We are told we should be consuming more protein. But where should we get our protein?
Meat is an obvious choice. But meat consumption is controversial. The arguments are intense.
There are those who claim that meat consumption, particularly red meat, increases our risk of cancer, heart disease, diabetes, and many other diseases. Others claim that meat has been maligned. It doesn’t increase disease risk. We should eat more of it, not less.
The problem is that both sides are basing their claims on published clinical studies. Studies on meat consumption and disease risk are all over the map.
I have covered this controversy in previous issues of “Health Tips From the Professor”. In attempting to make sense of the conflicting data I made the observation that studies showing meat consumption reduced disease risk tended to come from third world countries while studies showing meat consumption increased disease risk tended to come from high-income western countries.
The investigators used data from the UK Biobank Study, a study that recruited 503,317 young men and women throughout the UK between 2006 and 2010. Upon entry into the study participants completed questionnaires about physical data (height, weight, etc), biological data (blood sugar, cholesterol levels, etc.), and diet.
This particular study used data from a subset (474,985) participants who completed a 24-hour dietary recall questionnaire.
Participants were then linked to the National Health Service database to assess the first occurrence of the 25 leading non-cancerous causes of hospital admissions for each patient and followed for an average of 8 years.
Cancer admissions were excluded from this study because the International Agency for Research on Cancer (IARC), the cancer agency of the WHO, has already classified red meat as a probable carcinogen and processed meat as a likely carcinogen.
Does Meat Consumption Increase Disease Risk?
The investigators looked at four distinct categories of meat consumption (total meat, red meat, processed meat, and poultry) and the risk of 25 common diseases (excluding cancer). In each case, they divided meat consumption into quartiles and compared the disease risk for those in the highest quartile to those in the lowest quartile.
For the sake of simplicity, I will only report the most significant disease risks (those with p ≤001).
These differences are highly significant (p <001) and the study size was very large (~475,000 participants), so the increased risk is probably true for a high-income Western country like the UK.
However, some of these differences are relatively small. It’s easy to understand how they might be missed in smaller studies.
Even increased risk in the 25-30% range might disappear in studies that combine data from high-income countries and third world countries.
With this perspective it is easy to understand why previous studies have been so confusing.
Because the investigators looked at the effect of each kind of meat separately, one can get a better idea of the relative contribution of each meat to various diseases [With, of course, the caveat that people who consume more red meat also tend to consume more processed meat and vice versa.] For example:
Red meat appears to contribute more to heart disease risk than processed meat or poultry – possibly due to its high saturated fat and cholesterol content.
Processed meat appears to contribute more to stroke risk than red meat or poultry – possibly due to added nitrates and other food additives.
All meats appear to contribute to diverticular disease – possibly due to a change in gut bacteria because meats replace plant foods in the diet.
The increased risk of GERD and gastritis associated with poultry consumption was surprising, but the increased risk was small.
The authors concluded, “Our findings from this large prospective study of British adults show that meat consumption is associated with higher risks of several common conditions but a lower risk of iron deficiency anemia…Additional research is needed to evaluate whether these differences in risk reflect causal relationships, and if so what proportion [of these outcomes] could be prevented by decreasing meat consumption.”
Is It Meat Or Something Else?
Of course, the question, “Is it meat or something else in our diet that is causing the increased risk of disease?” One hint that something else might be contributing to disease risk came when the authors corrected the data for obesity. The results are shown below:
Total Meat Consumption Corrected For Obesity
Disease
Increased
Risk
Corrected
For Obesity
Heart Disease
29%
17%
Stroke
24%
22%
Diverticular Disease
29%
18%
Colon Polyps
14%
10%
Diabetes
85%
33%
Red Meat ConsumptionCorrected For Obesity
Disease
Increased
Risk
Corrected
For Obesity
Heart Disease
25%
16%
Stroke
NS
NS
Diverticular Disease
26%
17%
Colon Polyps
11%
8%
Diabetes
53%
21%
Processed Meat ConsumptionCorrected For Obesity
Disease
Increased
Risk
Corrected
For Obesity
Heart Disease
17%
9%
Stroke
23%
17%
Diverticular Disease
18%
17%
Colon Polyps
11%
8%
Diabetes
52%
24%
Poultry ConsumptionCorrected For Obesity
Disease
Increased
Risk
Corrected
For Obesity
Heart Disease
12%
8%
Stroke
NS
NS
Diverticular Disease
14%
10%
Colon Polyps
6%
7%
Diabetes
32%
14%
GERD
16%
17%
Gastritis
10%
12%
When corrected for obesity, the risk of:
Heart disease decreased by 33-47%.
Diverticular disease decreased by 23-38%.
Diabetes decreased by 54-61%.
But how do we interpret that? It would be easy to conclude that the influence of meat consumption on heart disease, diverticular disease, and diabetes is small. However, that’s not the real world. People aren’t meat eaters or overweight. In the real world, people are often meat eaters and overweight.
So, the important question to ask is why so many meat eaters are overweight.
It could simply be a question of calories. A serving of steak is around 680 calories, while a serving of beans is around 110 calories.
It could be what is eaten with the steak or beans. A medium baked potato with butter and sour cream adds 300-500 calories. A vegetable stir fry adds 170 calories.
It could be how we cook it. In our country over 50% of chicken we eat is fried. And to make matters worse, we often add French Fries and other highly processed foods to our fried chicken meal.
What Does This Study Mean For You?
This study shows that in a high-income western society like ours, meat consumption is likely to increase our risk of several diseases, For example:
Red meat is associated with increased risk of heart disease, diabetes, and diverticular disease.
Processed meat is associated with increased risk of stroke, diabetes, and diverticular disease.
Poultry consumption is associated with increased risk of diabetes and digestive diseases.
All three kinds of meat are associated with obesity.
While it is easy to blame meat consumption for all our ills, it may be how we cook it and what we eat along with it.
Perhaps we should eat our meat the way they do in Third World countries. Rather than eating it as a main course, perhaps we should use it as flavoring for a vegetable stir fry or a lentil stew.
The Bottom Line
A recent study looked at the association of meat consumption with disease risk in the UK. It found that:
Red meat is associated with increased risk of heart disease, diabetes, and diverticular disease.
Processed meat is associated with increased risk of stroke, diabetes, and diverticular disease.
Poultry consumption is associated with increased risk of diabetes and digestive diseases.
All three kinds of meat are associated with obesity.
For more information on this study and what it means for you, read the article above.
These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.
My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.
My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.
For more detail about FTC regulations for health claims, see this link.
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.
Vegans will tell you that any meat is bad for you. Keto enthusiasts haven’t found a meat they don’t like. To them grains and most fruits and vegetables are the problem.
But what about those of us who aren’t at either extreme? Which meat, if any, should be part of a healthy diet? And how much of them should we eat?
For years the paradigm had been clear:
Fish was best, especially fish rich in omega-3s. They were good for your heart and your brain. And some studies suggested that high intake of omega-3-rich fish might help you live longer.
Poultry and other white meats were neutral.
Red meat was probably bad for you. It was high in saturated fat and cholesterol, and some studies linked it to an increased risk of heart disease. Plus, the International Agency for Research on Cancer (IARC), an agency of the WHO, listed it as a probable carcinogen. [Note: Recent studies have questioned concerns about red meat. I will discuss this below.]
Processed meats were considered a “no-no” The IARC listed processed meat as a definite carcinogen for humans based on studies linking it to colon, stomach, lung, and pancreatic cancers. It is also linked to an increased risk of heart disease.
However, most of these studies were done in the United States. And our diet is very different from that of many other countries.
That’s why a recent study (R Iqbal et al, American Journal of Clinical Nutrition, 114:1049-1058, 2021) caught my eye. The study was designed to measure the association between unprocessed red meat & poultry and processed meat intake with the risk both mortality and major cardiovascular disease with cancer as a secondary end point. And the study used data from 21 countries around the world except the United States.
How Was This Study Done?
The authors used data from the Prospective Urban Rural Epidemiology (PURE) study. The study is a large-scale (164,007 individuals), prospective (meaning it follows the individuals over time rather than taking measurements from them at a single time) study. The individuals in the study were aged 35-70 years and were followed for an average of 9.5 years.
The individuals came from 21 low-, middle-, and high-income countries.
The low-income countries included Bangladesh, India, Pakistan, Tanzania, and Zimbabwe.
The middle-income countries included Argentina, Brazil, Chile, China, Columbia, Iran, Poland, South Africa, and Turkey.
The high-income countries included Canada, Saudi Arabia, Sweden, and the United Arab Emirates. [Note: The United States was not included in the study.]
At the beginning of the study and at 3, 6, and 9 years the following data were collected from everyone enrolled in the study.
Demographic information (age, sex, location, education, wealth index, and smoking status).
Lifestyle information (diet and physical activity).
Health history.
Medication use.
Cardiovascular events and mortality.
Will Processed Meat Kill You?
The authors compared high intake of processed meats (5 ounces per week, the equivalent of two sausages/week) with zero intake of processed meats. They reported that high intake of processed meats increased the risk of:
Mortality by 51%.
Major cardiovascular disease by 46%.
Non-cardiovascular mortality by 50%
Cancer by 84%.
Heart attack by 62%.
Stroke by 56%.
Furthermore, even as little as 1.5 ounces of processed meat per week significantly increased the risk of mortality.
For red meat and poultry, the authors compared high intake (9 ounces per week) with low intake (2 ounces per week). For both red meat and poultry they did not find any association between high weekly intake and any of the health outcomes.
[I would note however, that many Americans consume 4 ounces of chicken or an 8-ounce steak at dinner – that’s one meal on one day. The corresponding weekly intake would be 28 ounces of chicken or 56 ounces of red meat. That’s significantly higher than the highest weekly intake used in this study.]
The authors concluded, “We observed no significant association between the consumption of unprocessed red meat and poultry intake and health outcomes. And higher intake of processed meat was associated with higher risks of mortality and cardiovascular disease. These findings may indicate that limiting the intake of processed meat should be encouraged.”
In my opinion, there are so many studies linking the consumption of processed meat with heart disease, cancer, and premature death that the last sentence of their conclusion should have said, “These findings unambiguouslyconfirm that limiting the intake of processed meats should be encouraged.”
What Is The Truth About Meat?
Red Meat:
Yes, there is a lot of confusion about red meat. Many studies, like this one, find no adverse health effects associated with red meat consumption. That has led many experts to conclude that the dangers of red meat have been greatly exaggerated.
I think we should dig a little deeper. Most of the studies showing that red meat consumption increases the risk of heart disease, cancer, and mortality have been done in this country. So, perhaps we should be asking what is different about red meat consumption in our country.
There are several factors to consider:
Cooking Methods: The authors of this article pointed out that we often grill our meat at high temperatures which causes the formation of cancer-causing chemicals, while many of the countries in the PURE database stew their red meat at much lower temperatures.
Diet Context: As I have explained in a previous article of Health Tips From the Professor, fruits, vegetables, and whole grains are the antidotes to the cancer-causing chemicals formed when we cook red meat. And they bind to cholesterol in the intestine and flush it out of the body. Finally, they dilute the saturated fat in red meat with polyunsaturated fats, which helps create a healthier balance of fats.
In this country we often pair our steaks with French fries or a baked potato loaded with butter and sour cream. However, in low- and middle-income countries red meat is an expensive luxury and is often used as a garnish to dishes containing lots of vegetables and whole grains.
Amount Consumed: As a mentioned above, the amount of red meat most Americans consume in a week far exceeds the highest weekly intake of red meat in this study. The highest weekly consumption of red meat in this study is more consistent with using red meat as a garnish than as a main course.
Poultry:
For poultry, there is no confusion. Studies done in this country also find no association between poultry consumption and cardiovascular disease, cancer, or mortality. That may be due to a healthier fat profile and the ways in which poultry is usually cooked.
Processed Meat:
For processed meat, there is also no confusion. Virtually every published study from across the world agrees that it increases the risk of cancer, heart disease, and premature death. And the effect is not trivial. This study suggests that just 2 sausages a week is enough to increase your risk of premature death by 50%! So, the answer to the question, “Will processed meat kill you?” appears to be, “Yes”.
The authors of this article pointed out that the saturated fat and cholesterol in processed meat and red meat were very similar. They didn’t mention it, but the cooking techniques are also similar. So, neither of these explain why processed meat is so bad for us.
However, the amounts of preservatives and food additives in processed and unprocessed meats differ greatly. Based on this, the authors of the study and many other experts postulate that it is the preservatives and food additives that are responsible for the health risks of processed meats.
What Does this Mean For You?
This study agrees with many other studies showing that processed meats are bad for us. The authors recommend limiting your intake of processed meats.
However, their data show that as little as two strips of bacon, one hot dog, or half a large sausage per week significantly increases your risk of heart disease, cancer, and premature death. Based on that, my advice would be to avoid processed meats as much as possible.
As I described above, most experts feel that it is the preservatives and food additives that are responsible for the health risks associated with processed meats.
Some studies suggest that nitrates in processed meats may be the main culprit. Based on that belief, some food companies are offering nitrate-free processed meats as a healthier option.
However, there still may be some additives in nitrate-free processed meats (read the label carefully), and we have no clinical studies showing that the nitrate-free processed meats in the marketplace are good for us.
Red meat is more confusing. This study and others suggest it poses no health hazards. And many experts are telling you that the warnings about consuming red meat were overblown. They are telling you that red meat is good for you.
However, some studies suggest that red meat increases your risk of heart disease, cancer and premature death. When you examine the data behind the studies, I think that better advice would be that red meat can be good for you or bad for you depending on three factors:
Portion size: We should think of red meat as a garnish rather than a main course – 3-4 ounces is a healthy portion size. 8-12 ounces may be too much.
Cooking method: Many of the bad things associated with red meat are the result of high temperature cooking, especially over a flame or on a grill. Choose low temperature cooking methods whenever possible.
Diet context: Whole fruits, vegetables and whole grains are the antidotes to all the bad things associated with red meat. 3-4 ounces of red meat in a vegetable stir fry or green salad is likely to be much better for you than an 8-ounce steak with French fries.
Also, red meat already has more than enough saturated fat and cholesterol. Adding foods or sauces high in fat and cholesterol may overload the body’s ability to safely process them. But adding vegetables or vegetable oils helps to restore a better balance between good and bad fats.
Finally, this and other studies agree that white meat is healthy. My only advice is:
Avoid white meat that has been fried (especially by fast food restaurants that only change their oil every 20,000 miles) or cooked with fatty sauces.
Think of the whole diet rather than just the protein source. White meat will be the healthiest as part of a whole food, primarily plant-based diet.
The Bottom Line
A recent study reported that eating as 5 ounces of processed foods per week increases your risk of heart disease, cancer, and premature death by 50%. That is equivalent to two sausages per week!) The authors of the study recommended that you limit your intake of processed meats.
However, the study showed that even as little as 1.5 ounces (2 strips of bacon, one hot dog, or half of a large sausage) per week significantly increases your risk of all three. Based on that data, my recommendation is to consider avoiding processed meat altogether.
The study reported that unprocessed red and white meat are not associated with increased health risks. I put those findings into the context of other published studies on the topic. I discuss my recommendations for unprocessed red and white meat in the article above.
For more information on this study and what it means for you, read the article above.
These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.
My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.
My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.
For more detail about FTC regulations for health claims, see this link.
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.
The Effect Of Ultra-Processed Foods On Heart Disease Risk
Author: Dr. Stephen Chaney
Heart disease is a killer. It continues to be the leading cause of death – both worldwide and in industrialized countries like the United States and the European Union. When we look at heart disease trends, it is a good news – bad news situation.
The good news is that heart disease deaths are continuing to decline in adults over 70.
The decline among senior citizens is attributed to improved treatment of heart disease and more seniors following heart-healthy diets.
The bad news is that heart disease deaths are starting to increase in younger adults, something I reported in an earlier issue of “Health Tips From the Professor.”
The reason for the rise in heart disease deaths in young people is less clear. However, the obesity epidemic, junk and convenience foods, and the popularity of fad diets all likely play a role.
Everyone has a magic diet to reduce the risk of heart disease. The American Heart Association tells us to avoid fats, especially saturated fats. Vegans tell us to avoid animal protein. Paleo and Keto enthusiasts tell us carbs are the problem.
But what if we eliminated junk and convenience food AND switched to a really healthy diet? How much would that reduce heart disease risk? A recent study (Y Willett et al, The American Journal of Medicine, in press, 2026) looked at the first part of that question. It looked at the effect of ultra-processed food (what we call junk and convenience foods) consumption on the risk of developing heart disease.
How Was This Study Done?
The scientists analyzed data from 4787 participants in the most recently published (2021 to 2023) National Health and Nutrition Examination Survey (NHANES). The average age of participants in the survey was 55 years, with 56% of them being women.
All the participants in this study had completed a dietary survey of everything they ate over the last two days. They also reported whether they had ever experienced a heart attack or stroke.
Ultra-processed foods were defined as foods that are industrially modified and loaded with added fats, sugars, starches, salts, and chemical additives.
The percentage of ultra-processed foods in their diet was calculated, and the participants were divided into quartiles based on the percentage of ultra-processed foods they consumed.
Participants with the highest quartile of ultra-processed food consumption were compared to those in the lowest quartile with respect to the risk of cardiovascular disease (self-reported heart attack or stroke). The data were corrected for age, sex, race, ethnicity, smoking status, and income.
The Effect Of Ultra-Processed Foods On Heart Disease Risk
The results were striking:
The participants in the highest quartile for ultra-processed food consumption had a 47% higher risk of heart disease compared to those in the lowest quartile for ultra-processed food consumption.
The authors concluded, “Adults who consumed the highest amount of ultra-processed foods had a statistically significant 47% increased risk of heart disease. Large scale randomized trials are needed, but in the meantime, health care providers should advise patients to decrease consumption of ultra-processed foods in addition to adopting other therapeutic lifestyle changes and adjunctive drug therapies of proven benefit.”
The authors recognized the difficulty of making those changes in a world where ultra-processed foods are ubiquitous and cheap.
However, they drew parallels to tobacco use in this country. They said, “Just as it took decades for the dangers of smoking to become widely accepted, reducing reliance on ultra-processed foods may take time. This is partly due to the influence of large multinational companies that dominate the food market. In addition, many people face limited access to healthier food options.”
They went on to say, “Addressing ultra-processed foods isn’t just about individual choices – it’s about creating environments where the healthy option is the easy option.”
Can You Cut Your Risk Of Heart Disease By 90%?
The short answer is, “probably not”. But you can reduce the risk of heart disease by a lot – and probably by a lot more than 47%.
That’s because this study did not look at what the participants were replacing the ultra-processed foods with. Some participants may have replaced them with whole food, primarily plant-based diets. Others may have replaced ultra-processed foods with whole food, meat-based diets high in saturated fats.
So, let’s look at the other side of the equation – how much you can reduce your risk of heart disease by eating a healthier diet. In a recent issue of “Health Tips From The Professor”, I reviewed a meta-analysis published in 2022 that looked at 99 clinical studies with tens of thousands of participants that measured the associations between foods or food groups and heart disease risk.
That study reported that:
Processed Meat: A single serving of processed meat increased heart disease risk by 27% to 44%.
Red Meat: Unprocessed red meat increased heart disease risk by as much as 27% – but only at ≥3 servings per day. The results with lower intakes were inconsistent – some studies showed increased risk, but others did not.
Poultry, Eggs, and Dairy Foods: They did not appear to affect heart disease risk.
Fish: Two to four servings per week of fatty fish decreased heart disease risk by around 12%.
Fruit: Two servings per day of fruit reduced heart disease risk by 21-32%.
Vegetables: Two servings of vegetables per day reduced heart disease risk by 18-21%.
Legumes (beans and peas): Four servings per week reduced the risk of heart disease by around 14%.
Nuts: One serving (a handful) per day reduced the risk of heart disease by around 25%.
Whole Grains: Two servings of whole grains per day reduced the risk of heart disease by 25%-34%.
Overall: When heart-healthy foods were consumed as part of the Mediterranean diet heart disease risk was reduced by 47%. Similar overall reductions in heart disease risk are likely with other heart-healthy diets like DASH, MIND, Flexitarian (flexible semi-vegetarian), and vegan diets.
In summary:
The first study shows that eliminating ultra-processed foods (junk and convenience foods) from your diet can decrease heart disease risk by 47% – but doesn’t tell us what the ultra-processed foods were replaced with. And it would take a much larger study to determine which food swaps were most effective at reducing heart disease risk.
The second study was a meta-analysis that told us that eating more fish and plant foods in the context of a heart-healthy diet can decrease your risk of heart disease by 47% – but doesn’t tell us what those healthy foods were replacing. And many of the individual studies included in the meta-analysis were conducted when ultra-processed food consumption was much less than it is today.
It would be tempting to add 47% plus 47% and conclude that eliminating ultra-processed food consumption and replacing ultra-processed foods with heart-healthy foods could decrease your risk of heart disease by 94%. But it’s not that simple. There are too many unanswered questions from these studies.
But it is safe to say that if we eliminated ultra-processed foods AND replaced them with heart-healthy foods in the context of a heart-healthy diet, we should be able to reduce our heart disease risk by more than 47% – perhaps much more.
What Do These Studies Mean For You?
There are two important lessons from these studies:
#1: Eliminating ultra-processed foods from your diet will significantly decrease your risk of heart disease.
And it isn’t just heart disease. Other recent studies have shown that eliminating ultra-processed foods from your diet helps you:
Control your weight (It is perhaps the most important lifestyle change to make if you want to maintain GLP-1-aided weight loss).
Reduce your risk of cancer.
Reduce your risk of diabetes.
Reduce your risk of inflammatory diseases.
Reduce anxiety and depression.
Increase your healthspan (your healthy years).
In short, ultra-processed foods are killers.
#2: Replacing ultra-processed foods with heart-healthy foods (fruits, vegetables, legumes, nuts, whole grains, and fish) in the context of a healthy diet (Mediterranean, DASH, MIND, Flexitarian, and vegan, for example) is likely to decrease your risk of heart disease even more.
And if your diet consists of mostly heart-healthy foods, you can add moderate amounts of heart-neutral foods (poultry, eggs, and dairy).
And the latest evidence suggests that you can even add small amounts of red meat in the context of a heart-healthy diet (As I have said in previous issues of “Health Tips From the Professor”, plant foods contain the antidotes to all the bad things about red meat.)
Finally, you might ask why I emphasize both heart-healthy foods and heart-healthy diets. There are two reasons:
Most of us think in terms of foods rather than diets.
The food industry is only too happy to provide us with ultra-processed foods for “heart-healthy” diets like the vegan and Mediterranean diet.
The Bottom Line
Two recent studies have shown how each of us can dramatically reduce our risk of heart disease.
The first study showed that eliminating ultra-processed foods from our diet can significantly decrease our heart disease risk – but didn’t tell us what the ultra-processed foods were replaced with.
The second study showed that eating more heart-healthy foods in the context of a heart-healthy diet can significantly decrease our risk of heart disease – but didn’t tell us what those healthy foods were replacing.
Taken together, those studies show us a clear path for dramatically decreasing our heart disease risk.
For more details about these studies and what they mean for you, read the article above.
These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.
My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.
My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.
For more detail about FTC regulations for health claims, see this link.
Dr. Chaney has a BS in Chemistry from Duke University and a PhD in Biochemistry from UCLA. He is Professor Emeritus from the University of North Carolina where he taught biochemistry and nutrition to medical and dental students for 40 years. Dr. Chaney won numerous teaching awards at UNC, including the Academy of Educators “Excellence in Teaching Lifetime Achievement Award”.
Dr Chaney also ran an active cancer research program at UNC and published over 100 scientific articles and reviews in peer-reviewed scientific journals. In addition, he authored two chapters on nutrition in one of the leading biochemistry text books for medical students.
Since retiring from the University of North Carolina, he has been writing a weekly health blog called “Health Tips From the Professor”. He has also written two best-selling books, “Slaying the Food Myths” and “Slaying the Supplement Myths”. And most recently he has created an online lifestyle change course, “Create Your Personal Health Zone”. For more information visit https://chaneyhealth.com.
For the past 45 years Dr. Chaney and his wife Suzanne have been helping people improve their health holistically through a combination of good diet, exercise, weight control and appropriate supplementation.
New Year’s resolutions are just around the corner. Some of you will resolve to lose weight, and some of you will resolve to eat healthier. But can you do both?
Any restrictive diet will give you short-term weight loss. And weight loss will give you improvement in blood parameters that might signal a reduced risk of heart disease, stroke, and diabetes.
The operative word here is “might”. Long-term studies are required to determine whether a diet actually reduces the risk of chronic diseases.
So, the important question becomes, “Can weight loss diets be healthy long term”. For some of them, the answer is a clear no. Others are unlikely to be healthy but have not been studied long term, so we don’t know whether they are healthy or not.
That’s the dilemma most of you face this January. If most weight loss diets are unhealthy long term, do you have to choose between weight loss and good health when you make your New Year’s resolutions?
This was a randomized controlled trial, the gold standard of clinical studies. The investigators recruited 100 healthy, abdominally obese men and women aged 40-70. At the time of entry into the study none of the participants:
Had diabetes.
Smoked
Had a diagnosed medical condition.
Were on a medication that interfered with blood sugar control.
Were on a vegetarian diet.
The participants were randomly assigned to:
A high-nutrient quality diet that restricted calories by 25%.
A low-nutrient-quality diet that restricted calories by 25%.
A continuation of their habitual diet.
The study lasted 12 weeks. The participants met with a dietitian on a weekly basis. The dietitian gave them all the foods they needed for the next week and monitored their adherence to their assigned diet. They were advised not to change their exercise regimen during the study.
At the beginning and end of the study the participants were weighed, and cholesterol, triglycerides, and blood pressure were measured.
Can A Healthy Diet Help You Lose Weight?
This study compared a healthy diet to an unhealthy diet with the same degree of caloric restriction. And it compared both diets to the habitual diet of people in that area. This study was performed in the Netherlands, so both weight loss diets were compared to the habitual Dutch diet.
To put this study into context, these were not healthy and unhealthy diets in the traditional sense.
Both were whole food diets.
Both included fruits, vegetables, low-fat dairy, and lean meats.
Both restricted calories by 25%.
The diets were designed so that the “high-nutrient quality” diet had significantly more plant protein (in the form of soy protein), fiber, healthy fats (monounsaturated and omega-3 fats), and significantly less added sugars than the “low-nutrient-quality” diet.
When the investigators measured weight loss at the end of 12 weeks:
Participants lost significant weight on both calorie-restricted diets compared to the group that continued to eat their habitual diet.
That is not surprising. Any diet that successfully restricts calories will result in weight loss.
Participants on the high-nutrient quality diet lost 33% more weight than participants on the low-nutrient-quality diet (18.5 pounds compared to 13.9 pounds).
Participants on the high-nutrient quality diet lost 50% more inches in waist circumference than participants on the low-nutrient-quality diet (1.8 inches compared to 1.2 inches).
Waist circumference is a direct measure of abdominal obesity.
When the investigators measured blood pressure, fasting total cholesterol levels, and triglyceride levels at 12 weeks:
Prescription for good health overhead with stethoscope, healthy fresh food and exercise equipment, with copy space.
These cardiovascular risk factors were significantly improved on both diets.
Again, this would be expected. Any diet that causes weight loss results in an improvement in these parameters.
However, the reduction in total serum cholesterol was 2.5-fold greater in the high-nutrient quality diet group than in the low-nutrient-quality diet group.
The reduction in triglycerides was 2-fold greater in the high-nutrient quality diet group than in the low-nutrient-quality diet group.
The reduction in systolic blood pressure was 2-fold greater and the reduction in diastolic blood pressure was 1.67-fold greater in the high-nutrient quality diet group than in the low-nutrient-quality diet group.
The authors concluded, “Our results demonstrate that the nutrient composition of an energy-restricted diet is of great importance for improvements of metabolic health in an overweight, middle-aged population. A high-nutrient quality energy-restricted diet enriched with soy protein, fiber, monounsaturated fats, omega-3 fats, and reduced in fructose and other added sugars provided additional health benefits over a low-nutrient quality energy-restricted diet, resulting in greater weight loss…and promoting an antiatherogenic blood lipid profile.”
In short, participants in this study lost more weight and had a better improvement in risk factors for heart disease on a high-nutrient-quality diet than on a low-nutrient-quality diet. Put another way, a healthy diet can help you lose weight. Healthy eating helped them lose more weight and gave them greater improvement in their health.
What’s New About This Study?
Simply put this study confirms that:
Caloric restriction leads to weight loss, and…
Weight loss leads to improvement in cardiovascular risk factors like total cholesterol, triglycerides, and blood pressure.
This is not new. It is true for any diet that results in caloric restriction.
However, this study breaks new ground in that it shows a high-nutrient quality diet results in significantly better…
Weight loss and…
Reduction in cardiovascular risk factors….
…compared to a low-nutrient quality diet with the same degree of caloric restriction.
What Does This Study Mean For You?
As I said above, the distinction between a “high-nutrient-quality” diet and a “low-nutrient-quality” diet may not be what you might have expected.
Both diets were whole food diets. Neither diet allowed sodas, sweets, and highly processed foods.
Both included fruits, vegetables, grains, and lean meats.
Both reduced caloric intake by 25%.
If you want to get the most out of your weight loss diet, this is a good place to start.
However, in this study the investigators designed their “high-nutrient-quality” diet so that it contained:
More plant protein in the form of soy protein.
In this study they did not reduce the amount of animal protein in the “high-nutrient-quality” diet. They simply added soy protein foods to the diet. I would recommend substituting soy protein for some of the animal protein in your diet.
More fiber.
The additional fiber came from substituting whole grain breads and brown rice for refined grain breads and white rice, adding soy protein foods, and adding an additional serving of fruit.
More healthy fats (monounsaturated and omega-3 fats) in place of saturated fats.
The additional omega-3s came from adding a fish oil capsule providing 700mg of EPA and DHA.
Less added sugar.
All these changes make great sense if you are trying to lose weight.
I would group these changes into 7 recommendations.
1) Follow a whole food diet. Avoid sodas, sweets, and highly processed foods.
2) Include all 5 food groups in your weight loss diet. Fruits, vegetables, whole grains, dairy, and lean proteins all play an important role in your long-term health.
3) Eat a primarily plant-based diet. My recommendation is to substitute plant proteins for at least half of your high-fat animal proteins. And this study reminds us that soy protein foods are a convenient and effective way to achieve this goal.
4) Eat a diet high in natural fiber. Including fruits, vegetables, whole grains, beans, nuts, seeds, and soy foods in your diet is the best way to achieve this goal.
5) Substitute healthy fats (monounsaturated and omega-3 fats) for unhealthy fats (saturated and trans fats) in your diet. And this study reminds us that it is hard to get enough omega-3s in your diet without an omega-3 supplement.
6) Reduce the amount of added sugar in your diet. This is best achieved by eliminating sodas, sweets, and highly processed foods from the diet.
7) Finally, I would like to remind you of the obvious. No diet, no matter how healthy, will help you lose weight unless you cut back on calories. Fad diets achieve that by restricting the foods you can eat or the time you are allowed to eat. In the case of a healthy diet, the best way to do it is to cut back on portion sizes and choose foods with low caloric density.
The Bottom Line
A recent study asked, “Can a healthy diet help you lose weight?” This study was a randomized controlled study, the gold standard of clinical studies. The participants were randomly assigned to:
A high-nutrient quality diet that restricted calories by 25%.
A low-nutrient-quality diet that restricted calories by 25%.
Continue with their habitual diet.
These were not healthy and unhealthy diets in the traditional sense.
Both were whole food diets.
Both included fruits, vegetables, low-fat dairy, and lean meats.
Both restricted calories by 25%.
The diets were designed so that the “high-nutrient quality” diet had significantly more plant protein (in the form of soy protein), fiber, healthy fats (monounsaturated and omega-3 fats), and significantly less fructose and other added sugars than the “low-nutrient-quality” diet.
At the end of 12 weeks:
Participants on the high-nutrient quality diet lost 33% more weight and had better cardiovascular markers than participants on the low-nutrient-quality diet.
The authors concluded, “Our results demonstrate that the nutrient composition of an energy-restricted diet is of great importance for improvements of metabolic health in an overweight, middle-aged population. A high-nutrient quality energy-restricted diet enriched with soy protein, fiber, monounsaturated fats, omega-3 fats, and reduced in fructose and other added sugars provided additional health benefits over a low-nutrient quality energy-restricted diet, resulting in greater weight loss…and promoting an antiatherogenic blood lipid profile.”
In short, participants in this study lost more weight and had a better improvement in risk factors for heart disease on a high-nutrient-quality diet than on a low-nutrient-quality diet. Put another way, a healthy diet can help you lose weight. Healthy eating helped them lose more weight and gave them greater improvement in their heart health.
For more details on this study, what this study means for you, and my 7 recommendations for a healthy weight loss diet, 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.
Dr. Chaney has a BS in Chemistry from Duke University and a PhD in Biochemistry from UCLA. He is Professor Emeritus from the University of North Carolina where he taught biochemistry and nutrition to medical and dental students for 40 years.
Dr. Chaney won numerous teaching awards at UNC, including the Academy of Educators “Excellence in Teaching Lifetime Achievement Award”.
Dr Chaney also ran an active cancer research program at UNC and published over 100 scientific articles and reviews in peer-reviewed scientific journals. In addition, he authored two chapters on nutrition in one of the leading biochemistry text books for medical students.
Since retiring from the University of North Carolina, he has been writing a weekly health blog called “Health Tips From the Professor”. He has also written two best-selling books, “Slaying the Food Myths” and “Slaying the Supplement Myths”. And most recently he has created an online lifestyle change course, “Create Your Personal Health Zone”. For more information visit https://chaneyhealth.com.
For the past 45 years Dr. Chaney and his wife Suzanne have been helping people improve their health holistically through a combination of good diet, exercise, weight control and appropriate supplementation.
It’s almost the New Year. And with the New Year comes New Year’s resolutions. Weight loss is the second most popular New Year’s resolution, trailing only exercising more.
But if you are middle-aged and have been overweight most of your adult life, is it too late to lose weight? Has the damage to your health already been done? Has that ship already sailed?
There is good evidence that people who maintain an ideal weight throughout their adult years are healthier and live slightly longer than people who are overweight.
There is also good evidence that weight loss at any age provides short-term improvements to biomarkers of good health such as:
lower blood pressure.
lower cholesterol levels.
better blood sugar control.
reduction in chronic inflammation.
But surprisingly there are very few studies to show that weight loss results in long-term health benefits, especially for people who have been overweight through their 40s and 50s. To date there is only a single Chinese study of midlife weight loss, and that study suggested that health benefits were only apparent if the weight loss was maintained for 30 years or more.
The investigators used data from three large studies that followed healthy individuals in midlife for 10 years or more. None of these studies were designed as weight loss studies, but they measured weight, chronic disease incidence or mortality at multiple points during the study.
The first study was the Whitehall II Study (WHII). This study enrolled 10,308 British civil servants (Whitehall is the district where the British Civil Service is located) between 1985 and 1988 and is still ongoing. The data for this investigation was taken from clinical examinations that occurred around 1991 and 2013.
These exams provided information on weight and height, BMI, and risk factors like smoking, high blood pressure, high cholesterol, and insulin resistance and/or high blood sugar (indicative of prediabetes or diabetes).
The data set was linked to National Health Service records for diagnosed chronic diseases (type 2 diabetes, heart attack, stroke, cancer, asthma, and chronic obstructive pulmonary disease).
The study I am describing today included 4118 men and women aged 37-42 years (average = 39 years) from the WHII dara set who were free of chronic disease at the time of the 1991 clinical evaluation.
The second study was the Helsinki Businessmen Study (HBS). In this study 3490 White men, mostly businessmen and executives aged 38-45 years (average 42 years) underwent voluntary health checkups starting in 1964. Cardiovascular risk factors were assessed and the men received health education on diet, exercise, and weight control. Between 1974 and 1975 these men were offered a voluntary follow-up health checkup, and 2335 men completed both checkups.
In this study, BMI was measured at both health checkups and all-cause mortality data were obtained from the National Health Registry.
The third study was the Finnish Public Sector Study (FPS). In this study 77,111 men and women in public service were enrolled in 2,000. BMI was measured in 4-year intervals and health data were collected from the European Health Records. The data for this investigation used data from 16,696 men and women who were 34-43 (average age = 39) at the first assessment, had data from at least 3 consecutive assessments, and had no diagnosed chronic disease at the first assessment.
As with the WHII study, BMI and chronic disease were measured in at least 2 consecutive assessments.
The average follow-up for the three studies was 22.8 years between the first and last assessment.
In all three cases the study participants were divided into 4 groups:
Those who remain overweight (defined as a persistent BMI>25).
Those who gained weight – they went from a healthy weight to being overweight (defined as BMI<25 to BMI>25).
Those who lost weight – they went from overweight to a healthy weight (defined as BMI>25 to BMI<25).
The average weight loss was 11.5 pounds or 6.5% of body weight and was remarkably consistent in all 3 studies.
Those who remained at a healthy weight (defined as a persistent BMI<25).
In the WHII and FPS studies, weight differences were correlated with the diagnosis of a chronic disease between the first and last assessment.
In the HBS study, weight differences were correlated with all-cause mortality between the first and last assessment.
In all three cases, the data were corrected for major risk factors like smoking, high blood pressure, high cholesterol, and insulin resistance and/or high blood sugar.
In terms of the risk of developing a chronic disease (WHII and FPS studies) or risk of dying (HBS study) the always overweight group was assigned a risk of 1.0 and the other groups were compared to it.
The authors noted that all three studies were performed before surgical and pharmacological interventions were available. And people with pre-existing conditions were excluded from these studies, so disease-related weight loss was unlikely. Thus, the authors felt that the group who lost weight probably did so because of a conscious effort to change their diet and lifestyle, although this was not specifically measured in these studies.
Is It Too Late For A Weight Loss Goal?
If you remember the introduction, this question did not refer to short-term biomarkers of health. Multiple studies have shown that weight loss at any age will improve blood sugar control and lower blood pressure, cholesterol, and inflammation.
This study asked whether weight loss can be shown to have long-term health benefits – namely reduction in the risk of chronic diseases and increase in longevity.
And more specifically, it asked whether weight loss in middle age (the age of participants in these studies ranged from 39 to 42) can be shown to have long-term health benefits – even if they had been overweight for most of their adult life up to that point.
Or as the title of this segment suggested, “Is it too late to set a weight loss goal if you are middle aged.”
The answer from these studies was clear cut:
In the WHII study the risk of developing a chronic disease decreased by 48% compared to the always overweight group.
And when diabetes was excluded from the analysis the decreased risk was still significant (42%). This is important because diabetes is the most prevalent obesity related disease. The means that weight loss also significantly reduced the risk of the other chronic diseases measured in this study – such as cardiovascular disease and cancer.
In the FPS study the risk of developing a chronic disease decreased by 57% compared to the always overweight group.
Again, when diabetes was excluded from the analysis the decreased risk was still significant (45%).
Finally, in the HBS study, the risk of premature death decreased by 19% compared to the always overweight group.
In each of these studies:
The group that gained weight in their middle years did almost as poorly as the always overweight group.
The authors concluded, “Findings from 3 prospective cohort studies support maintaining a healthy weight (BMI<25) throughout life as the best option for overall health. [However] sustained midlife weight loss compared with persistent overweight was associated with a decreased risk of [diabetes and other chronic diseases] and decreased all-cause mortality.”
Simply put, this analysis of three long-term studies shows that weight loss can help you be healthier and live longer in your golden years – even if you waited until you were middle-aged to lose the weight.
What Does This Study Mean For You?
At the beginning of this article I posed the questions: If you are middle-aged and have been overweight most of your adult life, is it too late to set a weight loss goal this January? Has the damage to your health already been done? Has that ship already sailed?
This study shows that the answer to this question is clearly, “No. It’s not too late.” Sustained weight loss can still provide significant long-term benefits.
Three major studies show that sustained weight loss initiated by adults in their forties can reduce the risk of chronic disease by around 50% and reduce the risk of mortality by about 20% twenty years later. The authors of this study said that evidence from one of those studies suggests that the long-term health benefits are still apparent 30 years later.
Of course, these studies represent a single time point – weight loss initiated at age 40.
The benefits of sustained weight loss may wane if you delay longer, but we don’t know because those studies have not been done. However, it is likely that sustained weight loss at any age will have significant long-term health benefits.
The benefits of sustained weight loss may be even greater if you lose weight at a younger age. Again, we can’t predict how much greater the benefit will be because those studies also haven’t been done yet.
However, as the authors of this study said, “Maintaining a healthy weight throughout life is the best option for overall health.” That conclusion is supported by multiple studies.
There are a couple of other important points.
These benefits (a 50% reduction in chronic diseases and a 20% increase in longevity) do not require massive weight loss. The subjects in these studies only lost around 11-12 pounds (6.5% of their weight). You have previously heard that as little as 5% weight loss has significant short-term benefits. This study confirms that statement and indicates if the weight loss is sustained, it will significantly improve long-term health outcomes.
Weight loss has a bigger effect on quality of life (absence from chronic diseases)than it does on longevity. That is true of every healthy lifestyle improvement that has been studied. I’m sorry to say that losing weight will not help you live as long as Methuselah. But it will help you live your last years in good health.
Of course, losing weight is easy. There are many fad diets that can help you do that. But keeping the weight off is hard. This is where every diet eventually fails. Maintaining weight loss requires lifestyle change. It also requires a change in mindset. It requires that you change how you think about food and how you think about your ability to control what you eat.
This is why I created my online lifestyle change course, “Create Your Personal Health Zone”. If this is the year you have resolved to lose weight and keep it off, check out my course.
What About Weight Loss Surgery and GLP-1 Drugs?
Weight loss surgery and GLP-1 drugs result in faster and greater weight loss than diet and lifestyle changes alone. For example, clinical trials show that GLP-1 drugs can result in 15-20% body weight loss within the first year. [Subsequent studies suggest that real-life weight loss is often much smaller because of drug discontinuation due to side effects or cost.]
But assuming the 15-20% number, the question becomes whether these interventions have the same or greater benefits than the 6.5% body weight loss due to diet and lifestyle change seen in these studies.
The short answer is that we don’t know because we don’t have any long-term studies of these interventions. However, the authors of this study were skeptical. They said, “It remains uncertain whether the long-term benefits observed in our study extend to these interventions, where greater weight loss may be accompanied by a concurrent and potentially significant loss of lean body mass, which could pose challenges over time.”
I have discussed the importance of muscle mass for health and longevity in a previous issue of “Health Tips From the Professor”. This article shows why the accelerated loss of muscle mass seen with GLP-1 drugs is so concerning.
The Bottom Line
The time to set your New Year’s goals is just a few weeks away. If you are middle-aged and have been overweight most of your adult life, is it too late to set a weight loss goal this January? Has the damage to your health already been done? Has that ship already sailed?
A recent study examined that question. The study used data from three earlier studies on the long-term effects of sustained weight loss (20 years or more). These studies show that sustained weight loss initiated by adults in their 40s reduces the risk of:
Chronic disease by around 50%.
Mortality by about 20%.
Data from one of those studies suggests that the long-term health benefits were still apparent 30 years later.
For more information on this study, what it means for you, and where weight loss surgery and GLP-1 drugs fit into the picture, 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.
Dr. Chaney has a BS in Chemistry from Duke University and a PhD in Biochemistry from UCLA. He is Professor Emeritus from the University of North Carolina where he taught biochemistry and nutrition to medical and dental students for 40 years. Dr. Chaney won numerous teaching awards at UNC, including the Academy of Educators “Excellence in Teaching Lifetime Achievement Award”. Dr Chaney also ran an active cancer research program at UNC and published over 100 scientific articles and reviews in peer-reviewed scientific journals. In addition, he authored two chapters on nutrition in one of the leading Biochemistry textbooks for medical students.
Since retiring from the University of North Carolina, he has been writing a weekly health blog called “Health Tips From the Professor”. He has also written two best-selling books, “Slaying the Food Myths” and “Slaying the Supplement Myths”. And most recently he has created an online lifestyle change course, “Create Your Personal Health Zone”. For more information visit https://chaneyhealth.com.
For the past 53 years Dr. Chaney and his wife Suzanne have been helping people improve their health holistically through a combination of good diet, exercise, weight control and appropriate supplementation.
Nutrition is a bit like politics and religion. Everyone has an opinion, and there is not much grace for those with different opinions.
And everything is black or white. There is no middle ground. Red meat is a perfect example. Cardiologists tell us the saturated fat and cholesterol in red meat increases our risk of heart disease. Oncologists tell us red meat increases our risk of colon, breast, prostate, and pancreatic cancer.
The association with red meat consumption and colon cancer is so strong that the World Health Organization has classified red meat as a probable carcinogen.
Vegans and vegetarians tell you to avoid red meat at all costs and substitute plant proteins in its place.
Keto and carnivore diet enthusiasts tell you that red meat is healthy if you avoid any plant foods containing carbohydrates (which is most plant foods).
Who is right? Is red meat good for you or bad for you? As usual, the answer is somewhere in the middle. We also need to stop looking at individual foods and start looking at the overall diet. We need to ask how our overall diet alters the effect of red meat on our health.
But first, let’s explore:
Why red meat is good for us.
Why red meat is bad for us.
How diet can help us minimize the bad and maximize the good.
I call this section, “Everything You Wanted To Know About Red Meat”.
Everything You Wanted To Know About Red Meat
Why Red Meat Is Good For Us.
Red meat is an excellent source of protein, iron, and vitamin B12. Plus, the iron in red meat is primarily found in the heme molecule and heme iron is absorbed much more efficiently than other forms of iron.
Red meat contains creatine, which powers our muscles. You can think of creatine molecules as little power packs that are charged when we eat and release a burst of energy whenever we begin to exercise.
Red meat contains carnitine, which helps our muscles use fat as an energy source. This is particularly important for heart muscle.
But both creatine and carnitine also have a dark side, which I will discuss below.
Why Red Meat Is Bad For Us.
When we think about heart disease:
The traditional view is that saturated fat and cholesterol are the problem, and we can reduce our risk of heart disease simply by choosing leaner cuts of meat.
Other experts feel the link between red meat and heart disease is more complicated. For example, some recent studies have suggested that the carnitine in red meat can be converted by gut bacteria to TMAO, and TMAO increases our risk of heart disease. I have discussed this in a previous issue of “Health Tips From the Professor”.
When we think about cancer:
When fat and juices from the meat drip onto an open flame, carcinogenic polyaromatic hydrocarbons are formed that stick to the surface of the This can be reduced, but not eliminated, by lower fat meat choices.
When red meat is cooked at high temperatures, amino acids in the meat combine with creatine, which is found in all red meats, to form carcinogenic heterocyclic amines. This can be reduced, but not eliminated, by cooking the meat at lower
The nitrates and nitrites used as preservatives in many processed meats react with amino acids from the meat to form carcinogenic N-nitrosamines in our intestines.
Heme iron, which is found in all red meats, also combines with amino acids in the meat to form carcinogenic N-nitroso compounds in our intestines. This mechanism is inherent in all red meats and cannot be eliminated by choosing lower fat cuts or cooking at lower
Finally, diets high in red meat increase several markers of inflammation, and inflammation increases the risk of both heart disease and cancer.
How Can Diet Help Us Minimize The Bad And Maximize The Good?
I’m going to start this section with a provocative statement: “Plant foods are the antidote to all the bad effects of red meat.” Let me explain.
Plant foods are an excellent source of:
Antioxidants
Polyphenols and other phytonutrients
Fiber
Plus, the fiber and phytonutrients found in plant foods support the growth of beneficial gut bacteria.
Here is where it gets very complex:
Beneficial gut bacteria convert some of the foods we eat into compounds that are absorbed into the bloodstream and improve blood sugar control, reduce cholesterol synthesis, and reduce inflammation.
Polyphenols support the growth of certain gut bacteria, and those gut bacteria can convert these polyphenols into compounds that can be absorbed from the intestine. This necessary for many polyphenols to exert their beneficial effects in the body.
And, as you might expect, the gut bacteria of meat eaters and vegetarians is very different.
With this in mind, let’s come back to the concept of plant foods being the antidote for red meat.
In terms of heart health,
You may remember that I said above that the carnitine in red meat can be converted by gut bacteria into TMAO which increases the risk of heart disease. The operative wording here is “can be”. It turns out this only happens with the gut bacteria of habitual meat eaters. Here is the study that showed that:
When habitual meat eaters were fed an 8-ounce sirloin steak, both carnitine and TMAO increased in their blood and urine.
When vegans were fed the same 8-ounce steak, only carnitine increased. No TMAO was detected.
When the meat eaters were treated with an antibiotic that wiped out their gut bacteria prior to eating the steak, no TMAO was detected. This showed it was the gut bacteria in the meat eaters that were responsible for converting carnitine to TMAO.
Fiber from whole grains, fruits, and vegetables binds to cholesterol and flushes it out of the intestine, preventing its absorption into the bloodstream.
Plant-based diets are anti-inflammatory.
In terms of cancer,
The fiber found in fruits, vegetables and whole grains binds to polyaromatic hydrocarbons and heterocyclic amines and flushes them out through the intestines.
Polyaromatic hydrocarbons require activation by the liver before they become carcinogenic. Indoles and isothiocyanates found in broccoli, cabbage, and other cruciferous vegetables inhibit the enzymes that catalyze this activation.
Antioxidants found in fruits, vegetables and whole grains reduce the formation of N-nitroso compounds in the intestines.
A largely plant-based diet appears to favor a population of intestinal bacteria that is less likely to convert compounds in meat into cancer-causing chemicals. [Note: This is a new area of research, so the data supporting this mechanism of cancer prevention are less definitive than for the other three ]
These observations are based studies designed to identify the mechanisms by which plant-based diets negate the bad effects of red meat. For example, let me share a recent study (T Onali et al, Journal of Nutritional Biochemistry, 141, 109906, 2025) asking whether berries could negate the bad effects of adding red meat (pork) to a typical Finnish diet.
How Was This Study Done?
This study was conducted by a group of scientists at the University of Helsinki. They recruited 43 adults aged 20-68 and divided them into two groups. Each group was told to continue with their regular diet, except that consumption of any red meat or berries other than the foods they were provided with was prohibited.
Each group was given an extra 5 ounces of pork (minced pork, pulled pork, pork strips from fillet, cold cuts, sausages, and bacon) to eat each day.
One group was also given 1 cup of berries (bilberries, strawberries, cloudberries, raspberries, lingonberries, and blackcurrant) to eat each day.
Note: These are the foods most familiar to people from Finland in each category.
They were provided with these foods on a weekly basis.
This intervention portion of the study lasted four weeks.
Dietary intake was assessed in each group using 3-day food records (two weekdays and one weekend day) at the beginning and the end of the study.
Participants in the study collected stool samples on two consecutive days at the beginning and end of the study. These stool samples were analyzed in the following ways:
Bacterial DNA was extracted from the stool samples and used to determine which gut bacteria were present in the stools.
The stool samples were homogenized and filtered to:
Determine the polyphenols and polyphenol metabolites present in the stool samples.
Determine whether low molecular weight compounds present in the stool samples were able to inhibit the growth of human colon cancer cells in cell culture.
What Did The Study Show?
The dietary analysis found that total calories, protein, carbohydrate, fat, and saturated fat did not change significantly in either group. This indicates that the study participants likely substituted the pork they were given for other high-fat meats they were eating before the study.
However, in the group that was also given berries fiber, vitamin C, vitamin E, manganese, and several polyphenols increased significantly. This suggests that study participants likely substituted the berries for less healthy foods they were eating before the study.
The study found that:
In the red meat-only group the relative abundance of beneficial Roseburia and Fecalibacterium gut bacteria was decreased. This did not occur in the red meat + berries group.
In the red meat + berries group the concentration of several beneficial polyphenols and polyphenol metabolites was increased.
In the red meat + berries group, the filtrate obtained from stool samples inhibited the growth of several human colon cancer cell lines in cell culture experiments. These experiments did not identify which berry polyphenols were responsible for inhibiting the growth of cancer cells. It also did not determine whether the polyphenols came directly from the berries or were created when gut bacteria modified the polyphenol(s).
But these experiments did show that something from a high berry diet inhibited colon cancer cell growth.
The author’s concluded, “Berry supplementation to a diet high in red and processed meat led to berry-derived polyphenolic metabolites in the feces, beneficially modified gut microbiota, inhibited the viability of colon cancer cells, collectively suggesting potential in cancer prevention.
The difference seen in gut metabolism was probably induced by the higher intakes of dietary fiber, vitamin C and E, manganese, and polyphenols by the berry diet.”
Can Red Meat Be Good For You?
This study is one piece of the puzzle to help us understand the effect of diet on the benefits and risks of red meat consumption. Here is what I mean by that.
We can think of scientific investigations in terms of solving a large puzzle with lots of little pieces. If you are a puzzle enthusiast, you know the best way to solve a complicated puzzle is to put the edge pieces together first and then fill in the rest of the puzzle.
In this context, the studies showing that small amounts of red meat are not harmful in the context of healthy, primarily plant-based diets like the DASH and Mediterranean diets are the edge of the puzzle. Smaller studies that define the mechanisms of this effect and provide proof these mechanisms are accurate are the interior pieces that fill out the puzzle. This study is one of those interior pieces.
So, what does that mean for you? It means that diet context is important.
Most of the studies showing the bad effects of red meat have been done in the context of the typical American diet. That might consist of an 8 or 12-ounce steak with fries and either a soft drink or iced tea. Fruits and vegetables, if present at all, are minimal. Dessert usually consists of some sugary treats.
In this context, red meat is bad for you.
In contrast, consider the place red meat occupies in a primarily plant-based diet. Red meat becomes a condiment rather than the main course. Think of 2-3 ounces of red meat as part of a green salad or stir fry with a variety of greens and other vegetables. You might have beans, whole grains, or another vegetable to round out your plate. Dessert would be whatever fruit is in season. And your beverage might be water, milk, or herbal tea.
In this context, the bad effects of red meat disappear. In short, there are no bad foods, only bad diets.
I started this blog with the question, “Can red meat be good for you?” You may be wondering if I have answered that question.
At the beginning of this article, I listed the good things about red meat, namely that it is a good source of protein, iron, vitamin B12, carnitine, and creatine.
If you remove the bad, only the good remains. So, the answer is, “Yes. In the right diet context red meat can be good for you”.
The Bottom Line
You have heard that red meat is bad for you. It increases your risk of heart disease and cancer. You should avoid it at all costs.
But is that true? In the article above I:
Describe both the benefits and risks of red meat.
Discuss how plant foods negate many of the bad effects of red meat.
Share a study providing proof of that concept.
Share how you can enjoy the benefits of red meat while avoiding the bad effects of red meat consumption.
For more details read the article above.
These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.
My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.
My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.
For more detail about FTC regulations for health claims, see this link.
Dr. Chaney has a BS in Chemistry from Duke University and a PhD in Biochemistry from UCLA. He is Professor Emeritus from the University of North Carolina where he taught biochemistry and nutrition to medical and dental students for 40 years.
Dr. Chaney won numerous teaching awards at UNC, including the Academy of Educators “Excellence in Teaching Lifetime Achievement Award”.
Dr Chaney also ran an active cancer research program at UNC and published over 100 scientific articles and reviews in peer-reviewed scientific journals. In addition, he authored two chapters on nutrition in one of the leading biochemistry text books for medical students.
Since retiring from the University of North Carolina, he has been writing a weekly health blog called “Health Tips From the Professor”. He has also written two best-selling books, “Slaying the Food Myths” and “Slaying the Supplement Myths”. And most recently he has created an online lifestyle change course, “Create Your Personal Health Zone”. For more information visit https://chaneyhealth.com.
For the past 45 years Dr. Chaney and his wife Suzanne have been helping people improve their health holistically through a combination of good diet, exercise, weight control and appropriate supplementation.
It’s so confusing. Everyone claims they have clinical proof that their diet is the best. You will be healthier and live longer.
But the diets are so different. They range from vegan to keto. They can’t all be equally healthy. What is the truth?
To answer that question, we first need to understand how the proponents of each diet can claim theirs is the perfect diet for health and longevity. It’s because they base their claims on:
Short-term studies. Most of their claims are based on studies that range from a few weeks to a few months. You need 20- or 30-year studies to measure the effects of a particular diet on health outcomes.
Biological markers(Things like cholesterol and triglyceride levels, blood sugar control, and/or inflammation). Biological markers can predict possible health outcomes. But without long-term studies on actual health outcomes, you don’t know whether those predictions are accurate.
Comparisons with the typical American diet. Any diet looks good compared with the American diet.
Elimination of highly processed foods. While these diets emphasize different foods, they are all whole food diets. Again, any diet that eliminates processed foods is an improvement.
It doesn’t matter whether you restrict calories, restrict certain foods or food groups, or restrict the time you allow yourself to eat. You unconsciously eat less.
And when you eat less, you lose weight.
And when you lose weight, your cholesterol and triglyceride levels fall, your blood sugar control improves, and inflammation decreases.
That’s why short-term weight loss and improvement in biological markers are virtually identical with vegan and keto diets. Those diets are as different as any two diets could be. But they are both highly restrictive diets.
The take-home lesson is clear. Don’t be confused by claims based on short-term studies. What you should look for is:
Long-term studies (20 years or more)…
that look at the effect of diet on health outcomes, and…
do not compare their diet with the typical American diet.
When I first reviewed this topic 8 years ago, I could only find a few studies that met these criteria:
One study showed that people consuming primarily plant-based diets weighed less than people who consumed primarily meat-based diets for 20 years or more.
Other studies showed that people consuming primarily plant-based diets had a reduced risk of diabetes and heart disease compared to people consuming primarily meat-based diets for 20 years or more.
These are valuable observations, but they are limited. That’s why I was so excited when I came across a recent 30-year study (A-J Tessier et al, Nature Medicine, volume 31, pages 1644-1652, 2025) looking at the effect of 9 different diets on longevity and health outcomes. In short, this study looked at the effect of different diets on healthy aging.
How Was This Study Done?
The authors of this study used data from 105,015 participants in the Nurses’ Health Study (NHS) and Health Professionals Follow Up Study (HPFS). Both studies enrolled participants in 1986 and followed them through 2016. In short, they were both 30-year studies. Participants with preexisting chronic diseases were excluded from the study.
Lifestyle factors and medical histories were assessed every two years.
A detailed dietary assessment was conducted every four years. The assessments measured the intake of 152 foods. Food intakes were averaged over the duration of the study for each participant.
[Note: This study did not measure how the diets of participants changed between 1986 and 2016, although that is an interesting question. Perhaps a future study is planned.]
Based on the foods eaten, the diets of the participants were evaluated for adherence to 9 dietary patterns, which I have described in more detail below.
[Note: To be clear, the participants were not trying to follow these diets. They ate what they ate, and the investigators subsequently compared their dietary pattern with various healthy diets.]
For each of the diets included in this study, participants were divided into quintiles based on how closely their food intake adhered to the recommendations for that diet. Then the highest quintile was compared to the lowest quintile to determine how well that diet predicted “healthy aging” after a 30-year follow-up.
The term “healthy aging” was based on 5 criteria:
Longevity – achieving an age of 70 or more.
Absence of the top 11 major chronic diseases (cancer, diabetes, myocardial infarction (heart attack), coronary artery disease, congestive heart failure, stroke, Parkinson’s disease, multiple sclerosis, and ALS).
No impairment of cognitive function.
No impairment of physical health.
No mental health issues.
In other words, these were not just individuals who survived 70 years or more. They survived and thrived. They were enjoying their golden years because they still had good health and excellent quality of life.
Diets Included In This Study
The diets included in this study were:
AHEI – Alternative Healthy Eating Index (A scoring system developed by Harvard researchers to measure overall diet quality based on its ability to predict lower risks of heart attacks, strokes, and diabetes).
aMed– Alternative Mediterranean Diet Index (The aMed diet index differs from the original Med index by separating fruits and nuts into different groups, eliminating dairy, emphasizing whole grains, and excluding red and processed meats in favor of chicken and fish).
DASH – Dietary Approaches to Stop Hypertension (The name speaks for itself. But I also sometimes refer to this diet as “the Americanized version of the Mediterranean diet’ because it features foods more familiar to Americans. For example, it allows more red meat options than most of the other diets in this list.
MIND – Mediterranean-Dash intervention for Neurogenerative Delay (It is a dietary pattern designed to reduce the risk of Alzheimer’s disease and other forms of dementia. It combines elements of the Mediterranean and DASH diets but differs from both by emphasizing berries as a major fruit source, among other things.)
hPDI – Healthy Plant-Based Diet Index (It is a scoring system that measures adherence to a diet rich in healthy plant-based foods and lower consumption of less-healthy plant foods and animal foods.)
PHDI – Planetary Health Diet Index (It emphasizes foods (primarily plant foods) that are healthy and are good for the environment. Of the diets on this list, it is the most restrictive and closest to a vegan diet)
EDIH – Empirical Dietary Index For Hyperinsulinemia (It is a scoring system that measures the potential of a diet to cause chronically high insulin levels, which is associated with type 2 diabetes and certain cancers.)
EDIP – Empirical Dietary Inflammation Pattern (It is a scoring system that measures the inflammatory potential of a diet.)
UPF – Consumption of Ultraprocessed Foods (Since recent studies have shown that most Americans get between 55 and 70% of their calories from ultraprocessed foods, this is fast becoming a measure of the typical American diet.)
Note: Except for the UPF diet, these are all whole food, primarily plant-based diets.
What Diet Is Best For Healthy Aging?
Here are the results of the study (drum roll, please):
Of the 105,015 participants in this study, only 9.3% achieved healthy aging.
Adherence to any of the 8 healthy diets improved the probability of achieving healthy aging.
The odds of achieving healthy aging ranged from 1.45 for the Healthy Plant-Based Diet to 1.86 for the Alternative Healthy Eating Index.
If you were to pick one winner, it would be the Alternative Healthy Eating Index. And if you were to define healthy aging as achieving an age of 75 or more with the other 4 criteria, the odds increase to 2.24 (more than double) for the Alternative Healthy Eating Index.
As you might expect, adherence to a diet high in ultraprocessed foods had the opposite effect. It decreased the odds of achieving healthy aging by 32%.
When you look at each of the criteria for healthy aging individually, the results were a bit more nuanced:
For survival to 70+ years, the Alternative Healthy Eating Index and the Planetary Health Diet Index were tied. Both increased the odds of survival by more than 2-fold.
The Alternative Healthy Eating Index and the Planetary Health Diet Index were also tied for surviving to 70 with intake cognitive health and intact physical function.
The Empirical Dietary Index For Hyperinsulinemia edged out the Alternative Healthy Eating Index for freedom from 11 chronic diseases.
The effect of healthy diets on the odds of achieving healthy aging is independent from BMI, smoking, and physical activity. This means that:
The effects of healthy diets on healthy aging were not because people consuming healthy diets weighed less, smoked less, or exercised more.
Even if some of your lifestyle choices are suboptimal, choosing a healthy diet will increase your odds of surviving and thriving.
Finally, the study looked at the effects of individual foods on healthy aging. The results were:
Higher intakes of fruits, vegetables, whole grains, unsaturated fats, nuts, legumes, and low-fat dairy products increase your odds of healthy aging.
Higher intakes of trans fats, sodium, sugary beverages, and red or processed meats decrease your odds of achieving healthy aging.
The effects of these foods on healthy aging aren’t novel. They are consistent with dozens of other studies that have looked at the effect of individual foods on long-term health outcomes. In fact, the diets included in this study were chosen because they included foods that positively affect health outcomes and minimize foods that negatively affect health outcomes.
What About Primarily Meat-Based Diets?
I have good friends who advocate for primarily meat-based diets such as keto, paleo, and carnivore. I’m sure they are going to say, “This study is a sham. It only included primarily plant-based diets, so, of course, it is only going to show benefits for primarily plant-based diets.” I can hear their their questions now:
Why didn’t this study include any of the primarily meat-based diets? My answer is: “All the popular meat-based diets exclude one or more of the food groups associated with health and longevity and emphasize one or more of the food groups associated with a shorter, less healthy life. And these food associations are consistent among multiple long-term studies looking at the effect of various foods on health outcomes.
The authors could have constructed a similar index for each of the popular meat-based diets. But they would have been the inverse of the plant-based diet indices because the foods included and excluded from plant-based and meat-based diets are opposite. Therefore, just like the UPF index, they would have been associated with a decreased probability of achieving healthy aging.”
Why did the scientists designing this study ignore the proven health benefits of primarily meat-based diets? My answer is: “The “proven benefits” of primarily meat-based diets are based on short-term studies showing the effects of those diets on biological markers. Long-term studies looking at health outcomes are lacking.”
But modern primarily meat-based diets are a special case because they limit carbohydrates and cause ketosis. Why weren’t they included in the study? My answer is: “The Atkins diet limits carbohydrates and causes ketosis. It has been around for more than 50 years. And, to my knowledge, there are no studies showing it is beneficial long term. If the Atkins diet cannot be shown to have long-term health benefits, it is unlikely that modern diets that mimic it are healthy long term.
What Does This Study Mean For You?
The answer is clear. If you want to survive and thrive in your 70s and beyond, choose a whole food, primarily plant-based diet.
If you want the absolute best diet, follow the Alternative Healthy Eating Index recommendations. There are many online resources to guide you.
However, any whole food, primarily plant-based diet will do. The ones with the most online resources are the Mediterranean, DASH, and MIND diets. Choose the one that best fits your food preferences and lifestyle.
If you want to go more vegetarian, the Healthy Plant-Based Diet is a bit easier than a strict vegan diet.
If you are concerned about the environment, the Planetary Diet is best for you.
If you have specific health issues like hypertension, diabetes, or inflammation, there are diets designed just for you.
And if following structured diets is not your style, just:
Eat more fruits, vegetables, whole grains, unsaturated fats, nuts, legumes, and low-fat dairy products.
Eat less trans fats, sodium, sugary beverages, and red or processed meats, and ultraprocessed foods.
Finally, even if some of your lifestyle choices are suboptimal, this study shows choosing a healthy diet will increase your odds of surviving to your 70s and thriving.
The Bottom Line
A recent 30-year study looked at the effect of 8 whole food, primarily plant-based diets on healthy aging defined as:
Achieving an age of 70 or more.
The absence of the top 11 major chronic diseases.
No impairment of cognitive function.
No impairment of physical health.
No mental health issues.
The key findings were:
Adherence to any of 8 whole food, primarily plant-based diets improved the probability of achieving healthy aging.
The odds of achieving healthy aging ranged from 1.45 for the Healthy Plant-Based Diet to 1.86 for the Alternative Healthy Eating Index.
For more information on this study, why primarily meat-based diets were not considered healthy enough to be included in this study, and what this study means for you, read the article above.
These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.
My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.
My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.
For more detail about FTC regulations for health claims, see this link.
Dr. Chaney has a BS in Chemistry from Duke University and a PhD in Biochemistry from UCLA. He is Professor Emeritus from the University of North Carolina where he taught biochemistry and nutrition to medical and dental students for 40 years. Dr. Chaney won numerous teaching awards at UNC, including the Academy of Educators “Excellence in Teaching Lifetime Achievement Award”. Dr Chaney also ran an active cancer research program at UNC and published over 100 scientific articles and reviews in peer-reviewed scientific journals. In addition, he authored two chapters on nutrition in one of the leading Biochemistry textbooks for medical students.
Since retiring from the University of North Carolina, he has been writing a weekly health blog called “Health Tips From the Professor”. He has also written two best-selling books, “Slaying the Food Myths” and “Slaying the Supplement Myths”. And most recently he has created an online lifestyle change course, “Create Your Personal Health Zone”. For more information visit https://chaneyhealth.com.
For the past 53 years Dr. Chaney and his wife Suzanne have been helping people improve their health holistically through a combination of good diet, exercise, weight control and appropriate supplementation.
Over the past couple of weeks” I have talked about one of the greatest strengths of the scientific method – namely that investigators constantly challenge, and occasionally disprove, existing paradigms. That allows us to discard old models of how things work and replace them with better ones.
Two weeks ago, I shared a study that disproved the myth that low to moderate alcohol consumption is healthier than total abstinence.
Last week I shared a study that disproved the myth about chocolate helping you lose weight weight.
This week I tackle the “good” cholesterol myth. I will share several studies that challenge the belief that HDL cholesterol is good for your heart.
The belief that HDL is good for your heart has all the hallmarks of a classic paradigm.
It is supported by multiple clinical studies.
Elaborate metabolic explanations have been proposed to support the paradigm.
It is the official position of most medical societies, scientific organizations, and health information sites on the web.
It is the recommendation of most health professionals.
It has been repeated so often by so many trusted sources that everyone assumes it must be true.
Once we accept the HDL/heart health paradigm as true, we can construct other hypotheses on that foundation. For example:
Raising your HDL levels naturally takes effort. Pharmaceutical companies have been pursuing the “magic pill” that raises HDL levels without any effort on your part.
Low carb diets like the Keto and Paleo diets are high in saturated fat. The low carb enthusiasts claim this is a good thing because saturated fat raises HDL levels, and HDL is good for your heart.
But what if the paradigm that HDL is good for your heart isn’t true? What if it is a myth? These hypotheses would be like the parable of a house built on a foundation of sand. They will be washed away as soon as the paradigm is critically tested.
So, let’s look at experiments that have challenged the HDL/heart health paradigm.
Do Drugs That Increase HDL Levels Work?
The first hint that the HDL/heart health paradigm might be faulty happened when a pharmaceutical company developed a drug that selectively increased HDL levels.
The drug company thought they had found the goose that laid golden eggs. Just imagine. People wouldn’t have to lose weight, exercise, or change their diet. They could simply take a pill and dramatically decrease their heart disease risk. A drug like that would be worth billions of dollars.
The pharmaceutical company couldn’t believe it. Raising HDL levels just had to reduce heart disease risk. They concluded they didn’t have the right drug, and they continued to work on developing new drugs.
That was 18 years ago, and no HDL-increasing drug has made it to market. Have they just not found the right drug, or does this mean the HDL/heart health paradigm is incorrect?
Does Saturated Fat Decrease Heart Disease Risk?
Now let’s turn to two claims of low carb enthusiasts.
#1: Saturated fats decrease your risk of heart disease in the context of a low carb diet. I have debunked that claim in several previous issues of “Health Tips From The Professor”. But let me refer you to two articles here – one on saturated fat and heart disease risk and one on low-carb diets.
#2: Saturated fats decrease heart disease risk because they raise HDL levels. This is the one I will address today.
The idea that saturated fats decrease heart disease risk because they raise HDL levels is based on a simplistic concept of HDL particles. The reality is more complex. Several clinical studies have shown:
The type of fat determines the property of the HDL particles.
When polyunsaturated fats predominate, the HDL particles have an anti-inflammatory effect. When saturated fats predominate, the HDL particles have a pro-inflammatory effect.
Anti-inflammatory HDL particles relax the endothelial cells lining our blood vessels. That makes the lining of our blood vessels more pliable, which improves blood flow and reduces blood pressure.
Anti-inflammatory HDL particles also help reduce inflammation of the endothelial lining. This is important because an inflamed endothelial lining is more likely to accumulate fatty plaques and to trigger blood clot formation that can lead to heart attacks and strokes.
So, the question becomes, “What good is it to raise HDL levels if you are producing an unhealthy, pro-inflammatory HDL particle that may increase the risk of high blood pressure, heart attacks, and strokes?”
In short, these studies suggest it isn’t enough to just focus on HDL levels. You need to ask what kind of HDL particles you are creating.
Is HDL Good For Your Heart?
Once the studies were published showing that…
Drug-induced increase of HDL levels without any change in health habits is not sufficient to decrease heart attack risk, and…
Not all HDL particles are healthy. There are anti-inflammatory and pro-inflammatory HDL particles, which are likely to have opposite effects on heart attack risk…
…some people started to question the HDL/heart health paradigm. And one group came up with the perfect study to test the paradigm.
But before I describe the study, I need to review the term “confounding variables”. Here is a brief synopsis:
The studies supporting the HDL/heart health paradigm are association studies. Association studies measure the association between a single variable (in this case, increase in HDL levels) and an outcome (in this case, heart disease events, heart disease deaths, and total deaths).
Associations need to be corrected for other variables known to affect the same outcome (things like age, gender, smoking, and diabetes would be examples in this case).
Confounding variables are variables that also affect the outcome but are unknown or ignored. Thus, they are not used to correct the associations, which can bias the results.
The Good Cholesterol Myth
The authors of this study (M Briel et al, BMJ 2009:338.b92) observed that most interventions that increase HDL levels also lower LDL levels. Lowering LDL is known to decrease the risk of heart disease deaths. But this effect had been ignored in most studies looking at the association between HDL and heart disease deaths.
They hypothesized that the change in LDL levels was a confounding variable that had been ignored in previous studies and may have biased the results.
To test this hypothesis the authors searched the literature and identified 108 studies with 299,310 participants that:
Compared the effect of drugs, omega-3 fatty acids, or diet with either a placebo or usual care.
Measured both HDL and LDL levels.
Measured reduction in cardiovascular risk.
Had a randomized control design.
Lasted at least 6 months.
They found that every 10 mg/dl decrease in LDL levels in these studies was responsible for a:
1% reduction in heart disease events (both heart disease deaths and non-fatal heart attacks).
2% reduction in heart disease deaths.
4% reduction in total deaths.
After correcting for the effect of decreased LDL levels on these heart disease outcomes, the increase in HDL levels had no statistically significant effect on any of the outcomes.
The authors concluded, “Available data suggest that simply increasing the amount of circulating HDL cholesterol does not reduce the risk of coronary heart disease events, coronary heart disease deaths, or total deaths. The results support reduction in LDL cholesterol as the primary goal for lipid modifying interventions.”
In other words, this study:
Supports the author’s hypothesis that LDL levels were a confounding variable that biased the studies supporting the HDL/heart health paradigm.
Concludes that increasing HDL levels has no effect on heart disease outcomes, thus invalidating the HDL/heart health paradigm.
In short, this study destroyed the “good” cholesterol myth.
Is Everything You Knew About HDL Wrong?
Does that mean that everything you knew about HDL is wrong? Not exactly. It just means that you may need to change your perspective.
Don’t focus on HDL levels. Peek behind the curtain and focus on what’s behind the HDL levels. For example:
Losing weight when overweight increases HDL levels. But the decrease in heart disease outcomes is more likely due to weight loss than to the increase in HDL levels.
Exercise increases HDL levels. But the decrease in heart disease outcomes is more likely due to exercise than to the increase in HDL levels.
Reversing pre-diabetes or type 2 diabetes increases HDL levels. But the decrease in heart disease outcomes is more likely due to the reversal of diabetes than to the increase in HDL levels.
High-dose omega-3 fatty acids increase HDL levels. But the decrease in heart disease outcomes is more likely due to the omega-3 fatty acids than to the increase in HDL levels.
The Mediterranean diet increases HDL levels. But the decrease in heart disease outcomes is more likely due to the diet than to the increase in HDL levels.
And if you want to go the drug route:
Statins and some other heart drugs increase HDL levels, but the reduction in heart disease outcomes is probably due to their effect on LDL levels rather than their effect on HDL levels.
On the other hand:
Saturated fats increase HDL levels. But saturated fats increase heart disease risk and create pro-inflammatory HDL particles. So, in this case the increase in HDL levels is not a good omen for your heart.
Drugs have been discovered that selectively increase HDL levels. However, there is nothing of value behind this increase in HDL levels, so the drugs have no effect on heart disease outcomes.
The Bottom Line
In this article I discuss several studies that have challenged the good cholesterol myth – the belief that HDL is good for your heart.
For example, one group of investigators analyzed the studies underlying the HDL/heart health paradigm. They hypothesized that these studies were inaccurate because they failed to account for the effects of LDL levels on heart disease outcomes.
After correcting for the effect of decreased LDL levels on heart disease outcomes in the previous studies, the authors showed that increases in HDL levels had no significant effect on any heart disease outcome.
The authors concluded, “Available data suggest that simply increasing the amount of circulating HDL cholesterol does not reduce the risk of coronary heart disease events, coronary heart disease deaths, or total deaths. The results support reduction in LDL cholesterol as the primary goal for lipid modifying interventions.”
In other words, this study:
Supports the author’s hypothesis that LDL levels were a confounding variable that biased the studies supporting the HDL/heart health paradigm.
Concludes that increasing HDL levels has no effect on heart disease outcomes, thus invalidating the HDL/heart health paradigm.
Does that mean that everything you knew about HDL is wrong? Not exactly. It just means that you need to change your perspective. Don’t focus on HDL levels. Focus on what’s behind the HDL levels. For more information on that, read the article above.
For more information on this study, and what it means for you, read the article above.
These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.
My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.
My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.
For more detail about FTC regulations for health claims, see this link.
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 53 years Dr. Chaney and his wife Suzanne have been helping people improve their health holistically through a combination of good diet, exercise, weight control and appropriate supplementation.
You’ve seen the claims. “You should avoid all seed oils. They are toxic.”
Any time you see claims like, “Avoid all…[add the food villain of the day]” or “[a certain food] is toxic” your “truth-meter” should go on high alert. Claims like that are more likely to be hype than truth.
More specifically, the claims about seed oils are:
They are heavily processed.
They contain toxic ingredients.
They are genetically modified.
They cause inflammation and oxidative damage.
They increase your risk of inflammatory diseases, heart disease, and cancer.
A healthier option is to replace seeds oils with animal foods high in saturated fats.
Like any good food myth, there is a kernel of truth to each of these claims. In this article I will describe the kernel of truth associated with each of these claims, put them into perspective, and give practical guidelines for incorporating seed oils into your diet.
The topics I will cover are:
The truth about fats.
The truth about omega-6 fats.
The truth about saturated fats.
The truth about canola oil.
The truth about seed oils.
The Truth About Fats
The health authorities and media must think the American public is stupid. They oversimplify everything. They tell us:
Animal fats are saturated fat.
Olive oil is monounsaturated fat.
Vegetable oils are omega-6 polyunsaturated fat.
Fish oil is omega-3 polyunsaturated fat.
The truth is that every naturally occurring fat and oil is a mixture of all four kinds of fat. And each food contains a unique mixture of fats. The kernel of truth is:
Animal fats have a higher percentage of saturated fat than other fats and oils.
Olive oil has a higher percentage of monounsaturated fat than other oils.
Vegetable oils have a higher percentage of omega-6 polyunsaturated fat than other oils.
Fish oil has a higher percentage of omega-3 polyunsaturated fat than other oils.
But the full truth is that each food contains a unique mixture of fats. For example,
Meat and butter from grass-fed animals contain a greater percentage of omega-3 fats than meat and butter from animals which were fattened on corn.
Flaxseed oil has a higher percentage of omega-3 fats than other seed oils.
High-oleic sunflower oil has the highest percentage of monounsaturated fat than other seed oils.
Other vegetable oils with high monounsaturated fat content include olive oil, avocado oil, and canola oil. [Note: Although olive oil is the source of monounsaturated fat that we hear about most, avocado oil is equally high in monounsaturated fat and has a higher smoke point, which makes it a better choice for high-heat cooking.]
Walnuts have a higher percentage of omega-3 fats than other nuts.
Macadamia nuts and almonds have the highest percentage of monounsaturated fats than other nuts, with cashews and peanuts not far behind. Nut butters, of course, reflect the fat composition of the nuts.
The point I am making is that while myths are simple, the truth is much more complex.
Take Home Lesson:Every vegetable oil and every seed oil has a unique composition of fats. Each has its unique benefits and unique drawbacks.
That is something you will want to think about the next time you read an article about the dangers or the benefits of all seed oils. Every seed oil is unique. No generalization applies to all of them.
Biochemistry 101 – Essential Fats
Let’s start with the most important point.
Omega-6 fats and omega-3 fats are essential. Simply put, that means:
We can’t make them.
They are essential for life.
We must get them from our diet.
If they are essential, the next question is, “Why do we need them?” Let me start with a little “Biochemistry 101” and talk about their role in cell membranes and cellular regulation.
Cell Membranes:
You might think of cell membranes as a solid protective armor around the cells, but nothing could be farther from the truth. A better analogy would be the ocean that covers vast areas of our planet. Our membranes are quite fluid.
And that membrane fluidity is important. Our cell membranes contain receptors like the cholesterol receptor and insulin receptor that must cluster together for cholesterol and insulin to be transported into the cell. Those receptors cluster best when cell membranes are very fluid.
Our membranes are most fluid when they contain high levels of polyunsaturated fats (For membrane fluidity it doesn’t matter if they are omega-6 or omega-3). Conversely, our membranes are less fluid when they contain high levels of saturated fats.
And here is the most important point. Because our bodies cannot make omega-6 and omega-3 polyunsaturated fats, this is the one time it is literally true that, “We are what we eat”. If our diets are high in saturated fats, our membranes are high in saturated fats. If our diets are high in polyunsaturated fats, our membranes are high in polyunsaturated fats.
And the ratio of omega-6 and omega-3 polyunsaturated fats in our membranes reflects the ratio of omega-6 and omega-3 polyunsaturated fats in our diet.
Take Home Lesson: Diets high in omega-6 and/or omega-3 fats help lower cholesterol levels and improve blood sugar regulation.
Cellular Regulation:
Our cells also use the polyunsaturated fats in our cell membrane to make hormone-like substances called prostaglandins and leukotrienes that exert profound effects on nearby tissues. [Note: For the sake of simplicity, I will just talk about prostaglandins for the rest of this article, but what I say applies equally to leukotrienes.]
The enzymes that make prostaglandins do not distinguish between omega-6 and omega-3 polyunsaturated fats. They just use whatever polyunsaturated fat they come across.
That’s important because the effects of omega-6 and omega-3 prostaglandins are often different and are sometimes opposite.
Here’s where the “We are what we eat” principle comes into play. The ratio of omega-6 and omega-3s in our diet determines the omega-6 and omega-3 content of our membranes. And that determines the type of prostaglandins our cells produce.
Take Home Lessons:
Some of the benefits of omega-6s are unique because they are dependent on omega-6 prostaglandins. These benefits cannot be duplicated by diets high in omega-3s.
Because some effects of omega-6 and omega-3 prostaglandins are opposite, we need to look closely at the omega-6 to omega-3 ratio in the diet to optimize the health benefits of these two essential polyunsaturated fats.
Now, with Biochemistry 101 behind us, we are ready to look at the truth about omega-6 fats.
The Truth About Omega-6 Fats
Assortment Of Salad Dressing Bottles
Let’s start by looking at the pros and cons of omega-6 fats.
Pros Of Omega-6 Fats:
Cellular Health: Omega-6 and fats are important for maintaining proper membrane fluidity. And omega-6 prostaglandins also regulate cell metabolism and cellular repair mechanisms.
Heart Health: Omega-6s are associated with lower risk of heart disease. This is caused by:
Lower cholesterol levels due to proper membrane fluidity which allows clustering of cholesterol receptors.
More flexible endothelial cells lining our arteries, which helps lower blood pressure and prevent blockage of the arteries by blood clots. This is most likely due to more fluid cell membranes and the production of beneficial prostaglandins.
Some of these benefits are duplicated by omega-3 fats, but the American Heart Association stated in a recent Health Advisory (WS Harris et al, Circulation, 119, 902-907, 2009) that omega-6 fats are essential for some heart health benefits. They cannot be replaced by omega-3s.
Brain Health: Omega-3s get most of the press here, but experts feel that omega-6s play an important and independent role as well.
Fetal Growth and Development: Omega-6 fats are essential for normal neural development and growth. The mechanism(s) for this benefit are ill-defined.
Other Benefits:
Omega-6 fats support healthy skin, hair, and bones. The mechanisms for these effects are unknown, but most experts feel they are independent of omega-3 fats.
Omega-6 fats are also important for reproductive health. Most experts think this is due to the production of omega-6 prostaglandins.
Take Home Lesson: Omega-6 fats are essential for a healthy heart, a healthy brain, and normal fetal growth and development.
Cons Of Omega-6 Fats:
Oxidation: Omega-6 (and omega-3) fats are very susceptible to oxidation, especially at high temperatures. This can lead to free radical formation, which can promote the formation of cancer cells.
You may have seen the statement that omega-6 fats cause cancer. This is an oversimplification. A more accurate statement would be, “Improperly used, any polyunsaturated fat may increase cancer risk. But this is largely avoidable. Here are the precautions I recommend:
Choose your source carefully.
For seeds and nuts look for freshness. If they look or taste funny, throw them out.
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.
Don’t overheat them.
Most vegetable oils are only suitable for use as salad dressings and other room temperature cooking.
The exceptions are vegetable oils with high smoke points – for example, olive oil for stir fries and avocado oil for higher temperature cooking.
Store them safely. Don’t give them a chance to become oxidized.
We store sunflower seeds and almonds in our refrigerator and walnuts in our freezer.
We buy unsaturated vegetable oils in small quantities (so they are used up quickly) and store them in the refrigerator.
Take Home Lesson: Improperly used, omega-6 fats, like any unsaturated fat, can become oxidized and form free radicals (the kernel of truth). Choose your source carefully. Don’t overheat them. Store them safely.
Inflammation: This is the one you hear the most about. You have been told that omega-6 vegetable oils (seed oils) cause inflammation. As a blanket statement, it is mostly untrue. But it does have a kernel of truth.
Let’s start with the kernel of truth:
Omega-6 fats are inflammatory only when compared to omega-3 fats. You have also been told that omega-6 fats are inflammatory when compared to saturated fats. This is false, as I will discuss below.
Let me elaborate on the first statement with a little more Biochemistry 101 (If you haven’t guessed, that’s my favorite topic. Once a professor, always a professor).
Omega-6 fats are converted into one inflammatory prostaglandin. Omega-3 fats are converted into several anti-inflammatory prostaglandins (This is an example of some omega-6 and omega-3 prostaglandins having opposite effects).
Because of their opposite effects on inflammation, some experts say that the optimal ratio of omega-6 to omega-3 fats is in the range of 1:1 to 4:1. But the typical American diet is around 15:1.
If the omega-6 to omega-3 ratio is important (and not every expert agrees that it is), the statement that we should avoid omega-6-containing vegetable oils (seed oils) because they are inflammatory is mostly untrue.
Every omega-6 oil has a different omega-6 to omega-3 ratio. For example,
Corn oil has a 50:1 ratio and sesame oil has a 42:1 ratio. If you are just going by omega-6 to omega-3 ratios, you might want to avoid these.
Soybean oil has a 7:1 ratio and extra virgin olive oil has a 5:1 ratio. They are almost in the optimal range.
Canola oil has a 2:1 ratio. It’s in the optimal range.
And flaxseed oil is the clear winner with a 1:4 ratio.
But the truth is also much more complex than you have been led to believe.
The kernel of truth is that omega-6 fats can be converted to an inflammatory prostaglandin.
But omega-6 fats can also be converted to anti-inflammatory prostaglandins. And some omega-6 fats such as GLA are anti-inflammatory.
Human clinical studies find that omega-6 fats either have no effect on inflammation or decrease it slightly (A Poli et al, International Journal of Molecular Sciences, 24, 4567, 2023).
Take Home Lesson: Omega-6 fats are converted into one inflammatory prostaglandin (the kernel of truth). But they are also converted to anti-inflammatory prostaglandins. The net effect in the human body is a slight anti-inflammatory effect.
The Truth About Saturated Fats
You have been told that saturated fats are anti-inflammatory and decrease the risk of heart disease. For many Americans those claims are enticing because it means they don’t have to change their diet. But are the claims true?
You have been told that these claims are based on science. There are clinical studies behind them. Is that true?
The problem is that there are a lot of bad studies on saturated fats in the literature, and the Dr. Strangeloves of the world cherry pick the ones that support their beliefs.
If you want to compare the effect of different kinds of fat on either inflammation or heart health, you must make sure that all other components of the diet are the same. Too many of these studies have compared a whole food diet high in saturated fat with the typical American diet high in omega-6 fats. The results are predictable. Anything is better than the typical American diet.
In a previous issue of “Health Tips From The Professor” I discussed the criteria for a good study of fats. High quality studies must:
Show the subjects stick with the new diet for the duration of the study. Subjects find it difficult to adhere to a diet to which they are not accustomed long term and often revert to their more familiar diet. This requires either very close monitoring of what the subjects are eating or measurement of fat membrane composition to verify diet adherence, or both.
Carefully control or measure what the saturated fats are replaced with. In good studies only the fat composition of the diet changes. All other components of the diet remain the same.
Last two years or more. The fats we eat determine the fat composition of our cell membranes, and that is what ultimately determines both inflammation in our bodies and our risk of dying from heart disease. While it is true to say, “We are what we eat”, changing the fat composition of our cell membranes does not occur overnight. It takes 2 years or more to achieve a 60-70% change in the fat composition of cell membranes.
Measures multiple markers of inflammation or actual cardiovascular end points such as heart attack, stroke, and deaths due to heart disease.
When studies are done that meet these criteria the results are as follows:
Inflammation (A Poli et al, International Journal of Molecular Sciences, 24: 4567, 2023):
Replacing saturated fats with omega-6 fats reduces inflammation by 8%.
Replacing saturated fats with omega-3 fats reduces inflammation by 48%
Heart Disease(FM Sacks et al, Circulation, 136, Number 3, 2017):
Replacing saturated fats with omega-6 from decreased the risk of heart disease by 24%.
Replacing saturated fats with a mixture of both omega-6 and omega-3 fats decreased the risk of heart disease by 29%. This is equivalent to statin therapy, without the side effects.
When the replacement of saturated fats with omega-6 and omega-3 fats occurred in the context of a heart healthy diet such as the Mediterranean diet, heart disease risk was reduced by 47%.
The Food and Nutrition Board of the Institute of Medicine recommends that Americans not exceed 10% of calories from saturated fat.
Two thirds of Americans exceed this limit.
The Food and Nutrition Board recommends that omega-6 fats be around 5-6% of calories. Because omega-6 fats play an important role in heart health, the American Heart Association recommends they be at 5-10% of calories.
Americans get around 6.5% of their calories from omega-6 fats.
Take Home Lesson: Replacing saturated fat with omega-6 fats reduces both inflammation and heart disease risk. Adding omega-3 fats reduces both even more. So, bringing omega-6 and omega-3 into a better balance is a good idea. But omega-6 fats are essential and are at the recommended intake for most Americans, so don’t do this by cutting back on healthy omega-6 fats. Instead, add some more omega-3s.
The Truth About Canola Oil
There are a lot of things to like about canola oil:
It is an excellent source of healthy omega-6 fats.
It has a good omega-6 to omega-3 ratio (2:1), which makes it anti-inflammatory.
It is also a good source of monounsaturated fats and has a moderate smoke point, which makes it suitable for low heat cooking.
So, why is it so unpopular? Unfortunately, it suffers from a lot of undeserved myths. Each has a kernel of truth. But like a secret passed around the room, the myths have grown with each repetition, and the truth has become unrecognizable.
So, let’s try to separate the myths from the truth.
Myth: It is genetically engineered.
Truth: It was created by old-fashioned plant breeding.
Myth: Canola oil contains toxic ingredients.
Truth:
Rapeseed oil comes from the oilseed rape plant (a relative of mustard).
Rapeseed oil contains erucic acid and glucosinolates, both of which can be toxic in large amounts (the kernel of truth).
Baldur Stefansson from the University of Manitoba bred a “double low” variety the oilseed rape plant which produces an oil that contains <2% of both erucic acid and glucosinolates and is safe for human consumption. This new oil was named canola oil (from Canada and ola for oil). This was achieved by conventional plant breeding. Not genetic engineering.
Both cultivars of the oilseed rape plant are still grown. Rapeseed oil is used for industrial purposes, and canola oil is used for human consumption.
Canola oil is tightly regulated in Canada, the US, and the EU to <2% erucic acid.
98% of the canola oil sold in the US is grown in Canada and the northern US.
Myth: Canola oil is unhealthy.
Truth: Because it is one of the least expensive omega-6 oils, canola oil is often found as an ingredient in unhealthy, highly processed, food (the kernel of truth). The solution is simple. Avoid unhealthy foods. Adding a different kind of fat to unhealthy foods is not going to make them healthier.
The Truth About Seed Oils
By now I have covered most of the myths about seed oils in my sections on omega-6 fats, saturated fats, and canola oil, but here is a quick review.
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 chose your source wisely, 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.
It’s not easy to choose your source carefully. But this difficulty is not unique to seed oils. For example:
The term EVO is supposed to mean extra virgin olive oil was used, but cheaper oils are sometimes blended into the olive oil to save money.
If a company wishes to use the term “grass fed” on their product, they must file a certification with the USDA, but the USDA does not inspect to determine whether the certification is accurate.
Seed oils are also found as an ingredient in unhealthy, highly processed foods. The solution here is simple. Avoid unhealthy foods. Adding a different kind of fat to unhealthy foods is not going to make them healthier.
For more details about each of these Truth statements, read the article above.
The Bottom Line
There are many myths about seed oils. Each myth has a kernel of truth but is mostly false. In this week’s “Health Tips From the Professor” I discuss the myths and truths about seed oils. Because this is a complex subject, I have broken it down into individual topics that address one or more seed oil myths before talking about seed oil myths directly.
The topics I covered are:
The truth about fats.
The truth about omega-6 fats.
The truth about saturated fats.
The truth about canola oil.
The truth about seed oils.
For more details read the article above.
These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.
My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.
My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.
For more detail about FTC regulations for health claims, see this link.
Dr. Chaney has a BS in Chemistry from Duke University and a PhD in Biochemistry from UCLA. He is Professor Emeritus from the University of North Carolina where he taught biochemistry and nutrition to medical and dental students for 40 years.
Dr. Chaney won numerous teaching awards at UNC, including the Academy of Educators “Excellence in Teaching Lifetime Achievement Award”.
Dr Chaney also ran an active cancer research program at UNC and published over 100 scientific articles and reviews in peer-reviewed scientific journals. In addition, he authored two chapters on nutrition in one of the leading biochemistry text books for medical students.
Since retiring from the University of North Carolina, he has been writing a weekly health blog called “Health Tips From the Professor”. He has also written two best-selling books, “Slaying the Food Myths” and “Slaying the Supplement Myths”. And most recently he has created an online lifestyle change course, “Create Your Personal Health Zone”. For more information visit https://chaneyhealth.com.
For the past 45 years Dr. Chaney and his wife Suzanne have been helping people improve their health holistically through a combination of good diet, exercise, weight control and appropriate supplementation.
In short, the evidence that omega-3s reduce the risk of heart attacks and other forms of cardiovascular disease keeps getting stronger. However, the effect of omega-3s on heart failure is not as clear. Some studies suggest that omega-3s reduce the risk of heart failure and heart failure deaths. But other studies find little or no effect.
That’s unfortunate because heart failure is responsible for 45% of cardiovascular deaths and 14% of all deaths in the United States. In 2023 6.7 million Americans had heart failure, and that number is expected to increase to 8.5 million in 2030.
But numbers don’t tell the whole story. It is the trend in heart failure deaths that is truly concerning. Heart failure deaths per 100,000 Americans decreased by 20% between 1999 and 2012. Then the trend abruptly reversed. By 2021 heart failure deaths per 100,000 people was greater than in 1999. And the increase in heart failure deaths shows no signs of slowing down.
Nobody knows what is causing this rapid increase in heart failure deaths. But clearly the miracles of modern medicine are not working. And because the clinical studies on omega-3s and heart failure risk have been confusing, omega-3s are not currently recommended for heart failure patients.
This utilized data from the UK Biobank study. The UK Biobank study is an ongoing study that enrolled 502,366 subjects, aged 40-69, from the United Kingdom between April 1, 2007, and December 31, 2010. It regularly collects environmental, lifestyle, and genetic data on these individuals and tracks their health outcomes.
Within the study 273,033 participants had their blood levels of omega-3s determined by mass spectrometry. These measurements were used to calculate the Omega-3 Index (% of membrane fatty acids that are omega-3s) of these participants.
Of these participants:
271,794 did not have a heart failure diagnosis at the time the omega-3 levels were determined. This group was used to evaluate the effect of omega-3s on the risk of developing heart failure.
1,239 had a heart failure diagnosis at the time the omega-3 levels were determined. This group was used to determine whether omega-3s reduced the risk of death in heart failure patients.
20,000 from this group had a repeat measurement of omega-3 levels around 4 years after the first measurement to determine the consistency of omega-3 levels. On average the repeat measurements were slightly lower, but the differences were small.
These participants were followed for an average of 13.7 years.
A diagnosis of heart failure was based on international diagnosis standards.
Deaths were identified by using the central death registry in the United Kingdom.
The News About Omega-3s Just Got Better
The data were clear. When participants with an Omega-3 Index in the top 20% were compared to those with an Omega-3 Index in the bottom 20%:
The risk of developing heart failure during the 13.7-year follow-up period was reduced by 21%.
When participants with a heart failure diagnosis prior to omega-3 measurement were compared in the same manner:
All-cause mortality was reduced by 48%
Cardiovascular mortality was reduced by 43%.
When the investigators looked at the effect of omega-3 supplementation in this population:
The risk of developing heart failure was 5% lower for those who reported omega-3 supplement use. I will discuss the reason for the discrepancy between comparisons based on omega-3 supplement use and comparisons based on blood levels of omega-3s below.
The authors concluded, “Higher plasma levels of marine omega-3 fatty acids were associated with a lower incidence of heart failure. Furthermore, among patients with preexisting heart failure, higher omega-3 levels were associated with lower risks of all-cause mortality and cardiovascular mortality. These findings suggest that increasing plasma omega-3 levels, whether by diet or supplementation, could reduce both risk for development of heart failure and death in those with prevalent heart failure.”
What Are The Strengths And Weaknesses Of This Study?
This was a very large, very well-done study. There is the usual caveat for this type of study, namely that it looks at associations and cannot prove cause and effect. However, it would be impossible to perform a double blind, placebo-controlled study with that many people for almost 14 years.
And heart failure does not happen overnight. Studies of the size and length are required to show meaningful effects of diet and/or supplementation on health outcomes like heart failure are not feasible.
Another major strength of this study is that it measured blood levels of omega-3s and showed those blood levels were relatively stable over time rather than relying on participants remembering what they ate and/or what supplements they used.
In terms of supplement use, studies like this one simply ask whether omega-3 supplements were used. They do not ask what the dose was, how frequently they were taken, the form of the omega-3 supplement (fish oil, EPA-only, DHA-only), and whether they were consumed with food or not (which affects absorption).
Studies that rely on diet recall and/or supplement use also have another weakness, namely individual differences in the absorption and utilization of omega-3 fatty acids. Simply put, two individuals getting the same dose of omega-3s from diet and supplementation may have different levels of omega-3s in their cellular membranes.
The authors felt it was these differences that explained why they saw a much stronger and more accurate effect of omega-3s on heart failure when they based their comparison on blood levels of omega-3s rather than omega-3 supplement use.
In short, this study significantly strengthens the evidence that omega-3s reduce the risk of heart failure and improve survival for those with heart failure.
What Does This Study Mean For You?
Here are the take-home lessons from this study:
As I said above, this study significantly strengthens the evidence that omega-3s reduce the risk of heart failure and improve survival for those with heart failure. That means:
Optimizing your intake of omega-3s may be a good strategy for reducing your risk of heart failure. More importantly, optimizing omega-3 intake may also be a good strategy for improving your survival if you have been diagnosed with heart failure.
The authors said, “Because omega-3 is a well-tolerated over-the-counter nutrient…it is perplexing why this safe and affordable therapy…has not been widely incorporated into guideline-directed medical therapy for heart failure. Omega-3s…should be considered as add-on therapy to the standard regimen in the prevention and treatment of heart failure.” I agree.
But what is the optimum intake of omega-3s? This is what the authors had to say about that:
The top 20% of participants in this study had a blood Omega-3 Index of >5.45%, but this is not necessarily optimal.
Previous studies have suggested that an Omega-3 Index of 8% is the optimal target for reducing the risk of death from other forms of heart disease, and the authors feel this is also the optimal target for reducing the risk of heart failure.
The average American has an Omega-3 Index of 4-5%, which is associated with a high risk of heart disease.
Previous studies have indicated that an average intake of 1.4 g/day of EPA + DHA is required to move from an Omega-3 Index of 4% to 8%.
But the key word here is “average”.
None of us are average. We all absorb and retain omega-3s with different efficiencies. Many people will do great with 1.4 g/day. But some may need more to achieve an Omega-3 of 8%. And others will need less.
That’s why I recommend that you request blood tests of your Omega-3 Index and use those to guide you to an optimal 8% rather than relying on dosage of omega-3 supplements or frequency of omega-3-rich fish consumption alone.
However, I recognize that Omega-3 Index determinations are expensive and not all doctor’s offices are equipped to provide them. On average, an intake of 1-2 g/day of EPA + DHA is safe and likely effective at reducing risk of heart failure and other forms of heart disease. But it may not be optimal for you.
The Bottom Line
Previous studies have shown that an optimal intake of omega-3s is likely to reduce the risk of heart attacks and deaths from heart disease. But the news about omega-3s just got better. A recent study strengthened the evidence that omega-3s also reduce the risk of heart failure and improve survival for those with heart failure.
The authors concluded, “Higher plasma levels of marine omega-3 fatty acids were associated with a lower incidence of heart failure. Furthermore, among patients with preexisting heart failure, higher omega-3 levels were associated with lower risks of all-cause mortality and cardiovascular mortality. These findings suggest that increasing plasma omega-3 levels, whether by diet or supplementation, could reduce both risk for development of heart failure and death in those with prevalent heart failure.”
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.
Dr. Chaney has a BS in Chemistry from Duke University and a PhD in Biochemistry from UCLA. He is Professor Emeritus from the University of North Carolina where he taught biochemistry and nutrition to medical and dental students for 40 years. Dr. Chaney won numerous teaching awards at UNC, including the Academy of Educators “Excellence in Teaching Lifetime Achievement Award”. Dr Chaney also ran an active cancer research program at UNC and published over 100 scientific articles and reviews in peer-reviewed scientific journals. In addition, he authored two chapters on nutrition in one of the leading biochemistry text books for medical students.
Since retiring from the University of North Carolina, he has been writing a weekly health blog called “Health Tips From the Professor”. He has also written two best-selling books, “Slaying the Food Myths” and “Slaying the Supplement Myths”. And most recently he has created an online lifestyle change course, “Create Your Personal Health Zone”. For more information visit https://chaneyhealth.com.
For the past 45 years Dr. Chaney and his wife Suzanne have been helping people improve their health holistically through a combination of good diet, exercise, weight control and appropriate supplementation.
We are told we should be consuming more protein. But where should we get our protein?
The investigators used data from the UK Biobank Study, a study that recruited 503,317 young men and women throughout the UK between 2006 and 2010. Upon entry into the study participants completed questionnaires about physical data (height, weight, etc), biological data (blood sugar, cholesterol levels, etc.), and diet.
The investigators looked at four distinct categories of meat consumption (total meat, red meat, processed meat, and poultry) and the risk of 25 common diseases (excluding cancer). In each case, they divided meat consumption into quartiles and compared the disease risk for those in the highest quartile to those in the lowest quartile.
Of course, the question, “Is it meat or something else in our diet that is causing the increased risk of disease?” One hint that something else might be contributing to disease risk came when the authors corrected the data for obesity. The results are shown below:
This study shows that in a high-income western society like ours, meat consumption is likely to increase our risk of several diseases, For example:
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.
