700th Issue Celebration

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The Top 10 Stories From The Past Two Years

Author: Dr. Stephen Chaney 

celebrationIn the nearly fifteen 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 700th 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 the top 10 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 top 10 picks from the past two years.

#10: The Seed Oil Myths – June 2025 

Assortment Of Salad Dressing Bottles

Here is a quick review of the seed oil myths and the truth based on good science.

 

Myth: All seed oils are…[add your favorite derogatory term here].

Truth: Every seed oil has a unique composition of fats. Each has its unique benefits and unique drawbacks.

 

Myth: Seed oils are genetically modified.

Truth: The plants producing canola oil and high oleic sunflower oil have been modified (the kernel of truth), but they were modified by conventional plant breeding rather than genetic engineering.

 

Myth: Seed oils contain toxic ingredients. This myth is most often directed at canola oil.

Truth: Rapeseed oil contains components that can be toxic at high levels (the kernel of truth). However, the rapeseed plant has been bred to produce canola oil with safe levels of those components.

 

Myth: Seed oils are inflammatory, which increases your risk of inflammatory diseases and heart disease.

Truth: Seed oils contain omega-6 fats which can be converted into one inflammatory prostaglandin (the kernel of truth). But they are also converted to anti-inflammatory prostaglandins. The net effect in well done human clinical trials is a slight anti-inflammatory effect.

 

Myth: Seed oils cause oxidative damage, which increases your risk of cancer.

Truth: Seed oils (like any polyunsaturated fat) are susceptible to oxidation, especially at high temperatures. This can lead to free radical formation and oxidative damage (the kernel of truth). But this is only true when you use them improperly. The solution is to store them safely and to not overheat them when cooking.

 

Myth: Saturated fats are healthier than seed oils. Replacing saturated fat with the omega-6 fats found in seed oils increases inflammation and heart disease risk.

Truth: Many studies in this area of research are poorly designed. Well-designed studies show that replacing saturated fat with the omega-6 fats found in seed oils reduces both inflammation and heart disease risk.

 

Myth: Omega-3 fats are healthier than the omega-6 fats found in seed oils, so we should replace seed oils with omega-3 fats.

Fact: Omega-3 fats are more effective than omega-6 fats at reducing inflammation and heart disease risk (the kernel of truth). However, omega-6 fats are essential for a healthy heart, a healthy brain, and normal fetal growth and development. We can’t make them, so we must get them from our diet. Americans are currently consuming the recommended amount of omega-6 fats. So, we should not decrease the amount of omega-6 fats in our diet. Instead, we would benefit from adding more omega-3s to our diet.

 

Myth: Seed oils are highly processed. High heat processing alters the oils. Processing also removes beneficial antioxidants and polyphenols from the oils.

Truth: This is mostly true. The solution is to choose your brands carefully.

  • For oils choose reputable brands and choose ones that use low-heat processing. Also, look for ones with minimal processing. They may be cloudy rather than clear, but they will also contain naturally occurring antioxidants and polyphenols.

For more details about each of these Truth statements, read the article .

#9: The Estrogenic Myth – April 2025 

Myth Versus FactsIt 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.

#8: Is The New Food Guide Pyramid Healthy – January 2026

The USDA just released a new version of the Food Guide Pyramid and accompanying “Dietary Guidelines For Americans”, and they are very different from previous versions.

While the AMA and AHA have both endorsed the new guidelines, they have been controversial. In the article above, I have summarized the pros and cons of every recommendation. There are lots of recommendations, so this was a long article.

To help you make sense of the article I summarized the recommendations and criticisms by dividing the recommendations into 4 categories:

#1: Recommendations that are accepted by almost everyone except the food industry. These are non-controversial.

  • Eat real food
  • Eat vegetables and fruits throughout the day.
  • Focus on whole grains.
  • Limit highly processed foods, added sugar, and refined carbohydrates.

#2: Changes in recommendations that reflect recent scientific advances. Critics of these changes simply haven’t kept up with scientific publications over the past couple of decades.

  • Increasing the daily protein recommendations.
  • Including full-fat dairy as a healthy dairy food.

#3: Tempests in a teapot: There is a kernel of truth in these criticisms, but the changes are much more modest than the critics would have you believe.

  • Including red meat in the protein recommendations.
  • Including some saturated fats in the “healthy fats” category.
  • Not including specific limits on alcohol consumption, as the previous version had done.

#4: What I would have liked to have seen:

  • More emphasis on plant proteins.
  • Elimination of lard from the “healthy fat” category.
  • Inclusion of high-quality vegetable oils in the “healthy fats” category.

For more details about the pros and cons of the new Food Guide Pyramid read the article

#7: Is Melatonin Safe? – February 2026 

breaking newsRecent headlines claim that long-term melatonin use may be risky. Specifically, the headlines claim that long term melatonin use may increase the risk of heart failure by 90%.

As a melatonin user, that got my attention, so I analyzed the data behind the headlines and discovered the headlines greatly overemphasized the risk.

It has to do with the difference between relative risk and absolute risk.

Simply put:

  • Relative risk is the change in risk caused by an intervention (melatonin in this case) relative to the risk without the intervention.
    • Relative risk is generally used in describing the results of clinical studies because it gives much larger numbers and is, therefore, more newsworthy. It is more likely to generate the headlines you see and grab your attention.
  • Absolute risk is the actual change in risk that you experience.
    • This is the risk that matters to you.

With those simple definitions, let’s review the claims of this study:

  • The study said that long-term melatonin use increased the risk of heart failure by 90%. That sounds horrible, but it is an increase in relative risk!
  • However, when I analyzed the data and calculated the absolute risk of heart failure, it was 2%. When compared with the benefit of a good night’s sleep, that’s a risk I can live with.

For more details, read the article.

#6: Are Peptide Stacks Safe? – January 2026

Peptide stacks are the latest “magic” weight-loss potion. When I think of the allure of peptide stacks, the image that comes to mind is the sirens of Greek Mythology. They were variously described as bird-like or mermaid-like creatures who sat on the shoreline and sang such enchanting songs that they lured sailors to their deaths on the rocky shoals just off the coast.

In this article I described their allure. I also described the rocky shoals.

  • Peptide stacks are not natural. Peptide hormones are tightly controlled in our body. They increase under the appropriate conditions and are replaced by other peptide hormones as conditions change. Interfering with the carefully choreographed ebb and flow of peptide hormones may result in unexpected side effects.
  • There are no published human clinical studies on peptide stacks. That means:
    • We have no idea whether they are safe and effective. There is no evidence that the claimed benefits are true, and we don’t know what the side effects might be.
  • No one is monitoring the manufacturing practices and quality controls for peptide stacks. That means:
    • We have no idea whether they are pure and potent. We don’t know how much of each peptide hormone they contain and whether the hormones are pure.

In short, using the peptide stacks currently available online is like volunteering to be a guinea pig in a long-term clinical trial with an uncertain outcome.

For more information on peptide stacks and the best recommendations if you choose to use them, read the article.

#5: Is Your Protein Supplement Toxic? – February 2025

There are lots of good reasons for using protein supplements.

But the latest headlines claim that many protein supplements are toxic. They contain heavy metals that can destroy your health. In particular, the headlines claim that a high percentage of popular protein supplements are contaminated with lead and/or cadmium.

That’s downright scary. One study showed:

  • 47% of the products tested exceeded California Proposition 65 safety thresholds (MADLs) for lead and/or cadmium.
  • Plant-based protein supplements were more likely to be contaminated than animal-based protein supplements.
  • Organic protein supplements were more likely to be contaminated with heavy metals than non-organic protein supplements.
  • Chocolate-flavored protein supplements were more likely to be contaminated with heavy metals than vanilla-flavored protein supplements.

It is truly consumer beware in the protein supplement market. So, what can you do to avoid potentially toxic protein supplements?

You can’t rely on product labels or generic purity claims. But you can do a little sleuthing on your own. Here are the questions you should ask.

  • How many quality control tests do you run on the ingredients used in your protein supplements? The answer should be in the hundreds.
  • Do you test for heavy metal contamination? The answer should be yes.
  • Do you reject raw ingredients with heavy metal contamination? The answer should be yes.

And once you find a company that answers these 3 questions correctly stick with them. A cheaper product with poor quality controls is not worth the risk of heavy metal contamination.

For more details on this report read the article.

#4: Do NMN Supplements Increase Cancer Risk? – September 2026 

CancerMany of you have asked me to comment on recent headlines claiming that NAD+-boosting supplements like NMN may stimulate cancer cell growth and, therefore, increase cancer risk. So, I dug into the studies behind the headlines and evaluated the validity of those claims.

I searched the scientific literature to look for evidence to support that claim. Unfortunately, there are very few published studies on the relationship between NMN supplements and cancer risk. Here is what I found. 

  • 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 short, 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 can’t make a recommendation. I can only suggest that, 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.

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.

For more details on NMN and cancer risk and a comparison with previous supplement-cancer risk scares read the article.

#3: Are Our Healthy Years Getting Shorter? – December 2024

If you’ve ever traveled the subway system in London, you can’t have missed the “Mind the Gap” signs warning not to put your foot in the gap between the subway and the platform.

But today’s “Health Tip” is not about subway gaps. It’s about a far more important gap – the gap between our healthspan (how many years we enjoy good health) and our lifespan (how many years we live).

A recent study suggesting that our healthy years are getting shorter caught my attention. The study showed a constant worsening of health and disabilities from people born in the decade starting in 1925 to people born in the decade starting in 1955.

This pattern was seen for:

  • Obesity
  • Heart disease.
  • Diabetes
  • Lung disease.
  • High blood pressure.
  • High cholesterol.
  • Severe disabilities.
  • Reduction in grip strength.

This study compared health and disability of people at the same age. The only difference is when they were born. It tells us people in their 50s, 60s, or 70s born in 1955 or later are in poorer health than people of the same age who were born in 1925.

Two things should be noted for this pattern:

  • The worsening of health and the increase in severe disabilities comes despite the vast improvements in the health care system and improved understanding of the causes of these diseases.
  • Obesity is likely a major driver of our declining health and increased disability. However, it is not the only driver. If the investigators had graphed the percentage of highly processed foods in the diet or the decline in regular exercise, the pattern would have been similar.

What does this mean for you? The take home lesson should be, “This doesn’t have to be. You don’t have to be frail and sickly in your golden years. We know how to prevent this.”

  • It starts with a healthy diet – a whole food, primarily plant-based diet with lots of colorful fruits and vegetables, whole grains, nuts and seeds.
  • Add in a regular exercise program with a mixture of aerobic and resistance exercises.
  • Include an individualized supplement program.

You notice I didn’t list weight control as one of the top three prevention strategies. That’s because I don’t recommend fad diets and rapid weight loss programs. If you do the first three things well, your weight will come off naturally – a little bit at a time.

And once you have mastered all four things, you will increase your healthy years and narrow the gap between your healthspan and your lifespan. You can look forward to golden years filled with vitality and adventure.

For more details about this study and what it means for you read the article.

#2: Protein – The Longevity Nutrient – October 2025

If you want to delve into the latest protein research and what it means for you, I highly recommend the book, “Forever Strong: A New, Science-Based Strategy For Aging Well” by Dr. Gabrielle Lyon.

Her book is focused on helping each of us create adequate healthy muscle mass. She says, “Adequate muscle mass is essential for health and longevity. And muscle is the only organ over which we have voluntary and complete control.”

Of course, adequate muscle mass requires both exercise and adequate protein. Dr. Lyon covers both in her book, but exercise is not my expertise, so I will only cover adequate protein intake in this “Health Tips From the Professor” article.

In her book, Dr. Lyons details recent research on the amount of protein needed to optimize muscle mass. Dr. Lyon was the one who alerted me to the fact that the current protein RDA is based on outdated methodology from the 1930’s and that actual protein needs are much higher.

Dr. Lyon concludes that most Americans are not consuming enough protein to optimize their muscle mass and that adequate protein intake is essential for longevity, metabolic function, and quality of life. Specifically, she says that optimal muscle mass:

  • Improves strength and mobility.
  • Improves blood sugar control.
  • Decreases blood triglyceride levels.
  • Strengthens the immune system.
  • Improves bone mineral density and strength.
  • Reduces all-cause mortality (risk of dying) and morbidity (risk of disease).

In this article I used the latest science on protein needs described in her book and in recently published clinical studies to answer the important question, “How much protein do you need?”

For more details on Dr. Lyon’s book and my protein recommendations, read the article

#1: What Your Doctor Didn’t Tell You About GLP-1 – March 2026

GLP-1 drugs may seem like a weight loss miracle. Your appetite decreases. You eat less. And the pounds just melt away. But the health benefits of losing weight with GLP-1 drugs may be a mirage rather than a miracle.

That’s because what you eat while you are on GLP-1 drugs may be critical to your long-term health. And your doctor probably didn’t tell you about that when they were prescribing GLP-1.

Here are some other things your doctor may not have told you about GLP-1 drugs.

  • GLP-1 drugs have side effects, and some of them are serious. Do you know what side effects to look out for?
  • Long-term GLP-1 use may result in nutritional deficiencies. Has your doctor told you how to prevent them?
  • GLP-1 use can cause loss of muscle mass. Has your doctor told you how to prevent that?
  • GLP-1 weight loss plateaus. Has your doctor told you about that?
  • For some people, GLP-1 wight loss is transitory. Has your doctor mentioned that possibility?
  • Without diet and lifestyle changes, you may need to continue using GLP-1 drugs the rest of your live. Has your doctor talked with you about the diet and lifestyle changes you should be making?

For more details about the dangers of GLP-1 drugs, read the article.

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.

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.

Do You Need An MRI For Shoulder Pain?

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What Does This Study Mean For You? 

Author: Dr. Stephen Chaney

Your shoulder is painful. It interferes with your range of motion. It’s affecting your workouts and your daily activities. And it seems like the pain has hung on for far too long.

When you go to your physician, they suggest you get an MRI to see if PT (physical therapy) is sufficient or whether you need surgery to repair or replace portions of your shoulder.

This is a consequential decision. Let me share some statistics to illustrate why:

  • Around 31% of US adults experience shoulder pain at any given time. The prevalence of shoulder pain is highest between ages 45 and 64 and remains high past age 65.
  • MRI imaging is recommended by 50% of general practitioners as part of the initial evaluation of shoulder pain. It is considered essential by 82% of general practitioners and 56% of specialists.

The MRI imaging results often lead to a recommendation for surgery. But shoulder surgery is much more complicated than hip or knee replacement surgery.

  • Because our shoulders move in many directions, they are packed with a complex of tightly packed muscles and tendons. They need to be protected or reattached, depending on the kind of surgery.
  • Major nerves pass right next to the surgical zone, increasing the risk of nerve damage or numbness.

Because of this complexity, recovery times rotator cuff replacements are much longer and success rates lower than for knee or hip replacements.

  • Recovery time is 6-12 months for rotator cuff replacement compared to 6-12 weeks for hip replacement and 3-6 months for knee replacement.
  • The success rate for rotator cuff replacement surgery is 85-95% for small tears compared to 90-95% for knee replacement surgery and 95+% for hip replacement surgery.

And finally, there is the cost.

  • Shoulder surgery can cost individual patients up to $40,000.
  • Shoulder surgery costs the United States healthcare system around $12 billion a year.

That cost represents a burden to a healthcare system that is struggling to remain solvent. So, it is worthwhile asking whether that is a necessary cost.

Several small studies have suggested that the rotator cuff abnormalities detected by MRI are a normal part of aging rather than indicating the need for surgery unless there are additional indications that surgery is needed.

So, the authors of this study (T Ibouing et al, JAMA Internal Medicine, 186: 406-414, 2026) designed a large study to test the hypothesis that abnormal shoulder MRI readings were an indication of aging rather than an indication for surgical intervention.

How Was This Study Done?

clinical studyThe study drew participants from the Finnish Health 2000 Survey which enrolled 9922 individuals 18 and older in 2000 and has followed them continuously ever since.

In 2022, the Health 2000 database was reviewed to identify individuals who:

  • Had given consent for follow-up studies.
  • Had a maximum age of 75.
  • Did not have previous shoulder replacement surgery.

These individuals were invited to participate in the Finnish Imaging Study (FIMAGE). A total of 602 participants enrolled in the study. The average age of the participants was 58 (range = 41-76) with 52% females and 48% males.

Each of the participants was asked if they had experienced shoulder symptoms lasting more than 24 hours during the past week and whether the symptoms were persistent or intermittent. They were also asked whether they had experienced previous incidents of shoulder pain.

This was followed by clinical evaluation of shoulder pain and disability by experienced shoulder surgeons.

Finally, each participant underwent bilateral MRI imaging to detect rotator cuff abnormalities, and the abnormalities were classified according to severity as follows:

  • Tendinopathy – minor deformities of one the tendons attached to the rotator cuff.
  • PTT – A fluid-filled defect of the tendon tissue extending to either surface of the rotator cuff or the tendon insertion point.
  • FTT (most severe) – A fluid-filled defect of the tendon tissue extending to both surfaces of the rotator cuff.

Don’t get hung up on the definitions. That is a terminology only an anatomist could love. You just need to remember that tendinopathy was the least severe classification and FTT was the most severe.

Do You Need An MRI For Shoulder Pain?

Confused DoctorThe results were as follows:

  • MRI imaging detected rotator cuff abnormalities in 98.7% of the participants. Of these:
    • 25% had tendinopathy (mild abnormalities).
    • 62% had PTTs (moderate abnormalities).
    • 11% had FTTs (significant abnormalities)
  • The prevalence of abnormalities was similar in men and women.
  • Rotator cuff abnormalities showed age-related progression, with milder findings in younger participants and more advanced structural damage in older participants.

Of the participants in this study, 81.7% were asymptomatic and 18.7% reported symptoms of shoulder pain or disability in the week prior to their MRI imaging.

  • Rotator cuff abnormalities were observed in 96% of asymptomatic participants and 98% of symptomatic participants. This represented an absolute difference of 1.8%, which was not statistically significant.

When these data were broken down with respect to the severity of the abnormalities:

  • There was no significant difference in the prevalence of tendinopathy or PTTs in asymptomatic and symptomatic shoulders of individuals with shoulder pain or dysfunction.
  • FTTs (the most severe abnormalities) were more common in symptomatic shoulders (14.6%) than asymptomatic shoulders (6.5%).
    • However, this difference disappeared when it was corrected for positive clinical rotor cuff tests from the physical exam conducted prior to MRI imaging.

[Note: This means that rotator cuff abnormalities are best diagnosed by a physical evaluation by a specialist. MRI imaging did not add anything to the diagnosis.]

The authors concluded, “In this population-based study, rotator-cuff abnormalities [detected by MRI imaging] were nearly universal after age 40 years and showed poor correlation with shoulder symptoms. These findings suggest that rotator cuff abnormalities represent normal age-related changes rather than disease and call into question the clinical value of routine imaging for shoulder pain.”

My Wife’s Shoulder Pain Experience

A few years ago, my wife, Suzanne, had severe pain in her right shoulder. She could not lift her arm above her shoulder, and it was painful to even lift it to shoulder height.

Her doctor referred her to a shoulder specialist. To his credit, he didn’t order an MRI. But based on his clinical evaluation, he gave my wife two choices.

#1: She could get up to three corticosteroid shots to control inflammation. That treatment could not be used more than three times and came with a variety of side effects including:

  • Weight gain.
  • Mood changes.
  • Sleep disruption.
  • Suppressed immunity.
  • Bone loss.

#2: Shoulder surgery, which was his recommended option (he was a surgeon).

He didn’t mention physical therapy.

My wife didn’t like either of these options, so she asked her chiropractor for a referral to a physical therapist. The first physical therapist she tried didn’t help her, so found another physical therapist. That physical therapist also didn’t help her, so she kept looking.

[As you might have guessed, my wife doesn’t give up easily. That’s her superpower.]

The third physical therapist she tried was the charm. Within a couple of months, she was pain free and had regained full range of motion. He was so good she added him to her healthcare team.

Now he is her personal trainer (with physical therapy on the rare instances when she needs it.) Today she is lifting heavy weights and doing shoulder presses and pullups.

The take home lesson is clear. Don’t let yourself be rushed into corticosteroid shots or surgery without trying physical therapy first. It’s worth the investment.

What Does This Study Mean For You?

Questioning WomanLet me share a few quotations from the Discussion section of this study and interpret what they mean for you.

The Authors: “These findings have important implications for test interpretation in routine clinical care. In middle-aged and older adults, the extremely high probability of MRI-detected rotator cuff changes – approaching 100% in individuals over the age of 50 – means that the mere presence of an [MRI-detected] abnormality has limited diagnostic value.”

Your Take-Away: Don’t be stampeded into corticosteroid injections or shoulder surgery simply because MRI imaging of your shoulder detects tears or other abnormalities. Those changes could simply represent normal aging.

The Authors: “A positive MRI result does not confirm causality [meaning that abnormalities detected by MRI imaging are not necessarily responsible for the pain or loss of mobility you are experiencing] unless features such as a clear traumatic event [injury], acute strength loss, or persistent functional deficit increase the probability [of shoulder injury].”

Your Take-Away: If your shoulder pain is due to injury, you are experiencing severe loss of strength or range of motion, and these problems are persistent, you may wish to consult a shoulder specialist to determine your best course of action. In this case, MRI imaging does not play a diagnostic role, but it may help determine the best form of intervention.

However, corticosteroid therapy has significant side effects and shoulder surgery is not a minor surgical procedure. As my wife’s example shows, it is worth trying more natural approaches before taking the drug or surgical route. In my wife’s case, physical therapy, chiropractic care, and anti-inflammatory nutritional support help her avoid drugs and surgery.

The Authors: They closed by adding a very insightful comment about the way we should describe and think about MRI imaging.

“Reframing [MRI imaging] findings as normal age-related changes rather than disease may help guide more appropriate care and reduce unnecessary interventions…[This] may help avoid language that implicitly suggests that something is broken and requires fixing. Such terminology may reduce patient anxiety, discourage unnecessary surgical interventions, and help minimize overdiagnoses and overtreatment.”

Your Take-Away: It would be wonderful if every doctor reads this article, but most simply don’t have the time. So, when confronted with troubling MRI or X-ray results, you may want to ask a few questions like:

  • “Are these results typical for someone my age?”
  • “Is this something that should be watched or does it require immediate action?”
  • “Are there any natural approaches or treatment options you recommend?”

That last question may require some discussions with your healthcare provider. I have my doctor well trained. She starts with, “There is a drug for that” and quickly switches to “But I know you aren’t interested in that. Here are some natural options to consider.

The Bottom Line

Most of us experience shoulder pain and loss of range of motion at one or more times in our lives. If the problem is persistent and we consult our physician, they often order MRI imaging as the first step to see whether medical treatment is necessary. But is that the best tool for diagnosing shoulder injuries?

A recent study looked at the value of MRI imaging of shoulders as a diagnostic tool for determining the need for drug therapy or surgery. The study found:

  • MRI imaging detected rotator cuff abnormalities in 98.7% of the population over the age of 40.
  • Rotator cuff abnormalities showed age-related progression, with milder findings in younger participants and more advanced structural damage in older participants.
  • Rotator cuff abnormalities were identical in the symptomatic shoulder and the asymptomatic shoulder of individuals with shoulder pain or dysfunction.

The authors concluded, “In this population-based study, rotator-cuff abnormalities [detected by MRI imaging] were nearly universal after age 40 years and showed poor correlation with shoulder symptoms. These findings suggest that rotator cuff abnormalities represent normal age-related changes rather than disease and call into question the clinical value of routine imaging for shoulder pain.”

For more details about 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.

How Did Breakfast Cereals Get So Unhealthy?

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The Great Breakfast Cereal Scandal Continues

Author: Dr. Stephen Chaney 

Big Food Inc is not your friend. Big Food Inc follows the latest trends and is only too happy to give consumers what they want.

You want low-fat? No problem. You want low-carb, natural, organic, non-GMO, gluten-free, Paleo, Keto? No problem. However, their motive is a healthy bottom line, not your health.

They know humans are hardwired to desire sugar, salt, and fat. Foods with those ingredients sell. Convenience sells. At the end of the day, they are more interested in sales than they are in your health.

They don’t want you to buy whole foods and cook them from scratch. They don’t make money from whole foods. They want you to buy their pre-packaged convenience foods instead.

A prime example of how Big Food Inc of how Big Food takes a healthy food and turns it into a nutrition disaster is what I call “The Breakfast Cereal Scandal” or “How Did Breakfast Cereals Get So Unhealthy?”

How Did Breakfast Cereals Get So Unhealthy? 

It’s hard to believe that breakfast cereals started as health food, but they did. Dr. John Harvey Kellogg was a Seventh-day Adventist who took over the Western Reform Health Institute in 1877 and renamed it the Battle Creek Sanitarium.

It gained prominence as a health resort where people went to be healed through a combination of physical activity and healthy eating.

Dr. Kellogg invented Corn Flakes in 1878 as a healthier alternative to the high-fat breakfasts most Americans were consuming at that time. Corn Flakes had less than 5% sugar. It was a great idea for its time, but what happened next is nothing short of appalling.

It is a perfect example of how Big Food Inc leads us astray. The graphic above that I created illustrates what the major food companies have done to breakfast cereals over the decades since then.

It all started with Corn Flakes. Then other food companies started bringing out competing products. Cereals like Wheaties and Rice Krispies were still pretty healthy, but they had a bit more sugar, which gave them better consumer appeal.

As soon as the food companies figured out that sugar increased their sales, the race was on. The percentage sugar increased to 40%, then to 50%, and now to almost 60%.

No sane parent would fill their child’s cereal bowl half full of sugar, but that is exactly what they are doing when they feed them some of today’s breakfast cereals. The food companies are hiding the outrageous sugar content of their cereals with slogans like “Just a touch of honey.”

Speaking of deception, can anyone tell me how you label a product with 20% sugar 100% Bran Flakes?

I created the graphic above in the 1990’s. At that time, I assumed breakfast cereals couldn’t get much worse. But I was wrong. Big Food’s “race to the bottom” continues.

A recent study (A Zhao et al, JAMA Network Open, 8(5): e2511699, 2025) examined the nutritional content of children’s cereals introduced to the US market between 2010 and 2023.

How Was This Study Done? 

The investigators used data from the Mintel Global New Products Database, which tracks new product launches for foods and beverages. From this database they identified 1,200 new children’s cereals introduced in the US market from 2010 through 2023.

Children’s cereals were defined as breakfast cereal products explicitly marketed (through packaging or branding) to children between 5 and 12 years old.

Using product label information, they compared the total fat, sodium, total carbohydrate, sugar, protein, and dietary fiber per serving and analyzed the trends between 2010 and 2023.

The Great Breakfast Cereal Scandal Continues

If the previous decline in nutritional value of breakfast cereals between the 1870s and 1970s can be described can be described as “appalling”, the latest results can only be described as scandalous.

For newly introduced children’s breakfast cereals in the 13 years between 2010 and 2023,

  • Fat content increased 34%.
  • Sodium (salt) content increased 32%.
  • Sugar content increased by 11%.
  • Protein content decreased by 11%.
  • Fiber content decreased by 30%.

The authors of the study concluded, “Analysis of newly launched children’s RTE (ready to eat) cereals from 2010 to 2023 revealed concerning nutritional shifts: notable increases in fat, sodium, and sugar along decreases in protein and fiber.

Children’s cereals contain high levels of added sugar, with a single serving exceeding 45% of the American Heart Association’s daily recommended limit for children.

These trends suggest a potential prioritization of taste over nutritional quality in product development, contributing to childhood obesity and long-term cardiovascular health risks.”

In short, despite the American public’s increasing interest in a healthy diet, Big Food is still prioritizing sales over healthy foods. The race to the bottom continues.

What Does This Mean For You?

The take home lesson is clear. Don’t trust Big Food with your health. Their priority is sales, not your health.

Even when they claim their processed foods are healthy because they have removed fat or sugar, they have simply replaced them with a witch’s brew of chemicals, so they look, taste, and smell delicious.

And breakfast cereals are just the tip of the iceberg. For most Americans 60-70% of their diet comes from highly processed foods.

If you value health, the choice is clear. Choose whole, unprocessed food whenever possible.

The Bottom Line

The dramatic decline in the nutritional quality of breakfast cereals between the 1870s and 1970s is well documented. By the turn of the century most breakfast cereals had gotten so bad, you might assume they couldn’t get any worse. You would be wrong. Big Food’s race to the bottom continues.

A recent study evaluated the nutritional value of newly introduced children’s breakfast cereals between 2010 and 2023. In those 13 years,

  • Fat content increased 34%.
  • Sodium (salt) content increased 32%.
  • Sugar content increased by 11%.
  • Protein content decreased by 11%.
  • Fiber content decreased by 30%.

The authors of the study said, “These trends suggest a potential prioritization of taste over nutritional quality in product development, contributing to childhood obesity and long-term cardiovascular health risks.”

I agree. And this is just the tip of the iceberg. For most Americans 60-70% of their diet comes from highly processed foods.

If you value health, the choice is clear. Choose whole, unprocessed food whenever possible.

For more details 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 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.

Do NMN Supplements Increase Cancer Risk?

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What Can We Learn From Previous Supplement-Cancer Claims?

Author: Dr. Stephen Chaney 

Newspaper HeadlinesMany of you have asked me to comment on recent headlines claiming that NAD+-boosting supplements like NMN may stimulate cancer cell growth and, therefore, increase cancer risk. So, in today’s “Health Tips From the Professor” I will dig into the studies behind the headlines and evaluate the validity of those claims.

But before I do that, I’d like to remind you of what I call “Secrets Only Scientists Know”.

Secret #1: Most scientists design their experiments to disprove existing paradigms and create a new paradigm in the process. This constant testing and retesting of what we think we know is the strength of the scientific process.

The corollary of this in the supplement area is:

Corollary #1A: Many scientists design their studies of supplements to discover their dangers. This only makes sense. If a popular supplement is going to be used by millions of people, we should want to know if it poses any dangers.

The result is that we end up with contradictory studies on supplements in the scientific literature.

  • Some studies show a supplement’s benefits. Other studies may suggest it doesn’t work.
  • And you are almost always assured there will be some studies claiming that the supplement may be dangerous.

That brings us to the second “Secret Only Scientists Know”:

Secret #2: Every study has its flaws. Because of that, a good scientist never believes in a single study. We wait until there are multiple studies and ask what the majority of them show.

Finally, we don’t rely on cell culture or animal studies because they are unreliable. My research focus at the University of North Carolina was cancer drug development. From my experience, I can tell you that:

  • Of cancer drug candidates that looked good in cell culture models, only 1 out of 1,000 worked in humans.
  • Of cancer drug candidates that looked good in animal models, only 1 out of 100 worked in humans.

For that reason, good scientists insist on results from human clinical studies, preferably studies with thousands of subjects.

With that in mind, let’s look at some previous examples where headlines proclaimed certain supplements might cause cancer and what the human clinical studies actually showed.

What Can We Learn From Previous Supplement-Cancer Claims?

To add some perspective to the discussion of NMN and cancer risk, it is instructive to first look at past supplement-cancer myths.

The Soy – Breast Cancer Myth.

soyThis myth originated with a review discussing the cellular effects of soy isoflavones.

  • Some of those effects could theoretically stimulate the growth of breast cancer cells. Others could theoretically inhibit breast cancer cell growth.
    • The potential stimulatory effects of soy isoflavones were emphasized. The inhibitory effects were ignored.

This was followed by studies looking at effect of soy isoflavones on breast cancer cells in cell culture.

  • In some of those studies, soy isoflavones stimulated the growth of breast cancer cells in culture. In other studies, they had no effect on breast cancer growth.
    • The studies showing soy isoflavones stimulated growth of breast cancer cells were emphasized. The other studies were ignored.

This was followed by studies in mouse model systems.

  • In studies with mice lacking an immune system, soy isoflavones stimulated the growth of breast cancer cells. In studies with mice having a functional immune system, soy isoflavones inhibited breast cancer growth.
    • The studies showing soy isoflavones stimulated growth of breast cancer cells were emphasized. The other studies were ignored.

By now, the myth that soy supplements increased breast cancer risk was well established, so the medical community did the responsible thing. They tested the hypothesis in human clinical trials.

  • 18 clinical studies have been published looking at the effect of soy consumption on the risk of developing breast cancer.
    • Some studies reported that soy consumption decreased breast cancer risk. Others reported no effect of soy consumption on breast cancer risk.
    • None of the studies found that soy increased breast cancer risk.
    • A meta-analysis of all 18 studies found that soy consumption slightly decreased breast cancer risk.
  • 6 clinical studies have been published looking at the effect of soy consumption on breast cancer recurrence in women who were breast cancer survivors.
    • Some studies reported that soy consumption decreased breast cancer recurrence. Others reported no effect of soy consumption on breast cancer recurrence.
    • None of the studies found that soy increased the risk of breast cancer recurrence.
  • A meta-analysis of 5 of the studies (a total of11,206 breast cancer survivors) found that soy consumption decreased breast cancer recurrence by 23% and breast cancer mortality by 15%.

In short, the clinical evidence is clear. Soy does not increase either breast cancer risk or breast cancer recurrence in breast cancer survivors. If anything, it has a protective effect.

So, why is the myth that soy increases breast cancer risk so persistent?

  • The problem is that some doctors and most social media influencers do not understand the intricacies of human biology and do not know the “secrets only scientists know”.
  • They don’t base their opinions on the majority of published studies, as good scientists do. Instead, they select only the studies that support their opinions.
  • Motivation also plays a role. They are less interested in the accuracy of the information they post than the number of clicks, subscriptions, and sales their posts generate. And telling people that the scientific community is hiding the truth from them gets a lot more clicks than admitting the scientific community is right.

I have discussed the soy – breast cancer myth in more detail in a previous issue of “Health Tips From The Professor”.

The Folic Acid – Colon Cancer Myth.

folic acidThe origin of this myth is slightly different.

  • Folic acid is involved in at least 20 metabolic pathways in humans. Some of those pathways could theoretically stimulate cancer cell growth. Others could theoretically inhibit cancer cell growth.
  • Several population studies suggested that high intakes of folic acid might protect against cancer, especially colon cancer. So, several placebo-controlled clinical studies were conducted to test that hypothesis.
    • Some of those studies reported that folic acid reduced cancer risk. Others reported it had no effect.
    • None of the studies found that folic acid supplementation increased the risk of any kind of cancer.
  • In 1998 mandatory folic acid fortification of grain products was introduced in the United States. Since this meant that folic acid intake was increased for a significant portion of the US population, the placebo-controlled studies were repeated a few years later.
  • One of those studies reported that high folate intake was associated with an increased risk of colon adenomas. Adenomas are benign, but under certain conditions a small percentage of adenomas progress to carcinomas. This raised a red flag and was widely reported.
  • Once again, the medical community did the responsible thing. The American Cancer Society commissioned a very large study (43,512 men and 56,011 women were followed for 8 years) to test the hypothesis that high intakes of folic acid increase the risk of colon cancer.
    • The study found no evidence that folic acid increased the risk of colon cancer – even at intakes of up to 1,000 ug/day
    • In fact, the study reported that high intakes of folic acid were associated with a decrease in colon cancer risk.
  • Another meta-analysis of placebo-controlled studies with a total of 50,000 participants reported that folic acid supplementation did not increase the risk of any other form of cancer.

Once again, the clinical evidence is clear. Folic acid supplementation does not increase the risk of colon cancer or any other form of cancer. If anything, it has a protective effect.

And once again, the question remains, “Why is the myth that folic acid increases colon cancer risk still around?

  • The same factors that have perpetuated the soy-breast cancer myth apply here as well.
  • However, there is also an element of greed. Companies selling methylfolate supplements often perpetuate the folic acid-colon cancer myth to persuade people to buy their more expensive supplements.

I have discussed the folic acid – colon cancer myth in more detail in a previous issue  of “Health Tips From The Professor”.

Do NMN Supplements Cause Cancer?

CancerWith those two examples for perspective, let’s examine the evidence behind the claim that NMN supplements increase cancer risk.

I searched the scientific literature to look for evidence to support that claim. Unfortunately, there are very few published studies on the relationship between NMN supplements and cancer risk. Here is what I found.

  • There are over 300 metabolic pathways in the human body involving NAD+ or NADH. One recent review identified some NAD+-dependent pathways that could theoretically stimulate cancer cell growth and other NAD+-dependent pathways that could theoretically inhibit cancer cell growth.
    • The reviewer emphasized the pathways that might stimulate cancer cell growth and ignored the pathways that might inhibit cancer cell growth.
  • There are five studies utilizing cell culture and animal model systems [which as I have said above 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.
    • There is one clinical trial registered with the FDA asking whether an NMN supplement can improve the safety and efficacy of combined radiation and immunotherapy by supporting the immune system and improving normal tissue recovery during treatment. The results of this study are not yet available.
  • The lack of clinical data on the effect of NMN supplementation on cancer risk is a problem. As I showed above, it was not until well-designed, placebo-controlled clinical studies were published that we had a definitive answer about the validity of the soy-breast cancer and folic acid-colon cancer claims.

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.

What Does This Mean For You?

Question MarkThe claims that NMN supplements may increase cancer risk are clearly misleading. As I said above, we currently have no idea whether NMN supplements increase or decrease cancer risk. Based on currently published studies, both possibilities are equally probable.

But the real problem is that the only published studies we have were performed with cell culture or animals, and those kinds of studies do not reliably predict what happens in humans. Without published human clinical studies, any prediction that NMN might increase cancer risk is premature, to say the least. There is simply no clinical evidence to support that claim.

On the other hand, there is good clinical evidence that NMN supplements increase energy, strength, and endurance, especially in adults over 50. So, I understand why you might want to try an NMN supplement.

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.

The Bottom Line

Many of you have asked me about recent claims that NMN supplements increase cancer risk. After a careful search of the scientific literature, I have come to the following conclusions:

The claims that NMN supplements may increase cancer risk are clearly misleading. 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. There are no published clinical studies that might provide a more definitive answer.

For more detailed information about these studies and my recommendation on NMN use if you currently have or you have had 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 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.

What Can Twins Tell Us About The Vegan Diet?

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Are There Any Downsides To The Vegan Diet?

Author: Dr. Stephen Chaney 

Why is the advice on healthy diets so confusing? One blog claims the vegan diet is best. Another says it is the keto diet is best. The Mediterranean diet is popular, but other experts claim the DASH or MIND diet might be better. Blogs champion diets ranging from the familiar to downright weird.

If you try to keep up with the science, it seems like the science is constantly changing. Each week you see headlines saying the latest study shows diet “X” is best – and “X” keeps changing. Why is that? Why do studies on healthy diets keep coming up with conflicting conclusions?

I have discussed the strengths and weaknesses of clinical studies and why they provide conflicting results in detail in previous issues of “Health Tips From the Professor”. However, one factor I have not discussed in detail is the effect of genetics on how we utilize foods, something called nutrigenomics.

Simply put, we are all genetically different. The way we utilize foods is different. The effect that foods have on our bodies is different. I have touched on that briefly in a previous article discussing individual difference in blood sugar response to various foods. But that is just one of many examples.

We do not yet know enough about gene-nutrient interactions to use genomic data to accurately predict which diets are best. However, we do know that genetic differences have a big influence on which diet is best for us. And most clinical studies on diets do not even attempt to take genetic differences into account.

That is where twin studies come in. Identical twins (monozygotic twins) have identical genetic makeups and usually have an identical environment until they become adults. So, when I saw an identical twin study (MJ Landry et al, JAMA Network Open, 6(11):e2344457, 2023) comparing a vegan diet (only plant foods) with an omnivorous diet (both animal and plant foods), I wanted to review it and share it with you.

How Was The Study Done? 

clinical studyIdentical twins were recruited from the Stanford Twin Registry. Twenty-two identical twin pairs were chosen for this study. Their characteristics were average age = 40, BMI = 26% (moderately overweight), sex = 77% female, ethnicity = 73% white, followed by an approximately equal representation of Asian, black, multiracial, and Pacific Islander.

One unanticipated characteristic of this group of twins was that 70% of them still lived together and cooked together, so their environment was also very similar.

One twin of each pair was put on a healthy vegan diet and the other on a healthy omnivorous diet for 8 weeks. Both diets were designed by dietitians. The diets emphasized fruits, vegetables, and whole grains while limiting added sugars and refined grains.

Both diets were healthier than the diets the twins were eating prior to the study. Finally, the participants were not told how much to eat and were not instructed to lose weight.

For the first four weeks the participants were provided with all their meals by a nationwide food delivery company. The participants were also provided with training in purchasing and preparing healthy foods for their diet. This prepared them for the last 4 weeks of the study in which they purchased and prepared their own meals.

Participants visited the Stanford Clinical and Translational Science Research Unit at the beginning of the study and at the end of weeks 4 and 8 for weight measurement and a fasting blood draw.

Adherence to the diets was measured by a series of unannounced interviews to administer a 24-hour dietary recall questionnaire. These were scheduled for the weeks they visited the clinic.

What Can Twins Tell Us About The Vegan Diet? 

TwinsEven though the sample size was small, there were three statistically significant results.

  • LDL-cholesterol was reduced by 12% for the twin on the vegan diet, while it remained unchanged for the twin on the omnivorous diet.
  • The fasting insulin level was reduced by 21% for the twin on the vegan diet, while it remained unchanged for the twin on the omnivorous diet.

This suggests the twin on the vegan diet was experiencing improved LDL cholesterol and blood sugar control after just 8 weeks.

  • The twin on the vegan diet lost 4 pounds in 8 weeks, while weight remained the same for the twin on the omnivorous diet. This occurred even though neither twin was instructed to eat less nor to lose weight. It is most likely a consequence of the lower caloric density of the vegan diet (See my discussion of caloric density in last week’s issue of “Health Tips From the Professor”.
  • The changes in LDL-cholesterol and fasting insulin were remarkable because none of the twins in this study had elevated LDL-cholesterol or problems with blood sugar control at the beginning of the study.

The authors of this study concluded, “In this randomized clinical trial of the cardiometabolic effects of omnivorous vs vegan diets in identical twins, the healthy vegan diet led to improved cardiometabolic outcomes compared with a healthy omnivorous diet. Clinicians can consider this dietary approach as a healthy alternative for their patients.”

[Let me decipher the term cardiometabolic for you. The decrease in LDL-cholesterol is associated with heart health – the cardio portion of the term. The decrease in fasting insulin is associated with decreased risk of diabetes. Since diabetes is considered a metabolic disease, this is the metabolic portion of the term.]

Were There Any Downsides To The Vegan Diet? 

thumbs down symbolThis study also highlighted two well-known limitations of vegan diets.

  • Although the differences were not statistically significant, the authors expressed concern that vitamin B12 intake was less for twins on the vegan diet than twins on the omnivorous diet even though the vegan diet was designed by dietitians.

The authors noted that B12 deficiency among vegans is well known, and said, “Long-term vegans are typically encouraged to take a cyanocobalamin (vitamin B12) supplement.

  • Although both groups had excellent adherence to their assigned diets, those assigned to the vegan diet expressed a lower satisfaction with the diet, which suggests long-term adherence to the diet after the study ended was unlikely.

The authors said, “Although our findings suggest that vegan diets offer a protective cardiometabolic advantage compared with a healthy omnivorous diet, excluding all meats and/or dairy products may not be necessary because research suggests that cardiometabolic benefits can be achieved with modest reduction in animal foods and increases in healthy plant-based foods compared with typical diets.”

“We believe that lower dietary satisfaction in the vegan group may have been attributable to the strictness of the vegan diet…Some people may find a less restrictive diet preferable for LDL-cholesterol-lowering effects.”

I concur. That is why I recommend a whole-food, primarily plant-based diet rather than a strict vegan diet.

What Are The Pros And Cons Of Twin Studies? 

pros and consThe Pros are obvious. Most dietary studies cannot take genetic differences into account and have difficulty accounting for environmental differences. In this study genetics was identical for each twin pair and their environment was very similar. It offers a unique advantage over other studies.

But the strength of this study is also its greatest weakness. Because the general population is genetically and environmentally diverse, it is difficult to extrapolate the results to the general population.

If this were the only study to show cardiometabolic benefits of a plant-based diet, it would simply be an interesting observation.

  • But there are several studies showing that the vegan diet is associated with lower weight and reduced risk of heart disease and diabetes.
  • And there are dozens of studies showing that primarily plant-based omnivorous diets reduce the risk of heart disease and diabetes.

This study and the conclusions of the authors are fully consistent with these studies.

The Bottom Line 

A recent study put identical twins on either a healthy vegan diet (only plant foods) or a healthy omnivorous diet (both animal and plant foods) for 8 weeks. At the end of 8 weeks:

  • LDL-cholesterol was reduced by 12% for the twin on the vegan diet, while it remained unchanged for the twin on the omnivorous diet.
  • The fasting insulin level was reduced by 21% for the twin on the vegan diet, while it remained unchanged for the twin on the omnivorous diet.
  • The twin on the vegan diet lost 4 pounds in 8 weeks, while weight remained the same for the twin on the omnivorous diet. This occurred even though neither twin was instructed to eat less or to lose weight. It is most likely a consequence of the lower caloric density of the vegan diet.
  • The changes in LDL-cholesterol and fasting insulin were remarkable because none of the twins in this study had elevated LDL-cholesterol or problems with blood sugar control at the beginning of the study.

The authors of this study concluded, “In this randomized clinical trial of the cardiometabolic effects of omnivorous vs vegan diets in identical twins, the healthy vegan diet led to improved cardiometabolic outcomes compared with a healthy omnivorous diet. Clinicians can consider this dietary approach as a healthy alternative for their patients.”

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.

Processed Food And Obesity

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Why Do Processed Foods Make Us Fat? 

Author: Dr. Stephen Chaney 

You are probably tired of hearing about how bad processed foods are for you. If you have been following the headlines, you probably already know that diets high in processed foods are linked to obesity, type 2 diabetes, heart disease, some forms of cancer, memory loss, liver disease, kidney disease, depression, risk of dying from any cause, and much more.

And this is a serious problem because 60-70% of the American diet comes from processed foods.

In fact, you may have seen these headlines so frequently that your eyes glaze over, and your mind shuts down any time you see the words “processed foods” in the title.

This week I will be sharing the latest studies on why processed foods make us fat. Stick with me on this. This is not just another article on processed foods. While the focus of the article is on processed foods, the studies it covers are valuable because they also identify some unprocessed foods that can make us fat.

Spoiler alert! Today’s “Health Tip” is important because it teaches us that weight control is not as simple as eliminating processed foods from our diet. We also need to know which unprocessed or minimally processed foods to eat less of.

Before I proceed, I should give you a brief review of how processed foods are defined because that definition has changed in recent years.

What Are Processed Foods? 

ScientistEveryone used to have a good understanding of which foods were processed. But several years ago, the scientific community introduced a new food classification system called “The NOVA food classification system” and introduced a new category – ultra-processed foods. I have covered this classification system in previous “Health Tips From the Professor” articles, but I will review it here.

The NOVA system categorizes foods into four groups according to the extent of processing they have undergone:

  • Unprocessed or minimally processed foods.
    • This category includes foods like fruit, vegetables, milk, eggs, and meat.
  • Processed culinary ingredients.
    • This category includes foods you might find in restaurants or prepare yourself to which things like salt, sugar, vegetable oils, butter, or cream were added in the preparation.
  • Minimally processed foods.
    • This category includes foods like canned vegetables, freshly made breads, and cheeses.
  • Ultra-processed foods.
    • This category includes foods like soft drinks, chips, packaged snacks, most breakfast cereals, chicken nuggets & fish sticks, fast food burgers, hot dogs, and other processed meats.

The actual list is much longer, but you get the idea. What we used to call processed foods, scientists now call ultra-processed foods. The article I am discussing used the term “ultra-processed foods” in the title.

But, since the term “ultra-processed foods” has not yet entered the popular vocabulary, I will use the term “processed foods” in this article because it is more understandable to the average reader.

Do Processed Foods Make You Fat? 

clinical studyI shared a study in a previous issue of “Health Tips From the Professor” that suggested that the answer was yes but did not answer the question of why. That’s because of the way the experiment was designed.

The ultra-processed diet and unprocessed diets were matched with respect to:

  • Total calories in the food portions given to the subjects.
  • Caloric density (calories per serving size). That’s because caloric density has been linked to overeating (I’ll discuss that in more detail below.) The authors of the study eliminated that variable.
  • Macronutrients (carbohydrate, fat, & protein). I’m sure you’ve seen blogs suggesting that carbohydrates or fat cause weight gain. And you’ve probably seen blogs suggesting that high protein diets cause weight loss. The authors eliminated these variables.
  • Total sugar, fiber, and sodium. That’s because the sugar, fat, and sodium content of foods increase their tastiness (palatability), which has been linked to overeating (more below). The authors eliminated this variable.

In short, this study compared a tasty, healthy ultra-processed food diet with a tasty, healthy unprocessed food diet. [Note: This does not represent the real world. In the real world the ultra-processed foods eaten by most Americans are higher in caloric density, sugar, fat, and sodium and lower in fiber than unprocessed foods.]

However, in the scientific world, this was an excellent study design. By eliminating variables thought to explain the correlation between ultra-processed food consumption and obesity, the study was able to focus on two questions:

#1: With those variables eliminated, do ultra-processed foods still lead to overeating? Here the answer was a clear, yes.

  • The study participants eating ultra-processed foods ate 500 more calories per day than those eating unprocessed foods. (Both groups were presented with meals and snacks containing the same number of calories and told to eat as much as they wanted.)
  • Participants eating ultra-processed foods gained 2 pounds in just two weeks, while those eating unprocessed foods lost 2 pounds.

#2: If so, what else about ultra-processed foods leads to overeating? One popular theory of why ultra-processed foods lead to overeating is that they cause large blood sugar spikes and crashes, which stimulates appetite. But the authors of the study were disappointed to find no large blood sugar spikes following consumption of ultra-processed food meals.

So, why did the ultra-processed food group eat more in this study? This study did not provide an answer to that question, but other studies (described below) have provided probable answers to that question.

Processed Food And Obesity 

What do other studies tell us about why processed foods make us overeat and gain weight? Here are the top 7 mechanisms that have been suggested and what they mean for us.

candy bar#1: Caloric Density: Simply put, caloric density is the number of calories in a serving of food. When you consume foods with a high caloric density, you are more likely to consume excess calories without even thinking about it.

When I was still teaching medical students, I used this example to illustrate the effect of caloric density on calories consumed. “There are the same number of calories in a 2-ounce candy bar and a pound of apples. You can eat a 2-ounce candy bar and be ready to eat more. If you eat a pound of apples, you are done for a while”.

Since most processed foods have a higher caloric density than unprocessed foods, the simplest solution to weight control is to limit processed foods in your diet.

However, how you or your favorite restaurant prepares unprocessed foods is important as well. For example, the addition of cheese or cream sauces can significantly increase the caloric density of the food. This is why the NOVA food classification system I described above created a new category of “culinary foods” to describe these kinds of foods.

#2: Hyper-palatability: In prehistoric times foods that were sweet, salty, and fatty were essential for survival, so we are hardwired to desire those foods. Here is why:

  • We need a certain amount of sugar for our brain, red blood cells, and a few other tissues to function. Wild game provides almost no carbohydrate. Fruits were the best source of sugar, but fruits were scarce prior to farming. The craving for sweetness drove us to forage far and wide to find fruits and other plant sources of sugar and carbohydrate.
  • Sodium is essential for survival, but unprocessed plant and animal foods provide very little. That’s why even in Biblical times, salt was worth its weight in gold.
  • In prehistoric times, food was sometimes scarce, especially in winter. It might be a week or more between meals. Fat stores got prehistoric man through these times of scarcity, so it was important to eat fatty meals in times of plenty. [Note: We no longer live in times of scarcity, and those fat stores have gone from being an asset to being a health concern.]

Unfortunately, “Big Food, Inc” has weaponized these hardwired desires for sweet, salty, and fatty foods. Simply put, processed foods taste good because they fulfil our hardwired taste desires. Scientists call it “hyper-palatability”. But whatever you call it, we want to eat more, and that leads to overeating.

And again, the way we prepare the foods we eat also matters. It’s only natural to add extra salt, sugar, and/or fat to the foods we prepare so they taste better. And if we add too much, we make the healthy foods we eat hyper-palatable, and we are tempted to overeat.

On a personal note, I never knew you might want to add sugar and fat to the vegetables you cook before my family moved to the south. On the other hand, I had never eaten collard greens before either.

applesauce

#3: Food Consistency: When you look at studies on the effect of food consistency on calories consumed, you find that there are several different ways of defining food consistency, but they are all looking at the same thing from a different perspective – like the fable of the 6 blind men trying to describe an elephant.

  • Food Structure: The classic study, published in 2009, compared the effect of sliced apples, applesauce, and apple juice eaten shortly before a meal on the number of calories consumed at the meal. In terms of calories consumed during the meal, the results were clear. It was apple juice > applesauce > apple slices. 

This drew attention to the effect of food structure on calories consumed. Apples are a whole food with cellular structure intact. Applesauce contains all the nutrients, phytonutrients, and fiber of whole apples, but the cellular structure has been lost. Apple juice contains most of the nutrients and phytonutrients of applesauce, but the fiber has been lost.

Why does the structure of whole foods matter?

  • Cell structure must be destroyed before digestion can occur, the release of sugar and carbohydrates from the food is delayed. This reduces the spikes and valleys of blood sugar that can increase appetite.
  • Transit time of the food through the intestine is also delayed. Thus, the feeling of fullness persists longer, which reduces appetite.

There are two takeaway lessons from this study that may not be so obvious:

  • Neither applesauce nor apple juice meet the NOVA definition of an ultra-processed food. So, simply removing processed foods from your diet may not be enough to reduce your appetite and, therefore, your caloric intake.
  • In addition, adding fiber back to apple juice did not make it equivalent to applesauce in reducing appetite. So, despite what Big Food Inc tells you, adding fiber to processed foods does not turn them into health foods.
  • Soft Versus Hard Foods: Many processed foods are soft, and most unprocessed foods are hard. So, you could think of this as a description that separates processed foods from unprocessed foods.

But, if you consider the apples versus applesauce comparison I described above, it is obvious that soft versus hard description also pertains to minimally processed foods such as applesauce and whole, unprocessed foods such as apples. 

For example, one recent study comparing soft versus hard foods found it didn’t matter whether the soft foods were processed or unprocessed. People in the study ate more calories from all soft foods than from hard, unprocessed foods such as raw fruits and vegetables.

  • Fast Versus Slow Foods: This description separates foods based on the speed at which they are digested and pass through the intestine. Once again, you might think of this as a description that separates processed and unprocessed foods until you think about applesauce versus apples comparison.

And, as you might expect, a recent study comparing “fast” versus “slow” foods found it didn’t matter whether the fast and slow foods were processed or unprocessed. People in the study ate more calories from fast foods than from slow foods.

[Note: This study defined “slow” foods as harder, chunkier, more solid, and more viscous. While the first three adjectives describe what other scientists also refer to as “hard” foods, the final adjective broadens the category to include “soft” foods like oatmeal.]

How Can You Enjoy Eating Without Getting Fat? 

For most Americans, weight is a constant uphill battle. Their weight increases by a few pounds every year, and over time that continuing weight gain adds up. Diets are never enjoyable, which is part of the reason they almost always fail in the long term. You want to control your weight, but you also want to enjoy what you eat. Why is that so hard?

The secret to a healthy weight is to find foods you enjoy that don’t increase your appetite –  foods that fill you up, so you eat less naturally. Here are my 4 tips for eating foods you enjoy without getting fat.

Tip #1: Limit processed foods. Processed foods tend to have a high caloric density; are hyper-palatable, soft, and fast; and lack the intact cellular structure of whole, unprocessed foods. And multiple studies, such as the one I cited above, agree that processed foods cause us to eat more and to gain weight. So, the single most important step you can take to control your weight is to limit your intake of processed foods.

Tip #2: Choose minimally processed foods wisely. The studies I shared above suggest that avoiding processed foods may not be enough. We also need to look at the minimally processed foods we eat (applesauce, for example). These studies suggest we should also favor whole, unprocessed foods over minimally processed foods that are softer and faster (more quickly digested).

By now, you might be saying, “Wait a minute. I thought you said I could enjoy eating without getting fat. How can I enjoy eating if I have to give up my favorite processed and minimally processed foods?”

My short answer would be, “No. But you might want to broaden your horizons”. We all tend to be creatures of habit. We eat a relatively small variety of foods on a regular basis. When my wife and I decided to eat healthier, we kept trying new foods until we found new, healthier foods we loved.

The category of whole unprocessed foods offers many options. There are fruits, vegetables, many varieties of 100% whole grains, beans, nus, seeds, eggs, and meats. And we are blessed to live in a country with abundant choices. When you walk into your local supermarket you will find dozens of foods in each of these categories that you have never tried before. Be daring. Keep trying new foods until you find new favorite foods you love.

Tip #3: Be aware of how foods are prepared. The studies described above also suggest how we prepare the food is important. We can start out with a whole unprocessed food and end up with something no better than processed food if we prepare it incorrectly.

If we add lots of cream, cheese, butter, and/or sugar, we increase the caloric density. And this can lead to us consuming more calories without even thinking about it.

Throw in some salt and we have also made the food hyper-palatable, which makes us want to eat more.

Now you might be saying, “But I grew up with my food being cooked this way. This is my comfort zone. Do I have to completely change the way I cook my food, and the items I choose at my favorite restaurant?”

Again, my short answer would be, “No, but you might want to try new recipes.” I am not a cooking guru. That would be my wife. But I do know there are lots of books and web sites featuring healthy recipes. Once again, be bold. Try new recipes until you find new favorites. Try new items on your favorite restaurant’s menu or try new restaurants until you find healthier, restaurant foods you love.

Tip #4: Never say never. This is perhaps the most important tip. Whenever we tell ourselves we can never eat a food again, it becomes irresistible. We are setting ourselves up for failure. The goal should be to change unhealthy foods and unhealthy recipes from an everyday occurrence to an occasional pleasure.

The Bottom Line 

Multiple studies show that eating processed foods leads to weight gain. It may be no coincidence that 60-70% of the foods Americans eat is highly processed and 60-70% of us are overweight or obese.

In the article above, I summarize recent studies asking why processed foods make us fat. If you think these studies are only of interest to scientists, you would be wrong. These studies also help us to identify unprocessed and minimally processed foods in our diet that can make us fat.

For more information on these studies, and 4 tips on how you can enjoy eating without getting fat, 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.

Does Genetics Determine Your Destiny?

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The Influence Of Genetics And Diet On Type 2 Diabetes

Author: Dr. Stephen Chaney 

Does it ever feel like you have drawn the short straw?

Everyone in your family has succumbed to heart disease, diabetes, or cancer at a young age. Are you doomed to the same fate?

You ordered a DNA test. It sounded like fun. But when the gene report came back it said you had a “bad” genetic profile. You were told you are at high risk of diabetes, heart attack, stroke, cancer, or dementia. Are you doomed to a short and sickly life?

In both cases, you are probably wondering, “Is there anything I can do to improve my odds of a healthy life? What if I lost some of those extra pounds, exercised more, and ate a healthier diet? Would that make a difference?”

The study (J Merino et al, PLoS Medicine 19(4): e1003972, April 26, 2022) I will describe today was designed to answer these questions.

But before I describe the study, I should probably cover what I call Genetics 101: “How Genes Affect Your Health”.

Genetics 101: How Genes Affect Your Health

GeneticistIf you studied genetics in school, you probably learned about diseases like sickle cell anemia, which is caused by a single mutation in a single gene. If you get two copies of the “bad” gene, you will have sickle cell anemia. If you get one copy of the “bad” gene and one copy of the normal gene, you have sickle cell trait, which is much less severe.

Simply put, you either have the disease, or you don’t. It’s dependent on your genetics, and you can’t do much about it.

If you know someone who has been treated for breast cancer, you are probably familiar with a more complex relationship between genetics and health. There are several “bad” genes that increase the risk of breast cancer. And knowing which gene is involved is important for selecting the best treatment regimen.

But most of the diseases that shorten our lives (like diabetes, heart disease, most cancers, and dementia) are what we call polygenetic diseases. Simply put, that means that there are dozens of genes that increase the risk of these diseases. Each gene makes a small contribution to the increased risk. So, we can only measure the genetic contribution to these diseases by measuring hundreds of mutations in dozens of genes, something called a polygenetic risk score.

The study I will be describing today looked at the relative effect of genetics (measured as the type 2 diabetes polygenic risk score) and diet quality (measured as the Alternative Healthy Eating Index (AHEI)) on the risk of developing type 2 diabetes.\

How Was This Study Done?

clinical studyThe data for this study were obtained from 3 long-term clinical studies conducted in the United States – the Nurses’ Health Study (121,700 participants), the Nurses’ Health Study II (116,340 participants), and the Health Professionals Follow-Up Study (51,529 participants).

These studies measured lifestyle factors (including diet) every 4 years and correlated them with disease outcomes over 20+ years.

The study I will be discussing today was performed with 35,759 participants in those 3 studies for whom DNA sequencing data was available.

  • The DNA sequence data were used to generate a type 2 diabetes polygenic risk score for each participant in this study.
  • Food frequency questionnaires obtained every 4 years in these studies were used to calculate the Alternative Healthy Eating Index (AHEI) score for each participant.
    • The AHEI is based on higher intake of fruits, whole grains, vegetables, nuts and legumes, polyunsaturated fatty acids, long-chain omega-3 fatty acids, moderate intake of alcohol, and lower intake of red and processed meats, sugar sweetened drinks and fruit juice, sodium, and trans-fat).

The investigators used these measurements to estimate the relative effect of genetics and diet quality on the risk of developing type 2 diabetes.

The Influence Of Genetics And Diet On Type 2 Diabetes 

Genetic TestingThe participants were divided into low, intermediate, and high genetic risk based on their type 2 diabetes polygenic risk score. Compared with low genetic risk:

  • Intermediate genetic risk increased the risk of developing type 2 diabetes by 26%.
  • High genetic risk increased the risk of developing type 2 diabetes by 75%.

Put another way, each 1 standard deviation increase in the polygenetic risk score:

  • Increased the risk of developing type 2 diabetes by 42%.

Simply put, bad genes can significantly increase your risk of developing type 2 diabetes. That’s the bad news. But that doesn’t mean you should think, “Diabetes is in my genes. There is nothing I can do.”

The investigators also divided the participants into those who had a high-quality diet, those who had an intermediate quality diet, and those economic benefits of plant-based diets mediterranean dietswho had a low-quality diet based on their AHEI (Alternative Healthy Eating Index) score.

Finally, they divided the participants into groups depending on their BMI, a measure of obesity.

Compared to an obese person consuming a low-quality diet, a lean person consuming a high-quality diet:

  • Reduced their risk of developing type 2 diabetes by around 43% for each category of genetic risk.
  • More specifically, a lean person consuming a high-quality diet reduced their risk of developing type 2 diabetes:
    • By 41% if they were at low genetic risk.
    • By 50% if they were at intermediate genetic risk.
    • By 38% if they were at high genetic risk.

The investigators then made a statistical adjustment to remove BMI from their calculations, so they could focus on the effect of diet alone on the risk of developing type 2 diabetes.

Compared to a low-quality diet, a high-quality diet:

  • Reduced the risk of developing type 2 diabetes by around 33% for each category of genetic risk.
  • More specifically, a high-quality diet reduced the risk of developing type 2 diabetes:
    • By 31% for those at low genetic risk.
    • By 39% for those at intermediate genetic risk.
    • By 29% for those at high genetic risk.

Looking at it another way:

  • When people at high genetic risk consumed a high-quality diet, their risk of developing type 2 diabetes was only 13% higher than people at intermediate genetic risk who consumed a low-quality diet (such as the typical American diet).
  • When people at intermediate genetic risk consumed a high-quality diet, their risk of developing type 2 diabetes was 5% less than people at low genetic risk who consumed a low-quality diet.

Simply put:

  • If you are at intermediate genetic risk, a high-quality diet may completely reverse your risk of developing type 2 diabetes.
  • If you are at high genetic risk, a high-quality diet can partially reverse your risk of developing type 2 diabetes.

In short, the good news is that bad genes do not doom you to type 2 diabetes. Your genetics doesn’t have to determine your destiny.

  • The investigators did not provide similar information for the effect of an ideal weight on the risk of developing type 2 diabetes, but it is likely that the combination of diet plus weight management would result in an even more significant reduction in risk of developing type 2 diabetes for individuals in the even the highest risk category.

The authors concluded, “These data provide evidence for the independent associations of genetic risk and diet quality with incident type 2 diabetes and suggest that a healthy diet is associated with lower diabetes risk across all levels of genetic risk.”

Does Genetics Determine Your Destiny?

genetix and diet bestAt the beginning of this article I posed the question, “Does Genetics Determine Your Destiny?”

Based on this study, the good news is that bad genes don’t doom you type 2 diabetes. And just because most of your relatives are diabetic doesn’t mean that must be your fate.

  • This study shows that a healthy diet significantly reduces your risk of developing type 2 diabetes at every genetic risk level.
  • And the study suggests that a healthy diet plus a healthy weight is even more beneficial at reducing your risk of type 2 diabetes.
  • While not included in this study, other studies have shown that exercise also plays a role in reducing type 2 diabetes risk.

None of this information is new. What is new is that a healthy diet is equally beneficial at reducing type 2 diabetes risk even in individuals with a high genetic risk of developing the disease. Simply put, your genetics doesn’t have to determine your destiny. You can make a positive difference in your health no matter how how bad were the genes you inherited!

“And what is this magic diet?”, you might ask. In this study, it was based on AHEI score. Someone with a high AHEI score consumes:

  • Lots of fruits, whole grains, vegetables, nuts and legumes, polyunsaturated fatty acids, and long-chain omega-3 fatty acids.
  • Moderate or no amounts of alcohol.
  • Little or no red and processed meats, sugar sweetened drinks, fruit juices, sodium, and foods with trans-fat.

Any whole food, primarily plant-based diet from vegan to Mediterranean or DASH fits the bill.

Finally, while this study focused just on type 2 diabetes, other studies have come to similar conclusions for other diseases.

Should You Get Your DNA Tested?

If you are looking for guidance on how to reduce your risks, the answer is, “No”. In this study, the same diet and lifestyle changes lowered the risk of type diabetes at every genetic risk level. Despite what some charlatans may tell you, there is no special diet or magic potion for people with a high genetic risk for developing type 2 diabetes.

If you are looking for motivation, the answer may be, “Yes”. If knowing you are at high risk makes it more likely that you will make the diet and lifestyle changes needed to lower your risk of type 2 diabetes, a DNA test may be just what you need.

The Bottom Line

If a serious disease runs in your family or if you have had your DNA tested and found out you are at high risk for some disease, you are probably wondering whether there is anything you can do or whether your bad genes have doomed you to a short and sickly life.

A recent study answered that question for type 2 diabetes. It showed a healthy diet significantly reduces the risk of type 2 diabetes even in people at high genetic risk of developing the disease.

Other studies have come to similar conclusions for other diseases. In short, your genetics doesn’t have to determine your destiny. You can make a positive difference in your health no matter how how bad were the genes you inherited!

For more details about the 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 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.

Building Healthy Bones Part2

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Creating A Bone-Healthy Lifestyle

Author: Dr. Stephen Chaney 

calcium supplementsA major study (Tai et al, British Medical Journal, BMJ/2015; 351:h4183) reported that calcium supplementation in women over 50 resulted in only a very small increase in bone density, which translated into a very small (5-10%) decrease in the risk of bone fractures.

The authors concluded that the standard RDA recommendation of 1,000 – 1,200 mg/day of calcium for adults over 50 is unlikely to prevent osteoporosis or reduce the risk of bone fractures.

In last week’s issue of “Health Tips From the Professor” I discussed the many flaws of the study. In brief:

  • The study was a meta-analysis of 51 published clinical studies. Normally, meta-analyses are very strong, but they have an “Achilles Heel” – something called the Garbage-In, Garbage-Out Simply put, this means that the meta-analysis is only as strong as the individual studies that went into it. The authors included 40 years of clinical studies in their meta-analysis, and most of those studies had an inadequate design by today’s standards.
  • The study also made a number of what I would call apples to oranges comparisons that were of questionable validity.

In this week’s issue of “Health Tips From The Professor”, I would like to explore the other side of the coin. I would like to consider the possibility that the study might be correct and discuss what that might mean for you.

Creating A “Bone Healthy” Lifestyle

Despite the concerns I just mentioned. Let’s assume for a minute that the study might just be correct in spite of its many flaws. Let’s assume that the “one size fits all” RDA recommendation of 1,000 – 1,200 mg/day of calcium if you are over 50 may be flawed advice.

If so, perhaps it’s time to say good riddance! It may finally be time to put away the “magic bullet”, “one size fits all” thinking and start seriously considering holistic approaches.

Now that I have your attention, let’s talk about what you can do to prevent osteoporosis – and the role that supplementation should play. Let’s talk about a “bone healthy” lifestyle.

#1: Let’s start with supplementation: Bone is not built with calcium alone. Bone contains significant amounts of magnesium along with the trace minerals zinc, copper and manganese – and all of these are often present at inadequate levels in the diet. Most of us know by now that vitamin D is essential for bone formation, but recent research has shown that vitamin K is also essential (Kanellakis et al, Calcified Tissue International, 90: 251-262, 2012). An ideal calcium supplement should contain all of those nutrients.

#2: Next comes diet: Many of you probably already know that some foods are acid-forming and other are alkaline-forming in our bodies – and that it is best to keep our bodies on the alkaline side. What most of you probably don’t know is that calcium is alkaline and that our bones serve as a giant buffer system to help keep our bodies alkaline. Every time we eat acid-forming foods a little bit of bone is dissolved so that calcium can be released into the bloodstream to neutralize the acid. (My apologies to any chemists reading this for my gross simplification of a complex biological system).

Consequently, if we want strong bones, we should eat less acid-forming foods and more of alkaline-forming foods. Among acid-forming foods, sodas are the biggest offenders, but meat, eggs, dairy, and grains are all big offenders as well. Alkaline-forming foods include most fruits & vegetables, peas, beans, lentils, seeds and nuts. In simple terms, the typical American diet is designed to dissolve our bones. Calcium from diet or supplementation may be of little use if our diet is destroying our bones as fast as the calcium tries to rebuild them.

vitamin d#3: Test your blood 25-hydroxyvitamin D level: 25-hydroxy vitamin D is the active form of vitamin D in our bloodstream. We need a sufficient (20-50 ng/mL) blood level of 25-hydroxy vitamin D to be able to use calcium efficiently for bone formation. We now know that some people who seem to be getting adequate vitamin D in their diet still have low 25-hydroxy vitamin D levels.

In fact, various studies have shown that somewhere between 20-35% of Americans have insufficient blood levels of 25-hydroxy vitamin D. You should get your blood level tested. If it is low, consult with your health professional on how much vitamin D you need to bring your 25-hydroxy vitamin D into the sufficient range.

#4: Beware of drugs: The list of common medications that dissolve bones is a long one. Some of the worst offenders are anti-inflammatory steroids such as cortisone & prednisone, drugs to treat depression, drugs to treat acid reflux, and excess thyroid hormone.

I’m not suggesting that you avoid prescribed medications that are needed to treat a health condition. I would suggest that you ask your doctor or pharmacist (or research online) whether the drugs you are taking adversely affect bone density. If they do, you may want to ask your doctor about alternative approaches, and you should pay a lot more attention to the other aspects of a “bone healthy” lifestyle.

#5: Exercise is perhaps the most important aspect of a bone healthy lifestyle: Whenever our muscles pull on a bone, it stimulates the bone to get stronger. I’ll put the benefits of exercise in perspective in the next section.

Exercise Is A Critical Part of a “Bone Healthy” Lifestyle

weight lifting exerciseInstead of just quoting more boring studies, I’m going to share a couple of stories that help put the importance of exercise into perspective.

The first is my wife’s story. She ate a very healthy diet with minimal meat and lots of fruits and vegetables for years. She took calcium supplements on a daily basis. She walked 5 miles per day and took yoga classes several days each week. Yet when her doctor recommended a bone density scan in her early sixties she discovered she had low bone density. She was in danger of becoming osteoporotic!

Her doctor prescribed Fosamax. My wife tried it for one day and decided the side effects were worse than the disease. So she started asking holistic health practitioners what she should do. They recommended she find a personal trainer and start pumping iron. That was not an easy solution, but it was the right one. When she went in for her second bone scan 3 months later, her doctor excitedly announced that her bone density had increased by 7%. Her doctor said “We never get results that quickly with Fosamax”. When my wife told her she wasn’t taking Fosamax, her doctor became even more excited. (Most doctors actually do prefer holistic approaches. They just don’t recommend them.)

The moral of this story is that you can be doing everything else right, but if you’re not doing weight bearing exercises – if you’re not pumping iron, everything else you are doing may be for naught. Weight bearing exercise is an absolutely essential part of a “bone healthy” lifestyle!

But can exercise do it alone? Some people seem to think so. That brings up my second story. About 40 years ago one of my colleagues at UNC, who was an expert on calcium metabolism, was doing a bone density study on female athletes at UNC. One of the tennis players was nicknamed “Tab”. Tab was a popular soft drink at that time, and Tab was all she drank – no milk, no water, only Tab.

When my colleague measured the bone density of her playing arm, it was normal for a woman of her age. When he measured the bone density of her non-playing arm, it was that of a 65-year-old woman. The reason is simple. When we exercise a particular bone, our body will add calcium to that bone to make it stronger. If we are not getting enough calcium from our diet, our body simply dissolves the bones elsewhere in our body to get the calcium that it needs.

The moral of this story is that exercise alone is not enough. In terms of bone health, we absolutely need exercise to take advantage of the calcium in our diet, and we absolutely need sufficient calcium in our diet to take advantage of the exercise.

This is the most glaring deficiency of the meta-analysis I described last week. None of those studies included exercise. No wonder the increase in bone density was minimal!

Putting It All Together –  Building Healthy Bones

bone healthy lifestyleIf you seriously want to minimize your risk of osteoporosis, there are a few simple steps you can take (simple, but not easy).

  • Consume a “bone healthy” diet that emphasizes fresh fruits and vegetables, minimizes meats, and eliminates sodas and other acidic beverages. For more details on whether your favorite foods are acid-forming or alkaline-forming, you can find plenty of charts on the internet.
  • Minimize the use of medications that adversely affect bone density. You’ll need to work with your doctor on this one.
  • Get plenty of weight bearing exercise. This is an absolutely essential part of a bone healthy lifestyle. Your local Y can probably give you guidance if you can’t afford a personal trainer. Of course, if you have physical limitations or have a disease, you should consult with your health professional before beginning any exercise program.

 

  • Get your blood 25-hydroxy vitamin D level tested. If it is low, take enough supplemental vitamin D to get your 25-hydroxy vitamin D level into the sufficient range – optimal is even better. Sufficient blood levels of 25-hydroxy vitamin D are also absolutely essential for you to be able to utilize calcium efficiently.
  • Consider a calcium supplement. Even when you are doing everything else correctly, you still need sufficient calcium in your diet to form strong bones. “I’m not necessarily recommending a “one-size fits all” 1,000 to 1,200 mg/day. Supplementation is always most effective when you actually need it. For example:
    • If you are not including dairy products in your diet (either because they are acid-forming or for other health reasons), it will be difficult for you to get adequate amounts of calcium in your diet. You can get calcium from other food sources such as green leafy vegetables. However, unless you plan your diet very carefully you will probably not get enough.
    • If you are taking medications that decrease bone density, that may increase your need for supplemental calcium. Unfortunately, we don’t yet have guidelines on how much is needed.
    • If you do use a calcium supplement, make sure it is complete. Don’t just settle for calcium and vitamin D. At the very least you will want your supplement to contain magnesium and vitamin K. I personally recommend that it also contain zinc, copper, and manganese.
  • Unfortunately, we don’t really have good guidelines for how much calcium you need. Studies like the one described above are challenging the old RDAs, but we don’t yet have enough studies to know how much calcium we need to build strong bones when we are following a “bone healthy” lifestyle that includes proper diet, sufficient 25-hydroxy vitamin D blood levels and plenty of exercise.

What About Medications For Preventing Bone Loss?

Bone FractureThe danger is that as the conclusions of this meta-analysis get widely publicized and doctors stop prescribing calcium supplements, they probably aren’t going to recommend a holistic approach. They probably won’t recommend a “bone healthy” lifestyle. Instead, they will most likely recommend drugs to prevent bone loss. In fact, the authors of the study described last week specifically praised the use of bisphosphonate drugs (Fosamax and Zometa), and a related drug (Xgeva) that works by a similar mechanism, because they increased bone density by 5-9% over 3 years.

However, these drugs have a dark side, and it’s not just the acid reflux, esophageal damage and esophageal cancer that you hear about in the TV ads. These drugs all act by blocking bone resorption, the ability of the body to break down bone. In the short term, this prevents the bone loss associated with aging and reduces the risk of bone fractures.

However, you might remember from last week’s article that bone resorption is also an essential part of bone remodeling, the process that keeps our bones young and strong. When these drugs are used for more than a few years you end up with bones that are dense, but are also old and brittle. Long term use of these drugs is associated with jaw bones that simply dissolve and bones that easily break during everyday activities. This is yet another example of drugs with side effects that look a lot like the disease you were taking the drug for in the first place.

The Bottom Line

  • A recent study has reported that the RDA recommendation of 1,000 – 1,200 mg/day of calcium for people over 50 provides only a minimal increase in bone density (0.7-1.8%) over the first year or two. This translates into a very small (5-10%) decrease in risk of bone fractures. It did not matter whether the calcium came from dietary sources or from supplementation. The authors concluded that adding extra calcium to the diet, whether from foods or supplements, was not a very efficient way to increase bone density and prevent fractures.
  • This study suffers from some serious flaws, which I discussed in last week’s “Health Tips From the Professor”.
  • Unfortunately, many doctors are likely to take this study to heart. They are likely to stop recommending calcium and other natural approaches and start relying even more heavily on drugs to preserve bone mass. That’s bad news because, while the most frequently proscribed drugs do increase bone mass and prevent fractures short term, they also cause your bones to age more rapidly. After a few years you end up with bones that are dense but are also incredibly brittle and fracture very easily. That’s right. If you use these drugs long enough, they will cause the very condition you were trying to prevent.
  • We should also consider the possibility that this study may just be correct. Let’s assume for a minute that the RDA recommendation of 1,000 – 1,200 mg/day of calcium for everyone over 50 may be flawed advice. If so, it may finally be time to put away the “magic bullet” thinking and start seriously considering holistic approaches to preserving bone mass.
  • A far better choice is to follow a “bone healthy” lifestyle.
    • Start with a “bone healthy” diet. Avoid acid-forming foods like sodas, meats, eggs, dairy, and grains. Instead choose alkaline-forming foods like most fruits & vegetables, peas, beans, lentils, seeds and nuts.
    • Check on the medicines you are using. If they are ones that adversely affect bone density, ask your health professional if there are bone-healthier options.
    • Check your blood level of 25-hydroxy vitamin D on a regular basis. If it is low, consult with your health professional on the amount of vitamin D you need to take to bring your 25-hydroxy vitamin D into the optimal range.
    • Get plenty of weight bearing exercise. This means pumping iron. It is an absolutely essential part of a bone healthy lifestyle. Of course, if you have physical limitations or have a disease, you should consult with your health professional before beginning any exercise program.
  • If you are not getting sufficient calcium from your diet, consider a complete calcium supplement. In addition to calcium and vitamin D, a bone-healthy calcium supplement should at the very least contain magnesium and vitamin K. I also recommend it contains zinc, copper, and manganese.
  • Just don’t rely on a calcium supplement alone to keep your bone density where it should be. If your 25-hydroxy vitamin D isn’t where it should be and/or you aren’t doing weight bearing exercise on a regular basis, your calcium supplement may be almost useless. In my opinion, that may be the biggest take-home lesson from the recent meta-analysis.

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.

Building Healthy Bones Part1

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Do Calcium Supplements Prevent Bone Fractures?

Author: Dr. Stephen Chaney

Building Healthy Bones Part1

Osteoporosis is a debilitating and potentially deadly disease associated with aging. It affects 54 million Americans. It can cause debilitating back pain and bone fractures. 50% of women and 25% of men over 50 will break a bone due to osteoporosis. Hip fractures in the elderly due to osteoporosis are often a death sentence.

For that reason, the RDA for calcium has been set at 1,000 to 1,200 mg/day to reduce the risk of osteoporosis, and calcium supplements are often recommended to reach that target. However, recent headlines are proclaiming that calcium supplements do not actually prevent bone fractures. Are the RDA recommendations wrong? Should you throw out your calcium supplements?

In this article I will review the article behind the study and help you put it into perspective. After all, you don’t really want to know whether calcium supplementation is beneficial for the average adult. You want to know whether it will be beneficial for you.

Bone Metabolism and Osteoporosis 

Before you can truly understand osteoporosis and how to prevent it, you need to know a bit about bone metabolism. We tend to think of our bone metabolism osteoporosisbones as solid and unchanging, much like the steel girders in an office building. Nothing could be further from the truth. Our bones are dynamic organs that are constantly changing throughout our lives.

Cells called osteoclasts and osteoblasts constantly break down old bone (a process called resorption) and replace it with new bone (a process called accretion). Without this constant renewal process our bones would quickly become old and brittle (I’ll discuss more about this next week when I talk about the side effects of drugs commonly used to increase bone density).

When we are young the bone building process exceeds bone resorption and our bones grow in size and in density. During most of our adult years, bone resorption and accretion are in balance, so our bone density stays constant. However, as we age bone the bone building process (accretion) slows down and we start to lose bone density. Eventually our bones look like Swiss cheese and break very easily. This is called osteoporosis.

We should also think of our bones as calcium reservoirs.  We need calcium in our bloodstream 24 hours a day for our muscles, brain, and nerves to function properly, but we only get calcium in our diet at discrete intervals. Consequently, when we eat our body tries to store as much calcium as possible in our bones. Between meals, we break down bone material so that we can release the calcium into our bloodstream that our muscle, brain & nerves need to function.

If we lead a “bone healthy” lifestyle, all of this works perfectly. We build strong bones during our growing years, maintain healthy bones during our adult years, and only lose bone density slowly as we age – maybe never experiencing osteoporosis. We always accumulate enough calcium in our bones during meals to provide for the rest of our body between meals.

What is a “bone healthy” lifestyle, you might ask. Because calcium is a major component of bone, the medical and nutrition communities have long focused on calcium as a “magic bullet” that can assure bone health. Once the importance of vitamin D was understood, it was added to the equation.

For years we have been told that if we just get enough calcium and vitamin D in our diets, we would build strong bones when we were young, maintain bone density most of our adult years, and lose bone density as slowly as possible as we age. It is this paradigm that recent studies challenge.

Do Calcium Supplements Prevent Bone Fractures?

Calcium SupplementLet’s start by looking at one of the major studies behind the headlines (Tai et al, British Medical Journal, BMJ/2015; 351:h4183). This was a meta-analysis that included 15 studies (1533 participants) looking at dietary sources of calcium and 51 studies (12,257 participants) looking at calcium supplementation in women.

The results of the meta-analysis were thought provoking, but do not exactly support the headlines you have been reading. For example:

The headlines say, “Calcium Supplements Do Not Prevent Broken Bones”.

  • This study did not actually look at calcium supplementation and the risk of bone fractures. That was a previous study (Boland et al, BMJ 2015, 351:h4580) by the same authors.
  • This study showed that calcium supplementation increased bone density by 0.7-1.8%, which the authors concluded was sufficient to reduce fracture risk by about 5-10%. That’s a disappointingly small effect, but it is not zero – as the headlines suggested.

The headlines say, “It’s better to get your calcium from food than from supplements”.

  • This study showed that it did not matter whether the calcium came from food or from supplements. The increase in bone density was identical.

Garbage-In, Garbage-Out

Garbage In Garbage OutMeta-analyses such as this one can be very strong, but they can also suffer from the “garbage-in, garbage-out” phenomenon. In short, if most of the studies that went into the meta-analysis were poorly designed, the conclusions of the meta-analysis will be unreliable.

The problem is that many of the individual studies were conducted 10, 20, 30 or 40 years ago when our knowledge of bone metabolism was incomplete.

  • Thirty or 40 years ago it was “state of the art” to just use a calcium supplement. Then we learned that adequate vitamin D was essential for efficient calcium utilization.
    • Most of the studies included in this meta-analysis looked at calcium supplementation without vitamin D. Only 13 of the studies (25%) included vitamin D.
  • Ten or 20 years ago it was “state of the art” to just use a calcium supplement with vitamin D. Then we learned that the blood level of 25-hydroxyvitamin D (the active form of vitamin D in the bloodstream) did not necessarily reflect vitamin D intake from the diet. In today’s world a study in which the 25-hydroxy vitamin D level is not measured should be considered sub-standard.
    • Only 18 (35%) of the studies measured baseline 25-hydroxy vitamin D levels.
  • If dietary calcium intake at baseline is already adequate, it is illogical to expect additional calcium to significantly increase bone density.
    • The baseline calcium intake was <800 mg/day (clearly inadequate) in only 26 (51%) of the studies. Baseline calcium intake was either not determined in other studies or was already in the adequate range prior to supplementation.
  • In the future, we will probably want to include exercise as a component in the study (more about that next week). None of the studies included exercise as a component

In short, by today’s standards many, if not most, of the studies included in the meta-analysis had an inadequate design.

If I had designed the meta-analysis, I would have been a lot more restrictive in the studies I included.Skeptic

  • I would have started by including only studies in which the baseline intake of calcium was <800 mg/day. If you want to critically evaluate whether calcium supplementation has a beneficial effect, you need to start with people who have an inadequate dietary intake of calcium. If their diets are already calcium sufficient, supplementation is unlikely to have any benefit.
  • At the very least I would only include studies that used calcium supplements containing 400-800 IU of vitamin D as well. In fact, based on the latest data I would make sure that the calcium supplement I used also contained adequate levels of magnesium, vitamin K, zinc, copper and manganese. All of those have been shown to be important for bone formation, and we cannot assume they are present at sufficient levels in their diet (more about that next week).
  • I would only include studies that measured blood levels of 25-hydroxy vitamin D at baseline and following supplementation with vitamin D so that we knew that the 25-hydroxy vitamin D level was sufficient to support optimal calcium utilization.
  • Finally, I would only include studies that specifically measured the effect of exercise on calcium utilization or included exercise as an integral part of their study.

The number of studies included in the meta-analysis would be much less, but they would all be high quality studies.

Finally, the authors also noted that several studies in the supplement group showed significantly greater (2.5 – 5.0%) increase in bone density. They dismissed them as outliers. I would have preferred a closer look at those studies to see if there was anything about the population group or study design that might explain the greater bone density increase in those studies.

Apples and Oranges

apples orangesBecause the authors included a wide variety of clinical studies, they were able to state that “Increases in bone mineral density were similar in trials of calcium monotherapy [calcium by itself] versus co-administered calcium and vitamin D…and in trials where baseline dietary calcium intake was <800 [clearly insufficient] versus >800 [probably sufficient] mg/day.”

This could be considered a strength of their meta-analysis, but they are only valid comparisons if other important features of the studies being compared were uniform – i.e. they were comparing apples to apples.

But what if they were comparing apples and oranges?

For example, we know that vitamin D is required for efficient calcium utilization. When the authors compared studies having a baseline calcium intake of <800 mg/day with studies having a baseline calcium intake of >800 mg/day, they did not even check to see whether use of vitamin D was evenly distributed between the two groups.

  • If most of the studies with a baseline calcium intake of <800 mg/day did not include vitamin D with their calcium supplements, the authors would be comparing apples and oranges. The comparison would be invalid.

Similarly, we also know that if calcium intake at baseline is adequate, adding more calcium is unlikely to increase bone density significantly. When the authors compared studies with and without vitamin D, they did not even check to see whether baseline calcium intake was evenly distributed between the two groups.

  • If the participants in most of the studies utilizing supplements providing both calcium and vitamin D were already consuming sufficient calcium at baseline, they would be comparing apples to oranges. Again, the comparison would be invalid.

The authors of the meta-analysis simply did not provide the detail needed to determine whether their comparisons were apples to apples or apples to oranges. Thus, what seemed to be a strength of their study is actually a major weakness.

The Bottom Line

  • A recent study has reported that the RDA recommendation of 1,000 – 1,200 mg/day of calcium for people over 50 provides only a minimal increase in bone density (0.7-1.8%) over the first year or two. This translates into a very small (5-10%) decrease in risk of bone fractures.

It did not matter whether the calcium came from dietary sources or from supplementation. The authors concluded that adding extra calcium to the diet, whether from food or supplements, was not a very efficient way to increase bone density and prevent fractures.

  • This study suffers from some serious flaws. It is a meta-analysis of previous clinical trials looking at the effects of calcium on bone density. Meta-analyses can be very strong studies because they average the effects of many individual studies. However, meta-analyses can also suffer from the “garbage-in, garbage-out” phenomenon.

Simply put, the quality of the meta-analysis is only as good as the studies that go into it. In this case the meta-analysis included many clinical studies that were done 10, 20, 30 and even 40 years ago. Based on what we now know about bone metabolism, the design of many of those early studies was clearly inadequate (details are given in the article).

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.

Do NAD Levels Decrease With Age?

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Why Do We Care About NAD Levels?

Author: Dr. Stephen Chaney 

We have heard for years that NAD decreases as we age and supplements like NMN that increase NAD levels may be beneficial because they:

  • Increase cellular energy production which can reduce fatigue and improve stamina.
  • Activate sirtuins (your anti-aging genes) which, among other things, enhance DNA repair and reduce cellular stress.
  • Enhance energy metabolism in the brain. Studies are currently ongoing to evaluate its effectiveness in combating neurodegenerative conditions like Alzheimer’s and Parkinson’s diseases.
  • Enhance energy production in muscle which could improve physical performance and exercise capacity in older adults.
  • Regulate your circadian rhythms which could improve sleep quality and reduce systemic inflammation.

But what if none of this were true? A recent study has reported that blood levels of NAD don’t decline with age (MM Tretowicz et al, Nature Metabolism, 8: 1282-1290, 2026).

The headlines from social media influencers and bloggers, and even the New York Times, are saying things like:

  • “The idea that NAD levels decrease as we age is a myth”
  • “Supplements that raise NAD levels are a waste of money”

You are probably confused by the headlines. You are wondering, “What is true and what is a myth?” To answer that question, I need to evaluate the study behind the headlines.

But first it’s time for the professor’s favorite topic, Metabolism 101. It’s time to ask, “Why do we care about NAD levels?”

Why Do We Care About NAD Levels”

Let’s start by looking at the structures of NMN and NAD, so you can envision their relationship.

In the upper left corner, you see the structure of NMN, the abbreviation for nicotinamide mononucleotide. It contains nicotinamide (a form of vitamin B3), the 5-carbon sugar ribose, and a phosphate.

In the lower left corner, you see the structure of adenine mononucleotide, consisting of adenine, ribose, and phosphate. However, the better-known name for that structure is adenosine monophosphate, or AMP. If you add two phosphates to that molecule, you have ADP. If you add three phosphates to that molecule, you have ATP, which is the energy currency of the cell.

If you join nicotinamide mononucleotide and adenine mononucleotide together, you get nicotinamide adenine dinucleotide or NAD, which is the structure on the right.

With that behind us, let’s get back to the original question, “Why do we care about NAD levels?” Below I have put together a simplistic, conceptual diagram to explain the importance of NAD.

Simply put, the foods we eat are primarily composed of carbon, hydrogen, and oxygen, with an occasional nitrogen or sulfur thrown in for good measure. As the foods we eat are broken down in our cells…

  • The carbons and oxygens are converted to CO2, which we exhale.
  • The hydrogens are transferred to NAD to produce NADH.

In an oxygen environment hydrogen, or more properly the electrons it possesses, are “high energy”.

When NADH enters our mitochondria, it encounters a biochemical pathway called the electron transport chain.

  • NADH transfers its hydrogen to the oxygen we breathe in to produce H2O, or water.
  • It transfers its electrons to the electron transport chain where they provide the energy to convert ADP to ATP, which is the energy currency of the cell.

NAD does have a sister molecule called FAD which plays a similar role. As you can see from the simplistic diagram above, they are essential for energy (ATP) production in our cells. By feeding electrons into the electron transport chain, they are responsible for 90% of the energy our bodies need to survive and thrive. With that in mind, you can begin to appreciate why a decrease in the levels of either one of these molecules is concerning.

On a personal note, my thesis advisor at UCLA, Dr. Paul Boyer, received the Nobel Prize for deciphering the complex mechanism by which the electron transport chain uses electrons to generate ATP. 

Do NAD Levels Decrease With Age?

Peek Behind The CurtainSo, now it is time to peak behind the curtain. It’s time to look at the study behind the headlines.

The researchers obtained blood samples from seven small clinical studies that looked at the variation in blood NAD levels with age. They used a very high precision method for measuring blood levels of NAD and applied it to the blood samples obtained from each study.

[Note: This is important because some of the variability in blood NAD levels between studies could have been due to variations in the way blood NAD levels were measured.]

They reported that:

  • Whole-blood NAD levels remained remarkably stable with age. This is different from the generally accepted paradigm.
  • Whole-blood NAD levels were not influenced by lifestyle.
    • Elite athletes had blood NAD levels comparable to sedentary controls.
    • Exercise had little effect on blood NAD levels.
    • Diet had little effect on blood NAD levels.
  • Whole-blood NAD levels increased with NMN supplementation. This confirms previous studies.

They concluded:

  • “Our results challenge the utility of blood NAD levels as a biomarker of ageing or lifestyle factors.”

That conclusion is significantly different from the headlines you may have seen. The headlines suggest that the whole NAD hypothesis is a myth. This study is just saying that measuring blood NAD levels is easy, but it may not be the best way to gauge the effect of age or lifestyle on NAD stores.

 

But before I discuss that further, I should point out that this study has some glaring flaws. Let me share what the critics of this study are saying about it. 

What Are The Critics Saying?

flawsHere are the top four criticisms that other experts have raised about this study:

  • “Lack of Red Blood Cell Normalization: The study did not adjust NAD measurements for red blood cell (RBC) count, hematocrit, or hemoglobin—values that normally decrease with age and tend to be lower in women than in men.” 

Why Is This Important? The authors of this study measured whole blood NAD levels. Red blood cells typically make up 40-45% of total blood volume. Red blood cells lack mitochondria, so they don’t need as much NAD as energy-intensive tissues. However, white blood cells do have mitochondria and do need higher levels of NAD.

As the percentage of red blood cells decrease with age, the percentage of white blood cells increases. This leaves open the possibility that a decrease in NAD levels in white cells might be offset by an increase in the number of white cells in the same volume of blood.

What do other studies show? Studies that normalize whole blood measurements for the red blood cell count generally show a decrease in blood levels of NAD with age.

One Step Forward, Two Steps Back. The scientists who designed the study should be commended for using the same, high-precision method to measure NAD levels in blood samples from different studies. However, neglecting to normalize for red blood cell count is a fatal flaw that may invalidate their study.

  • “Insufficient Sample Size: The study pooled several smaller observational studies and clinical trials rather than drawing from a single large cohort—an approach that introduces heterogeneity and limits the ability to detect modest but real biological effects.”

My Perspective: This is what I call the Garbage-in, Garbage-out principle that invalidates many well-intentioned meta-analysis studies.

  • “Pre-Analytical Variability Across Cohorts: The study combined blood samples from seven studies collected under different conditions, introducing potential variability from factors such as collection tubes, processing delays, storage temperature, and freeze-thaw handling—all of which can substantially influence NAD measurements. The variation between studies in this meta-analysis was approximately 10-15 nmol/mL—while the age-related decrease they were looking for was only around 1.5 nmol/mL. When technical variation is nearly ten times the size of the biological signal, it is very difficult to draw confident conclusions.”

garbageMy Perspective: Another example of Garbage-in, Garbage-out.

  • “Measurements Were Done In The Wrong Tissue: The critical distinction that is easily lost in most coverage is that the study measured NAD in whole blood—not in the organs and tissues where age-related NAD biology may be most relevant. Whole blood is a complex matrix dominated by red blood cells and circulating immune cells. It may tell us relatively little about NAD status in energy-intensive tissues like the brain, skeletal muscle, skin, liver, or kidney—the compartments where the scientific case for age-related NAD decline is mostly built.”

“Concluding from stable whole blood NAD levels that NAD does not decline with aging anywhere in the body is the scientific equivalent of measuring the temperature outside your front door and concluding it must be the same temperature in every room of your house.” 

What Do Other Studies Show? Previous studies have shown an age-related NAD decline in skin, brain, skeletal muscle, and liver.

My Perspective: Even if this study, despite many flaws, is correct in concluding that blood NAD levels do not decline with age, that finding is irrelevant. In essence, that is what the authors were saying when they concluded, “Our results challenge the utility of blood NAD levels as a biomarker of ageing or lifestyle factors.”

So, ignore what you may be hearing from social media, your favorite health blogger, or other sources. Anything beyond saying that a recent study showed that blood may not be the best place to measure the effect of aging on NAD levels is pure fiction.

And don’t forget that the study also confirmed that NMN supplementation was effective at increasing NAD levels.

The Bottom Line 

You may have seen headlines saying things like:

  • “The idea that NAD levels decrease as we age is a myth”
  • “Supplements that raise NAD levels are a waste of money”

When we peak behind the curtain and look at the study behind the headlines, we discover the study came to two conclusions:

  • It confirmed that NMN supplements were effective at increasing NAD levels in our blood.
  • It concluded that blood NAD levels may not be useful biomarkers of aging or lifestyle factors.

Neither of these conclusions look anything like the headlines you may have seen.

Experts who have reviewed that study have concluded that:

  • It is highly flawed.
  • Even if blood levels of NAD do not decrease with age, that is irrelevant because NAD levels have been shown to decrease with age in energy-intensive tissues like brain, muscle, skin, liver, and kidney.

As one of the experts put it, “Concluding from stable whole blood NAD levels that NAD does not decline with aging anywhere in the body is the scientific equivalent of measuring the temperature outside your front door and concluding it must be the same temperature in every room of your house.”

So, ignore what you may be hearing from social media, your favorite health blogger, or other sources. Anything beyond saying that a recent study showed that blood may not be the best place to measure the effect of aging on NAD levels is pure fiction.

For more details on the study and what critics are saying about it, 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.

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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.

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.

Health Tips From The Professor