Mediterranean diet

Is It Too Late To Save Your Mind?

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What Does A Brain Healthy Diet Look Like?

Author: Dr. Stephen Chaney 

Memory loss due to Dementia and Alzheimer’s disease with the medical icon of a tree in the shape of a human head and brain losing leaves.

Age-related cognitive decline is increasing at an alarming rate. For example:

  • Newly diagnosed cases of Alzheimer’s disease in Americans over 65 reached 6.5 million in 2022.
  • That’s expected to double by 2060.

We have known for years that a whole food, primarily plant-based diet significantly reduces the risk of cognitive decline and Alzheimer’s.

But in our 20s and 30s we tend to ignore that advice. We feel immortal. Aging is something that affects our grandparents – not us.

When we reach our 40s and 50s reality kicks in. Some of our parents, aunts, and uncles start to show symptoms of cognitive decline. Some of our grandparents are suffering from dementia and Alzheimer’s. Maybe we aren’t immortal.

We start to think about changing to a healthier diet and lifestyle. But then the troubling thoughts creep in. “Is it too late? Should I have made those changes in my 20s? Has that ship already sailed?”

A recent study (Y Song et al, Alzheimer’s & Dementia, 2023) was designed to answer that question

How Was This Study Done?

clinical studyThe authors used data from the New York University Women’s Health Study. They studied 5116 women (average age = 46) who enrolled in the study between 1985 and 1991 and were followed for an average of 33 years (average age at the end of the study = 79).

At the beginning of the study, each participant filled out a questionnaire about demographics (age, gender, ethnicity, income, education, and marital status), physical activity, reproductive history, cancer history, and medication use. They also filled out a food frequency questionnaire.

Using the foods reported in the food frequency questionnaires, the scientist rated each woman with respect to adherence to the DASH diet. The women were then separated into quartiles based on their adherence to the DASH diet.

The participants filled out follow-up questionnaires every 3-5 years. Those who did not return the questionnaires were contacted by phone. The last two follow-up questionnaires included a survey of subjective cognitive complaints (SCCs) such as:

  • Recent changes in the ability to remember things.
  • Difficulty remembering recent events.
  • Difficulty remembering a short list of items, such as a shopping list.
  • Difficulty understanding or following spoken instructions.
  • Difficulty following a group conversation or a plot in a TV program.
  • Difficulty navigating familiar streets.

Previous studies have shown that the SCCs survey is an accurate predictor of future dementia and Alzheimer’s.

Finally, the scientists looked at the correlation between adherence to the DASH diet at age 46 with the number of subjective cognitive complaints at age 79.

Is It Too Late To Save Your Mind?

This is what the authors reported:

  • There was an inverse association between adherence to foods in the DASH diet (which was called “DASH adherence” by the authors of this study) at age 46 and subjective cognitive complaints (SCCs) at age 79.
  • Women in the highest quartile of DASH adherence at age 46 had a 17% reduction in 2 or more SCCs at age 79.
  • Every quartile increase in DASH adherence increased the risk of 2 or more SCCs by 7%.

The most frequently reported SCCs were:

  • Recent changes in the ability to remember things (40%).
  • Difficulty remembering a short list of items (19%).
  • Difficulty remembering recent events (17%).

When they looked at the effect of different foods on SCCs (subjective cognitive complaints):

  • Consumption of sweets, red meat, and processed meats were associated with an increased risk of SCCs, with sweets having the largest effect.
  • Consumption of fruits, vegetables excluding potatoes, legumes and nuts were associated with a decreased risk of SCCs at age 79, with fruits having the largest effect.

There were two other findings of interest:

  • The effect of DASH adherence was stronger for Black women than for White women.
  • The protective effect of DASH adherence was stronger in women with no previous history of cancer.

The authors concluded, “We found that a higher level of adherence to the DASH diet in mid-life was associated with lower SCCs later in life among women. These findings suggest that improvements in diet quality in mid-life…may have a role in maintaining an optimal subjective cognition among women…”

What Does This Study Mean For You? 

Questioning WomanLet me start by putting this study into perspective:

  • The strength of this study is that it has the longest follow-up period (33 years) and most diverse population of any study on this topic.
  • It is consistent with several previous studies with shorter follow-up periods, including the Nurses Health Study which also looked at the effect of DASH adherence at mid-life on SCCs later in life.
  • Several studies have shown that the Mediterranean diet protects against cognitive decline. And one recent study showed that mid-life adherence to the Mediterranean diet also offers similar protection against late-life cognitive decline in men.
    • This suggests that any whole food, primarily plant-based eating pattern, is likely to offer similar benefits. That is important because most of us find it easier to focus on foods rather than rigid diets.
  • Three studies that just compared DASH adherence and SCCs when subjects were already in their 60s to 90s, found no protective effect of DASH adherence.
    • This suggests that if we wait until old age and are already starting to experience mental decline, switching to a healthier diet may not be as beneficial for protecting our mind as we would like it to be. However, I would never advise anyone to just throw up their hands and say, “I might as well eat what I like and die happy.” That’s because:
      • Healthy dietary patterns have a multitude of health benefits. Cognitive benefits are just the tip of the iceberg.
      • Statistics report averages, and none of us are average. Some people will experience much better cognitive benefits than others by switching to a healthier diet, even if they wait until their “golden years” to do so.
  • There aren’t any clinical studies looking at adherence to a healthy diet in our 20s or 30s and cognitive outcomes in our 70s. The time span is just too great for clinical studies.
    • So, while we can confidently say, “It’s not too late to save your mind” by switching to a healthier diet pattern like DASH or Mediterranean in middle age, there are no clinical studies showing we might get even better results if we started eating healthy in our 20s or 30s. However, logic tells us that is a likely outcome.
  • This and most studies on this topic have been done with women. That’s because two thirds of Alzheimer’s patients are women.
    • However, the few studies that have been done with men have reported similar results. So, guys, this affects us too.
  • Finally, the fact that DASH adherence was more effective in women who have not had a cancer diagnosis is interesting.
    • In my opinion this is likely because many cancer treatments leave residual “brain fog” and increase the risk of cognitive decline as we age. As someone who spent his life in cancer research, I consider a healthy diet and healthy lifestyle vitally important in helping the body recover from the ravages of cancer treatment.

What Does A Brain-Healthy Diet Look Like? 

According to the most recent US News & World Health ratings of the best diets in various categories, the top 4 diets for brain health are:

  • MIND diet (The MIND diet combines the best of the Mediterranean and DASH diets with an emphasis on brain healthy foods such as berries.)
  • Mediterranean diet.
  • Flexitarian diet (a flexible version of a semi-vegetarian diet).
  • DASH diet.

My Comments:

  • All four diets are whole food, primarily plant-based diets.
  • Although the MIND diet was specifically designed for brain health, it does not perform significantly better than the Mediterranean and DASH diets in slowing cognitive decline.

Of course, most people prefer to think in terms of foods rather than diets. In terms of brain-healthy foods, a recent Harvard Health Review suggests these are the foods we should emphasize for brain health:

  • Green Leafy Vegetables: Kale, spinach, broccoli, and collards are rich in brain-healthy nutrients like vitamin K, lutein, folate, and beta-carotene.
  • Fatty Fish: Salmon, trout, sardines, and mackerel provide omega-3 fatty acids, which are crucial for brain function and for reducing dementia risk.
  • Berries: Blueberries, strawberries, and blackberries contain antioxidants that have been shown to delay cognitive decline.
  • Nuts and Seeds: Walnuts are high in omega-3 fatty acids (ALA), while others provide vitamin E.
  • Healthy Fats: Olive oil is recommended as the primary cooking fat.
  • Whole Grains and Legumes: Oats, quinoa, beans, and lentils provide a steady, slow release of glucose for brain energy. Plus, their fiber supports the growth of friendly bacteria that produce brain-healthy nutrients (This is sometimes referred to as the gut-brain axis).
  • Other Foods: Avocados (monounsaturated fats), beets (nitrates for blood flow), and cocoa (flavonoids) are beneficial.

The Bottom Line 

A recent study showed that adherence to a healthy eating pattern like the DASH diet at middle age can help protect our brain from cognitive decline 30 years later.

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

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

_______________________________________________________________________________

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

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

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

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

 _______________________________________________________________________

About The Author 

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

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

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

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

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

Can You Cut Your Risk Of Heart Disease By 90%?

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The Effect Of Ultra-Processed Foods On Heart Disease Risk
 

Author: Dr. Stephen Chaney

strong heartHeart 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?

Clinical StudyThe 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

Fast Food DangersThe 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%.Vegan Foods
  • 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.

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

_______________________________________________________________________

About The Author 

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

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

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

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

 

Do Eggs Prevent Cognitive Decline?

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Are Eggs Brain Food?

Author: Dr. Stephen Chaney 

VillainFor much of the past 10 or 20 years, eggs have villainized. We were told that their high cholesterol levels would clog our arteries and increase our risk of heart attack and stroke.

We were told to eat egg whites, egg substitutes (even though egg substitutes were a witch’s brew of chemicals), or avoid eggs altogether.

But in recent years, the ground has shifted.

  • Cholesterol is no longer viewed as the demon it once was. It is now thought of as more of a bit player in a cast of dozens of factors contributing to increased risk of heart disease and stroke.

And when it comes to increased risk of heart disease, the AHA (American Heart Association) position on egg consumption and heart disease risk has shifted dramatically. They now recommend:

  • “Healthy adults can eat up to one whole egg per day as part of a heart-healthy diet.”
  • Diet context is very important. The AHA recommends:
    • “Eggs should not be paired with high-saturated fat foods like bacon, sausage, or butter. Instead, they should be poached, soft-boiled, or cooked in healthy fats like olive oil.”
    • I would add that recent studies have shown that if you are consuming a whole-food, primarily plant-based diet, consuming one or two eggs per day actually decreases your risk of heart disease.
  • Your body’s ability to regulate cholesterol levels is also important. For that reason, the AHA recommends:
    • “Individuals with diabetes, high blood cholesterol, or existing heart disease should be more cautious…limiting yolk consumption to 4 per week…[I would add obesity to this list].”

For more information on the studies behind these recommendations, go to https://www.chaneyhealth.com/healthtips/ and put eggs in the search box.

Are Eggs Brain Food?

There are lots of reasons to think of eggs as brain food. The authors of the study I am about to share observed:

  • “Eggs are a good source of protein (6.29 gram/medium egg), which has been linked to improved memory and reaction time in healthy young adults and reduced risk of cognitive impairment in older adults.”
  • “Egg protein is a good source of the essential amino acid tryptophan (77 mg per egg), which is converted to the neurotransmitter serotonin, involved in decision-making and memory.”
  • “Egg yolks are a good source of choline (150 mg per egg), which is a precursor to acetylcholine, a neurotransmitter involved in memory and learning. The authors went on to say, “Choline intake between 187 mg and 399 mg per day has consistently been associated with improved cognitive performance for both healthy younger and older adults.
  • “Egg yolks are also a good source of phospholipids (3.3 gm per egg), which are an important part of nerve membranes. Phospholipids modulate neurotransmitter receptors and have been linked to enhanced reaction time in healthy middle-aged men.”
  • “Egg yolks are a good source of DHA (between 25 to 50 mg DHA for commercially produced eggs and 100-150 mg of DHA for pasture-raised eggs) which has been associated with a lower risk of dementia.”

In short, there are lots of reasons to think that eggs might be good for the brain and might reduce the risk of age-related cognitive decline.

So, the authors of this study (N Sultan et al, Journal of Nutrition, Health, and Aging, 29, 100696, 2025) decided to conduct a systematic review of existing studies to evaluate the association between whole egg consumption and cognitive decline in healthy adults.

How Was The Study Done?

clinical studyThe authors set out to create a systematic review of studies looking at the effect of egg consumption on cognitive decline in older adults. This was not an easy undertaking because:

  • Most published studies in this area have looked at the effect of diets (e.g. MIND or Mediterranean diets) on cognitive decline rather than the effect of individual foods.
  • There are many ways to measure cognitive function, and no two studies used the same measures of cognitive function.

The authors utilized the top 5 databases of clinical studies and identified 10 studies with a total of >38,000 participants that investigated the effect of whole egg consumption on cognitive outcomes in healthy, older adults (average age = 68, 50% female).

Because the studies used different measures of cognitive function, the outcomes were divided into the following cognitive domains:

  • Global cognitive functioning.
  • Language functioning.
  • Verbal learning.
  • Memory.
  • Processing speed.
  • Decision-making.
  • Attention.
  • Executive function.
  • Risk-taking.
  • Reaction time.
  • Visuospacial ability.
  • Orientation.
  • Cognitive flexibility.
  • Interoception.

From these individual domains an overall cognitive function score was derived.

Do Eggs Prevent Cognitive Decline?

Memory loss due to Dementia and Alzheimer’s disease with the medical icon of a tree in the shape of a human head and brain losing leaves.

This is what the authors reported:

  • Two studies reported a reduced risk of dementia or cognitive impairment associated with moderate egg consumption (0.5-1 egg per day).
  • One study reported increased risk at high intake levels (> 1 egg per day).
  • Several studies showed improvements in memory, verbal fluency, and/or processing speed with moderate, but not high, egg intake.

The authors concluded, “This systematic review identified preliminary observational evidence that moderate habitual egg consumption may be associated with better cognitive performance, particularly in memory and verbal fluency domains, and reduced risk of cognitive impairment in adults without chronic disease…Further rigorous studies are required to determine whether egg consumption contributes to cognitive resilience and to clarify dose-response relationships. These efforts will help determine whether eggs can be recommended as part of evidence-based dietary strategies to support cognitive function in aging populations.”

As the authors said, this is not a definitive study. It is a preliminary study that lays the groundwork for future definitive studies. As someone who had dozens of publicly funded grants during my research career, I can tell you that publications like this are important, because they can be used to support requests for public funding of future research projects on that topic.

What kind of future research projects would be definitive? The authors said:

  • “Further rigorous studies are required to determine whether egg consumption contributes to cognitive resilience [as we age] and to clarify dose-response relationships.” Ideally these studies would:
    • Be designed to test the dose-response relationship.
    • Use similar measurement of cognitive function, so the study results would be easy to compare.
    • Look at diet context. For example, do eggs have the same cognitive benefits in whole food, primarily plant-based diets and diets that are high in saturated fats and processed foods?
    • Look at the effect of health status. Cholesterol build up can block arteries leading to the brain. Studies on heart health have shown eggs may not be beneficial for people who already have elevated cholesterol, diabetes, and arterial disease.

What Does This Study Mean For You? 

questionsHere are my thoughts:

  • As I outlined above, there are lots of reasons to think of eggs as brain food.
  • Moderate egg consumption may help protect against cognitive decline as we age. The current data are suggestive, but not definitive.
  • The American Heart Association now says that moderate egg consumption can be part of a heart-healthy diet. So, the major reason for avoiding eggs has been removed.
  • Egg consumption is likely to be most beneficial as part of a whole food, primarily plant-based diet. When I grew up Alabama a normal breakfast was eggs cooked in butter, sausage, grits and “red-eye gravy” (gravy made from ham fat). To say that it was probably not a brain-healthy way to eat eggs would be an understatement.
  • If you are already struggling with high cholesterol, diabetes and arterial disease, you should probably consult your doctor before increasing your egg consumption.

What Does A Brain-Healthy Diet Look Like? 

According to the most recent US News & World Health ratings of the best diets in various categories, the top 4 diets for brain health are:

  • MIND diet (The MIND diet combines the best of the Mediterranean and DASH diets with an emphasis on brain healthy foods such as berries.)
  • Mediterranean diet.
  • Flexitarian diet (a flexible version of a semi-vegetarian diet).
  • DASH diet.

My Comments:

  • All four diets are whole food, primarily plant-based diets.
  • Although the MIND diet was specifically designed for brain health, it does not perform significantly better than the Mediterranean and DASH diets in slowing cognitive decline.

Of course, most people prefer to think in terms of foods rather than diets. In terms of brain-healthy foods, a recent Harvard Health Review suggests these are the foods we should emphasize for brain health:

  • Green Leafy Vegetables: Kale, spinach, broccoli, and collards are rich in brain-healthy nutrients like vitamin K, lutein, folate, and beta-carotene.
  • Fatty Fish: Salmon, trout, sardines, and mackerel provide omega-3 fatty acids, which are crucial for brain function and for reducing dementia risk.
  • Berries: Blueberries, strawberries, and blackberries contain antioxidants that have been shown to delay cognitive decline.
  • Nuts and Seeds: Walnuts are high in omega-3 fatty acids (ALA), while others provide vitamin E.
  • Healthy Fats: Olive oil is recommended as the primary cooking fat.
  • Whole Grains and Legumes: Oats, quinoa, beans, and lentils provide a steady, slow release of glucose for brain energy. Plus, their fiber supports the growth of friendly bacteria that produce brain-healthy nutrients (This is sometimes referred to as the gut-brain axis).
  • Other Foods: Avocados (monounsaturated fats), beets (nitrates for blood flow), and cocoa (flavonoids) are beneficial.

My Comment:

  • Based on their nutrient content and studies like this one, I would add eggs (consumed in moderation) to the list.

The Bottom Line 

There are lots of reasons to think of eggs as brain food. A recent study suggests that moderate egg consumption may help slow cognitive decline as we age.

For more information on this study and what a brain-healthy diet looks like, read the article above.

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

_____________________________________________________________________________

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

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

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

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

___________________________________________________________________________

About The Author 

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

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

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

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

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

 

 

Which Diets Were Best In 2025?

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Which Diet Should You Choose For Good Health?

Author: Dr. Stephen Chaney

Question MarkMany of you started 2026 with goals of losing weight and/or improving your health. In many cases, that involved choosing a new diet.

And for many of you the “bloom” has already gone off the new diet you started so enthusiastically January 1st.

  • Perhaps the diet isn’t working as well as advertised…
  • Perhaps the diet is too restrictive. You are finding it hard to stick with…
  • Perhaps you are always hungry or constantly fighting food cravings…
  • Perhaps you are starting to wonder whether there is a better diet than the one you chose January 1st…
  • Perhaps you are wondering whether the diet you chose is the wrong one for you…

If you are rethinking your diet, you might want to know which diets the experts recommend. Unfortunately, that’s not as easy as it sounds. The diet world has become just as divided as the political world.

Fortunately, you have an impartial resource. For 15 consecutive years US News & World Report has invited a panel of experts with different points of view to evaluate popular diets. They then combined the input from all the experts into rankings of the diets in various categories.

They did not rank diets this year but said that little has changed since their last rankings in 2025.

If you are still searching for your ideal diet, I will summarize the US News & World Report’s “Best Diets In 2026”. For the full report, click on this link.

How Was This Report Created?

Scientists-ConversingUS News & World Report recruited panel of 69 nationally recognized experts in diet, nutrition, obesity, food psychology, diabetes, and heart disease to review the most popular diets. This year they reviewed 38 diets in 21 different categories based on the most common reasons for choosing a specific diet.

Of course, fad diets come and go. Each year they drop diets that are no longer popular and add ones that are either new or have recently surged in popularity.

The panel rated diets based on:

  • Nutritional Completeness: The best diets include a variety of nutrient-dense foods that provide essential carbohydrates, protein, healthy fats, vitamins, and minerals.
  • Health Benefits and Risks: These diets are evidenced-based, promote health benefits, reduce disease risks, and focus on high-fiber, nutrient-rich, and antioxidant-packed foods.
  • Proven and Sustainable: These diets are supported by a large body of evidence that they protect against chronic disease and promote a long, healthy life. These diets also provide clear guidelines on what to eat more of and what to eat less of while allowing flexibility to suit personal preferences, including flavors, cultural cuisines and budget. Because these diets are adaptable, they are more sustainable in the long run and less likely to promote a rigid eating approach.

US News & World Report converted the experts’ ratings to scores 5 (highest) to 1 (lowest). They then used these scores to construct 21 categories of Best Diets rankings. I have included the following 8 categories in this Health Tips Blog.

  • Best Diets Overall ranks diets on several different parameters, including whether all food groups are included in the diet, the availability of the foods needed to be on the diet and the use of additional vitamins or supplements.

They considered if the diet was evidence-based and adaptable to meet cultural, religious, or other personal preferences.

In addition, the criteria also included evaluation of the prep and planning time required for the diet and the effectiveness of the diet for someone who wants to get and stay healthy.

  • Best Plant-Based Diets used the same approach as Best Diets Overall to rank the plans emphasizing minimally processed foods from plants that were included in this year’s ratings.
  • Best Healthy Weight-Loss Diet ratings were generated by combining the safety of the weight loss program and the likelihood of the plan to result in successful long-term weight loss and maintenance of weight loss.
  • Best Fast Weight-Loss Diets were scored on their effectiveness for someone who wants to lose weight in three months or less.
  • Best Diabetes Diet ratings were calculated equally from the effectiveness of the diet for someone who wants to lower risk factors for diabetes, the nutritional quality of the diet, and research evidence-based support for the diet.
  • Best Heart-Healthy Diet ratings were calculated equally from the effectiveness of the diet for someone who wants to lower risk factors for hypertension and other forms of heart disease, the nutritional quality of the diet, and evidence-based support for the diet.
  • Best Diets for Inflammation were diets of whole, minimally processed foods like vegetables, fruits, whole grains, healthy fats, nuts, seeds, beans, fatty fish and lean proteins that have been shown to decrease inflammation. 
  • Easiest Diets to Follow represents panelists’ averaged scores for the relevant lifestyle questions, including whether all food groups are included and if the recommended foods are readily available at the average supermarket.

Which Diets Were Worst In 2025?

Emoticon-BadI did not include the worst diets in each category I listed below, but the US News & World Report article gave clear guidelines on what to avoid when choosing a healthy diet. In their words:

  • Avoid processed foods and sugary snacks: Sure, they taste great, but these can leave you with energy crashes and cravings that lead to overeating.
  • Watch out for “diet” foods: Just because something says “low-fat” or “diet” doesn’t mean it’s healthy. These foods often have added sugars or artificial ingredients. It is worth checking the label.
  • Skip extreme restrictions: Cutting out entire food groups or drastically slashing calories might work short term, but it’s hard to stick with and usually leads to burnout or regaining weight.
  • Focus on progress, not perfection: The best weight-loss strategies are about balance and flexibility, not rigid rules. Life happens, so it’s better to aim for consistency over time than to stick to an overly strict plan you can’t keep up with.
  • Focus on lifestyle change, not a quick fix: Healthy weight loss isn’t about quick fixes. It’s about building a lifestyle you enjoy and change sustain. Small changes, like adding more veggies to your meals or choosing water rather than sodas, may not seem like much, but they add up to lasting results over time.
  • Consistency over time beats perfection: An occasional slice of cake or pizza with friends won’t ruin your progress.

Which Diets Were Best In 2025?

Are you ready? If this were an awards program, I would be saying “Envelop please” and would open the envelop slowly to build suspense.

However, I am not going to do that. Below I have listed the top 5 diets in each of the 8 categories I have chosen (If your favorite diet is not on the list and you would like to see where it is ranked, you will need to subscribe to US News & World Report).

Finally, I have excluded commercial diets from this review. I have focused on whole food diets based on foods you can easily find in your local grocery store or farmer’s market.

Best Diets Overall

The best overall diets were:

#1: Mediterranean Diet. The Mediterranean diet has been ranked #1 for 10 consecutive years.

#2: DASH Diet (This diet was designed to keep blood pressure under control, but you can also think of it as an Americanized version of the Mediterranean diet.)

#3: Flexitarian Diet (A flexible semi-vegetarian diet).

#4: MIND Diet (A combination of the Mediterranean and DASH diets with foods selected that support brain health).

#5: The Mayo Clinic Diet (A 12-week program based on evidence-based behavioral science to establish life-long healthy eating habits).

Best Plant-Based Diets 

plant-based diets vegetablesThe top diets in this category were:

#1: Flexitarian Diet.

#2: Mediterranean Diet.

#3: Vegan Diet (a plant-based diet that eliminates all animal products).

#4: MIND Diet

#5: Ornish Diet (A low-fat, plant-based diet designed by Dr. Dean Ornish as part of a heart-healthy lifestyle program that has successfully reversed atherosclerotic buildup in some patients).

Best Healthy Weight-Loss Diets

The top diets in this category are proven. They are associated with lower weight and a reduced risk of chronic Weight Lossdiseases in long-term clinical studies. The top diets are:

#1: Mediterranean Diet

#2: Volumetrics Diet (A diet based on the caloric density (calories per serving) of foods).

#3: Mayo Clinic Diet (A diet designed to establish lifelong healthy eating habits).

#4: Flexitarian Diet.

#5: DASH Diet.

Best Fast Weight-Loss Diets

weight lossOnce again, the report emphasized the dangers of quick weight loss diets. If you choose one of these diets to achieve a quick weight loss goal, the authors recommend you use these diets as a stepping stone toward a healthier lifestyle rather than a final solution.

Here are the rapid weight loss ratings:

#1: Keto Diet (A very low carb, high fat diet designed to produce ketosis in your body).

#2: South Beach Diet (A low carb, high protein approach to weight loss).

#3 Atkins Diet (The grandfather of the keto diet).

#4: Volumetrics Diet.

#5: Keyto Diet (A low-carb version of the Mediterranean diet).

Best Diabetes Diets

The key criteria for the best diabetes diets were that they were well-balanced, healthy diets that were designed to Diabetes and healthy diekeep glucose levels within the normal range throughout the day.

They are whole food diets that cut back on added sugars and refined carbs. The top diets in this category are: 

#1: Mediterranean Diet

#2: Flexitarian Diet

#3: MIND Diet

#4: DASH Diet.

#5: Mayo Clinic Diet.

#7: Vegan Diet.

Best Heart-Healthy Diets

strong heartThe top diets in this category were:

#1: DASH Diet

#2: Mediterranean Diet

#3: MIND Diet.

#4: Vegan Diet.

#5: Flexitarian Diet.

#6: TLC Diet. (The TLC (Therapeutic Lifestyle Change) diet was designed by the NIH to lower LDL cholesterol levels naturally.

Best Diets for Inflammation

The top diets in this category are:Flames

#1: Mediterranean Diet.

#2: Dr. Weil’s Anti-Inflammatory Diet.

#3: Flexitarian Diet.

#4: DASH Diet.

#5: MIND Diet.

#7: Vegan Diet.

Easiest Diets to Follow

EasyThe authors of this report considered easy diets to be ones that:

  • Fit into your lifestyle, letting you enjoy indulgences while still being wholesome and nutritious – whether you’re eating out or at home. They focus on building long-term habits, not quick fixes, making them easier to stick with daily.
  • Focus on filling, tasty meals instead of strict restrictions.

They only listed four diets that were healthy, based on whole foods that were readily available, offered easy to follow recipes, and fit the criteria listed above.

#1: Mediterranean Diet (For those who enjoy Mediterranean foods).

#2: Flexitarian Diet (For those who enjoy flexible, semi-vegetarian meals).

#3: DASH Diet (For those who prefer American foods).

#4: MIND Diet (For those who could go either Mediterranean or American and are concerned with brain health).

Which Diet Should You Choose For Weight Loss?

1) If you are looking for rapid weight loss, any whole food restrictive diet will do.

  • In previous year’s evaluations both vegan and keto diets ranked near the top of the rapid weight loss category. Keto and vegan diets are both very restrictive, but they are polar opposites in terms of the foods they allow and restrict.
    • The keto diet is a meat heavy, very low carb diet. It restricts fruits, some vegetables, grains, and most legumes.
    • The vegan diet is a very low-fat diet that eliminates meat, dairy, eggs, and animal fats.
  • Whole food, very low carb diets like Atkins and keto are good for rapid weight loss, but they rank near the bottom of the list for every healthy diet category.
    • If you choose to lose weight on the Atkins or keto diets, switch to a healthier diet once you reach your desired weight loss.

2) If you are looking for healthy weight loss or just a healthy diet, the Mediterranean diet tops the list year after year, followed closely by the DASH, MIND, and flexitarian diets.

  • They are all whole food, primarily plant-based diets, that are backed by dozens of clinical studies showing that they are associated with a healthy weight and low risk of chronic disease long term.

Of course, GLP-1 drugs are the “elephant in the room” when we talk about weight loss. GLP-1 drugs work, but:

  • They are associated with concerning side effects such as:
    • Anxiety, depression, and suicidal thoughts. This is particularly concerning for anyone who has a tendency for anxiety or depression.
    • Muscle loss. This is particularly concerning for seniors who are already prone to age-related muscle loss.
    • Rarer side effects include increased risk of pancreatitis, kidney problems, and some cancers.
  • Unless they are coupled with dietary and lifestyle changes, their effects are temporary. The weight comes roaring back as soon as they are discontinued.
    • This is a concern because of their expense and side effects. Long-term use of these drugs:
      • Increases the cost of healthcare which increases health insurance costs for all of us (a topic which is in the news lately).
      • Increase the risk of side effects.

Which Diet Should You Choose For Good Health?

Food ChoicesWith rapid weight loss out of the way, let’s get back to the question, “Which Diet Should You Choose For Good Health?”

The Mediterranean diet tops the list year after year, followed closely by the DASH, MIND, and Flexitarian diets. But how do you choose between them? My recommendations are:

1) Choose a diet that fits your needs. That is one of the things I like best about the US News & World Report ratings. The diets are categorized. If your main concern is diabetes, choose one of the top diets in that category. If your main concern is heart health… You get the point.

2) Choose diets that are healthy and associated with long term weight loss. If that is your goal, you will notice that primarily plant-based diets top these lists. Meat-based, low carb diets like Atkins and keto are near the bottom of the lists.

3) Choose diets that are easy to follow. The less-restrictive primarily plant-based diets top this list – diets like Mediterranean, DASH, MIND, and flexitarian. They are also at or near the top of almost every diet category.

4) Choose diets that fit your lifestyle and dietary preferences. For example, if you don’t like fish and olive oil, you will probably do much better with the DASH or Flexitarian diet than with the Mediterranean diet.

4) Finally, focus on what you have to gain, rather than on foods you have to give up.

  • On the minus side, none of the diets include America’s favorite foods such as sodas, junk foods, and highly processed foods. These foods should go on your “No-No” list. Sweets should be occasional treats and only as part of a healthy meal. Meat, especially red meat, should become a garnish rather than a main course.
  • On the plus side, primarily plant-based diets offer a cornucopia of delicious plant foods you probably didn’t even know existed. Plus, for any of the top-rated plant-based diets, there are websites and books full of mouth-watering recipes. Be adventurous.

The Bottom Line

For many of you the “bloom” has gone off the new diet you started so enthusiastically in January. If you are rethinking your diet, you might want to know which diets the experts recommend. Unfortunately, that’s not as easy as it sounds. The diet world has become just as divided as the political world.

Fortunately, you have an impartial resource. Each year US News & World Report invites a panel of experts with different points of view to evaluate popular diets. They then combine the input from all the experts into rankings of the diets in various categories according to individual health goals. In the article above I summarize the US News & World Report’s “Best Diets In 2025”.

There are probably two questions at the top of your list.

#1: Which diets are best for weight loss? Here are 2 general principles:

  • If you are looking for rapid weight loss, any whole food restrictive diet will do. The Keto diet tops this list but ranks near the bottom of the healthy diet categories.
  • If you are looking for healthy, long-term weight loss the Mediterranean diets tops the list followed by the Volumetrics, Mayo Clinic, Flexitarian, and DASH diets.

#2: Which diet should you choose for good health? Once again, the Mediterranean diet tops the list followed by the DASH, Flexitarian, MIND, and Mayo Clinic diets. The Vegan diet is the top 10 of most healthy diet lists, while the keto diet is near the bottom.

For more details on 2026 US News & World Report on Best Diets and my advice on how to choose a healthy diet that is best for you, read the article above.

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

_______________________________________________________________________________

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

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

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

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

 _______________________________________________________________________

About The Author 

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

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

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

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

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

 

 

How To Live To 117

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The Secrets To A Long And Healthy Life

Author: Dr. Stephen Chaney

SecretsToday’s “Health Tip” is a bit unusual. It’s not based on a clinical study with thousands of participants. It’s not even a clinical study based on dozens of people. It’s a case study of one individual.

The study was published in Cell Reports Medicine, but I learned about it in our local newspaper (Yes, the professor still reads the newspaper in addition to published clinical studies. I don’t rely on the internet for all my information.)

I chose this case study because it was so interesting. It is based on the life of a woman, Maria Branyas Morera, who lived in good health to the age of 117. In her later years she asked her physician, Dr. Manel Estellar – chair of genetics at University of Barcelona’s School of Medicine, to study her and see if he could find out why she lived so long.

The results were fascinating. And while it could be argued that the data from a single individual may be misleading, the conclusions from her doctor’s investigation were consistent with the results of the much larger “Blue Zone” study of centenarians living in regions where a high percentage of people lived to 100 and beyond. I will talk about that study below.

How To Live To 117 

Maria Branyas was born in San Francisco in 1907 of Spanish immigrant parents. Her father died when she was 8 and her mother moved back to Spain to be with her family. She married and had a son who died at age 52 and two daughters who are now 92 and 94.

Part of the reason for her longevity was that she took good care of herself:

  • She followed a Mediterranean diet.
  • She did not smoke or drink.
  • She walked an hour every day until her 90s. Eventually she had to cut back because of physical limitations but remained as active as possible. When walking became difficult she entered a nursing home.
  • She kept mentally active. For example, she played the piano every day until she was 112.

Part of the reason was socioeconomic.

  • She and her family lived in the same town.
  • She had a close circle of friends and family for emotional support.
  • And as her friends died, she made new ones.
    • This is something that is often not discussed in the aging literature. As you age and your friends die off, it is easy to become isolated, which increases the likelihood of depression and death. The decision to make new friends in your latter years is a choice.

And part of the reason was genetic.

  • In the words of her doctor, “She won the genetic lottery with respect to genetic variants that protect against risk factors like high cholesterol, dementia, heart disease, and cancer.”
    • However, we need to remember that genetics is not everything. Other members of her immediate family shared the same genetic traits, yet died prematurely from Alzheimer’s, cancer, tuberculosis, and heart disease.
    • I like to say, “Genetics loads the gun. Lifestyle pulls the trigger”. In short, both contribute to longevity.

The final part of the puzzle goes beyond genetics.

  • She had an immune system that was unusually strong for someone her age and inflammation that was unusually low for someone her age. Those were probably due to:
    • Epigenetic modifications to her DNA that are associated with younger individuals.
      • Quick review: Epigenetic modifications affect gene activity and are controlled by diet, lifestyle, and the environment.
      • We can never know exactly what caused her youthful epigenetics, but she did have a very healthy diet and lifestyle.
    • She had a microbiome associated with low inflammation.
      • Quick Review: The term microbiome refers to all the microorganisms in our gut and elsewhere on our body. Our microbiome is strongly affected by what we eat and other lifestyle factors such as body weight.
      • In her case, one example of her anti-inflammatory microbiome was a high abundance of Bifidobacteria, probably a direct result of the three yogurts she ate each day.

The Secrets To A Long And Healthy Life 

blue zonesThis brings me to the “Blue Zone” study. I have talked about it in a previous issue of “Health Tips From The Professor”. Let me give you the short version here.

Dan Buettner is a journalist who was fascinated by the topic of longevity. He identified five regions from around the world where an unusually high percentage of people lived into their 100s. He then put together a team of top scientists in the fields of demographics, social anthropology and statistics to study the characteristics of centenarians in each of these regions and got National Geographic to fund the study.

You can see his book on the left, and I will summarize the main conclusions of his study below. Of course, the most important question is how the information garnered from Maria Branyas compares with the conclusions of the “Blue Zone” study. I will indicate that below.

#1: They engage in moderate intensity exercise every day. The answer for Maria is a clear, “Yes”.

#2: They stop eating before they are full. We don’t know this for sure, but she did appear to be at ideal weight towards the end of her life.

#3: They eat a mostly plant-based diet. She ate a Mediterranean diet which qualifies.

#4: They have a libation with their meals. For Maria, this is a “No”.

#5: They have a purpose in their life. We have no information on this aspect of Maria’s life.

#6: They set aside time for relaxation with friends and family. Clearly, this was important for Maria. As old friends died off, she searched for new ones.

#7: They participate in a spiritual community. We have no information on this aspect of Maria’s life.

#8: They put family first. Clearly, family was very important to Maria.

#9: They surround themselves with communities that share their values. It also appears that this was important to Maria.

In short, in his study of Maria’s secrets to longevity Dr. Esteller approached the question of longevity from a different perspective than Dan Buettner. It is regrettable that he didn’t use the data accrued by the “Blue Zone” study as a starting point for his study. But it is clear that Maria epitomized many of the longevity characteristics identified in the “Blue Zone” study.

And, of course, Dr. Esteller’s expertise is human genetics, and he added important information about the importance of genetics, epigenetics, and our microbiome in influencing longevity.

The Bottom Line

The world’s oldest human recently died at age 117. Before she died, gave her doctor permission to study her and determine how she was able to live so long. In short, she asked her doctor to use her life to understand how to help other people live a long and healthy life.

That study has recently been published. The results showed:

  • Her lifestyle mirrored many of the lifestyle characteristics that were associated with longevity in the previous “Blue Zone” study of centenarians (people living to 100 and beyond).
  • This study also identified genetic, epigenetic, and microbiome factors associated with longevity

For more details about the study, read the article above.

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

_____________________________________________________________________________

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

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

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

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

________________________________________________________________________

About The Author 

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

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

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

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

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

 

What Diet Is Best For Healthy Aging?

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What About Primarily Meat-Based Diets?

Author: Dr. Stephen Chaney

Pinochio

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

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

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

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

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

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

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

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

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

How Was This Study Done?

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

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

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

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

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

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

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

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

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

Diets Included In This Study

The diets included in this study were:

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

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

What Diet Is Best For Healthy Aging?

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

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

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

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

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

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

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

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

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

What About Primarily Meat-Based Diets?

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

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

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

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

What Does This Study Mean For You?

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

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

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

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

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

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

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

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

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

The Bottom Line

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

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

The key findings were:

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

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

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

 ____________________________________________________________________________

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

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

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

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

 _______________________________________________________________________

About The Author 

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

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

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

 

 

The Low Carb Myth

by

The “Goldilocks Effect”

Author: Dr. Stephen Chaney

low carb dietThe low carb wars rage on. Low carb enthusiasts claim that low-carb diets are healthy. And they claim the lower you go, the healthier you will be. Let me start with some definitions:

  • The typical American diet is high carb. It gets about 55% of its calories from carbohydrates. [Note: The Mediterranean and DASH diets also get about 55% of their calories from carbohydrates. I’ll talk more about that later.]
  • Moderate carb diets get 26-46% of their calories from carbohydrates. Examples include the low carb Mediterranean diet and the Paleo, South Beach, and Zone diets.
  • Low carb diets get <26% of their calories from carbohydrates. The Atkins diet is the classic example of a low carb diet.
  • Very low carb diets get <10% of their calories from carbohydrates. Examples are the Keto and Carnivore diets.

And I don’t need to tell you that the Keto and Carnivore diets are receiving a lot of favorable press lately.

But some health experts warn that low carb and very low carb diets may be dangerous. For example, several studies have reported that low carb diets increase the risk of mortality (shorten lifespan).

As a consumer you are probably confused by the conflicting claims. Are low carb diets healthy, or is this another myth? In this issue of “Health Tips From the Professor” I am going to discuss two very large studies that came to opposite conclusions.

Both were what we call meta-analysis studies. Simply put, that means they combine the data from several smaller studies to obtain more statistically reliable data. But as Mark Twain said, “There are lies. There are damn lies. And then there are statistics.”

The first study, called the Prospective Urban Rural Epidemiology (PURE) study, was published a few years ago. It included data from 135,335 participants from 18 countries across 5 continents. That’s a very large study, and normally we expect very large studies to be accurate.

It showed a linear relationship between carbohydrate intake and mortality. Simply put, the more carbohydrate people consumed, the greater their risk of premature death. The results from the PURE study had low carb enthusiasts doing a victory lap and claiming it was time to rewrite nutritional guidelines to favor low carb diets.

SkepticWhenever controversies like this arise, reputable scientists are motivated to take another look at the question. They understand that all studies have their weaknesses and biases. So, they look at previous studies very carefully and try to design a study that eliminates the weaknesses and biases of those studies. Their goal is to design a stronger study that reconciles the differences between the previous studies.

And this study had two glaring weaknesses.

  • The percent carbohydrate intake ranged from 40% to 80%. It showed that a moderate carbohydrate intake might be healthier than a high carbohydrate intake, but it provided no information about low carb or very low carb diets.
  • The data was primarily from Asian countries. It was not clear whether it was relevant to the kind of diets consumed in North America and Europe.

A second study published a year later (SB Seidelmann et al, The Lancet, doi.org/10.1016/S2468-2667(18)30135-X) eliminated these weaknesses and resolved the conflicting data.

How Was The Second Study Done?

clinical studyThis study was performed in two parts. This first part drew on data from the Atherosclerosis Risk in Communities (ARIC) study. That study enrolled 15,428 men and women, aged 45-64, from four US communities between 1987 and 1989. This group was followed for an average of 25 years, during which time 6283 people died.

Carbohydrate intake was calculated based on food frequency questionnaires administered when participants enrolled in the study and again 6 years later. The study evaluated the association between carbohydrate intake and mortality.

The second part was a meta-analysis that combined the data from the ARIC study with all major clinical studies since 2007 that measured carbohydrate intake and mortality and lasted 5 years or more. The total number of participants included in this meta-analysis was 432,179, and it included data from previous studies that claimed low carbohydrate intake was associated with decreased mortality.

The Low Carb Myth

The results from the ARIC study were:

GravestoneThe relationship between mortality and carbohydrate intake was a U-shaped curve.

    • The lowest risk of death was observed with a moderate carbohydrate intake (50-55%). This is the intake recommended by current nutrition guidelines.
    • The highest risk of death was observed with a low carbohydrate intake (<20%).
    • The risk of death also increased with very high carbohydrate intake (>70%).
  • When the investigators used the mortality data to estimate life expectancy, they predicted a 50-year-old participant would have a projected life expectancy of:
    • 33.1 years if they had a moderate intake of carbohydrates.
    • 4 years less if they had a very low carbohydrate intake.
    • 1.1 year less if they had a very high carbohydrate intake.
  • And the risk associated with low carbohydrate intake was affected by what the carbohydrate was replaced with.
    • When carbohydrates were replaced with animal protein and animal fat there was an increased risk of mortality on a low-carb diet.

The animal-based low-carb diet contained more beef, pork, lamb, chicken, and fish. It was also higher in saturated fat.which low carb diets are healthy

    • When carbohydrates were replaced with plant protein and plant fats, there was a decreased risk of mortality on a low-carb diet. The plant-based low-carb diet contained more nuts, peanut butter, dark or whole grain breads, chocolate, and white bread. It was also higher in polyunsaturated fats.
  • The effect of carbohydrate intake on mortality was virtually the same for all-cause mortality, cardiovascular mortality, and non-cardiovascular mortality.
  • There was no significant effect of carbohydrate intake on long-term weight gain (another myth busted).

The results from the dueling meta-analyses were actually very similar in some respects. When the data from all studies were combined:

  • Very high carbohydrate diets were associated with increased mortality.
  • Meat-based low-carb diets increased mortality, and plant-based low-carb diets decreased mortality.
  • The results were the same for total mortality, cardiovascular mortality, and non-cardiovascular mortality.

The authors concluded: “Our findings suggest a negative long-term association between life-expectancy and both low carbohydrate and high carbohydrate diets…These data also provide further evidence that animal-based low carbohydrate diets should be discouraged.

Alternatively, when restricting carbohydrate intake, replacement of carbohydrates with predominantly plant-based fats and proteins could be considered as a long-term approach to healthy aging.”

Simply put, that means if a low carb diet works best for you, it is healthier to replace the carbs with plant-based fats and protein rather than animal-based fats and protein.

The “Goldilocks Effect”

Goldilocks EffectThis study also resolved the discrepancies between previous studies. The authors pointed out that the PURE study relied heavily on data from Asian and developing countries, and the average carbohydrate intake is very different in Europe and the US than in Asian and developing countries.

  • In the US and Europe mean carbohydrate intake is about 50% of calories and it ranges from 25% to 70% of calories. With that range of carbohydrate intake, it is possible to observe the increase in mortality associated with both very low and very high carbohydrate intakes.
  • The US and European countries are affluent, which means that low carb enthusiasts can also afford diets high in animal protein.
  • In contrast, white rice is a staple in Asian countries, and protein is a garnish rather than a main course. Consequently, overall carbohydrate intake is greater in Asian countries and very few Asians eat a truly low carbohydrate diet.
  • High protein foods tend to be more expensive than high carbohydrate foods. Thus, very few people in developing countries can afford to follow a very low carbohydrate diet, and overall carbohydrate intake also tends to be higher in those countries.

Therefore, in Asian and developing countries the average carbohydrate intake is greater (~61%) than in the US and Europe (~50%), and the range of carbohydrate intake is from 45% to 80% of calories instead of 25% to 70%. With this range of intake, it is only possible to see the increase in mortality associated with very high carbohydrate intake.ARIC Study

In fact, when the authors of the current study overlaid the data from the PURE study with their ARIC data, there was an almost perfect fit. The only difference was that their ARIC data covered both low and high carbohydrate intake while the PURE study touted by low carb enthusiasts only covered moderate to high carbohydrate intake.

[I have given you my rendition of the graph on the right. If you would like to see the data yourself, look at the paper.]

Basically, low carb advocates are telling you that diets with carbohydrate intakes of 26% or less are healthy based on studies that did not include carbohydrate intakes below 40%. That is misleading. The studies they quote are incapable of detecting the risks of low carbohydrate diets.

In short, the ARIC study finally answered the question, “How much carbohydrate should we be eating if we desire a long and healthy life?” The answer is “Enough”.

I call this “The Goldilocks Effect”. You may remember “Goldilocks And The Three Bears”. One bed was too hard. One bed was too soft. But one bed was “just right”. One bowl of porridge was too hot. One was two cold. But one was “just right”.

According to this study, the same is true for carbohydrate intake. High carbohydrate intake is unhealthy. Low carbohydrate intake is unhealthy. But moderate carbohydrate intake is “just right”.

What Does This Study Mean For You?

QuestionsThere are several important take-home lessons from this study:

1) All major studies agree that very high carbohydrate intake is unhealthy. In part, that reflects the fact that diets with high carbohydrate intake are likely to be high in sodas and sugary junk foods. It may also reflect the fact that diets which are high in carbohydrates are often low in plant protein or healthy fats or both.

2) All studies that cover the full range of carbohydrate intake agree that low and very low carbohydrate diets are also unhealthy. They shorten the life expectancy of a 50-year-old by about 4 years.

3) The studies quoted by low carb enthusiasts to support their claim that low-carb and very low carb diets are healthy don’t include carbohydrate intakes below 40%. That means their claims are misleading. The studies they quote are incapable of detecting the risks of low carbohydrate diets. Their claims are a myth.

4) Not all high carb diets are created equally. As I noted above, the Mediterranean and DASH diets are just as high in carbohydrates as the typical American diet, but their carbohydrates come from whole fruits and vegetables, whole grains, beans, nuts, and seeds. And multiple studies show that both diets are much healthier than the typical American diet.

5) Not all low carb diets are created equally. Meat-based low-carb diets decrease life expectancy compared to the typical American diets while plant-based low carb diets increase life expectancy.

6) The health risks of meat-based low-carb diets may be due to the saturated fat content or the heavy reliance on red meat. However, the risks are just as likely to be due to the foods these diets leave out – typically fruits, whole grains, legumes, and some vegetables.

7) Proponents of low-carb diets assume that you can make up for the missing nutrients by just taking multivitamins. However, each food group also provides a unique combination of phytonutrients and fibers. The fibers, in turn, influence your microbiome. Simply put, whenever you leave out whole food groups, you put your health at risk.

The Bottom Line

The low-carb wars are raging. Several studies have reported that low carb diets increase risk of mortality (shorten lifespan). However, a study published a few years ago came to the opposite conclusion. That study had low carb enthusiasts doing a victory lap and claiming it is time to rewrite nutritional guidelines to favor low-carb diets.

However, a study published a year later resolves the conflicting data and finally answers the question: “How much carbohydrate should we be eating if we desire a long and healthy life?” The answer is “Enough”.

I call this “The Goldilocks Effect”. According to this study, high carbohydrate intake is unhealthy. Low carbohydrate intake is unhealthy. But moderate carbohydrate intake is “just right”.

Specifically, this study reported:

  • Moderate carbohydrate intake (50-55%) is healthiest. This is the carbohydrate intake found in healthy diets like the Mediterranean and DASH diets, and is the intake recommended by current nutritional guidelines.
  • All major studies agree that very high carbohydrate intake (60-70%) is unhealthy. It shortens the life expectancy of a 50-year-old by about a year.
  • All studies that cover the full range of carbohydrate intake agree that low carbohydrate intake (<26%) is also unhealthy. It shortens the life expectancy of a 50-year-old by about 4 years.
  • The studies quoted by low carb enthusiasts to support their claim that low-carb diets are healthy don’t include carbohydrate intakes below 40%. That means their claims are misleading. The studies they quote are incapable of detecting the risks of low carbohydrate diets.
  • Meat-based low-carb diets decrease life expectancy while plant-based low carb diets increase life expectancy. This is consistent with the results of previous studies.

The authors concluded: “Our findings suggest a negative long-term association between life-expectancy and both low carbohydrate and high carbohydrate diets…These data also provide further evidence that animal-based low carbohydrate diets should be discouraged.”

Simply put, the latest study means that the supposed benefits of low carb diets are a myth.

For more details, read the article above.

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

___________________________________________________________________________

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

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

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

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

 ______________________________________________________________________

About The Author 

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

Do Bad Genes Doom You To Bad Health?

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The Influence Of Genetics And Diet On Type 2 Diabetes

Author: Dr. Stephen Chaney 

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

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

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

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

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

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

Genetics 101: How Genes Affect Your Health

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

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

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

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

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

How Was This Study Done?

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

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

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

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

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

The Influence Of Genetics And Diet On Type 2 Diabetes 

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

Compared with low genetic risk:

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

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

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

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

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

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

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

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

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

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

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

Looking at it another way:

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

Simply put:

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

In short, the good news is that bad genes do not doom you to type 2 diabetes.

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

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

Do Bad Genes Doom You To Bad Health?

Bad GenesAt the beginning of this article I posed the question, “Do bad genes doom you to bad health?”

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

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

None of this information is new. What is new is that a healthy diet is equally beneficial at reducing type 2 diabetes risk even in individuals with a high genetic risk of developing the disease. Simply put, you can reverse the effects of bad genes.

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

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

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

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

Should You Get Your DNA Tested?

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

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

The Bottom Line

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

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

Other studies have come to similar conclusions for other diseases. In short, bad genes don’t doom you to bad health.

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

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

_____________________________________________________________________________

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

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

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

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

_______________________________________________________________________

About The Author 

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

Is Olive Oil Overrated?

by

What Is The Truth About Olive Oil And You? 

Author: Dr. Stephen Chaney 

You may have seen headlines claiming that olive oil doesn’t deserve its “health halo”. It isn’t as healthy as many experts have claimed. It is overrated.

These headlines aren’t referring to the scandalous practice of selling “extra virgin” olive oil that contains cheaper oils. That is another topic for another day.

The headlines are claiming that, while the Mediterranean diet is healthy, it is fruits, vegetables, whole grains, legumes, and fish that make the Mediterranean diet healthy. Their claim is that olive oil has little to do with it.

To evaluate these claims I have reviewed the study (AK Krenek et al, Journal of the American Heart Association, Volume 13, Number 15:e035034, July 24, 2024) behind the headlines.

And to provide context, I have also reviewed another recent study (M Guasch-Ferre et al, Journal of the American College of Cardiology, Volume 79, Number 2, 2022).

How Were These Studies Done?

clinical studyThe two studies were very different:

The First Study used a randomized cross-over design to compare high and low olive oil diets.

In the randomized cross-over design participants were randomly assigned to one of the two diets at the beginning of the study. They followed that diet plan for 4 weeks. And after a one week “washout” they followed the other diet plan for 4 weeks. In this type of study each participant serves as their own control.

Study participants (50 obese participants, average age = 64, 75% women, 72% white, ≥ 5% risk of heart disease) were all eating a typical American diet.

Each of the experimental diets was a whole food plant-based diet, with comparable amounts of fruits, vegetables, whole grains, legumes, nuts, and seeds. Both diets were high in fiber, low in added sugar, and contained less than an ounce of animal products a day. In other words, the base diet was a healthy plant-based diet.

Participants in the high olive oil group were asked to add 4 tablespoons/day of extra virgin olive oil to their diet while participants in the low olive oil group were asked to restrict their olive oil intake to < 1 teaspoon/day.

No effort was made to control portion sizes or caloric intake. As we will see below, this was a major weakness of the study. As you might expect, fat intake was significantly greater for those on the high olive oil diet (49% of calories) compared to the low olive oil diet (32% of calories). Consequently, caloric intake was also significantly greater on the high olive oil diet.

All participants met with a dietitian/chef at the beginning of the study and were given access to online training programs and a dietitian hotline for questions. Dietary intake was measured by a 24-hour dietary recall 4-7 times prior to the study and 4 times during each diet period.

Fasting blood and urine samples were collected prior to the study and at the end of each 4-week diet period to measure biomarkers with possible predictive value for heart disease, such as LDL cholesterol.

The Second Study was a prospective cohort study using data obtained from 60,582 women in the Nurses Health Study and 31,801 men in the Health Professionals Follow-Up Study.

In a prospective cohort study a cohort or group of people (in this case, the 60,582 women and 31,801 men in the two studies) are followed over time (in this case for 28 years from1990 to 2018). The study then measures the association between some aspect of their diet and lifestyle (in this case the kind of fat in their diet) and health outcomes at the end of the study (in this case all-cause mortality, cardiovascular mortality, cancer mortality, neurodegenerative disease mortality, and respiratory disease mortality).

A strength of this study was that the diet of all participants was assessed every 4 years, which allowed the investigators to track changes in their diet over time. The intake of most fats was remarkably stable over the entire 28-year duration of the study.

However, as the bad news about margarine and the good news about olive oil entered the popular media, margarine consumption declined, and olive oil consumption increased. Because the investigators were able to track these changes over time, they were able to correct for them in their data analysis.

Is Olive Oil Overrated?

thumbs down symbolResults From The First Study: If we restrict ourselves to statistically significant observations, the results were as follows:

  • Switching from the baseline diet (typical American diet) to either the high olive oil or low olive oil diets for 4 weeks resulted in a significant decrease in total cholesterol, LDL cholesterol, HDL cholesterol, and blood glucose levels.
  • In this case, there was no statistically significant difference between the two diets.

However, when transitioning from the low olive oil diet to the high olive oil diet and from the high olive oil diet to the low olive oil diet, some statistically significant differences were observed.

For example, transitioning from the high olive oil diet to the low olive oil diet resulted in:

  • A 7% decrease in total cholesterol.
  • An 11% decrease in LDL-cholesterol.
  • A 2.2% decrease in HDL-cholesterol.
  • A 2% decrease in blood glucose levels.

And transitioning from the low olive oil diet to the high olive oil diet resulted in:

  • A 14% increase in total cholesterol.
  • A 14% increase in LDL-cholesterol.
  • A 15% increase in HDL-cholesterol.
  • A 17% decrease in blood glucose levels.

The authors of this study said, “Although both [whole food, primarily plant-based] diets improved [risk factors for heart disease], a low olive oil intervention may provide superior LDL-cholesterol lowering in individuals at highest risk [of heart disease]. Future studies are needed to determine if these short-term effects are sustainable and translate to improvements in cardiac outcomes…Nevertheless, a whole food primarily plant-based diet with relatively lower olive oil may be a useful tool for clinicians for improving cardiovascular risk compared with greater olive oil intake.”

The authors also went on to say, “…olive oil may not be the beneficial additive of a Mediterranean diet.”

thumbs upResults From The Second Study:

Higher intake of olive oil (>0.5 tablespoons/day compared to ≤1 teaspoon/day) resulted in:

  • A 19% decrease in the risk of all-cause mortality. And when that was broken down by cause it amounted to:
    • A 19% decrease in the risk of cardiovascular mortality.
    • A 17% decrease in the risk of cancer mortality.
    • A 29% decrease in the risk of neurodegenerative disease mortality.
    • An 18% decrease in the risk of respiratory disease mortality.

In a substitution analysis calculating the effect of consuming 10 g/day of olive oil instead of 10 g/day of:

  • Butter resulted in a 14% decrease in the risk of all-cause mortality.
  • Margarine or dairy fat resulted in a 13% decrease in the risk of all-cause mortality.
  • Mayonnaise resulted in a 9% decrease in the risk of all-cause mortality.
  • Other vegetable oils had no effect on all-cause mortality.
  • Results were similar when the investigators looked at the effect of replacing fats with olive oil on mortality due to cardiovascular disease, cancer, neurodegenerative disease, and respiratory disease.

The authors of the second study concluded, “Higher olive oil intake was associated with lower risk of total and cause-specific mortality. Replacing margarine, butter, mayonnaise, and dairy fat with olive oil was associated with lower risk of mortality.”

How can we reconcile these conflicting viewpoints? Let me start by looking at the flaws in the first study. Then I will summarize the “truth” about olive oil based on what these two studies tell us.

Is The Study Behind The Headlines Misleading?

flawsFirst let me summarize why I consider the study to be misleading. Then I will discuss why the headlines about the study are misleading.

Why The Study Is Misleading: The main conclusion of this study was that adding olive oil to a primarily plant-based diet increased the risk of heart disease. While this study is well-designed in some respects, it is flawed in others. I will summarize the flaws here:

Flaw Number 1: The authors rely on the relative effects of the high and low olive oil diets on LDL-cholesterol levels in predicting the effect of the two diets on heart disease risk. However, there is a major problem with this argument:

  • HDL-cholesterol levels move in the same direction. Both are decreased in the transition from the high olive oil to the low olive oil diet. Both are increased in the transition from the low olive oil to high olive oil diet. The ratio of HDL to LDL cholesterol changes very little, so it is almost impossible to predict what effect these changes will have on heart disease outcomes.

Flaw Number 2: This is related to the flaw I mentioned earlier. No effort was made to control portion size or caloric intake of participants on these diets. The high olive oil diet added 4 tablespoons of olive oil to the low olive oil diet. This significantly increased the fat and caloric intake of participants on the high olive oil diet.

  • Participants lost weight on both diets, but weight loss was significantly greater on the low olive oil diet. In their discussion, the authors admitted that the greater reduction in LDL-cholesterol on the low olive oil diet could have been due to the greater reduction in weight on that diet.

Flaw Number 3: I call this the “straw man” flaw. By adding 4 tablespoons of olive oil to the high olive oil diet the authors created the equivalent of a straw man that was easy knock over. Even if their conclusions were correct, nobody has recommended the addition of 4 tablespoons of olive oil to any diet as a heart-healthy approach.

Mediterraneans don’t add 4 tablespoons of olive oil to their diet. Olive oil is part of the foods they eat and the way they prepare their food.

Why The Headlines Are Misleading: Of course, the headlines were misleading because they ignored the many flaws of the study.

However, I find it amusing that some of the headlines came from “Forks Over Knives” an organization that advocates for a very low-fat plant-based diet. They were using this study to question the value of olive oil as part of a whole-food plant-based diet.

However, when you look at the study, 32% of calories came from fat in the low olive oil diet, and 49% of calories came from fat in the high olive oil diet.

For perspective:

  • The low-fat whole-food plant-based diet recommended by “Forks Over Knives” has <10-15% of calories from fat.
  • The Mediterranean diet typically contains 35-40% of calories from fat.
    • Around 18-19% of that is monounsaturated fat.
    • Around 8% of that is saturated fat.
  • The typical American diet also contains 35-40% of calories from fat.
    • Around 12-14% of that is monounsaturated fat.
    • Around 12% of that is saturated fat.

In other words, the low olive oil diet in this study resembles the fat content of the Mediterranean and typical American diets, not the low-fat whole food plant-based diet recommended by “Forks Over Knives”.

And the high olive oil diet contains fat levels not seen in any natural diet. Except for a few keto enthusiasts, I don’t know of any experts who think getting almost 50% of your calories from any kind of fat is a good thing.

What Is The Truth About Olive Oil And You?

The TruthAs described above, the study behind the headlines is a very small, very short study with multiple flaws. So, you can ignore headlines like “Olive oil is overrated” or “Olive oil doesn’t deserve its health halo.”

The second study I discussed is much larger (92,383 participants) and of much longer duration (28 years). More importantly, it measures health outcomes, not blood biomarkers that might predict health outcomes.

Finally, the second study was not measuring the health benefits of the Mediterranean diet, as many other studies have done. It was looking at the effect of varying olive oil intakes in the American diet. The high olive oil intakes in this study were less than those seen in the Mediterranean diet. This is good news for the average American who may feel overwhelmed trying to adopt to a Mediterranean diet.

This study reinforces previous studies showing that olive oil is healthy. But let me put this into context.

  • Olive oil is not a superfood. This study showed that it is no healthier than other plant oils. It is, however, considered one of the best vegetable oils for sauteing. It is also less susceptible to oxidation than seed oils, although I still recommend you store it in the refrigerator.
  • It is not something you add to your diet. It is something you incorporate into your diet. People who live in Mediterranean regions:
    • Cook with olive oil.
    • Use olive oil in their salad dressings and drizzle a little olive oil on cooked vegetable and pasta dishes instead of adding butter.
    • Dip their bread in olive oil rather than using butter or mayonnaise.
    • Use it in spreads like tapenade or hummus.
    • Use olives in cooking.
  • Finally, look for extra virgin olive oil. That doesn’t mean you need to spend “an arm and a leg”. But I would do a little online research before I bought the cheapest brand at the discount store.

The Bottom Line

You may have seen recent headlines claiming that olive oil is overrated and that it doesn’t deserve its “health halo”. So, I looked at the study behind the headlines.

It was a very small, very short study with multiple flaws. You can forget the headlines.

For context I also reviewed another recent study. It was a much larger (92,383 participants) and longer duration (28 years) study. More importantly, it measured actual health outcomes, not just blood biomarkers that might predict health outcomes.

It concluded that olive oil is good for us. It is healthier than most fats commonly found in the American diet, but it is no healthier than other plant oils.

For more details on these studies, what they mean for you, and how to incorporate more olive oil into your 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.

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

_____________________________________________________________________

About The Author 

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

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

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

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

 

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

Which Diets Are Best For The Planet?

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Which Diets Are Best For Your Health?

Author: Dr. Stephen Chaney

HotIs it hot enough yet? I’m not going to take a stand in the global warming debate. But I will say this summer has been extraordinarily hot – even for North Carolina.

So, what can we do about it? I will list some options below. But with “tongue in cheek” I will give voice to both sides of each option.

  • We can elect politicians of our choice and hope they have the wisdom to balance reductions in global warming with the energy needs of our country – but there has been little evidence of that wisdom from either end of the political spectrum.
  • We can purchase electric cars – despite their cost, limited range, and long refueling times.
  • We can recycle – even though most of what we recycle ends up in regular trash.
  • We can turn up our thermostats in summer and down in winter – and choose to swelter in summer and shiver in winter.
  • We can change our diet – but wait. Could this be a win no matter what our views are on climate change? Could the same diets that are better for the planet also be better for our health?

That is the hypothesis today’s study (K. O’Malley et al, The American Journal of Clinical Nutrition, 117: 701-708, 2023) set out to test.

How Was The Study Done?

clinical studyThe investigators analyzed 24-hour dietary recall data from 16,412 participants from the 2005 – 2010 NHANES survey. NHANES (National Health and Nutrition Examination Survey) is an ongoing, nationally representative, survey to measure the health and nutrition status of the US population. This investigation used data collected between 2005 and 2010.

The dietary data were used to categorize the intake of individual participants into different diets as follows:

  • Vegan – plant foods only.
  • Vegetarian – includes eggs and dairy but excludes meat.
  • Pescatarian – includes fish as the major source of meat.
  • Paleo – excludes grains, legumes, and dairy.
  • Keto – excludes grains, legumes, fruits, and starchy vegetables.
  • Omnivore – Any diet not included in the categories above.

The omnivore diet was further divided to identify people following the DASH and Mediterranean diets.

The environmental impact of each diet was calculated based on the amount of CO2 and methane produced in the production of the foods included in the diet.

The impact on our health of each diet was calculated based on the Alternative Healthy Eating Index.

  • The Healthy Eating Index was first developed in 1995 as tool to gauge how well a diet followed the Dietary Guidelines for Americans established by the Department of Health & Human Services and the USDA.
  • The Alternative Healthy Eating Index was first developed in 2002 to include a wider range of foods and to better predict the effect of diet on chronic diseases based on clinical studies of health outcomes.
  • Each of these indices are regularly updated as more data become available.

Which Diets Are Best For the Planet?

I have put the data in a graphical format, so it is easier to visualize.The vertical axis is greenhouse gas emissions expressed as kg of CO2 equivalents per 1,000 calories (The term CO2 equivalents is used because cows and sheep produce methane which is a much more potent greenhouse gas than CO2). Lower is better.

On the horizontal axis the diets from left to right are vegan, vegetarian, pescatarian, paleo, keto, omnivore, DASH, and Mediterranean. The diets with the least greenhouse gas emissions are shown in green (the greener the better), and the diets with the most greenhouse gas emissions are shown in orange and red.

Which Diets Are Best For Your Health?

Once again, I have chosen a graphical representation.

The vertical axis is the Alternative Healthy Eating Index. In this case, higher is better.

The color score is the same as above. However, I would note that:

  • Fish is the main animal protein source in the pescatarian diet. I suspect that the vegan and vegetarian diets would score just as high as the pescatarian diet in the Alternative Healthy Eating Index if an omega-3 supplement was taken along with the diets.
  • The Alternative Healthy Eating Index is weighted heavily on clinical studies showing that a particular diet reduces the risk of heart disease, diabetes, and/or cancer. That is likely why the DASH diet ranks so high. It was designed to decrease the risk of hypertension. Because of that there have been dozens of studies showing it reduces the risk of strokes and heart attacks.

The available evidence suggests that the Mediterranean diet is just as effective as the DASH diet at reducing the risk of strokes, heart attacks, and diabetes. But we do not yet have as many studies looking at the effect of the Mediterranean diet on those diseases. Based on the currently available evidence, I consider the Mediterranean diet to be just as healthy as the DASH diet.

Finally, I would like to point out the obvious. This and other studies show that the same diets that are good for the planet are good for our health.

For example, the authors estimated:

  • For any given day, if a third of omnivores in the United States switched to a vegetarian diet, it would be equivalent to eliminating 340 million passenger miles in gas-powered vehicles.
  • If this change were implemented year-round, it would amount to almost 5% of the reductions in greenhouse gas emissions needed to meet the original US targets in the Paris accords.
  • For those omnivores who made the switch to a vegetarian diet, it would improve diet quality by 6%.

Of course, if all omnivores in the United States switched to a vegetarian diet, these percentages would be tripled, but that is wildly unrealistic.

What Does This Study Mean For You?

Planetary DietThe take home lesson from this study is clear.

If your primary concern is climate change, choose the planet-healthy diet that best fits your food preferences and lifestyle. [The ones with the lowest greenhouse gas emissions are shown in green in the first graph above – the greener, the better.] Any of these diets will also be good for your health.

If your primary concern is health, choose the healthy diet that best fits your food preferences and lifestyle. [The ones with the highest Alternate Healthy Eating Index are shown in green in the second graph above – the greener, the better.] Any of these diets will also be good for the planet.

 

The Bottom Line

A recent study compared 8 popular diets (vegan, vegetarian, pescatarian, paleo, keto, omnivore, DASH, and Mediterranean) with respect to their impact on the environment and on your health.

The results were clear-cut. The diets that were best for the planet were best for your health and vice-versa.

For example, the authors estimated:

  • For any given day, if a third of omnivores in the United States switched to a vegetarian diet, it would be equivalent to eliminating 340 million passenger miles in gas-powered vehicles.
  • If this change were implemented year-round, it would amount to almost 5% of the reductions in greenhouse gas emissions needed to meet the original US targets in the Paris accords.
  • For those omnivores who made the switch to a vegetarian diet, it would improve diet quality by 6%.

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

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

 ______________________________________________________________________________

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

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

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

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

 About The Author 

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

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

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

 

Health Tips From The Professor