

  • Lower LDL cholesterol and a reduced risk of heart disease.
  • Bone health.
  • A strong immune system.
  • A reduction in menopause symptoms.

The Bottom Line

  • It is time to put the myth that soy increases breast cancer risk to rest and focus on the many health benefits of soy. This myth is based on cell culture and animal studies, and those studies were inconclusive.
  • Multiple clinical studies have shown that soy either has no effect on breast cancer risk, or that it reduces the risk.
  • Multiple clinical studies have also shown that soy either has no effect on breast cancer recurrence in women who are breast cancer survivors, or that it reduces recurrence.
  • The most recent clinical study is fully consistent with previous studies. It reports:
    • There was a 21% decrease in all-cause mortality for women who had the highest soy consumption compared to those with the lowest soy consumption.
    • The protective effect of soy was strongest for those women who had receptor negative breast cancer. This is significant because receptor-negative breast cancer is associated with poorer survival rates than hormone receptor-positive cases.
    • The protective effect was also greatest (35% reduction in all-cause mortality) for women with the highest soy consumption following breast cancer diagnosis. This suggests that soy may play an important role in breast cancer survival.
  • No clinical studies have provided any evidence to support the claim that soy increases either breast cancer risk or breast cancer recurrence.

For more information on this study and the benefits of soy consumption read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

__________________________________________________________________________

My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.

My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance

_____________________________________________________________________

About The Author 

Dr. Chaney has a BS in Chemistry from Duke University and a PhD in Biochemistry from UCLA. He is Professor Emeritus from the University of North Carolina where he taught biochemistry and nutrition to medical and dental students for 40 years.  Dr. Chaney won numerous teaching awards at UNC, including the Academy of Educators “Excellence in Teaching Lifetime Achievement Award”. Dr Chaney also ran an active cancer research program at UNC and published over 100 scientific articles and reviews in peer-reviewed scientific journals. In addition, he authored two chapters on nutrition in one of the leading Biochemistry textbooks for medical students.

Since retiring from the University of North Carolina, he has been writing a weekly health blog called “Health Tips From the Professor”. He has also written two best-selling books, “Slaying the Food Myths” and “Slaying the Supplement Myths”. And most recently he has created an online lifestyle change course, “Create Your Personal Health Zone”. For more information visit https://chaneyhealth.com.

For the past 54 years Dr. Chaney and his wife Suzanne have been helping people improve their health holistically through a combination of good diet, exercise, weight control and appropriate supplementation.

 

 

Will Processed Meat Kill You?

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What Is The Truth About Meat?

Author: Dr. Stephen Chaney 

Vegans will tell you that any meat is bad for you. Keto enthusiasts haven’t found a meat they don’t like. To them grains and most fruits and vegetables are the problem.

But what about those of us who aren’t at either extreme? Which meat, if any, should be part of a healthy diet? And how much of them should we eat?

For years the paradigm had been clear:

  • Fish was best, especially fish rich in omega-3s. They were good for your heart and your brain. And some studies suggested that high intake of omega-3-rich fish might help you live longer.
  • Poultry and other white meats were neutral.
  • Red meat was probably bad for you. It was high in saturated fat and cholesterol, and some studies linked it to an increased risk of heart disease. Plus, the International Agency for Research on Cancer (IARC), an agency of the WHO, listed it as a probable carcinogen. [Note: Recent studies have questioned concerns about red meat. I will discuss this below.]
  • Processed meats were considered a “no-no” The IARC listed processed meat as a definite carcinogen for humans based on studies linking it to colon, stomach, lung, and pancreatic cancers. It is also linked to an increased risk of heart disease.

However, most of these studies were done in the United States. And our diet is very different from that of many other countries.

That’s why a recent study (R Iqbal et al, American Journal of Clinical Nutrition, 114:1049-1058, 2021) caught my eye. The study was designed to measure the association between unprocessed red meat & poultry and processed meat intake with the risk both mortality and major cardiovascular disease with cancer as a secondary end point. And the study used data from 21 countries around the world except the United States.

How Was This Study Done?

Clinical StudyThe authors used data from the Prospective Urban Rural Epidemiology (PURE) study. The study is a large-scale (164,007 individuals), prospective (meaning it follows the individuals over time rather than taking measurements from them at a single time) study. The individuals in the study were aged 35-70 years and were followed for an average of 9.5 years.

The individuals came from 21 low-, middle-, and high-income countries.

  • The low-income countries included Bangladesh, India, Pakistan, Tanzania, and Zimbabwe.
  • The middle-income countries included Argentina, Brazil, Chile, China, Columbia, Iran, Poland, South Africa, and Turkey.
  • The high-income countries included Canada, Saudi Arabia, Sweden, and the United Arab Emirates. [Note: The United States was not included in the study.]

At the beginning of the study and at 3, 6, and 9 years the following data were collected from everyone enrolled in the study.

  • Demographic information (age, sex, location, education, wealth index, and smoking status).
  • Lifestyle information (diet and physical activity).
  • Health history.
  • Medication use.
  • Cardiovascular events and mortality.

Will Processed Meat Kill You?

The authors compared high intake of processed meats (5 ounces per week, the equivalent of two sausages/week) with zero intake of processed meats. They reported that high intake of processed meats increased the risk of:

  • Mortality by 51%.
  • Major cardiovascular disease by 46%.
  • Non-cardiovascular mortality by 50%
  • Cancer by 84%.
  • Heart attack by 62%.
  • Stroke by 56%.

Furthermore, even as little as 1.5 ounces of processed meat per week significantly increased the risk of mortality.

For red meat and poultry, the authors compared high intake (9 ounces per week) with low intake (2 ounces per week). For both red meat and poultry they did not find any association between high weekly intake and any of the health outcomes.

[I would note however, that many Americans consume 4 ounces of chicken or an 8-ounce steak at dinner – that’s one meal on one day. The corresponding weekly intake would be 28 ounces of chicken or 56 ounces of red meat. That’s significantly higher than the highest weekly intake used in this study.]

The authors concluded, “We observed no significant association between the consumption of unprocessed red meat and poultry intake and health outcomes. And higher intake of processed meat was associated with higher risks of mortality and cardiovascular disease. These findings may indicate that limiting the intake of processed meat should be encouraged.”

In my opinion, there are so many studies linking the consumption of processed meat with heart disease, cancer, and premature death that the last sentence of their conclusion should have said, “These findings unambiguously confirm that limiting the intake of processed meats should be encouraged.”

What Is The Truth About Meat? 

truthRed Meat:

Yes, there is a lot of confusion about red meat. Many studies, like this one, find no adverse health effects associated with red meat consumption. That has led many experts to conclude that the dangers of red meat have been greatly exaggerated.

I think we should dig a little deeper. Most of the studies showing that red meat consumption increases the risk of heart disease, cancer, and mortality have been done in this country. So, perhaps we should be asking what is different about red meat consumption in our country.

There are several factors to consider:

  • Cooking Methods: The authors of this article pointed out that we often grill our meat at high temperatures which causes the formation of cancer-causing chemicals, while many of the countries in the PURE database stew their red meat at much lower temperatures.
  • Diet Context: As I have explained in a previous article of Health Tips From the Professor, fruits, vegetables, and whole grains are the antidotes to the cancer-causing chemicals formed when we cook red meat. And they bind to cholesterol in the intestine and flush it out of the body. Finally, they dilute the saturated fat in red meat with polyunsaturated fats, which helps create a healthier balance of fats.

In this country we often pair our steaks with French fries or a baked potato loaded with butter and sour cream. However, in low- and middle-income countries red meat is an expensive luxury and is often used as a garnish to dishes containing lots of vegetables and whole grains.

  • Amount Consumed: As a mentioned above, the amount of red meat most Americans consume in a week far exceeds the highest weekly intake of red meat in this study. The highest weekly consumption of red meat in this study is more consistent with using red meat as a garnish than as a main course.

Poultry:

For poultry, there is no confusion. Studies done in this country also find no association between poultry consumption and cardiovascular disease, cancer, or mortality. That may be due to a healthier fat profile and the ways in which poultry is usually cooked.

Processed Meat:

For processed meat, there is also no confusion. Virtually every published study from across the world agrees that it increases the risk of cancer, heart disease, and premature death. And the effect is not trivial. This study suggests that just 2 sausages a week is enough to increase your risk of premature death by 50%! So, the answer to the question, “Will processed meat kill you?” appears to be, “Yes”.

The authors of this article pointed out that the saturated fat and cholesterol in processed meat and red meat were very similar. They didn’t mention it, but the cooking techniques are also similar. So, neither of these explain why processed meat is so bad for us.

However, the amounts of preservatives and food additives in processed and unprocessed meats differ greatly. Based on this, the authors of the study and many other experts postulate that it is the preservatives and food additives that are responsible for the health risks of processed meats.

What Does this Mean For You? 

This study agrees with many other studies showing that processed meats are bad for us. The authors recommend limiting your intake of processed meats.

However, their data show that as little as two strips of bacon, one hot dog, or half a large sausage per week significantly increases your risk of heart disease, cancer, and premature death. Based on that, my advice would be to avoid processed meats as much as possible.

As I described above, most experts feel that it is the preservatives and food additives that are responsible for the health risks associated with processed meats.

Some studies suggest that nitrates in processed meats may be the main culprit. Based on that belief, some food companies are offering nitrate-free processed meats as a healthier option.

However, there still may be some additives in nitrate-free processed meats (read the label carefully), and we have no clinical studies showing that the nitrate-free processed meats in the marketplace are good for us.

Red meat is more confusing. This study and others suggest it poses no health hazards. And many experts are telling you that the warnings about consuming red meat were overblown. They are telling you that red meat is good for you.

However, some studies suggest that red meat increases your risk of heart disease, cancer and premature death. When you examine the data behind the studies, I think that better advice would be that red meat can be good for you or bad for you depending on three factors:

  • Portion size: We should think of red meat as a garnish rather than a main course – 3-4 ounces is a healthy portion size. 8-12 ounces may be too much.
  • Cooking method: Many of the bad things associated with red meat are the result of high temperature cooking, especially over a flame or on a grill. Choose low temperature cooking methods whenever possible.
  • Diet context: Whole fruits, vegetables and whole grains are the antidotes to all the bad things associated with red meat. 3-4 ounces of red meat in a vegetable stir fry or green salad is likely to be much better for you than an 8-ounce steak with French fries.

Also, red meat already has more than enough saturated fat and cholesterol. Adding foods or sauces high in fat and cholesterol may overload the body’s ability to safely process them. But adding vegetables or vegetable oils helps to restore a better balance between good and bad fats.

Finally, this and other studies agree that white meat is healthy. My only advice is:

  • Avoid white meat that has been fried (especially by fast food restaurants that only change their oil every 20,000 miles) or cooked with fatty sauces.
  • Think of the whole diet rather than just the protein source. White meat will be the healthiest as part of a whole food, primarily plant-based diet.

The Bottom Line 

A recent study reported that eating as 5 ounces of processed foods per week increases your risk of heart disease, cancer, and premature death by 50%. That is equivalent to two sausages per week!) The authors of the study recommended that you limit your intake of processed meats.

However, the study showed that even as little as 1.5 ounces (2 strips of bacon, one hot dog, or half of a large sausage) per week significantly increases your risk of all three. Based on that data, my recommendation is to consider avoiding processed meat altogether.

The study reported that unprocessed red and white meat are not associated with increased health risks. I put those findings into the context of other published studies on the topic. I discuss my recommendations for unprocessed red and white meat in the article above.

For more information on this study and what it means for you, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

____________________________________________________________________________

My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.

My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance

_____________________________________________________________________

About The Author 

Dr. Chaney has a BS in Chemistry from Duke University and a PhD in Biochemistry from UCLA. He is Professor Emeritus from the University of North Carolina where he taught biochemistry and nutrition to medical and dental students for 40 years.

Dr. Chaney won numerous teaching awards at UNC, including the Academy of Educators “Excellence in Teaching Lifetime Achievement Award”.

Dr Chaney also ran an active cancer research program at UNC and published over 100 scientific articles and reviews in peer-reviewed scientific journals. In addition, he authored two chapters on nutrition in one of the leading biochemistry text books for medical students.

Since retiring from the University of North Carolina, he has been writing a weekly health blog called “Health Tips From the Professor”. He has also written two best-selling books, “Slaying the Food Myths” and “Slaying the Supplement Myths”. And most recently he has created an online lifestyle change course, “Create Your Personal Health Zone”. For more information visit https://chaneyhealth.com.

For the past 54 years Dr. Chaney and his wife Suzanne have been helping people improve their health holistically through a combination of good diet, exercise, weight control and appropriate supplementation.

Can Red Meat Be Good For You?

by

Everything You Wanted To Know About Red Meat 

Author: Dr. Stephen Chaney 

ArgumentNutrition is a bit like politics and religion. Everyone has an opinion, and there is not much grace for those with different opinions.

And everything is black or white. There is no middle ground. Red meat is a perfect example. Cardiologists tell us the saturated fat and cholesterol in red meat increases our risk of heart disease. Oncologists tell us red meat increases our risk of colon, breast, prostate, and pancreatic cancer.

The association with red meat consumption and colon cancer is so strong that the World Health Organization has classified red meat as a probable carcinogen.

  • Vegans and vegetarians tell you to avoid red meat at all costs and substitute plant proteins in its place.
  • Keto and carnivore diet enthusiasts tell you that red meat is healthy if you avoid any plant foods containing carbohydrates (which is most plant foods).

Who is right? Is red meat good for you or bad for you? As usual, the answer is somewhere in the middle. We also need to stop looking at individual foods and start looking at the overall diet. We need to ask how our overall diet alters the effect of red meat on our health.

But first, let’s explore:

  • Why red meat is good for us.
  • Why red meat is bad for us.
  • How diet can help us minimize the bad and maximize the good.

I call this section, “Everything You Wanted To Know About Red Meat”.

Everything You Wanted To Know About Red Meat

thumbs upWhy Red Meat Is Good For Us.

  • Red meat is an excellent source of protein, iron, and vitamin B12. Plus, the iron in red meat is primarily found in the heme molecule and heme iron is absorbed much more efficiently than other forms of iron.
  • Red meat contains creatine, which powers our muscles. You can think of creatine molecules as little power packs that are charged when we eat and release a burst of energy whenever we begin to exercise.
  • Red meat contains carnitine, which helps our muscles use fat as an energy source. This is particularly important for heart muscle.
  • But both creatine and carnitine also have a dark side, which I will discuss below.

Why Red Meat Is Bad For Us.thumbs down

When we think about heart disease:

  • The traditional view is that saturated fat and cholesterol are the problem, and we can reduce our risk of heart disease simply by choosing leaner cuts of meat.
  • Other experts feel the link between red meat and heart disease is more complicated. For example, some recent studies have suggested that the carnitine in red meat can be converted by gut bacteria to TMAO, and TMAO increases our risk of heart disease. I have discussed this in a previous issue of “Health Tips From the Professor”.

SteakWhen we think about cancer:

  • When fat and juices from the meat drip onto an open flame, carcinogenic polyaromatic hydrocarbons are formed that stick to the surface of the This can be reduced, but not eliminated, by lower fat meat choices.
  • When red meat is cooked at high temperatures, amino acids in the meat combine with creatine, which is found in all red meats, to form carcinogenic heterocyclic amines. This can be reduced, but not eliminated, by cooking the meat at lower
  • The nitrates and nitrites used as preservatives in many processed meats react with amino acids from the meat to form carcinogenic N-nitrosamines in our intestines.
  • Heme iron, which is found in all red meats, also combines with amino acids in the meat to form carcinogenic N-nitroso compounds in our intestines. This mechanism is inherent in all red meats and cannot be eliminated by choosing lower fat cuts or cooking at lower

Finally, diets high in red meat increase several markers of inflammation, and inflammation increases the risk of both heart disease and cancer.

How Can Diet Help Us Minimize The Bad And Maximize The Good?

Question MarkI’m going to start this section with a provocative statement: “Plant foods are the antidote to all the bad effects of red meat.” Let me explain.

Plant foods are an excellent source of:

  • Antioxidants
  • Polyphenols and other phytonutrients
  • Fiber
  • Plus, the fiber and phytonutrients found in plant foods support the growth of beneficial gut bacteria.

Here is where it gets very complex:

  • Beneficial gut bacteria convert some of the foods we eat into compounds that are absorbed into the bloodstream and improve blood sugar control, reduce cholesterol synthesis, and reduce inflammation.
  • Polyphenols support the growth of certain gut bacteria, and those gut bacteria can convert these polyphenols into compounds that can be absorbed from the intestine. This necessary for many polyphenols to exert their beneficial effects in the body.
  • And, as you might expect, the gut bacteria of meat eaters and vegetarians is very different.

With this in mind, let’s come back to the concept of plant foods being the antidote for red meat.

strong heartIn terms of heart health,

  • You may remember that I said above that the carnitine in red meat can be converted by gut bacteria into TMAO which increases the risk of heart disease. The operative wording here is “can be”. It turns out this only happens with the gut bacteria of habitual meat eaters. Here is the study that showed that:
    • When habitual meat eaters were fed an 8-ounce sirloin steak, both carnitine and TMAO increased in their blood and urine.
    • When vegans were fed the same 8-ounce steak, only carnitine increased. No TMAO was detected.
    • When the meat eaters were treated with an antibiotic that wiped out their gut bacteria prior to eating the steak, no TMAO was detected. This showed it was the gut bacteria in the meat eaters that were responsible for converting carnitine to TMAO.
  • Fiber from whole grains, fruits, and vegetables binds to cholesterol and flushes it out of the intestine, preventing its absorption into the bloodstream.
  • Plant-based diets are anti-inflammatory.

CancerIn terms of cancer,

  • The fiber found in fruits, vegetables and whole grains binds to polyaromatic hydrocarbons and heterocyclic amines and flushes them out through the intestines.
  • Polyaromatic hydrocarbons require activation by the liver before they become carcinogenic. Indoles and isothiocyanates found in broccoli, cabbage, and other cruciferous vegetables inhibit the enzymes that catalyze this activation.
  • Antioxidants found in fruits, vegetables and whole grains reduce the formation of N-nitroso compounds in the intestines.
  • A largely plant-based diet appears to favor a population of intestinal bacteria that is less likely to convert compounds in meat into cancer-causing chemicals. [Note: This is a new area of research, so the data supporting this mechanism of cancer prevention are less definitive than for the other three ]

These observations are based studies designed to identify the mechanisms by which plant-based diets negate the bad effects of red meat. For example, let me share a recent study (T Onali et al, Journal of Nutritional Biochemistry, 141, 109906, 2025) asking whether berries could negate the bad effects of adding red meat (pork) to a typical Finnish diet.

How Was This Study Done?

Clinical StudyThis study was conducted by a group of scientists at the University of Helsinki. They recruited 43 adults aged 20-68 and divided them into two groups. Each group was told to continue with their regular diet, except that consumption of any red meat or berries other than the foods they were provided with was prohibited.

  • Each group was given an extra 5 ounces of pork (minced pork, pulled pork, pork strips from fillet, cold cuts, sausages, and bacon) to eat each day.
  • One group was also given 1 cup of berries (bilberries, strawberries, cloudberries, raspberries, lingonberries, and blackcurrant) to eat each day.
    • Note: These are the foods most familiar to people from Finland in each category.
  • They were provided with these foods on a weekly basis.
  • This intervention portion of the study lasted four weeks.

Dietary intake was assessed in each group using 3-day food records (two weekdays and one weekend day) at the beginning and the end of the study.

Participants in the study collected stool samples on two consecutive days at the beginning and end of the study. These stool samples were analyzed in the following ways:

  • Bacterial DNA was extracted from the stool samples and used to determine which gut bacteria were present in the stools.
  • The stool samples were homogenized and filtered to:
    • Determine the polyphenols and polyphenol metabolites present in the stool samples.
    • Determine whether low molecular weight compounds present in the stool samples were able to inhibit the growth of human colon cancer cells in cell culture.

What Did The Study Show?

Questioning WomanThe dietary analysis found that total calories, protein, carbohydrate, fat, and saturated fat did not change significantly in either group. This indicates that the study participants likely substituted the pork they were given for other high-fat meats they were eating before the study.

However, in the group that was also given berries fiber, vitamin C, vitamin E, manganese, and several polyphenols increased significantly. This suggests that study participants likely substituted the berries for less healthy foods they were eating before the study.

The study found that:

  • In the red meat-only group the relative abundance of beneficial Roseburia and Fecalibacterium gut bacteria was decreased. This did not occur in the red meat + berries group.
  • In the red meat + berries group the concentration of several beneficial polyphenols and polyphenol metabolites was increased.
  • In the red meat + berries group, the filtrate obtained from stool samples inhibited the growth of several human colon cancer cell lines in cell culture experiments. These experiments did not identify which berry polyphenols were responsible for inhibiting the growth of cancer cells. It also did not determine whether the polyphenols came directly from the berries or were created when gut bacteria modified the polyphenol(s).

But these experiments did show that something from a high berry diet inhibited colon cancer cell growth.

The author’s concluded, “Berry supplementation to a diet high in red and processed meat led to berry-derived polyphenolic metabolites in the feces, beneficially modified gut microbiota, inhibited the viability of colon cancer cells, collectively suggesting potential in cancer prevention.

The difference seen in gut metabolism was probably induced by the higher intakes of dietary fiber, vitamin C and E, manganese, and polyphenols by the berry diet.”

Can Red Meat Be Good For You?

This study is one piece of the puzzle to help us understand the effect of diet on the benefits and risks of red meat consumption. Here is what I mean by that.

We can think of scientific investigations in terms of solving a large puzzle with lots of little pieces. If you are a puzzle enthusiast, you know the best way to solve a complicated puzzle is to put the edge pieces together first and then fill in the rest of the puzzle.

In this context, the studies showing that small amounts of red meat are not harmful in the context of healthy, primarily plant-based diets like the DASH and Mediterranean diets are the edge of the puzzle. Smaller studies that define the mechanisms of this effect and provide proof these mechanisms are accurate are the interior pieces that fill out the puzzle. This study is one of those interior pieces.

So, what does that mean for you? It means that diet context is important.

Most of the studies showing the bad effects of red meat have been done in the context of the typical American diet. That might consist of an 8 or 12-ounce steak with fries and either a soft drink or iced tea. Fruits and vegetables, if present at all, are minimal. Dessert usually consists of some sugary treats.

In this context, red meat is bad for you.

In contrast, consider the place red meat occupies in a primarily plant-based diet. Red meat becomes a condiment rather than the main course. Think of 2-3 ounces of red meat as part of a green salad or stir fry with a variety of greens and other vegetables. You might have beans, whole grains, or another vegetable to round out your plate. Dessert would be whatever fruit is in season. And your beverage might be water, milk, or herbal tea.

In this context, the bad effects of red meat disappear. In short, there are no bad foods, only bad diets.

I started this blog with the question, “Can red meat be good for you?”  You may be wondering if I have answered that question.

At the beginning of this article, I listed the good things about red meat, namely that it is a good source of protein, iron, vitamin B12, carnitine, and creatine.

If you remove the bad, only the good remains. So, the answer is, “Yes. In the right diet context red meat can be good for you”.

The Bottom Line

You have heard that red meat is bad for you. It increases your risk of heart disease and cancer. You should avoid it at all costs.

But is that true? In the article above I:

  • Describe both the benefits and risks of red meat.
  • Discuss how plant foods negate many of the bad effects of red meat.
  • Share a study providing proof of that concept.
  • Share how you can enjoy the benefits of red meat while avoiding the bad effects of red meat consumption.

For more details read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

______________________________________________________________________________

My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.

My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance

______________________________________________________________________

About The Author 

Dr. Chaney has a BS in Chemistry from Duke University and a PhD in Biochemistry from UCLA. He is Professor Emeritus from the University of North Carolina where he taught biochemistry and nutrition to medical and dental students for 40 years.

Dr. Chaney won numerous teaching awards at UNC, including the Academy of Educators “Excellence in Teaching Lifetime Achievement Award”.

Dr Chaney also ran an active cancer research program at UNC and published over 100 scientific articles and reviews in peer-reviewed scientific journals. In addition, he authored two chapters on nutrition in one of the leading biochemistry text books for medical students.

Since retiring from the University of North Carolina, he has been writing a weekly health blog called “Health Tips From the Professor”. He has also written two best-selling books, “Slaying the Food Myths” and “Slaying the Supplement Myths”. And most recently he has created an online lifestyle change course, “Create Your Personal Health Zone”. For more information visit https://chaneyhealth.com.

For the past 45 years Dr. Chaney and his wife Suzanne have been helping people improve their health holistically through a combination of good diet, exercise, weight control and appropriate supplementation.

The Estrogenic Myth

by

What Does Increase Breast Cancer Risk? 

Author: Dr. Stephen Chaney 

breaking newsIt seems like every time you turn around there are new headlines warning us that a particular food or supplement increases your risk of cancer. If you believe all those headlines, there would be little you could eat. You might starve to death trying to avoid eating anything that increases your risk of cancer.

So, it’s important to ask which of those warnings are true and which are just myths.

For example, a few days ago, a friend called me and said, “I just heard that resveratrol is estrogenic and causes breast cancer. Should I read the labels of the herbal supplements I take and avoid anything with resveratrol in it.”

I assured her that this was just a myth. The likelihood that resveratrol and related polyphenols cause breast cancer is very low. And if she was concerned about breast cancer, there were much more important things to worry about.

But as I started to explain why it was a myth, I realized the explanation was complex. I was able to explain it to my friend in a 20-minute discussion. But it was then I realized I needed to write a “Health Tips From the Professor” article to help explain it to the general public.

Why Are We Concerned?

Questioning WomanYou might be asking, “Why is this such a big deal? Why do we care if something has estrogenic properties?” Let me start at the beginning.

When I first started teaching medical students in 1972, hormone replacement therapy (a combination of estrogen and progesterone) was thought to be a safe and effective treatment for menopausal symptoms and post-menopausal bone loss, and it was very widely prescribed.

That practice came to a screeching halt in 2002 when the Woman’s Health Initiative study showed that it increased the risk of breast, endometrial, and ovarian cancer. Today,

  • The hormone composition of hormone replacement therapy has been changed.
  • It is only prescribed for severe menopausal symptoms. And drugs are the treatment of choice to reduce post-menopausal bone loss.
  • It is prescribed for the shortest possible time to limit exposure.

These simple changes in hormone replacement therapy represent the single most important intervention for reducing breast cancer risk in the past 50 years. Yes, you heard that right. These changes were more effective than any other medication or preventative strategy for reducing the number of women developing and dying from breast cancer.

This lesson made a big impression on the medical community. So, it is easy to understand why anything resembling estrogen is immediately suspected of increasing the risk of breast cancer. But the reality is far more complicated. So, it’s time for another of my “Biochemistry 101” segments.

Biochemistry 101: What Does Estrogenic Mean?

professor owlLet’s start at the beginning with what polyphenols are. They comprise a diverse group of compounds with these common features.

  • If you look at their structures, they contain multiple rings (A chemist would tell you they have more than one phenol group, hence the term polyphenol. But that terminology is only useful if you are a chemist).
  • They are found in plants. Specifically, they are found in fruits, vegetables, herbs, spices and beverages (coffee, tea, and cocoa, for example).
  • They have antioxidant properties.

Types of polyphenols include flavonoids, phenolic acids, lignans, and stilbenes. I mention this only because soy isoflavones, which I will talk about later, are flavonoids.

Some of these compounds have structures that resemble estrogen. If they bind to estrogen receptors and have the same effect as estrogen in cultured human cells, they are said to have “estrogenic properties”.

That’s why you see blogs warning about foods and herbal ingredients we should avoid because of their “estrogenic” properties. Some of these blogs are written by people with “Dr” on front of their name. But they aren’t biochemists and don’t know what biochemists know.

Let’s dig a little deeper. Here are some of the complexities that most bloggers either don’t know about or ignore.

  • There is more than one kind of estrogen receptor.
  • Different estrogen receptors have different effects in the cell. For example, some estrogen receptors activate pathways that increase cancer risk. Other receptors activate pathways that decrease cancer risk.
  • The same estrogen receptor can have different effects in different cell types. That’s why estrogen replacement therapy reduced menopausal symptoms and post-menopausal bone loss AND increased cancer risk in other tissues.

The Estrogenic Myth

breast cancerA couple of weeks ago I talked about “The Soy Myth”, specifically the myth that soy isoflavones increase breast cancer risk. That myth was based on the observation that soy isoflavones have estrogenic properties and a simplistic interpretation of what that means. But in fact, soy isoflavones:

  • Are found naturally in most soy foods unless they are highly processed.
  • Bind strongly to the estrogen receptors that decrease cancer risk.
  • Bind weakly to the estrogen receptors that increase breast cancer risk.

In contrast, estrogen:

  • Binds strongly to the estrogen receptors that increase breast cancer risk.
  • Binds weakly to the estrogen receptors that decrease breast cancer risk.
  • Soy isoflavones compete with estrogen for binding to the receptors that increase breast cancer risks. This helps protect breast cells from the cancer-promoting effects of estrogen.

So, it is true that soy isoflavones bind to estrogen receptors, but on the balance, you would predict that soy isoflavones decrease, rather than increase breast cancer risk.

The key word here is “predict” breast cancer risk. If you are a woman, you don’t want a prediction, you want to know one way or the other.

That’s why multiple human clinical studies have been conducted to determine the effect of soy foods on breast cancer risk. As I told you two weeks ago:

  • Some studies showed no effect of soy consumption on the risk of getting breast cancer or breast cancer recurrence if you have previously had breast cancer.
  • Other studies found that soy consumption reduced the risk of breast cancer occurrence and recurrence.
  • No studies found that soy consumption increased the risk of breast cancer occurrence or recurrence.

So, for soy the answers are clear.

  • Yes, soy isoflavones have estrogenic properties. That is a fact.
  • No, soy consumption is not associated with an increased risk of breast cancer. That is a myth.

grape polyphenolsThe situation with resveratrol is similar:

  • It is found naturally in grapes and many other fruits.
  • It has estrogenic properties.
  • Cell culture experiments show that it activates pathways that reduce cancer risk.
  • Animal studies predominantly show that it reduces cancer risk. The only exceptions are a few animal studies with very high doses of resveratrol.
  • The few clinical studies that have been done show that it either has no effect on breast cancer risk or reduces cancer risk.
  • No human clinical trials have shown that resveratrol increases cancer risk.

The take home lesson is clear. Knowing that a food or herbal ingredient has estrogenic properties is meaningless unless you have data from human clinical trials on cancer outcomes.

So, the next time you see headlines telling you that you should avoid a food or herbal ingredient because it has “estrogenic properties” treat them skeptically. Unless the claim is backed up by human clinical trials showing an increased cancer risk, the claim is probably a myth.

What Does Increase Breast Cancer Risk?

American Cancer SocietyThe take home lesson is clear. If you are concerned about your risk of breast cancer or any other form of cancer you should ignore the social media posts, podcasts, and blogs about the cancer risks of estrogenic foods and herbal ingredients.

Unless they are backed by human clinical trials showing they increase cancer risks, the claims are likely to be mythical rather than real.

If they have any effect on cancer risk, it is likely to be small. Instead, focus on the important risk factors.

According to the American Cancer Society, the top 5 risk factor for breast cancer, and most other cancers, are:

#1: Overweight and obesity. The American Cancer Society recommends that you get and stay at a healthy weight.

Let me put this in perspective for you. Even if things like soy and resveratrol increased your risk of breast cancer, their effect is very small compared to estrogen and you are only exposed to them briefly once or twice a day.

In contrast, fat cells produce estrogen, and if you are overweight, fat cells accumulate in your breasts. Those fat cells are bathing your breast cells in a bath of pure estrogen 24/7.

#2: Inactivity. The American Cancer Society recommends that adults get at least 150 to 300 minutes of moderate intensity or 75 to 150 minutes of vigorous intensity activity each week (or a combination of these), preferably spread throughout the week.

#3: Alcohol use. The American Cancer Society says it is best not to drink alcohol at all. For women who do drink, they should have no more than 1 alcoholic drink a day.

#4: Hormone use after menopause. The American Cancer Society recommends talking to your health care provider about non-hormonal options to treat menopausal symptoms.

#5: Poor diet. The American Cancer Society recommends a diet low in fat, processed and red meat, and sugary drinks, but high in fruits and vegetables.

The Bottom Line 

It seems like every day you hear about another food or supplement you should avoid because it has “estrogenic properties” and is likely to cause cancer. I call this the estrogenic myth because those claims are generally mythological rather than factual. In this article:

  • I discuss why these claims are myths rather than facts using soy isoflavones and resveratrol as examples.
  • Tell you what the American Cancer Society tells you to focus on if you want to decrease your risk of breast cancer and other cancers.

For more details on these studies and what they mean for you, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

 ____________________________________________________________________________

My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.

My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance

 ______________________________________________________________________

About The Author 

Dr. Chaney has a BS in Chemistry from Duke University and a PhD in Biochemistry from UCLA. He is Professor Emeritus from the University of North Carolina where he taught biochemistry and nutrition to medical and dental students for 40 years.  Dr. Chaney won numerous teaching awards at UNC, including the Academy of Educators “Excellence in Teaching Lifetime Achievement Award”. Dr Chaney also ran an active cancer research program at UNC and published over 100 scientific articles and reviews in peer-reviewed scientific journals. In addition, he authored two chapters on nutrition in one of the leading Biochemistry textbooks for medical students.

Since retiring from the University of North Carolina, he has been writing a weekly health blog called “Health Tips From the Professor”. He has also written two best-selling books, “Slaying the Food Myths” and “Slaying the Supplement Myths”. And most recently he has created an online lifestyle change course, “Create Your Personal Health Zone”. For more information visit https://chaneyhealth.com.

For the past 53 years Dr. Chaney and his wife Suzanne have been helping people improve their health holistically through a combination of good diet, exercise, weight control and appropriate supplementation.

What Diet Is Best For Healthy Aging?

by

What About Primarily Meat-Based Diets?

Author: Dr. Stephen Chaney

Pinochio

It’s so confusing. Everyone claims they have clinical proof that their diet is the best. You will be healthier and live longer.

But the diets are so different. They range from vegan to keto. They can’t all be equally healthy. What is the truth?

To answer that question, we first need to understand how the proponents of each diet can claim theirs is the perfect diet for health and longevity. It’s because they base their claims on:

  • Short-term studies. Most of their claims are based on studies that range from a few weeks to a few months. You need 20- or 30-year studies to measure the effects of a particular diet on health outcomes.
  • Biological markers (Things like cholesterol and triglyceride levels, blood sugar control, and/or inflammation). Biological markers can predict possible health outcomes. But without long-term studies on actual health outcomes, you don’t know whether those predictions are accurate.
  • Comparisons with the typical American diet. Any diet looks good compared with the American diet.
  • Elimination of highly processed foods. While these diets emphasize different foods, they are all whole food diets. Again, any diet that eliminates processed foods is an improvement.
    • It doesn’t matter whether you restrict calories, restrict certain foods or food groups, or restrict the time you allow yourself to eat. You unconsciously eat less.
    • And when you eat less, you lose weight.
    • And when you lose weight, your cholesterol and triglyceride levels fall, your blood sugar control improves, and inflammation decreases.
    • That’s why short-term weight loss and improvement in biological markers are virtually identical with vegan and keto diets. Those diets are as different as any two diets could be. But they are both highly restrictive diets.

The take-home lesson is clear. Don’t be confused by claims based on short-term studies. What you should look for is:

  • Long-term studies (20 years or more)…
  • that look at the effect of diet on health outcomes, and…
  • do not compare their diet with the typical American diet.

When I first reviewed this topic 8 years ago, I could only find a few studies that met these criteria:

  • One study showed that people consuming primarily plant-based diets weighed less than people who consumed primarily meat-based diets for 20 years or more.
  • Other studies showed that people consuming primarily plant-based diets had a reduced risk of diabetes and heart disease compared to people consuming primarily meat-based diets for 20 years or more.

These are valuable observations, but they are limited. That’s why I was so excited when I came across a recent 30-year study (A-J Tessier et al, Nature Medicine, volume 31, pages 1644-1652, 2025) looking at the effect of 9 different diets on longevity and health outcomes. In short, this study looked at the effect of different diets on healthy aging.

How Was This Study Done?

Clinical StudyThe authors of this study used data from 105,015 participants in the Nurses’ Health Study (NHS) and Health Professionals Follow Up Study (HPFS). Both studies enrolled participants in 1986 and followed them through 2016. In short, they were both 30-year studies. Participants with preexisting chronic diseases were excluded from the study.

  • Lifestyle factors and medical histories were assessed every two years.
  • A detailed dietary assessment was conducted every four years. The assessments measured the intake of 152 foods. Food intakes were averaged over the duration of the study for each participant.

[Note: This study did not measure how the diets of participants changed between 1986 and 2016, although that is an interesting question. Perhaps a future study is planned.]

Based on the foods eaten, the diets of the participants were evaluated for adherence to 9 dietary patterns, which I have described in more detail below.

[Note: To be clear, the participants were not trying to follow these diets. They ate what they ate, and the investigators subsequently compared their dietary pattern with various healthy diets.]

For each of the diets included in this study, participants were divided into quintiles based on how closely their food intake adhered to the recommendations for that diet. Then the highest quintile was compared to the lowest quintile to determine how well that diet predicted “healthy aging” after a 30-year follow-up.

The term “healthy aging” was based on 5 criteria:

  • Longevity – achieving an age of 70 or more.
  • Absence of the top 11 major chronic diseases (cancer, diabetes, myocardial infarction (heart attack), coronary artery disease, congestive heart failure, stroke, Parkinson’s disease, multiple sclerosis, and ALS).
  • No impairment of cognitive function.
  • No impairment of physical health.
  • No mental health issues.

In other words, these were not just individuals who survived 70 years or more. They survived and thrived. They were enjoying their golden years because they still had good health and excellent quality of life.

Diets Included In This Study

The diets included in this study were:

  • AHEI – Alternative Healthy Eating Index (A scoring system developed by Harvard researchers to measure overall diet quality based on its ability to predict lower risks of heart attacks, strokes, and diabetes).
  • aMed – Alternative Mediterranean Diet Index (The aMed diet index differs from the original Med index by separating fruits and nuts into different groups, eliminating dairy, emphasizing whole grains, and excluding red and processed meats in favor of chicken and fish).
  • DASH – Dietary Approaches to Stop Hypertension (The name speaks for itself. But I also sometimes refer to this diet as “the Americanized version of the Mediterranean diet’ because it features foods more familiar to Americans. For example, it allows more red meat options than most of the other diets in this list.
  • MIND – Mediterranean-Dash intervention for Neurogenerative Delay (It is a dietary pattern designed to reduce the risk of Alzheimer’s disease and other forms of dementia. It combines elements of the Mediterranean and DASH diets but differs from both by emphasizing berries as a major fruit source, among other things.)
  • hPDI – Healthy Plant-Based Diet Index (It is a scoring system that measures adherence to a diet rich in healthy plant-based foods and lower consumption of less-healthy plant foods and animal foods.)
  • PHDI – Planetary Health Diet Index (It emphasizes foods (primarily plant foods) that are healthy and are good for the environment. Of the diets on this list, it is the most restrictive and closest to a vegan diet)
  • EDIH – Empirical Dietary Index For Hyperinsulinemia (It is a scoring system that measures the potential of a diet to cause chronically high insulin levels, which is associated with type 2 diabetes and certain cancers.)
  • EDIP – Empirical Dietary Inflammation Pattern (It is a scoring system that measures the inflammatory potential of a diet.)
  • UPF – Consumption of Ultraprocessed Foods (Since recent studies have shown that most Americans get between 55 and 70% of their calories from ultraprocessed foods, this is fast becoming a measure of the typical American diet.)

Note: Except for the UPF diet, these are all whole food, primarily plant-based diets.

What Diet Is Best For Healthy Aging?

Here are the results of the study (drum roll, please):

  • Of the 105,015 participants in this study, only 9.3% achieved healthy aging.
  • Adherence to any of the 8 healthy diets improved the probability of achieving healthy aging.
  • The odds of achieving healthy aging ranged from 1.45 for the Healthy Plant-Based Diet to 1.86 for the Alternative Healthy Eating Index.
  • If you were to pick one winner, it would be the Alternative Healthy Eating Index. And if you were to define healthy aging as achieving an age of 75 or more with the other 4 criteria, the odds increase to 2.24 (more than double) for the Alternative Healthy Eating Index.
  • As you might expect, adherence to a diet high in ultraprocessed foods had the opposite effect. It decreased the odds of achieving healthy aging by 32%.

When you look at each of the criteria for healthy aging individually, the results were a bit more nuanced:

  • For survival to 70+ years, the Alternative Healthy Eating Index and the Planetary Health Diet Index were tied. Both increased the odds of survival by more than 2-fold.
  • The Alternative Healthy Eating Index and the Planetary Health Diet Index were also tied for surviving to 70 with intake cognitive health and intact physical function.
  • The Empirical Dietary Index For Hyperinsulinemia edged out the Alternative Healthy Eating Index for freedom from 11 chronic diseases.

The effect of healthy diets on the odds of achieving healthy aging is independent from BMI, smoking, and physical activity. This means that:

  • The effects of healthy diets on healthy aging were not because people consuming healthy diets weighed less, smoked less, or exercised more.
  • Even if some of your lifestyle choices are suboptimal, choosing a healthy diet will increase your odds of surviving and thriving.

Finally, the study looked at the effects of individual foods on healthy aging. The results were:

  • Higher intakes of fruits, vegetables, whole grains, unsaturated fats, nuts, legumes, and low-fat dairy products increase your odds of healthy aging.
  • Higher intakes of trans fats, sodium, sugary beverages, and red or processed meats decrease your odds of achieving healthy aging.

The effects of these foods on healthy aging aren’t novel. They are consistent with dozens of other studies that have looked at the effect of individual foods on long-term health outcomes. In fact, the diets included in this study were chosen because they included foods that positively affect health outcomes and minimize foods that negatively affect health outcomes.

What About Primarily Meat-Based Diets?

the paleo dietI have good friends who advocate for primarily meat-based diets such as keto, paleo, and carnivore. I’m sure they are going to say, “This study is a sham. It only included primarily plant-based diets, so, of course, it is only going to show benefits for primarily plant-based diets.” I can hear their their questions now:

  • Why didn’t this study include any of the primarily meat-based diets? My answer is: “All the popular meat-based diets exclude one or more of the food groups associated with health and longevity and emphasize one or more of the food groups associated with a shorter, less healthy life. And these food associations are consistent among multiple long-term studies looking at the effect of various foods on health outcomes. 

The authors could have constructed a similar index for each of the popular meat-based diets. But they would have been the inverse of the plant-based diet indices because the foods included and excluded from plant-based and meat-based diets are opposite. Therefore, just like the UPF index, they would have been associated with a decreased probability of achieving healthy aging.”

  • Why did the scientists designing this study ignore the proven health benefits of primarily meat-based diets? My answer is: “The “proven benefits” of primarily meat-based diets are based on short-term studies showing the effects of those diets on biological markers. Long-term studies looking at health outcomes are lacking.”
  • But modern primarily meat-based diets are a special case because they limit carbohydrates and cause ketosis. Why weren’t they included in the study? My answer is: “The Atkins diet limits carbohydrates and causes ketosis. It has been around for more than 50 years. And, to my knowledge, there are no studies showing it is beneficial long term. If the Atkins diet cannot be shown to have long-term health benefits, it is unlikely that modern diets that mimic it are healthy long term.

What Does This Study Mean For You?

confusionThe answer is clear. If you want to survive and thrive in your 70s and beyond, choose a whole food, primarily plant-based diet.

If you want the absolute best diet, follow the Alternative Healthy Eating Index recommendations. There are many online resources to guide you.

However, any whole food, primarily plant-based diet will do. The ones with the most online resources are the Mediterranean, DASH, and MIND diets. Choose the one that best fits your food preferences and lifestyle.

If you want to go more vegetarian, the Healthy Plant-Based Diet is a bit easier than a strict vegan diet.

If you are concerned about the environment, the Planetary Diet is best for you.

If you have specific health issues like hypertension, diabetes, or inflammation, there are diets designed just for you.

And if following structured diets is not your style, just:

  • Eat more fruits, vegetables, whole grains, unsaturated fats, nuts, legumes, and low-fat dairy products.
  • Eat less trans fats, sodium, sugary beverages, and red or processed meats, and ultraprocessed foods.

Finally, even if some of your lifestyle choices are suboptimal, this study shows choosing a healthy diet will increase your odds of surviving to your 70s and thriving.

The Bottom Line

A recent 30-year study looked at the effect of 8 whole food, primarily plant-based diets on healthy aging defined as:

  • Achieving an age of 70 or more.
  • The absence of the top 11 major chronic diseases.
  • No impairment of cognitive function.
  • No impairment of physical health.
  • No mental health issues.

The key findings were:

  • Adherence to any of 8 whole food, primarily plant-based diets improved the probability of achieving healthy aging.
  • The odds of achieving healthy aging ranged from 1.45 for the Healthy Plant-Based Diet to 1.86 for the Alternative Healthy Eating Index.

For more information on this study, why primarily meat-based diets were not considered healthy enough to be included in this study, and what this study means for you, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

 ____________________________________________________________________________

My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.

My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance

 _______________________________________________________________________

About The Author 

Dr. Chaney has a BS in Chemistry from Duke University and a PhD in Biochemistry from UCLA. He is Professor Emeritus from the University of North Carolina where he taught biochemistry and nutrition to medical and dental students for 40 years.  Dr. Chaney won numerous teaching awards at UNC, including the Academy of Educators “Excellence in Teaching Lifetime Achievement Award”. Dr Chaney also ran an active cancer research program at UNC and published over 100 scientific articles and reviews in peer-reviewed scientific journals. In addition, he authored two chapters on nutrition in one of the leading Biochemistry textbooks for medical students.

Since retiring from the University of North Carolina, he has been writing a weekly health blog called “Health Tips From the Professor”. He has also written two best-selling books, “Slaying the Food Myths” and “Slaying the Supplement Myths”. And most recently he has created an online lifestyle change course, “Create Your Personal Health Zone”. For more information visit https://chaneyhealth.com.

For the past 53 years Dr. Chaney and his wife Suzanne have been helping people improve their health holistically through a combination of good diet, exercise, weight control and appropriate supplementation.

 

 

The Soy Myth

by

Why Is There So Much Confusion About Soy?

Author: Dr. Stephen Chaney

soyWhat is the truth about soy and breast cancer? Does it increase the risk of breast cancer, or is that just a myth? If you are a woman, particularly a woman with breast cancer, it is an important question.

Some experts say soy should be avoided at all costs. They say that soy will increase your risk of breast cancer. Other experts say soy is perfectly safe and may even reduce your risk of breast cancer. Who is right?

If you are a breast cancer survivor, the question of whether soy increases or decreases your risk of disease recurrence is even more crucial. You have already endured surgery, chemotherapy, and/or radiation. You never want to go through that again.

Why Is There So Much Confusion About Soy?

Questioning WomanSoy isoflavones decrease estrogen production, strengthen the immune system, inhibit cell proliferation, and reduce the production of reactive oxygen species. These are all effects that might reduce breast cancer risk.

On the other hand, soy isoflavones also bind to estrogen receptors and exhibit weak estrogenic activity. This effect has the potential to increase breast cancer risk.

Cell culture and animal studies have only confused the issue. Soy isoflavones stimulate the growth of breast cancer cells in a petri dish. Soy isoflavones also stimulate breast cancer growth in a special strain of mice lacking an immune system. However, in studies in both mice and rats with a functioning immune system, soy isoflavones decrease breast cancer risk.

The confusion has been amplified by claims and counterclaims on the internet. There are bloggers who are more interested in the spectacular than they are in accuracy (Today we call this fake news). They have taken the very weak evidence that soy isoflavones could possibly increase breast cancer risk and have blown it all out of proportion.

Their blogs claim that soy definitely increases breast cancer risk and should be avoided at all costs. Their claims have been picked up by other web sites and blogs. Eventually, the claims have been repeated so many times that people started to believe them. A “myth” has been created. I call it a myth because it was never based on convincing scientific evidence.

In the meantime, scientists looked at the cell culture and animal studies and took a more responsible approach. They said “If this is true, it is an important public health issue. We need to do clinical trials in humans to test this hypothesis.”

What Have Previous Clinical Studies Shown?

breast cancerThe question of whether soy consumption increased the risk of developing breast cancer was settled a long time ago. Some studies have shown no effect of soy consumption on breast cancer risk. Others have reported that soy consumption decreased breast cancer risk. A meta-analysis of 18 previous clinical studies found that soy slightly decreased the risk of developing breast cancer (J Natl Cancer Inst, 98: 459-471, 2006). None of those studies found any evidence that soy increased the risk of breast cancer.

What about recurrence of breast cancer in women who are breast cancer survivors? There have been five major clinical studies looking at the effects of soy consumption on breast cancer recurrence in both Chinese and American populations. Once again, the studies have shown either no effect of soy on breast cancer recurrence or a protective effect. None of them have shown any detrimental effects of soy consumption for breast cancer urvivors.

A meta-analysis of all 5 studies was published in 2013 (Chi et al, Asian Pac J Cancer Prev., 14: 2407-2412, 2013). This study combined the data from 11,206 breast cancer survivors in the US and China. Those with the highest soy consumption had a 23% decrease in recurrence and a 15% decrease in mortality from breast cancer.

What Did The Most Recent Study Show?

Clinical StudyIn earlier clinical studies the protective effect of soy has been greater in Asian populations than in North American populations. This could have been because Asians consume more soy. However, it could be due to other population differences as well.

To better evaluate the effect of soy consumption on breast cancer survivors in the North America, a group of investigators correlated soy consumption with all-cause mortality in breast cancer survivors in the US and Canada (Zhang et al, Cancer, DOI: 10.1002/cncr.30615, March 2017).

The data were collected from The Breast Cancer Family Registry, an international research infrastructure established in 1995. The women enrolled in this registry either have been recently diagnosed with breast cancer or have a family history of breast cancer.

This study included 6235 breast cancer survivors from the registry who lived in the San Francisco Bay area and the province of Ontario in Canada. The women represented an ethnically diverse population and had a median age of 51.8 at enrollment. Soy consumption was assessed either at the time of enrollment or immediately following breast cancer diagnosis. The women were followed for 9.4 years, during which time 1224 of them died.

The results were as follows:

  • There was a 21% decrease in all-cause mortality for women who had the highest soy consumption compared to those with the lowest soy consumption.
  • The protective effect of soy was strongest for those women who had receptor negative breast cancer. This is significant because receptor-negative breast cancer is associated with poorer survival rates than hormone receptor-positive cases.
  • The protective effect was also greatest (35% reduction in all-cause mortality) for women with the highest soy consumption following breast cancer diagnosis. This suggests that soy may play an important role in breast cancer survival.
  • The authors concluded “In this large, ethnically diverse cohort of women with breast cancer, higher dietary intake of [soy] was associated with reduced total mortality.”

In an accompanying editorial, Omer Kucuk, MD, of the Winship Cancer Institute of Emory University, noted that the United States is the number 1 soy producer in the world and is in a great position to initiate changes in health policy by encouraging soy intake.  He said “We now have evidence that soy foods not only prevent breast cancer but also benefit women who have had breast cancer. Therefore, we can recommend women to consume soy foods because of soy’s many health benefits.”

The Soy Myth

Myth Versus FactsEvery clinical study has its limitations. If there were only one or two studies, the question of whether soy increases breast cancer risk might still be in doubt. However, multiple clinical studies have come to the same conclusion. Either soy has no effect on breast cancer risk and breast cancer recurrence, or it has a protective effect.

Not a single clinical study has found any evidence that soy increases breast cancer risk. It is clear that consumption of soy foods is safe, and may be beneficial, for women with breast cancer. The myth that soy increases breast cancer risk needs to be put to rest.

On the other hand, we should not think of soy as a miracle food. Breast cancer risk is also decreased by a diet that:

  • Contains lots of fruits and vegetables.
  • Is low in processed grains & sweets and high in whole grains.
  • Is low in saturated & trans fats and high in omega-3 and monounsaturated fats.
  • Is low in red & processed meats and high in beans, fish & chicken.

Furthermore, diet is just one component of a holistic approach for reducing the risk of breast cancer. In addition to a healthy diet, the American Cancer Society recommends that you:

  • Control your weight
  • Be physically active
  • Limit alcohol
  • Don’t smoke
  • Limit hormone replacement therapy unless absolutely necessary.
  • Reduce stress

The Bottom Line

  • It is time to put the myth that soy increases breast cancer risk to rest. This myth is based on cell culture and animal studies, and those studies were inconclusive.
  • Multiple clinical studies have shown that soy either has no effect on breast cancer risk, or that it reduces the risk.
  • Multiple clinical studies have also shown that soy either has no effect on breast cancer recurrence in women who are breast cancer survivors, or that it reduces recurrence.
  • The most recent clinical study is fully consistent with previous studies. It reports:
    • There was a 21% decrease in all-cause mortality for women who had the highest soy consumption compared to those with the lowest soy consumption.
    • The protective effect of soy was strongest for those women who had receptor negative breast cancer. This is significant because receptor-negative breast cancer is associated with poorer survival rates than hormone receptor-positive cases.
    • The protective effect was also greatest (35% reduction in all-cause mortality) for women with the highest soy consumption following breast cancer diagnosis. This suggests that soy may play an important role in breast cancer survival.
  • No clinical studies have provided any evidence to support the claim that soy increases either breast cancer risk or breast cancer recurrence.

For more information on this study and other things you can do to reduce the risk of breast cancer read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

 ___________________________________________________________________________

My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.

My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance

About The Author 

Dr. Chaney has a BS in Chemistry from Duke University and a PhD in Biochemistry from UCLA. He is Professor Emeritus from the University of North Carolina where he taught biochemistry and nutrition to medical and dental students for 40 years.  Dr. Chaney won numerous teaching awards at UNC, including the Academy of Educators “Excellence in Teaching Lifetime Achievement Award”. Dr Chaney also ran an active cancer research program at UNC and published over 100 scientific articles and reviews in peer-reviewed scientific journals. In addition, he authored two chapters on nutrition in one of the leading Biochemistry textbooks for medical students.

Since retiring from the University of North Carolina, he has been writing a weekly health blog called “Health Tips From the Professor”. He has also written two best-selling books, “Slaying the Food Myths” and “Slaying the Supplement Myths”. And most recently he has created an online lifestyle change course, “Create Your Personal Health Zone”. For more information visit https://chaneyhealth.com.

For the past 53 years Dr. Chaney and his wife Suzanne have been helping people improve their health holistically through a combination of good diet, exercise, weight control and appropriate supplementation.

 

 

The Methylfolate Myths

by

The Lies Of The Supplement Industry

Author: Dr. Stephen Chaney

Pinochio

How do the myths of the food supplement industry originate? Some of them start innocently enough. They are often based on a kernel of truth which is misinterpreted by some well-meaning medical doctors.

It’s not their fault. We teach future doctors what I call “metabolism light” in medical school. There simply isn’t room in the medical curriculum to teach all the details and nuances of human metabolism.

We also try to teach them the basics of how to interpret scientific literature. However, it takes years of experience to get good at picking out the strengths and weaknesses of clinical studies.

The doctors form their hypothesis and test it on a few patients. If it works, they publish a paper. At that point their idea is picked up by the “sensationalist” bloggers. These are the bloggers who like to focus on the sensational. They delight in writing about “new findings” that go against what the medical profession has been telling you for years.

The bloggers don’t stop there. They usually expand the claims. They ‘cherry pick” the scientific literature by quoting only studies that support their viewpoint and ignoring studies that refute it. In short, they put together a very compelling story. Soon the story is picked up by other bloggers who embellish it further. After it appears in enough sites, people start believing it. A myth is born.

Then supplement companies get in the act. They sense there is money to be made. They manufacture supplements to provide nutrients supported by the myths. They embellish the mythology even more and put together a compelling story to market their products.

This is where the mythology becomes deception. Companies have the responsibility to design their products based on the best science. They have an obligation to tell the truth about their products. When they make claims they know cannot be true, they are lying to you.

The saga of methylfolate is a perfect example of how observations based on a kernel of truth became myths and eventually became downright lies. Let me share that story with you.

The Kernel Of Truth About Methylfolate

Let’s start with one of the “kernel of truth” that launched the whole methyl folate saga. It started with a doctor who was having a very difficult time finding a solution for a patient with some significant health issues. The doctor ordered a genetic test and discovered the patient had a deficiency in the methylene tetrahydrofolate reductase (MTHFR) gene.

MTHFR ReactionThe doctor remembered the reaction catalyzed by MTHFR, and a light bulb went off. “Eureka”, he said. His patient must be unable to make N5-methyltetrahydrofolate (commonly referred to as methylfolate or methyl folate), and methylfolate is required for some very important methylation reactions in the cell.

He gave his patient methylfolate, and the patient’s symptoms got better. The doctor leapt to the conclusion that other patients with MTHFR deficiency needed methylfolate as well. Many of those patients responded to methylfolate as well. He didn’t bother to check whether they responded equally well to folic acid. He just assumed methylfolate was the magic elixir.

He wrote a paper on his clinical observations, and the methylfolate story was launched. It all seemed so logical.

However, the story was not nearly as straight forward as the doctor and the people publicizing his findings assumed. Let me walk you through some “Metabolism 101”. Don’t worry. There won’t be a quiz.

Why The Original Assumptions About Methylfolate Were Misleading

MTHFR mutants only have a partial loss of activity.

  • Individuals with 2 copies of a mutation from A to C at position 1298 of the MTHFR gene (A1298C homozygotes) comprise about 5% of the US population. They have 60% enzyme activity and appear to be normal in clinical studies.
  • Individuals with 2 copies of a mutation from C to T at position 677 of the MTHFR gene (C677T homozygotes) have 30% enzyme activity. They comprise about 10% of the US population. C677T homozygotes often have elevated homocysteine levels. The homozygous C677T mutation is associated with depression, anxiety, and mood swings in some people, but not in others (I will come back to the significance of that qualifying statement later).
  • C677T heterozygotes (one mutant gene) have 65% activity and are normal.

We Don’t Need 100% MTHFR Activity

Our human body is wonderfully designed. For many of our most essential metabolic reactions we have built in redundancy. We don’t require 100% activity of key enzymes. This helps protect us from bad effects of mutations as they arise.

The best analogy I can think of is the US space program. Most space vehicles had built in redundancy so that if one system failed, the mission could go on. For example, you may remember the Hubble space telescope. It was launched with four gyroscopes to keep the telescope pointed in the right direction.After a few years, one gyroscope gave out. That was not a problem because there were three left. A few years later the second gyroscope gave out. Again, there was no problem because there were still two gyroscopes left.

It was only after the third gyroscope gave out that Hubble became a bit “wonky”, and a space shuttle was sent up to replace the gyroscopes. It is the same with MTHFR. Only when you get down to around 30% activity, does it become a bit wonky”. (That’s about as non-technical as I get.)

Not Everyone With MTHFR Deficiency Experiences Symptoms

This is due to a phenomenon my geneticist friends refer to as penetrance. Simply put, that means that not everyone with the same mutation experiences the same severity of symptoms. That is because the severity of a mutation is influenced by diet, lifestyle, and genetic background.

Let me start with genetic background. In terms of MTHFR mutants you can think of genetic background as being mutations in a related methylation pathway. People who have a mutation in both MTHFR and a gene in a related pathway will experience more severe symptoms and are more likely to require methylfolate. Once you understand penetrance, you realize that individuals requiring methylfolate may represent only a small subset of people with MTHFR mutations.

Penetrance is a concept that most proponents of the methylfolate hypothesis completely ignore. The most severe MTHFR mutation (C677T homozygote) increases the probability that individuals will exhibit symptoms, but some individuals with that mutation are completely normal. Now that you understand the concepts of redundancy and penetrance, you can understand why that is.

When Did The Kernel of Truth Become A Myth?

Up to this point the hype around methylfolate could be chalked up to an honest misunderstanding.

  • The doctors who published the original papers may not have known that MTHFR mutations only resulted in a partial reduction in enzyme activity.
  • They probably didn’t know the concepts of redundancy (our cells don’t need 100% enzyme activity) or penetrance (the same mutation may cause severe symptoms in some patients and have no effect in others).
  • It seemed logical to assume that everyone with a MTHFR mutation might do better with methylfolate supplementation. That was incorrect, but it was an honest mistake.

However, the message was picked up by the bloggers who specialize in sensational stories, especially stories that contradict what experts have been telling you for years. They picked up the methylfolate story and distorted it beyond recognition.

  • They knew that “natural” is a buzz word, so they told you that methylfolate was natural and folic acid is synthetic.
  • They told you that methylfolate was better utilized than folic acid.
  • They told you that methylfolate was more effective than folic acid.
  • They told you folic acid was toxic. It was going to increase your risk of cancer.
  • Suddenly, it was no longer about people with MTHFR deficiency. You were told that everyone should avoid folic acid and use methylfolate instead.

On the surface, these pronouncements should not have passed the “If it sounds too good to be true…” test, or in this case, the “If it sounds too bad to be true…” test. You were being asked to believe that folic acid, which has been in use for over 80 years and is backed by hundreds of studies showing it is safe and effective, was neither safe nor effective. You were asked to believe that the government was poisoning you by fortifying foods with folic acid.cherry picking studies

However, to make their blogs sound more convincing, they listed clinical studies supporting their stories. The problem is they “cherry picked” the studies that supported their story and ignored the rest. Their bias was particularly outrageous when it came to the “story” that folic acid increases cancer risks. They ignored 10 or 20 studies showing no cancer risk and reported one suggesting it might increase risk. I call that deceptive.

Unfortunately, the myths created by the bloggers have been repeated often enough that many people now believe they are true. It is time for me to debunk the methylfolate myths.

The Methylfolate Myths 

Myth Versus FactsMyth: Methylfolate is natural. It comes from whole food. Folic acid is synthetic.

Fact: Methylfolate is chemically synthesized from folic acid. It is physically impossible to extract enough from whole foods. Here are the facts:

  • Methyfolate is only one of several naturally occurring folates in foods.
  • The best food sources of folates are beans, leafy greens, and broccoli.
  • To obtain the RDA of methyfolate for a single tablet you would need to start with 1 cup of lentils, two cups of cooked spinach, or 4 cups of broccoli.
  • You do the math! It just isn’t possible.

 

Myth: Methylfolate is better utilized by the body than folic acid.

Fact: This claim is based on levels of methylfolate in the blood after taking supplements providing equivalent amounts of methylfolate and folic acid. However, methylfolate has no biological activity in our blood. The measurement that matters is total folate levels (methylfolate plus other folates) in our cells.

If you take equivalent amounts of folic acid and methylfolate, you end up with identical folate levels in your cells (B.J. Venn et al, The Journal of Nutrition, 132: 3333-3335, 2002) In short, there is no difference in our ability to utilize methylfolate and folic acid.

 

Myth: If you have a mutation in the MTHFR gene, folic acid isn’t effective.

Clinically ProvenFact: MTHFR slightly increases the need for folic acid (from 400 ug to between 600 and 800 ug), but multiple studies show that folic acid supplementation is effective in people with MTHFR mutations.

For example, homocysteine levels are easily measured and are a reliable indicator of methylfolate status.

  • One study has shown that folic acid and methylfolate were equally effective at lowering plasma homocysteine in people who were MTHFR C677T homozygotes (P. Fohr et al, American Journal of Clinical Nutrition, 75: 275-282, 2002).
  • That study also showed that folic acid was more effective than methylfolate at lowering homocysteine in people who were C677T heterozygotes and in people with normal MTHFR activity.
  • Another study showed folic acid was just as effective as a diet providing equivalent quantities of folate from foods at lowering homocysteine levels in people with various MTHFR mutations (A. Ashfield-Watt et al, American Journal of Clinical Nutrition, 76: 180-186, 2002).

At present, lowering of homocysteine levels is the only indicator of methylfolate status for which methylfolate and folic acid have been directly compared. However, there are other studies suggesting that folic acid is likely to be effective for people with MTHFR defects. For example:

  • Folic acid has been shown in multiple studies to be effective in preventing neural tube defects (M. De-Regil et al, Cochrane Database Systematic Reviews 2010 Oct 6;(10):CD007950. PMID: 20927767), which are highly associated with the C677T MTHFR gene defect.
  • Three studies have shown that supplementation with folic acid, B12, and B6 slowed cognitive decline in older people with elevated homocysteine levels ( Durga et al, The Lancet, 369: 208-216, 2007; A.D. Smith et al, PLoS ONE 5(9): e12244. doi:10.1371/journal.pone.0012244, 2010; G. Douaud et al, Proceedings of the National Academies of Sciences, 110: 9523-9528, 2013).
  • In contrast, the one study that substituted methylfolate for folic acid showed no effect (A. McMahon et al, New England Journal of Medicine, 354: 2764-2769, 2006).

 

CancerMyth: Folic acid causes cancer.

Fact: The few studies suggesting that folic acid supplementation might increase the risk of cancer were “outliers”.  By that I mean they contradicted many other studies showing no increased risk.

Scientists are accustomed to this. We know that studies sometimes come up with conflicting results. In some cases, we can point to an error in experimental design or statistical analysis as the cause of the aberrant results.

In other cases, we never know the reason for the differences, so we go with the weight of experimental evidence (what the majority of studies show). The weight of evidence clearly supports the safety of folic acid,

However, that is not enough. If there is the slightest possibility that something causes cancer, we investigate it further. Consequently, the scientific community followed up with larger studies.

Those studies showed either reduced cancer risk or no difference in cancer risk with folic acid supplementation. None of the studies found any evidence that folic acid increased cancer risk. I have covered this in detail for folic acid and colon cancer risk in a previous issue of “Health Tips From The Professor”.

There have also been a couple of small studies suggesting that folic acid might increase the risk of prostate and breast cancer. Although these were small, individual studies, they have been widely hyped by the methylfolate advocates. Once again, the definitive study has been done (S.E. Vollset et al, The Lancet, 381: 1029-1036, 2013).

It was a meta-analysis of 13 placebo-controlled studies involving over 50,000 subjects. The results were clear cut. Folic acid supplementation caused no increase in overall cancer risk, and no increase in the risk of colon cancer, prostate cancer, breast cancer, or any other individual cancer. Moreover, the average dose of folic acid in those studies was 2 mg/day, which is 5 times the RDA.

Of course, the bloggers and the companies selling methylfolate supplements ignore the definitive studies showing folic acid does not increase cancer risk. The myths and lies continue.

 

Myth: Folic acid can mask a B12 deficiency.

Fact: True but irrelevant if you use a supplement with folic acid and B12 in balance.

The Lies Of The Supplement Industry

deceptionIf you are writing a blog, you are covered by “freedom of speech”. You can say whatever you want. It doesn’t have to be true. However, if you are a supplement manufacturer, you are held to a higher standard. Ignorance is no longer an excuse. You can no longer cherry pick the “facts” you like and ignore the rest. You are ethically obligated to research all the available literature and be guided by the best scientific evidence.

Reputable companies have been guided by scientific evidence and have not jumped on the methylfolate bandwagon. They know folic acid is both safe and effective in a wide variety of clinical situations. They also know that, while methylfolate may be just as effective as folic acid, it has not been shown to be superior to folic acid for any clinical application.

They may offer a methylfolate option for people who believe they need it. But they make no claim that it is superior to their products containing folic acid.

Less reputable companies, however, sensed money to be made by capitalizing on the buzz around methylfolate. They repeated the myths of the bloggers and claimed their products were superior to others on the market. They call it marketing. I call it lying. They have an obligation to fact check their claims and only make claims that are true.

Let me give you an example. In preparing for this article, I looked at the claims of several companies that were promoting their methylfolate supplements. One in particular claimed they had studies showing:

  • Their methylfolate supplement was effective at reducing the risk of adverse pregnancy outcomes.
  • Their methylfolate supplement was twice as bioavailable as folic acid.
  • Their methylfolate supplement was able to lower homocysteine levels better than conventional folic acid supplementation.

All three studies were bogus.

  • With respect to the first study, it was likely true that their methylfolate supplement decreased adverse pregnancy outcomes. But there are dozens of studies showing that folic acid does the same thing.

And because they did not compare methylfolate and folic acid supplementation in their studies, they have no basis for claiming their supplement was superior.

  • The second study compared levels of methylfolate and folic acid in the blood. As I mentioned above, methylfolate has no biological activity in our blood. The measurement that matters is total folate levels (methylfolate plus other folates) in our cells. And previous studies have shown that equivalent amounts of methylfolate and folic acid give identical amounts of methyfolate in our cells.
  • The third study compared their supplement, which contained B6, B12, zinc, and betaine in addition to methylfolate, to folic acid alone. That’s comparing apples to oranges. That is because there are three pathways for lowering homocysteine levels, and B6, B12, and betaine play important roles in each of these pathways.
    • B12 is an integral part of the enzyme methionine synthase, an enzyme that converts homocysteine to the amino acid methionine. Methylfolate transfers its methyl group to the enzyme-bound vitamin B12, and methyl B12 transfers the methyl group to homocysteine, which converts it to methionine. In other words, methylfolate cannot lower homocysteine levels by itself. It needs vitamin B12.
    • Betaine also serves as a methyl donor in another pathway for converting homocysteine to methionine by an enzyme called betaine-homocysteine methyltransferase.
    • B6 is essential for yet another pathway that lowers homocysteine levels by converting homocysteine to the amino acid cysteine.

You might argue that the company was simply ignorant of the importance of B6, B12, and betaine for lowering homocysteine levels. However, that is unlikely. Why else would they have included B6, B12, and betaine in their supplement?

They must have known the study they designed was bogus. That suggests they conducted the study with the sole purpose of deceiving you, the consumer. I call that lying.

Finally, in case you were wondering, I am not recommending you select a single supplement with folic acid, B6, and B12. I do recommend you get your folic acid from a multivitamin or B complex supplement that provides all three B vitamins in balance.

Betaine deficiency is very rare, so I don’t include betaine in my recommendations.

What Does This Mean For You?

Questioning WomanMTHFR mutations only result in partial loss of activity. Most individuals with MTHFR defects remain symptom free with the RDA, or slightly above the RDA, of folic acid.

However, there may be some individuals with a MTHFR defect and additional gene defects in metabolic pathways involving methylation who might benefit from methylfolate. This is due to a phenomenon that geneticists call penetrance and would likely represent a small subset of the population with MTHFR defects.

Finally,the claims that everyone would benefit from methylfolate instead of folic acid are false. They are contradicted by human metabolism and multiple published clinical studies.

In short, folic acid has been used for over 80 years. There are hundreds of clinical studies showing it is safe and effective, even in most individuals with a MTHFR deficiency. I can’t tell you whether the companies selling methylfolate are ignorant of basic metabolism and the published studies refuting their claims or whether they are purposely trying to deceive the public—but neither is a good thing.

The Bottom Line

Some supplement manufacturers are claiming that methylfolate is more natural and more effective than the folic acid that has been used in supplements for the past 80 years. In this issue of “Health Tips From the Professor” I debunk the methylfolate myths used by the supplement manufacturers to sell their methylfolate products.

I can’t tell you whether the companies selling methylfolate are ignorant of basic metabolism and the published studies refuting their claims or whether they are purposely trying to deceive the public—but neither is a good thing.

For more specifics, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

 _____________________________________________________________________________

My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.

My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance 

_____________________________________________________________________________

About The Author 

Dr. Chaney has a BS in Chemistry from Duke University and a PhD in Biochemistry from UCLA. He is Professor Emeritus from the University of North Carolina where he taught biochemistry and nutrition to medical and dental students for 40 years.  Dr. Chaney won numerous teaching awards at UNC, including the Academy of Educators “Excellence in Teaching Lifetime Achievement Award”. Dr Chaney also ran an active cancer research program at UNC and published over 100 scientific articles and reviews in peer-reviewed scientific journals. In addition, he authored two chapters on nutrition in one of the leading biochemistry textbooks for medical students.

Since retiring from the University of North Carolina, he has been writing a weekly health blog called “Health Tips From the Professor”. He has also written two best-selling books, “Slaying the Food Myths” and “Slaying the Supplement Myths”. And most recently he has created an online lifestyle change course, “Create Your Personal Health Zone”. For more information visit https://chaneyhealth.com.

For the past 53 years Dr. Chaney and his wife Suzanne have been helping people improve their health holistically through a combination of good diet, exercise, weight control and appropriate supplementation.

How Much Should You Walk?

by

Walking Your Way To Health 

Author: Dr. Stephen Chaney 

Overweight People ExercisingYou’ve made your New Year’s resolutions. And if you are like millions of Americans, you may already be making plans to join a gym, get a personal trainer, or join a spin class.

The problem is these are all expensive options. And a good portion of that money is wasted. To put it into perspective, let’s look at some statistics

  • Around 6 million Americans buy gym memberships every January.
    • 67% of those memberships are never used.
    • For those memberships used in January, another 50% are not in use 6 months later.
  • Americans spend about 1.6 billion dollars on unused gym memberships every year.
    • And that doesn’t include those gym memberships that are only occasionally used.

If you want to get fit and healthy in the new year, perhaps you should consider a less expensive option – like walking. Your only investments are a good pair of walking shoes and a device that keeps track of the number of steps you take (eg, Fitbit, smart watch, or smart phone).

You still may give up on your New Year’s goal of getting fitter at some point. But you won’t have wasted so much money.

Of course, you probably have some questions about the benefits of walking, such as:

1) Is walking enough to significantly improve my fitness and health?

2) How far (how many steps) should I walk?

3) How fast should I walk?

Fortunately, two recent studies (B del Pozo-Cruz et al, JAMA Internal Medicine, 182: 1139-1148, 2022) and (J del Pozo-Cruz et al, Diabetes Care, 45: 2156-2158, 2022) have answered all three questions.

How Were These Studies Done?

clinical studyThe first study (B del Pozo-Cruz et al, JAMA Internal Medicine, 182: 1139-1148, 2022) followed 78,500 participants (average age 61, 55% female, 97% white) enrolled in the UK Biobank study for an average of 7 years.

At the time of enrollment, each participant was given an accelerometer (a device that measures the number and frequency of steps) to wear on their dominant wrist for 24 hours/day for 7 days. The investigators used the accelerometer data to categorize several types of physical activity.

  • Daily step counts (the average number of steps per day for 7 days). These step counts were further subdivided into two categories:
    • Incidental steps (It was assumed that ˂40 steps/min represented steps taken that were incidental to normal daily activities).
    • Purposeful steps (It was assumed that ≥40 steps/min represented steps taken as part of planned exercise).
  • Stepping intensity (the highest frequency of steps/min averaged over 30 min intervals for all 7 days).

At the end of the study, each of these variables was correlated with the risk of premature deaths due to all causes, cancer, and heart disease.

The second study (J del Pozo-Cruz et al, Diabetes Care, 45: 2156-2158, 2022) was similar except that it:

  • Used data from 1687 adults (average age = 55, 56% male, with diabetes or prediabetes when the study began) in the 2005-2006 National Health and Nutrition Examination Survey in the US.
  • Followed participants for 9 years instead of 7.
  • Only measured total steps/day.
  • Correlated total steps per day with premature death for participants who already had prediabetes or diabetes when they entered the study.

Walking Your Way To Health

woman walking dogStudy 1 looked at the effect of walking on health outcomes in multiple ways.

#1: Increase in number of steps/day:

  • On average study participants took an average of 7200 steps per day, but this ranged from a low of 3,200 steps/day to a high of 12,200 steps/day.
  • Each increase of 2,000 steps/day was associated with a:
    • 8% decrease in all-cause mortality.
    • 11% decrease in cancer mortality.
    • 10% decrease in heart disease mortality.
  • Overall, increasing from 3,200 steps/day to 10,000 steps/day decreased all-cause, cancer, and heart disease mortality by around 36%.
  • There was no minimum threshold to this beneficial effect of walking on the risk of premature death.
  • The benefits of walking appeared to plateau at 10,000 steps/day.

#2: Increase in number of incidental steps/day (steps taken that are incidental to normal daily activities):

  • On average study participants took 3240 incidental steps/day, but this ranged from a low of 2,100 steps/day to a high of 4,400 steps/day.
  • Each 10% increase in incremental steps/day was associated with a:
    • 6% decrease in all-cause mortality.
    • 6% decrease in cancer mortality.
    • 10% decrease in heart disease mortality.

#3: Increase in number of purposeful steps/day (steps taken as part of planned exercise):

  • On average study participants took 4,600 purposeful steps/day, but this ranged from a low of 1,600 steps/day to a high of 8,600 steps/day.
  • Each 10% increase in purposeful steps/day was associated with a:
    • 7% decrease in all-cause mortality.
    • 8% decrease in cancer mortality.
    • 10% decrease in heart disease mortality.

#4: Increase in speed of walking or cadence. The measurement they used was “peak-30 cadence” – the Walking Fasthighest average steps/min during a 30-minute interval within a day:

  • On average study participants had a “peak-30 cadence” of 76 steps/min, but this ranged from a low of 47 steps/min to a high of 109 steps/min.
  • Each 10% increase in “peak-30 cadence” was associated with a:
    • 8% decrease in all-cause mortality.
    • 9% decrease in cancer mortality.
    • 14% decrease in heart disease mortality.
  • The benefits of walking rapidly (increase in “peak-30 cadence”) were in addition to the benefits seen by increasing the number of steps per day.
  • Overall, increasing from a “peak-30 cadence” of 47 steps/min to 109 steps/min decreased all-cause, cancer, and heart disease mortality by an additional 34%.
  • There was no minimum threshold to this beneficial effect of increasing “peak-30 cadence” (the speed of walking) on the risk of premature death.
  • The benefits of increasing “peak-30 cadence” appeared to plateau at 100 steps/min.

strong heart#5 Effect of walking on the prevention of heart disease and cancer: The investigators measured this by looking at the effect of walking on the “incidence” of heart disease and cancer (defined as new diagnoses of heart disease and cancer) during the study. They found.

  • Each 2,000-step increase in the total number of steps/day decreased the risk of developing heart disease and cancer by 4% during this 7-year study.
  • Each 10% increase in the number of purposeful steps/day decreased the risk of developing heart disease and cancer by 4% during this study.
  • Each 10% increase in “peak-30 cadence” decreased the risk of developing heart disease and cancer by 7% during this study.

The authors concluded, “The findings of this population-based…study of 78,500 individuals suggest that up to 10,000 steps/day may be associated with a lower risk of mortality and cancer and CVD incidence. Steps performed at a higher cadence may be associated with additional risk reduction, particularly for incident disease.”

Study 2 extended these findings to diabetes. They started with participants that had either prediabetes or diabetes diabetesand followed them for 9 years. They found that:

  • Study participants with prediabetes ranged from a low of 3,800 steps/day to a high of 10,700 steps/day.
    • Prediabetic participants walking 10,700 steps/day were 25% less likely to die during the study than participants walking only 3,800 steps/day.
  • Study participants with diabetes ranged from a low of 2,500 steps/day to a high of 10,200 steps/day.
    • Diabetic participants walking 10,200 steps/day were also 25% less likely to die during the study than participants walking only 2,500 steps/day.
  • Even small increases in the number of steps per day decreased the risk of premature death for both prediabetic and diabetic participants.
  • Once again, 10,000 steps/day appeared to be the optimal dose to lower the risk of premature death for both diabetic and prediabetic patients.

The authors of this study concluded, “Accumulating more steps/day up to ~10,000 steps/day may lower the risk of all-cause mortality of adults with prediabetes and diabetes.”

How Much Should You Walk?

Walking CoupleThat was a lot of information. You are probably wondering what it means for you. Let’s start with the big picture:

  • Going from couch potato to 10,000 steps per day may reduce your risk of premature death due to all causes, cancer, and heart disease by 36% (24% if you are already prediabetic or diabetic).
  • Increasing the speed with which you walk from 47 steps/min to 109 steps/min sustained for 30 minutes may reduce your risk of premature death by an additional 34%.

In other words, simply walking more and walking faster can have a significant effect on your health. I am not recommending walking as your only form of exercise. I’m just saying not to consider it inferior to other forms of exercise.

  • There is no lower limit to the benefits of walking. Even small increases in the number of steps/day you take and the speed with which you walk may have a beneficial effect on your health.

In other words, you don’t need to speed walk 10,000 steps/day to reap a benefit from walking. Even small increases are beneficial. That’s good news for those of you who may not be able to speed-walk long distances. It also means that if you are a couch potato, you don’t need to attempt 10,000 steps at high speed from day 1. You can work up to it gradually.

  • Incidental walking (walking that is incidental to your daily activities) is almost as beneficial as purposeful walking (walking as part of a planned exercise).

That’s good news for those of you who may not have time for long walks. It also means that advice like “park your car at the far end of the parking lot and walk” or “take the stairs rather than the elevator” can have a meaningful impact on your health.

  • The benefits of walking appear to max out at around 10,000 steps per day and a cadence of 100 steps/min sustained for 30 minutes.

That means once you get to those levels, it’s time to consider adding other kinds of exercise to your regimen. More and faster walking may offer little additional benefit.

Finally, in the words of the authors, “This information could be used to motivate the least active individuals to increase their steps and the more-active individuals to reach the 10,000-step target.”

The Bottom Line 

You’ve made your New Year’s resolutions. And if you are like millions of Americans, you may already be making plans to join a gym, get a personal trainer, or join a spin class.

If you want to get fit and healthy in the new year, perhaps you should also consider a less expensive option – like walking.

Of course, you probably have some questions about the benefits of walking, such as:

  1. Is walking enough to significantly improve my fitness and health?

2) How far (how many steps) should I walk?

3) How fast should I walk?

Fortunately, two recent studies have answered all three questions. They found:

  • Going from couch potato to 10,000 steps per day may reduce your risk of premature death due to all causes, cancer, and heart disease by 36% (24% if you are already prediabetic or diabetic).
  • Increasing the speed with which you walk from 47 steps/min to 109 steps/min sustained for 30 minutes may reduce your risk of premature death by an additional 34%.
  • There is no lower limit to the benefits of walking. Even small increases in the number of steps/day you take and the speed with which you walk may have a beneficial effect on your health.
  • Incidental walking (walking that is incidental to your daily activities) is almost as beneficial as purposeful walking (walking as part of a planned exercise).
  • The benefits of walking appear to max out at around 10,000 steps per day and a cadence of 100 steps/min sustained for 30 minutes.

In the words of the authors of these studies, “This information could be used to motivate the least active individuals to increase their steps and the more-active individuals to reach the 10,000-step target.”

For more details on these studies and what they mean for you, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

 _____________________________________________________________________________

My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.

My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance

 ______________________________________________________________________

About The Author 

Dr. Chaney has a BS in Chemistry from Duke University and a PhD in Biochemistry from UCLA. He is Professor Emeritus from the University of North Carolina where he taught biochemistry and nutrition to medical and dental students for 40 years.

Dr. Chaney won numerous teaching awards at UNC, including the Academy of Educators “Excellence in Teaching Lifetime Achievement Award”.

Dr Chaney also ran an active cancer research program at UNC and published over 100 scientific articles and reviews in peer-reviewed scientific journals. In addition, he authored two chapters on nutrition in one of the leading biochemistry text books for medical students.

Since retiring from the University of North Carolina, he has been writing a weekly health blog called “Health Tips From the Professor”. He has also written two best-selling books, “Slaying the Food Myths” and “Slaying the Supplement Myths”. And most recently he has created an online lifestyle change course, “Create Your Personal Health Zone”. For more information visit https://chaneyhealth.com.

For the past 45 years Dr. Chaney and his wife Suzanne have been helping people improve their health holistically through a combination of good diet, exercise, weight control and appropriate supplementation.

600th Issue Celebration

by

Nutrition Advances Over The Last Two Years

Author: Dr. Stephen Chaney 

celebrationIn the nearly twelve years that I have been publishing “Health Tips From The Professor”, I have tried to go behind the headlines to provide you with accurate, unbiased health information that you can trust and apply to your everyday life.

The 600th issue of any publication is a major cause for celebration and reflection – and “Health Tips From The Professor” is no different.

I am dedicating this issue to reviewing some of the major stories I have covered in the past 100 issues. There are lots of topics I could have covered, but I have chosen to focus on three types of articles:

  • Articles that have debunked long-standing myths about nutrition and health.
  • Articles that have corrected some of the misinformation that seems to show up on the internet on an almost daily basis.
  • Articles about the issues that most directly affect your health.

Here are my picks from the last two years:

Weight Loss Diets

weight lossSince it is almost January, let’s start with a couple of articles about diet and weight loss (or weight gain). I have covered the effectiveness of the Paleo, Keto, Mediterranean, DASH, vegetarian, and Vegan diets for both short and long-term weight loss in my book “Slaying The Food Myths”, so I won’t repeat that information here. Instead, I will share a few updates from the past 100 issues.

Is Time-Restricted Eating Better Than Other Diets? Time-restricted eating is one of the latest fads. But is it really better than other diets for weight loss and improved health? In this article I reviewed two studies that compare time-restricted eating with diets that do not restrict time of eating but cut calories to the same extent. You may be surprised at the results.

Can You Lose Weight Without Dieting? In this article I share 8 tips for losing weight without going on a diet. The article is based on research by Dr. Brian Wansink, a behavioral psychologist who specializes in studying how external clues influence our eating patterns. As you might suspect his 8 tips for losing weight have nothing to do with counting calories or going on restrictive diets.

Healthy Diets

dairy foodsIs Whole Fat Dairy Healthy? For years dietary guidelines have been telling us to select low fat dairy foods. But some health gurus are telling you that isn’t true. They claim whole fat dairy is healthy. So, you are probably wondering, “What is the scoop (as in ice cream) on whole fat dairy?” In this article I look at the study behind the headlines and answer that question. But the answer is not a simple “Yes” or “No”. The answer is more nuanced. It turns out that whole fat dairy is healthier in some diets than in others. 

Are Low Carb Diets Healthy? Are low carb diets good for you or bad for you? It depends on which study you quote. Two major studies in recent years have come to opposite conclusions. In this article I help you sort through the conflicting studies and rephrase the question. Instead of, “Are low carb diets healthy”, the question should be, “Which low carb diets are healthy?”

Are All Plant-Based Diets Healthy? Plant-based diets have acquired a “health halo” in recent years. Your mama told you to eat your fruits and vegetables. And many health gurus have been telling you not to neglect your grains, legumes, nuts, and seeds as well. But some of these foods require a lot of food preparation.

Never fear! The food industry has come to your rescue with a wide variety of processed plant-based foods. No need for food prep. But are they as good for you as the unprocessed plant foods they replace? In this article I review a study that answers that question.

You probably know what that answer is, but the article is worth a read anyway. That is because the study also asks whether vegan and vegetarian diets are healthier than other primarily plant-based diets. And you may not know the answer to that question.

Diet And Heart Disease

egg confusionAre Eggs Bad For You? For years we were told that eggs are bad for us because they contain cholesterol. Then we were told that eggs in moderation may not increase our risk of heart disease. And recently studies have appeared claiming eggs may be good for our hearts. What is the truth about eggs and heart disease? In this article I review a recent study claiming eggs are bad for our heart and put that study into the context of other recent studies to clear up the “eggfusion”.

Which Diets Are Heart Healthy? Every popular diet claims to help you lose weight, reduce your risk of diabetes, and reduce your risk of heart disease. All these claims can’t be true. Which diets deliver on their promises, and which are just pretenders? In this article I review a recent study that answered that question for heart disease.

This study was a very large metanalysis of over 40 studies with 35,548 participants that looked at the effect of different diets on heart disease outcomes. The study identified two diets that significantly reduced the risk of heart disease. There are other diets that might reduce the risk of heart disease, but their benefits have not been proven by high quality clinical studies. They are merely pretenders.

The Dangers Of Processed Foods 

In previous issues of “Health Tips From the Professor” I have shared articles showing that diets high in processed foods are associated with an increased risk of obesity, diabetes, and heart disease. But the story keeps getting worse. Here are two articles on recent studies about processed foods that appeared in “Health Tips From The Professor” in the last two years.

Why Does Processed Food Make You Fat? We already know that eating a lot of highly processed food is likely to make us fat. But what is it about processed food that makes us fat? In this article I review a recent study that answers that question.

This study is interesting for two reasons.

  • It identifies the characteristics of processed foods that make us want to eat more.
  • It identifies some minimally processed foods that have the same characteristics and suggests we should choose minimally processed foods wisely. Simply put, knowledge is power. We may want to avoid minimally processed foods that have the same obesity-inducing characteristics as processed foods.

Do Processed Foods Cause Cancer? Previous studies have shown that processed food consumption is associated with a higher risk of obesity, diabetes, and heart disease. Can it get any worse? In this article I review a recent study that shows processed food consumption is associated with an increased risk of several kinds of cancer.

Maintaining Muscle Mass As We Age

As we age, we begin to lose muscle mass, a process called sarcopenia. Unless we actively resist loss of muscle mass it will eventually impact our quality of life and our health.

We can prevent this loss of muscle mass with resistance exercise, adequate protein intake, and adequate intake of the amino acid leucine. Previous studies have shown people over 50 need more of each of these to maintain muscle mass, but the amount they need has been uncertain until now. Three recent studies have given seniors better guidelines for maintaining muscle mass.

Can You Build Muscle In Your 80s? In this article I review a recent study that enrolled a group of octogenarians in a high-intensity exercise program to see if they could gain muscle mass. They were able to increase their muscle mass, but the intensity of the exercise required may surprise you.

Optimizing Protein Intake For Seniors. In this article I review two recent studies that looked at the amount, timing, and kind of protein needed for seniors in their 60s and 70s to maximize gain in muscle mass.

How Much Leucine Do Seniors Need? In this article I review a recent study that determined the amount of leucine seniors in their 70s need to optimize gains in muscle mass and strength.

The Benefits And Risks Of Supplementation

Omega-3s And Heart DiseaseIf you listen to Big Pharma or the medical profession, you hear a lot about the “risks” of supplementation and very little about the benefits. In “Health Tips From the Professor” I try to present a more balanced view of supplementation by sharing high-quality studies showing benefit from supplementation and studies that put the supposed risks into perspective.

The Good News About Omega-3s and Stroke. Multiple studies have shown that omega-3 supplementation reduces the risk of ischemic strokes (strokes caused by a blood clot). But it has been widely assumed they might increase the risk of hemorrhagic strokes (strokes caused by bleeding). In this article I review a meta-analysis of 29 clinical studies with 183,000 participants that tested that assumption.

How Much Omega-3s Are Best For Blood Pressure? Multiple studies have shown that omega-3 supplementation can reduce high blood pressure. But the doses used vary widely from one study to the next. In this article I review a meta-analysis of 71 double-blind, placebo-controlled clinical studies that determined the optimal dose of omega-3s for controlling blood pressure.

Omega-3 Supplements Are Safe. As I said above, it has been widely assumed that omega-3 supplementation increases the risk of bleeding and hemorrhagic stroke. In this article I review the definitive study on this topic. More importantly, it reveals which omega-3 supplements might increase bleeding risk and which do not.

Are Calcium Supplements Safe? Big Pharma and the medical profession have been warning us that calcium supplements may increase heart disease risk. In this article I review the definitive study on this topic.

Prenatal Supplements

prenatal dha supplementIf you are pregnant or thinking of becoming pregnant, your health professional has likely recommended a prenatal supplement. You probably assume that prenatal supplements provide everything you need for a healthy pregnancy. Unfortunately, recent research has shown that assumption is not correct.

Is Your Prenatal Supplement Adequate? In this article I review a study that should serve as a wakeup call for every expectant mother. It showed that most prenatal supplements were woefully inadequate for a healthy pregnancy.

What Nutrients Are Missing In Prenatal Supplements? In this article I review a study that identified additional nutrients that are missing in most prenatal supplements.

Prenatal Supplements Strike Out Again. In this article I review a study that looked at the diet of pregnant women to determine their needs and compared that to the nutrients found in prenatal supplements. Once again, most prenatal supplements were woefully inadequate. Is it, “Three strikes and you are out”?

Exercise

Walking FastWalking Your Way To Health. We have been told that walking is good for our health. But how many steps should you take, how fast should you walk, and does it matter whether these steps are part of your daily routine or on long hikes? In this article I review a study that answers all these questions.

Which Exercise Is Best For Reducing Blood Pressure? If you have high blood pressure, you have probably been told to exercise more. But which exercise is best? In this article I review a study that answers that question. And the answer may surprise you.

Did You Know? 

Question MarkIf you have been reading “Health Tips From the Professor” for a while, you probably know that I enjoy poking holes in popular myths. Here are two new ones I deflated in past two years.

Is Low Alcohol Consumption Healthy? You have probably heard that low alcohol intake (that proverbial glass of red wine) is good for you. But is that true? In this article I review a recent study that shows that myth was based on faulty interpretation of the data and provides a more nuanced interpretation of the data.

Is HDL Good For Your Heart? You have been told that increasing your HDL levels reduces your risk of heart disease so many times it must be true. But is it? In this article I review HDL metabolism and a recent study to provide a more nuanced interpretation of the relationship between HDL and heart disease risk.

How To Talk With Your Doctor About Cancer 

Because of my years in cancer research, I am often asked whether someone should follow their oncologist’s advice and go on a recommended chemotherapy or radiation regimen. Of course, it would be unethical for me to provide that kind of advice.

In this article I tell you the questions to ask your oncologist about the prescribed treatment regimen, so you can make an informed decision. However, I also recommend you only ask these questions if you can handle the answers.

The Bottom Line

I have just touched on a few of my most popular articles above. You may want to scroll through these articles to find ones of interest to you that you might have missed over the last two years. If you don’t see topics that you are looking for, just go to https://chaneyhealth.com/healthtips/ and type the appropriate term in the search box.

In the coming years, you can look for more articles debunking myths, exposing lies and providing balance to the debate about the health topics that affect you directly. As always, I pledge to provide you with scientifically accurate, balanced information that you can trust. I will continue to do my best to present this information in a clear and concise manner so that you can understand it and apply it to your life.

Final Comment: You may wish to share the valuable resources in this article with others. If you do, then copy the link at the top and bottom of this page into your email. If you just forward this email and the recipient unsubscribes, it will unsubscribe you as well.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

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My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.

My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance

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About The Author 

Dr. Chaney has a BS in Chemistry from Duke University and a PhD in Biochemistry from UCLA. He is Professor Emeritus from the University of North Carolina where he taught biochemistry and nutrition to medical and dental students for 40 years.  Dr. Chaney won numerous teaching awards at UNC, including the Academy of Educators “Excellence in Teaching Lifetime Achievement Award”. Dr Chaney also ran an active cancer research program at UNC and published over 100 scientific articles and reviews in peer-reviewed scientific journals. In addition, he authored two chapters on nutrition in one of the leading biochemistry text books for medical students.

Since retiring from the University of North Carolina, he has been writing a weekly health blog called “Health Tips From the Professor”. He has also written two best-selling books, “Slaying the Food Myths” and “Slaying the Supplement Myths”. And most recently he has created an online lifestyle change course, “Create Your Personal Health Zone”. For more information visit https://chaneyhealth.com/lifestylechange/.

For the past 45 years Dr. Chaney and his wife Suzanne have been helping people improve their health holistically through a combination of good diet, exercise, weight control and appropriate supplementation.

Health Tips From The Professor