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Are All Plant-Based Diets Healthy?

September 10, 2024 by Dr. Steve Chaney

Why Are Plant-Based Diets Healthy?

Author: Dr. Stephen Chaney

Unless you are like Rip van Winkle and have been asleep for the past 30 years, you have probably heard that plant-based diets are good for you. In fact, that advice is sound. It is based on multiple long-term studies.

But you may still be hesitant to make the switch. You are probably wondering if you have to be a vegan purist to benefit from a plant-based diet. If so, you are wondering whether you can make that drastic a change in your diet. Or, you may have already decided “that is a bridge too far” and don’t want to even consider it.

So, one important question is, “Do you have to go vegan to benefit from a plant-based diet?”

On the other hand, “Big Food, Inc” has made it easier than ever to switch to more “plant-based” eating. After all, sugar comes from plants. And highly processed grains come from plants. Add a few chemicals and you can come up with an endless supply of highly processed plant-based foods.

So, another important question is, “Can a diet of highly processed plant-based foods be as healthy as a diet of whole, unprocessed plant-foods?”

The study (Y. Wang et al., Nutrition Journal, 22: 46, 2023) I am reviewing today was designed to answer these two questions. It also represents the first meta-analysis to combine data from studies on the effects of plant-based diets on diabetes, heart disease, cancer, and mortality into a single study.

How Was The Study Done?

The investigators performed a meta-analysis of 76 studies with 2,230,443 participants that looked at the associations of plant-based dietary patterns and the incidence of type 2 diabetes, cardiovascular disease, cancer, and mortality among adults 18 years or older.

The characteristics of study participants ranged from:

25 to 87 years old.
BMI of 20 to 30.

And the duration of the studies within the meta-analysis ranged from 2 to 36 years.

The adherence to plant-based diets was defined as higher consumption of plant-based foods and lower consumption or exclusion of animal-based foods.

The meta-analysis also included studies looking at the effect of changing from a more animal-based to a more plant-based dietary pattern.

The meta-analysis included studies looking at the benefit of vegan and vegetarian diets. In terms of participants these studies represented just over 50% of the data in the meta-analysis. So, this meta-analysis was ideally positioned to determine whether vegan and vegetarian diets were more beneficial than other primarily plant-based dietary patterns that included some animal foods.

The methodology used to classify diets as primarily plant-based varied from study to study. But in each case the study participants were divided into quartiles ranging from consuming the most plant-based diet to consuming the least plant-based diet.

The study then compared study participants with the highest adherence to plant-based diets to those with the lowest adherence to plant-based diets with respect to type 2 diabetes, cardiovascular disease, cancer, and mortality.

Finally, the study also compared adherence to healthy plant-based dietary patterns (whole or minimally processed fruits, vegetables, whole grains, beans, nuts, and seeds) to unhealthy plant-based dietary patterns (foods and drinks with added sugar, highly processed plant foods, and starchy vegetables).

Are Plant-Based Diets Healthy?

When comparing highest to lowest adherence to plant-based dietary patterns the risk of:

Type-2 diabetes was reduced by 18%.

Cardiovascular disease was reduced by 10%.

Cancer was reduced by 12%.

Mortality was reduced by 16%.

In short, all the news was good for primarily plant-based dietary patterns.

Are All Plant-Based Diets Healthy?

Increased adherence to a healthy plant-based dietary pattern (That term is defined in the methods section above) was associated with an even better reduction in disease risk. For example:

Type-2 diabetes was reduced by 21%.

Cardiovascular disease was reduced by 15%.

Cancer was reduced by 13%.

Mortality was reduced by 14%, which was statistically indistinguishable from the reduction in mortality associated with all plant-based dietary patterns above.

In contrast, increased adherence to an unhealthy plant-based dietary pattern was associated with increased risks of disease. For example:

The risk of type 2 diabetes increased by 8%.

The risk of cardiovascular disease increased by 14%.

The risk of cancer increased by 7%.

The risk of mortality increased by 16%.

In short, plant-based dietary patterns consisting of whole or minimally processed plant foods are good for you. Plant-based dietary patterns consisting of highly processed plant foods are not.

Are Vegan and Vegetarian Diets More Beneficial Than Other Plant-Based Dietary Patterns?

Twenty seven of the studies within this meta-analysis compared vegetarian or vegan dietary patterns with animal-based dietary patterns. These studies had 1,343,967 participants, which amounts to 57% of the participants in the meta-analysis.

Thus, this meta-analysis was well positioned to determine relative benefits of vegan and vegetarian diets compared to other primarily plant-based dietary patterns that include some animal foods. The investigators reported that:

The risk reduction for type 2 diabetes was greater in studies with vegan and vegetarian diets than in studies with other primarily plant-based diets.

No other statistically significant benefits were observed for vegan and vegetarian diets compared to other primarily plant-based diets.

In short, you don’t need to become a vegan to experience the health benefits of a plant-based diet.

In contrast, increased adherence to an unhealthy plant-based dietary pattern was associated with increased risks of disease. For example:

The risk of type 2 diabetes increased by 8%.

The risk of cardiovascular disease increased by 14%.

The risk of cancer increased by 7%.

The risk of mortality increased by 16%.

In short, plant-based dietary patterns consisting of whole or minimally processed plant foods are good for you. Plant-based dietary patterns consisting of highly processed plant foods are not.

What If You Change From An Animal-Based To A Plant-Based Diet?

If you have been consuming an animal-based diet for years, you may be wondering whether it is too late to change. Has the damage already been done?

Six studies within this meta-analysis examined the effect of changing from an animal-based diet to a plant-based diet on type 2 diabetes and mortality. Changing to a more plant-based dietary pattern:

Reduced diabetes by 17% and mortality by 5%.

In short, it’s never too late to switch to a more plant-based dietary pattern.

Why Are Plant-Based Diets Healthy?

The short answer is that we don’t know for sure, but the authors mentioned several popular hypotheses.

Obesity is a risk factor for type 2 diabetes, cardiovascular disease, and certain types of cancer. And studies have shown that people consuming plant-based diets tend to weigh less.

The increased fiber content and higher ratio of polyunsaturated fats to saturated fats lower cholesterol levels and improve blood lipid profiles, which are associated with a lower risk of cardiovascular disease.

Plant-based diets are anti-inflammatory, which reduces the risk of all three diseases.

Plant foods are rich in polyphenols and other phytonutrients that are associated with reduced risk of cardiovascular disease, lower blood pressure, and improvements in insulin sensitivity.

Plant foods are metabolized by gut bacteria to metabolites that are associated with reduced risk of type 2 diabetes and cardiovascular disease.

Plant foods support healthy gut bacteria associated with a reduced risk of several diseases.

Finally, plant-based dietary patterns are associated with no or reduced consumption of red and processed meats, which increase the risk of type 2 diabetes, cardiovascular disease, and certain types of cancer.

For a more detailed discussion read the article).

What Does This Study Mean For You?

The authors of this study concluded, “Higher adherence to plant-based dietary patterns, especially from healthy sources, may be universally beneficial for the primary prevention of type 2 diabetes, cardiovascular disease, cancer, and mortality. The current study provides further evidence in support of current recommendations that emphasize consuming high-quality plant-based foods for achieving optimal health.”

“Future studies are needed to elucidate…mechanistic pathways linking plant-based diets with multiple disease outcomes.”

I would just like to emphasize a few points:

These are all association studies. It takes decades for diseases like diabetes, heart disease, and cancer to develop. So, it is impossible to confirm these findings with double blind, placebo-controlled studies. However, when you have 76 studies with over 2 million participants all pointing to the same conclusion, it is hard to ignore the findings.

The good news is that you don’t have to become a vegan to experience these benefits. There are many healthy primarily plant-based diets available. Choose the one that best fits your food preferences and lifestyle.

Be aware that whatever diet you choose, Big Food Inc is only too happy to provide you with highly processed foods that fit that dietary pattern. Don’t fall for that trap. Stick with whole or minimally processed plant foods.

If your current diet isn’t the best, it is never too late to switch to a healthier primarily plant-based diet.

The Bottom Line

A recent meta-analysis of 76 studies with 2,230,443 participants looked at the associations of plant-based dietary patterns and the incidence of type 2 diabetes, cardiovascular disease, cancer, and mortality among adults 18 years or older.

The authors of the study concluded, “Higher adherence to plant-based dietary patterns, especially from healthy sources, may be universally beneficial for the primary prevention of type 2 diabetes, cardiovascular disease, cancer, and mortality. The current study provides further evidence in support of current recommendations that emphasize consuminh high-quality plant-based foods for achieving optimal health.”

Other key points from the study are:

These are all association studies. It takes decades for diseases like diabetes, heart disease, and cancer to develop. So, it is impossible to confirm these findings with double blind, placebo-controlled studies. However, when you have 76 studies with over 2 million participants all pointing to the same conclusion, it is hard to ignore the findings.

The good news is that you don’t have to become a vegan to experience these benefits. There are many healthy primarily plant-based diets available. Choose the one that best fits your food preferences and lifestyle.

Be aware that whatever diet you choose, Big Food Inc is only too happy to provide you with highly processed foods that fit that dietary pattern. Don’t fall for that trap. Stick with whole or minimally processed plant foods.

If your current diet isn’t the best, it is never too late to switch to a healthier primarily plant-based diet.

For more details about how the authors came to these conclusions 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.

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

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

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

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

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About The Author

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

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

For the past 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?

August 13, 2024 by Dr. Steve Chaney

Which Diets Are Best For Your Health?

Author: Dr. Stephen Chaney

Is 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?

The 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?

The 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.

______________________________________________________________________________

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

Is The Blood Type Diet A Myth?

February 27, 2024 by Dr. Steve Chaney

What Does This Study Mean For You?

Author: Dr. Stephen Chaney

In 1997 Dr. Peter J. D’Adamo wrote a book about the blood type diet called “Eat Right 4 Your Type”. Dr. D’Adamo claims that people with different blood types process food differently, so their blood type determines the type of diet that is healthiest for them. Specifically, he claims that people with:

Blood group O are descended from hunters and should consume meat-oriented diets.

Blood group A are descended from farmers and should consume a near vegetarian diet – completely avoiding red meats.

Blood group B are descended from nomads. They have the most flexible digestive system and can eat the widest variety of foods – even dairy products, which he does not recommend for any of the other blood types.

Blood group AB is an enigma and are somewhere between blood group A and blood group B.

It’s an interesting concept. Dietary recommendations are made for populations and there is tremendous genetic variation for individuals in every population. Because of this genetic variation, there is no perfect diet for everyone. Every knowledgeable health expert will tell you that.

The question then becomes “How do you know what kind of diet is healthiest for you?”

The blood type diet is a very simple system. Your blood type is easy to determine. Once you know your blood type you know what to eat. There’s no guesswork.

Could it really be so simple? Over 7 million copies of Dr. D’Adamo’s book have been sold. Several celebrities swear by it. Millions of people believe in this concept. So, it is only fitting to ask, “Is it true?”

There is no doubt that blood type is related to some human genetic and physical traits, especially inflammation and immunity. It is also associated with disease risk.

Type A individuals are more likely to have elevated total and LDL cholesterol are slightly more likely to develop heart disease.

Type O individuals are slightly more likely to develop type 2 diabetes.

But the important question is whether blood type is related to the health outcomes of different diets – the central thesis of Dr. D’Adamo’s book.

In this article, I discuss a recent study (ND Barnard et al, Journal of the Academy of Nutrition and Dietetics, 121: 1080-1086, 2021) that asks whether the beneficial effects of a vegan diet (the ultimate vegetarian diet) are influenced by blood type. I will also reference previous studies with other diets that asked the same question.

How Was The Study Done?

The investigators enrolled 244 people from the Washington DC area in a 16-week study to measure the metabolic effects of a low-fat vegan diet. Because of the resources necessary to support the study, the subjects were enrolled into 4 replications of the study with 60+ people each between January 2017 and December 2018.

During the second replication of the study (68 participants) blood typing was done to determine whether blood type had any influence on the results. A low-fat vegan diet is the ultimate vegetarian diet. It allows no meat, no dairy, and no animal fats. According to the Blood Type Diet, type A individuals should have much better results on a vegan diet than type O individuals.

The subjects were randomly divided into two groups. One group was assigned to follow a low-fat vegan diet for 16 weeks. The other group was told to follow their regular diet for 16 weeks. Subjects in both groups were advised to follow their usual level of physical activity.

The vegan diet group was instructed to avoid animal products; eat a variety of fruits, vegetables, grains, and legumes; and to limit added oils, nuts, and seeds. They were provided with a B12 supplement to assure none of them developed a B12 deficiency.

The vegan group attended weekly classes that provided dietary guidance and encouraged diet adherence. The classes were conducted by study physicians and registered dietitians. And participants were given handouts at each class to help them follow the diet.

Finally, compliance was assessed by a 3-day diet record interview conducted by trained experts at baseline and week 16.

Is The Blood Type Diet A Myth?

The baseline characteristics of study participants were:

80% female

Average age = 54.

Average BMI = 32 (obese).

Average HbA1c = 5.6 (normal blood sugar control).

Total cholesterol = 195 mg/dL (at the high end of normal).

LDL cholesterol = 115 mg/dL (at the high end of normal).

And, as expected from previous studies, type A individuals had higher total and LDL cholesterol than other groups. They were borderline high in both categories.

Across all blood type groups, 16 weeks on a low-fat vegan diet significantly decreased:

Weight (14 pounds).

BMI (7%).

Fat mass (11%).

Belly fat (15%).

HbA1c (15%).

Total cholesterol (9%).

LDL cholesterol (11%).

But the important observations were that:

When type A individuals were compared with all non-type A individuals there were no significant differences for any of those parameters.

When type O individuals were compared with all non-type O individuals there were no significant differences for any of those parameters.

More importantly, no significant differences were observed between type A and type O individuals for any of these parameters.

But the authors also said, “This does not discount the possibility that the effects of diet on health may be dependent on other genetic components.”

What Do Other Studies Show?

Two previous studies have looked at the relationship between blood groups and the effect of diet and health parameters.

The Toronto Nutrigenomics and Health Study (J Wang et al, PLoS One, 9(1):e84740, 2014) was a cross-sectional examination of young adults aged 20-29 to determine whether there was any association of blood type with the optimal diet of those individuals. It found:

Those with the closest adherence to a blood type A diet had lower BMI, waist circumference, serum cholesterol, serum triglycerids, and blood sugar control) regardless of which blood type they were.

Those with the closest adherence to a type O diet had lower serum triglycerides regardless of which blood type they were.

The Toronto Health Diet Study ( DJA Jenkins et al, Journal of the American College of Cardiology, 69: 1103-1112, 2017) was a 6-month intervention study that emphasized plant-derived foods but did not exclude meat and dairy. It found:

Those with best adherence to the prescribed diet had improved levels of several cardiometabolic risk factors (cholesterol, triglycerides, and blood sugar control) regardless of which blood type they were.

In other words, both previous studies showed that primarily plant-based diets significantly reduce multiple risk factors for heart disease and diabetes. They also showed that blood types had no effect on the correlation between diets and health.

The most recent study reinforced these conclusions because it was an intervention study utilized the most rigid form of a plant-based diet. If there were any effect of blood type on the optimal diet, the vegan diet should have produced radically different results in individuals with different blood types.

What Does This Study Mean For You?

First and foremost, the Blood Type Diet is a myth. It has now been proven to be false in multiple clinical studies. If you have a copy of Dr. D’Adamo’s book, my best advice is to throw it in the trash. Normally, I would favor recycling, but I would hate for a book that inaccurate to influence someone else.

And to my friends who have in the past said that they were blood type O and the type O (meat based) blood type diet worked for them, I would refer them to the words of the authors when they said, “This does not discount the possibility that the effects of diet on health may be dependent on other genetic components.”

In other words, there may be some people who do better on a meat-based diet. And that may be based on certain yet-unidentified genes. But it is not based on blood type.

But this study also brings the benefits of primarily plant-based diets into focus. As I have said in previous issues of “Health Tips From the Professor”:

Short term studies show that whole food, primarily plant-based diets reduce risk factors associated with multiple chronic disease.

Long term studies show that whole food, primarily plant-based diets reduce the risk of heart disease, diabetes, and some kinds of cancer.

A well designed and supplemented vegan diet is very healthy. However:

- Vegan diets are rigid and hard for most Americans to maintain. That’s why only 4% of Americans follow a vegan diet on a regular basis.

Fortunately, you don’t have to go full vegan to reap the benefits of a plant-based diet. Diets ranging from semi-vegetarian to Mediterranean, DASH, and MIND provide similar benefits. For example, the diet used in the Toronto Health Study referenced above was very similar to the DASH diet.

Finally, clinical studies are based on averages. The current studies tell us that most Americans benefit from a primarily plant-based diet.

- However, we cannot currently exclude the possibility that some people might benefit from a primarily meat-based diet. Unfortunately, we have no long-term studies that support that possibility.

The Bottom Line

Dr. Peter J. D’Adamo wrote a book about the blood type diet called “Eat Right 4 Your Type”. Dr. D’Adamo claims that people’s blood type determines the type of diet that is healthiest for them. For example, he claims that blood type A individuals do best with a plant-based diet and blood type O individuals do best with a meat-based diet.

A recent study asked whether the beneficial effects of a vegan diet (the ultimate plant-based diet) are influenced by blood type. It found:

Individuals put on a vegan diet for 16 weeks had reduced weight, BMI, body fat, belly fat, cholesterol levels, and blood sugar control and those benefits were not affected by blood type.

The authors concluded, “These results indicate that blood type is not associated with the effect of a plant-based diet on body weight, body fat, plasma lipid [cholesterol] concentrations or glycemic [blood sugar] control.” These results are supported by two previous studies that reached the same conclusion using less rigid primarily plant-based diets.

But the authors also said, “This does not discount the possibility that the effects of diet on health may be dependent on other genetic components.”

For more information on this and previous 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.

_____________________________________________________________________________

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 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.

What Can Twins Tell Us About Diet?

January 30, 2024 by Dr. Steve Chaney

What Are The Pros And Cons Of Twin Studies?

Author: Dr. Stephen Chaney

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

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

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

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

We do not yet know enough about gene-nutrient interactions to use genomic data to accurately predict which diets are best. Again, I have covered that topic in a previous issue of “Health Tips From the Professor”. However, we do know that genetic differences have a big influence on which diet is best for us. And most clinical studies on diets do not even attempt to take genetic differences into account.

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

How Was The Study Done?

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

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

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

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

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

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

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

What Can Twins Tell Us About Diet?

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

LDL-cholesterol was reduced by 12% for the twin on the vegan diet, while it remained unchanged for the twin on the omnivorous diet.

The fasting insulin level was reduced by 21% for the twin on the vegan diet, while it remained unchanged for the twin on the omnivorous diet. This suggests the twin on the vegan diet was experiencing improved blood sugar control after just 8 weeks.

The twin on the vegan diet lost 4 pounds in 8 weeks, while weight remained the same for the twin on the omnivorous diet. This occurred even though neither twin was instructed to eat less nor to lose weight. It is most likely a consequence of the lower caloric density of the vegan diet (See my discussion of caloric density in last week’s issue of “Health Tips From the Professor”.

The changes in LDL-cholesterol and fasting insulin were remarkable because none of the twins in this study had elevated LDL-cholesterol or problems with blood sugar control at the beginning of the study.

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

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

Were There Any Downsides To The Vegan Diet?

This study also highlighted two well-known limitations of vegan diets.

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

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

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

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

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

I concur.

What Are The Pros And Cons Of Twin Studies?

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

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

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

But there are several studies showing that the vegan diet is associated with lower weight and reduced risk of heart disease and diabetes.

And there are dozens of studies showing that primarily plant-based omnivorous diets reduce the risk of heart disease and diabetes.

This study is fully consistent with those studies.

The Bottom Line

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

LDL-cholesterol was reduced by 12% for the twin on the vegan diet, while it remained unchanged for the twin on the omnivorous diet.

The fasting insulin level was reduced by 21% for the twin on the vegan diet, while it remained unchanged for the twin on the omnivorous diet. This suggests the twin on the vegan diet was experiencing improved blood sugar control after just 8 weeks.

The twin on the vegan diet lost 4 pounds in 8 weeks, while weight remained the same for the twin on the omnivorous diet. This occurred even though neither twin was instructed to eat less or to lose weight. It is most likely a consequence of the lower caloric density of the vegan diet.

The changes in LDL-cholesterol and fasting insulin were remarkable because none of the twins in this study had elevated LDL-cholesterol or problems with blood sugar control at the beginning of the study.

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

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

_____________________________________________________________________________

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

For the past 35 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 Heart Healthy?

September 26, 2023 by Dr. Steve Chaney

What Does A Heart Healthy Diet Look Like?

Author: Dr. Stephen Chaney

Heart disease is a big deal. According to the CDC, “Heart disease is the leading cause of death for men, women, and people of most racial and ethnic groups in the United States. One person dies every 33 seconds in the United States from cardiovascular disease. About 695,000 people in the United States died from heart disease in 2021 – that’s 1 in every 5 deaths”.

This doesn’t have to happen. According to the Cleveland Clinic, “90 percent of heart disease is preventable through healthier diet, regular exercise, and not smoking”. For this issue of “Health Tips From the Professor”, I will focus on the role of diet on heart health.

The problem is many Americans are confused. They don’t know what a heart-healthy diet is. There is so much conflicting information on the internet.

Fortunately, the American Heart Association has stepped in to clear up the confusion.

In 2021 they reviewed hundreds of clinical studies and published “Evidence-Based Dietary Guidance to Promote Cardiovascular Health”.

And recently they have published a comprehensive review (CD Gardner et al, Circulation, 147: 1715-1730, 2023) of how well popular diets align with their 2021 dietary guidelines.

I will cover both publications below. But first I want to address why Americans are so confused about which diets reduce heart disease risk.

Why Are Americans Confused About Diet And Heart Disease Risk?

I should start by addressing the “elephant in the room”.

As I discussed in last week’s “Health Tips From the Professor” article, Big Food Inc has seduced us. They have developed an unending supply of highly processed foods that are cheap, convenient, easy to prepare, and fulfill all our cravings. These foods are not heart-healthy, but they make up 73% of our food supply.

The Institute of Medicine, the scientific body that sets dietary standards, states that a wide range of macronutrient intakes are consistent with healthy diets. Specifically, they recommend carbohydrate intake at 45% to 65%, fat intake at 20% to 35%, and protein intake at 10% to 35% of total calories. (Of course, they are referring to healthy carbohydrates, fats, and proteins.)

The authors of this article pointed to several reasons why Americans have been misled about heart-healthy diets.

Many of the most popular diets fall outside of the “Acceptable Macronutrient Range”.

Many popular diets exclude heart-healthy food groups.

And, the words of the authors,

“Further contributing to consumer misunderstanding is the proliferation of diet books, [and] blogs [by] clinicians with limited understanding of what the dietary patterns entail and the evidence base for promoting cardiometabolic health.” I call these the Dr. Strangeloves of our world.

What Does A Heart Healthy Diet Look Like?

Let me start by sharing the American Heart Association’s 10 “Evidence-Based Dietary Guidelines to Promote Cardiovascular Health.

#1: Adjust energy intake and expenditure to achieve and maintain a healthy body weight
#2: Eat plenty of vegetables and fruits; choose a wide variety
#3: Choose foods made mostly with whole grains rather than refined grains
#4: Choose healthy sources of protein
	Mostly from plants (beans, other legumes, and nuts)
	Fish and seafood
	Low-fat or fat-free dairy products instead of full-fat dairy products
	If meat or poultry are desired, choose lean cuts and avoid processed forms
#5. Use liquid plant oils (olive, safflower, corn) rather than animal fats (butter and lard) and tropical oils (coconut and palm kernel)
#6. Use minimally processed foods instead of highly processed foods
#7: Minimize intake of beverages and foods with added sugars
#8: Choose and prepare foods with little or no salt
#9: If you do not drink alcohol, do not start; if you choose to drink alcohol, limit intake
#10: Adhere to this guidance regardless of where food is prepared or consumed

Here are my comments on these guidelines:

If you have been reading my “Health Tips From the Professor” blog for a while, you probably realize that these aren’t just guidelines to promote heart health. These guidelines also reduce the risk of diabetes, cancer, inflammatory diseases, and much more.

If you have read my post on coconut oil, you will know that I have a minor disagreement with the AHA recommendation to avoid it. There is no long-term evidence that coconut oil is bad for the heart. But there is also no long-term evidence that it is good for the heart. My recommendation is to use it sparingly.

And you probably know there has been considerable discussion recently about whether full fat dairy is actually bad for the heart. In my most recent review of the topic, I concluded that if full fat dairy is heart healthy, it is only in the context of a primarily plant-based diet and may only be true for fermented dairy foods like unpasteurized yogurt and kefir.

Finally, guideline 10 may need some translation. Basically, this guideline is just asking how easy it is to follow the diet when you are away from home.

Which Diets Are Heart Healthy?

In evaluating how well diets adhered to the American Heart Association guidelines the authors ignored item 1 (energy intake) because most of the diets they evaluated did not provide any guidelines on how many calories should be consumed.

Each diet was given a score between 0 (Fail) and 1 (A+) for each of the other 9 guidelines by a panel of experts. The points for all 9 guidelines were added up, giving each diet a rating of 0 (worst) to 9 (best). Finally, a score of 9 was assigned 100%, so each diet could be given a percentage score for adherence to heart-healthy guidelines.

Here are the results:

Tier 1 diets (the most heart healthy diets) received scores of 86% to 100%. Going from highest (100%) to lowest (86%), these diets were:

DASH, Nordic, Mediterranean, Pescetarian (vegetarian diets that allow fish), and Ovo-Lacto Vegetarian (vegetarian diets that allow dairy, eggs, or both).

You will notice that these are all primarily plant-based diets.

Tier 2 diets were Vegan and other low-fat diets (TLC, Volumetrics). They both received scores of 78%.

The Vegan diet received 0 points for category 10 (ease of following the diet when eating out). It was also downgraded in category 7 for not having clear guidance for the use of salt when preparing foods.

The other low-fat diets were downgraded in categories 7, 10, and 5 (use of tropical oils).

Tier 3 diets received scores of 64% to 72%. They included very-low fat diets (<10% fat, very strict vegan diets) and low-carb diets (Zone, South Beach, Low-Glycemic Index).

They received 0 points for category 10 and were downgraded for eliminating heart-healthy food groups (liquid plant oils for the very low-fat diets, and fruits, vegetables, whole grains, and plant proteins for the low-carb diets).

Tier 4 diets (the least heart healthy diets) were the Paleo diet with a score of 53% and very low-carb diets (Atkins and Ketogenic) with a score of 31%.

The Paleo diet received 0 points for categories 10, 3 (choose whole grains), and 5 (using liquid plant oils rather than animal fats or tropical oils). It was also downgraded for lack of healthy plant-based protein sources.

The very low-carb diets were the least heart healthy. They received 0 points for categories 2 (eat plenty of fruits and vegetables), 3 (choose whole grains), 3 (healthy protein sources), 5 (use liquid plant oils instead of animal fats), 7 (minimize salt consumption), and 10 (ease of following the diet away from home).

The authors concluded, “Numerous [dietary] patterns [are] strongly aligned with 2021 American Heart Association Dietary Guidance (ie, Mediterranean, DASH, pescetarian, vegetarian) [and] can be adopted to reflect personal and cultural preferences and budgetary constraints.

Thus, optimal cardiovascular health would be best supported by developing a food environment that supports adherence to these patterns wherever food is prepared or consumed.”

Given our current food environment that last statement is wildly optimistic. But at least you have the information needed to make the best food choices for you and your family

The Bottom Line

In 2021 the American Heart Association published 10 guidelines for evaluating heart-healthy diets. A recent study looked at how well popular diets adhered to those guidelines. The authors separated the diets into four categories (tiers) based on how heart-healthy they were. The results were not surprising:

Tier 1 diets (the most heart healthy diets) were DASH, Nordic, Mediterranean, Pescetarian (vegetarian diets that allow fish), and Ovo-Lacto Vegetarian (vegetarian diets that allow dairy, eggs, or both).

Tier 2 diets were Vegan and other low-fat diets (TLC, Volumetrics).

Tier 3 diets included very-low fat diets (<10% fat, very strict vegan diets) and low-carb diets (Zone, South Beach, Low-Glycemic Index).

Tier 4 diets (the least heart healthy diets) were the Paleo diet and very low-carb diets (Atkins and Ketogenic).

Thus, optimal cardiovascular health would be best supported by developing a food environment that supports adherence to these patterns wherever food is prepared or consumed.”

Given our current food environment that last statement is wildly optimistic. But at least you have the information needed to make the best food choices for you and your family.

For more information on this 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.

____________________________________________________________________________

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

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

Are Sustainable Diets Nutritionally Complete?

September 5, 2023 by Dr. Steve Chaney

How Do Sustainable Diets Compare With Meat-Based Diets?

Author: Dr. Stephen Chaney

In a previous issue of “Health Tips From the Professor” I have discussed a sustainable diet popularly known as the planetary diet. Here is a brief synopsis of that article:

The planetary diet came from an international commission called the “EAT-Lancet Commission on Healthy Diets From Sustainable Food Systems” (Bureaucrats and scientists love long names.)

They were commissioned to recommend a diet that was both healthy and sustainable (good for the environment) through the year 2050.

The commission reported that the methods of food production required to support our current diets:

- Occupy 40% of global land.

- Are responsible for 30% of global greenhouse gas production and 70% of freshwater use.

They further reported that:

- Reaching the Paris Agreement of limiting global warming…is not possible by only decarbonizing the global energy systems (In other words, we cannot limit global warming just by switching to electric cars and stoves.).

- Transformation to healthy diets from sustainable food systems is essential to achieving the Paris Agreement.”

- The world’s population is expected to reach 10 billion by 2050. The current system of food production is unsustainable.

The planetary diet they recommended is a primarily plant-based diet. But it is not any plant-based diet. It limits animal foods to an extent that approaches a vegan diet.

That raises two important questions:

Are sustainable diets like the planetary diet healthy? The answer to that question is a resounding, “Yes”. Numerous studies have shown that primarily plant-based diets are healthier than meat-based diets long term.

2) Are sustainable diets nutritionally complete? That is the question the authors of the current study (N Neufingerl and A Eilander, Nutrients, 14: 29, 2022) set out to answer.

How Was This Study Done?

The authors searched the literature and identified 147 high-quality articles published between 2000 and January 2020 that compared the nutritional adequacy of primarily plant-based diets or vegan diets with meat-based diets.

They excluded:

Intervention studies because the nutritionists designing those studies assured the nutritional adequacy of the plant-based diet used in the study.

Overly restrictive plant-based diets such as the raw food diet or macrobiotic diet.

Primarily plant-based diets for disease prevention like the Mediterranean or DASH diets because they were too unlike the planetary diet.

Studies with pregnant or lactating women, populations with specific diseases, and athletes.

They chose diets that measured intakes of energy (calories), protein, PUFA (polyunsaturated fats), total omega-3 fats, ALA, EPA, DHA, fiber, vitamins A, B1, B6, B12, niacin, folate, C, D, E, iron, zinc, calcium, iodine, magnesium, and phosphorous. [Note: Not all studies measured intakes of all the nutrients in this list.]

Their goal was to compare the nutritional adequacy of the diets, not the health of the diets. So, they did not report on the saturated fat, cholesterol, sugar, or percent processed food content of the diets.

How Do Sustainable Diets Compare With Meat-Based Diets?

The Study showed that:

Vegan diets:

Tended to be inadequate in EPA, DHA, vitamins B12, D, calcium, iodine, iron, and zinc.

Tended to have favorably high intakes of fiber, PUFA, ALA, vitamins B1, B6, C, E, folate, and magnesium.

Vegetarian diets:

Tended to be inadequate in fiber, EPA, DHA, vitamins B12, D, E, calcium, iodine, iron, and zinc.

Tended to have favorably high intakes of PUFA, ALA, vitamin C, folate, and magnesium.

Meat-eaters:

Tended to be inadequate in fiber, PUFA, ALA, vitamins D, E, folate, calcium, and magnesium.

Tended to have favorably high intakes of protein, niacin, vitamin B12, and zinc.

Other observations:

Pesco-vegetarians (vegetarians who include fish as a major protein source) had the highest intake EPA and DHA of any of the groups studied.

Both vegetarians and vegans had lower protein intake than meat-eaters, but their average protein intake was adequate.

Finally, there are two important reminders as you look at the data.

The data for each nutrient was based on average intake of that nutrient in the diet group. The authors did not report the percent of people consuming that diet who had inadequate intake.

The authors were comparing the nutritional completeness of each diet, not the effect of the diets on diseases like heart disease and diabetes. However, this comparison is important because nutritional inadequacies left untreated for a long period of time can have significant health consequences.

Are Sustainable Diets Nutritionally Complete?

The authors concluded “…there are dietary inadequacies in any [restrictive] diet.” This is no surprise.

With respect to sustainable plant-based diets, the authors said, “In people following self-selected plant-based diets, especially vegan diets, intake of certain nutrients is lower compared to meat-containing diets.”

So, the answer to the question, “Are sustainable diets nutritionally complete?”, is clearly, “No. They do not provide 100% of the essential nutrients you need.”

Long-term nutritional deficiencies can have serious health implications. So, what should you do about it?

The authors made the following recommendations, “As plant-based diets are generally better for health and the environment, public health strategies should facilitate the transition to a [more] balanced diet…through consumer education, food fortification, and possible supplementation.”

Let me comment on the three recommendations they listed:

Consumer education is a great idea, but it is usually drowned out by Big Food Inc’s advertising budgets and the misleading information provided by the Dr. Strangeloves of the world.

Food fortification is also a useful idea. After all, it has eliminated several deficiency diseases in the past. But it is hard to fortify fruits and vegetables. And eating more highly processed plant-food products is not the way to better health – even if they are fortified. Besides, I wouldn’t hold my breath waiting for the USDA to act.

That leaves responsible supplementation as the only viable option for anyone wanting to switch to a plant-based diet to save the planet. And if the environment is important to you, you will probably want to choose a supplement company that follows sustainable practices and is certified carbon neutral.

The Bottom Line

Primarily plant-based diets are healthier for you and healthier for the planet. But are they nutritionally complete?

A recent systemic review of 147 published studies was designed to answer that question. As you might suspect, the answer was a clear, “No”.

Vegan diets:

Tended to be inadequate in EPA, DHA, vitamins B12, D, calcium, iodine, iron, and zinc.

Vegetarian diets:

Tended to be inadequate in fiber, EPA, DHA, vitamins B12, D, E, calcium, iodine, iron, and zinc.

The authors concluded, “As plant-based diets are generally better for health and the environment, public health strategies should facilitate the transition to a balanced diet…through consumer education, food fortification, and possible supplementation.”

Let me comment on the three recommendations they listed:

Consumer education is a great idea, but it is usually drowned out by Big Food Inc’s advertising budgets and the misleading information provided by the Dr. Strangeloves of the world.

Food fortification is also a useful idea. But it is hard to fortify fruits and vegetables. And eating more highly processed plant-food products is not the way to better health – even if they are fortified.

That leaves responsible supplementation as the only viable option for anyone wanting to switch to a plant-based diet to save the planet. And if the environment is important to you, you will probably want to choose a supplement company that follows sustainable practices and is certified carbon neutral.

For more information on this study, and the science behind my summary of 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.

___________________________________________________________________________

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

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

Is Vegan Breast Milk Sufficient?

June 27, 2023 by Dr. Steve Chaney

What Can Vegan Moms Do?

Author: Dr. Stephen Chaney

A whole food vegan diet is incredibly healthy:

Vegans are less likely to be overweight than the general population.

Vegans have a lower risk of diabetes, heart disease, cancer, hypertension, and several other diseases than the general population.

Whole food vegan diets are anti-inflammatory, so they lower the risk of autoimmune diseases and the “itis” diseases.

But vegan diets leave out meat, dairy, and eggs. Vegetarians without proper dietary advice are at high risk of inadequate intake of vitamin B12, vitamin D, iron, iodine, calcium, and DHA. And, of course, the risk of inadequate intake is even greater for vegans than it is for vegetarians, who may include some dairy and eggs in their diet.

So, it is legitimate to ask whether a vegetarian or vegan diet is sufficient for pregnancy and lactation. The short answer is that they can be if they are properly designed and properly supplemented.

But that is not an easy task, as evidenced by a recent study (N Ureta-Velasco et al., Nutrients 15:1855, 2023) comparing the breast milk of omnivore moms with the breast milk of vegetarian and vegan moms.

How Was This Study Done?

This study was done with 92 omnivore moms, 9 vegetarian moms (5-ovo-vegetarian and 4 lacto-ovo-vegetarians) and 11 vegan moms between August 2017 and February 2020 at the Regional Human Milk Bank at the “12 de Octubre” University Hospital in Madrid, Spain. The vegetarian and vegan moms were grouped together for data analysis.

On Day 0 of the study, participants went to the regional milk bank for blood and urine samples to determine nutritional status, a screening to determine health and socioeconomic status, and for food frequency questionnaire to characterize their habitual diet.

On days 1-5, they returned to the regional milk bank with a 24-hour diet recall of the previous day and to express 25 ml of breast milk to determine its nutrient content. On day 6, they returned to express a larger sample of breast milk to determine its lipid content (including EPA and DHA).

Note: Both the food frequency questionnaire and the 24-hour dietary recalls included nutrients derived from supplements.

What Did The Study Show About Dietary Intake of Key Nutrients?

This was a comprehensive study, so I will just cover the highlights here:

Birth Weight: Compared to the children of omnivore moms, the children of vegetarian/vegan moms were more likely to:

Have less weight gain during pregnancy (2 pounds less on average).

Be underweight at birth (60% of babies born to vegetarian/vegan moms were in the underweight category of birth weights versus 25% for babies born to omnivore moms).

This is probably because vegetarian/vegan moms:

Consumed slightly fewer calories per day (2146 versus 2319).

Consumed significantly less protein (67 g/d versus 96 g/d).

Were 10 times more likely to be underweight prior to pregnancy (10% versus 1%).

This is a concern because low birth weight increases the risk of physical and mental health issues later in life.

Supplement Use: The nutrients of greatest concern in a vegetarian/vegan diet are vitamin B12, vitamin D, iron, iodine, calcium, and DHA. For all these nutrients except DHA, this message appears to have gotten out to most vegetarian/vegan mothers because they were compensating for these potential deficiencies through supplementation.

For example, when they looked at average daily intake of these key nutrients from supplements, they found:

Nutrient	Vegetarian/Vegan Moms	Omnivore Moms
Vitamin D	1,080 IU (27mcg)	240 IU (6 mcg)
Folic acid	400 mcg	280 mcg
Vitamin B12	312 mcg	2 mcg
Calcium	566 mg	164 mg
Iron	40 mg	29 mg
DHA	100 mg	180 mg

However, that doesn’t tell the whole story, because not all vegetarian/vegan moms took supplements. When the investigators looked at the percent taking supplements, this is what they found.

Nutrient	Vegetarian/Vegan Moms	Omnivore Moms
Vitamin D	50%	50%
Folic acid	35%	61%
Vitamin B12	85%	60%
Calcium	15%	37%
Iron	25%	43%
DHA	10%	16%

Dietary Intake (Food + Supplements): The extra supplementation clearly played an important role because when the investigators looked at the overall intake from food and supplements, they found:

Nutrient	Vegetarian/Vegan Moms	Omnivore Moms
Vitamin D	224 IU (5.6 mcg)	432 IU (10.8 mcg)
Folate + Folic acid	668 mcg	473 mcg
Vitamin B12	258 mcg	6.9 mcg
Calcium	910 mg	1148 mg
Iron	31 mg	25 mg
DHA	110 mg	380 mg

Again, this doesn’t tell the whole story. Some women didn’t supplement. When the investigators looked at the percentage of women getting an inadequate intake of key nutrients from food plus supplements they found:

Nutrient	Vegetarian/Vegan Moms	Omnivore Moms
Vitamin D	75%	88%
Folate + Folic acid	0%	39%
Vitamin B12	25%	0%
Calcium	45%	40%
Iron	Not reported	Not reported
DHA	Not reported	Not reported

These results clearly show the need for supplementation. While the average intake from food plus supplements looked good, there were a significant percentage of women who weren’t getting adequate intake of key nutrients because they didn’t supplement.

The exceptions were folate + folic acid for vegetarian/vegans because their diet is rich in folate-containing foods and vitamin B12 for omnivores because their diet is rich in foods containing B12.

Is Vegan Breast Milk Sufficient?

Of course, the proof is in the pudding. When the investigators looked at the nutrient content of breast milk, this is what they found:

Nutrient	Vegetarian/Vegan Moms	Omnivore Moms	Reference Value*
Vitamin D3	1.1 mcg/L	3.4 mcg/L	0.25-2 mcg/L
Folate + Folic acid	19 mcg/L	20 mcg/l	80 mcg/L
Vitamin B12	0.74 mcg/L	0.65 mcg/L	0.5 mcg/L
Calcium	83 mg/L	99 mg/L	200-300 mg/L
Iron	Not reported	Not reported
DHA	0.15 g/100 g fat	0.33 g/100 g fat	0.35 g/100 g fat

*Reference values established by WHO

The chief difference between breast milk from vegetarian/vegan moms was in DHA levels.

That’s because the diet of vegetarians and vegans contains very little DHA, and very few vegetarian/vegan women in this study supplemented with DHA.

This study also found that breast milk from both vegetarian/vegan moms and omnivore moms was low in folate + folic acid, calcium, nicotinamide, and selenium. They said that requires follow-up in future studies.

The authors concluded, “The most important contribution of this study is the detailed and comprehensive description of micronutrients and lipids in human milk from omnivore milk donors and vegetarian/vegan women…Of particular concern is the lower DHA content in the milk of our vegetarian/vegan group. However, raising awareness and administering proper supplementation could bridge the gap, as has been the case with vitamin B12.”

What Can Vegan Moms Do?

This study emphasizes the importance of careful planning and supplementation during pregnancy and lactation if you are a vegetarian or vegan mom.

For example, the vegetarian/vegan women in this study were more likely to have low birthweight babies, and low birthweight infants are at risk for health issues later in life. That means:

Careful planning is required to select calorie- and protein-rich plant foods.

A high-quality plant protein supplement can be a great help.

Supplementation is particularly important during lactation to assure your breast milk adequately nourishes your newborn baby. For example, in this study:

The vitamin B12 level in the breast milk from vegetarian/vegan moms was adequate because 85% of them supplemented with vitamin B12.

The DHA level in the breast milk from vegetarian/vegan moms was inadequate because only 10% of them supplemented with DHA.

The authors of this study recommended that vegetarian and vegan moms consume at least 200 mg of DHA from algal sources while they are breastfeeding.

However, finding a prenatal supplement that provides all the nutrients you need prior to pregnancy, during pregnancy, and while breastfeeding is challenging. I gave you 7 tips for choosing the best prenatal supplements in a previous “Health Tips From the Professor” article.

The Bottom Line

A recent study asked whether the breast milk of vegetarian and vegan moms was sufficient for the needs of their newborn babies. The study found that:

Folate levels in their breast milk were sufficient because the diets of vegetarians and vegans contain many folate-rich foods.

Vitamin B12 levels in their breast milk were sufficient because 85% of the vegetarian and vegan women in this study supplemented with vitamin B12.

DHA levels in their breast milk were insufficient because the diets of vegetarian and vegan women are very low in DHA, and only 10% of the women in this study supplemented with DHA.

The authors of this study recommended that vegetarian and vegan moms consume at least 200 mg of DHA from algal sources while they are breastfeeding.

This study reinforces the need for supplementation during lactation to assure your breast milk adequately nourishes your newborn baby.

However, finding a prenatal supplement that provides all the nutrients you need prior to pregnancy, during pregnancy, and while breastfeeding is challenging. I gave you 7 tips for choosing the best prenatal supplement in a previous “Health Tips From the Professor” article.

For more information on this 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.

___________________________________________________________________________

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

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

Tips For Successful Weight Loss

January 3, 2023 by Dr. Steve Chaney

Which Diet Is Best?

Author: Dr. Stephen Chaney

It’s the beginning of January. Weight loss season has just launched again. Like millions of Americans, you have probably set a goal to eat healthier, lose weight, or both. But which diet is best? Vegan, Paleo, Keto, 360, Intermittent Fasting, low-carb, low fat – the list is endless.

And then there are the commercial diets: Meal replacements, low calorie processed foods, prepared meals delivered to your door – just to name a few of the categories.

You can choose to count calories, focus on portion sizes, or keep a food journal.

And, if you really want to live dangerously, you can try the latest diet pills that claim to curb your appetite and rev up your metabolism.

The advertisements for all these diets sound so convincing. They give you scientific-sounding mumbo jumbo to explain why they work. Then they talk about clinical studies they say prove their diet works.

If you are like most Americans, you have already tried several of these diets. They worked for a while, but the pounds came back – and brought their friends with them.

But, as the saying goes, “Hope springs eternal in the human breast”. Surely some diet you haven’t tried yet will work for you.

There are such diets. But they will require effort. They will require a change of mindset. There is no magic wand that will chase the extra pounds away forever.

If you are searching for the perfect diet to start the new year, let me be your guide. Here are:

4 tips on mistakes to avoid and…

6 tips on what to look for…

7 tips for making weight loss permanent…

…when you are choosing the best diet for you.

Mistakes To Avoid When Choosing The Best Diet

1. Endorsements

Endorsements by your favorite athlete or public person are paid for. They don’t necessarily represent their opinion. Nor do they assure you that they follow that diet or use that diet supplement.

Endorsements by Dr. Strangelove and his buddies can be equally misleading. They usually tell you that the medical establishment has been lying to you, and they have discovered the “secret” to permanent weight loss and the “Fountain of Youth”.

Recommendations of the medical and scientific communities usually represent a consensus statement by the top experts in their field. I would choose their advice over Dr. Strangelove’s opinion any day.

2) Testimonials

Most of the testimonials you see online or in print are either paid for or are fake.

Testimonials by your friends can be equally misleading. We are all different. What works for your friend or for your trainer may not work for you.

For example, some of us do better on low-carb diets, and others do better on low fat diets.

[Note: Some DNA testing companies claim they can sequence your DNA and tell you which diet is best. However, as I reported in a recent article in “Health Tips From The Professor”, independent studies show that DNA testing is of no use in predicting whether low-carb or low-fat diets are better for you.]

3) Diets Based on “Magic” Or “Forbidden” Foods or Food Groups.

I have often said we have 5 food groups for a reason. Each food group provides a unique blend of nutrients and phytonutrients. And each plant food group provides a unique blend of fibers that support the growth of different types of friendly gut bacteria.

The bottom line is that each of us does better with some foods than others, but there are no “magic” or “forbidden” foods that apply to everyone.

4) “Magic” Diets.

I have written perhaps the first diet book, “Slaying The Food Myths”, that doesn’t feature a “magic” diet that is going to make the pounds melt away and allow you to live to 100. Instead, I recommend a variety of healthy diets and suggest you choose the one that fits you best.

However, I understand the allure of “magic” diets. Dr. Strangelove claims the diet will be effortless. He gives you some scientific-sounding mumbo-jumbo to convince you the diet is scientifically sound. Then he cites some clinical studies showing the diet will cause you to lose weight and will improve your health parameters (things like cholesterol, triglycerides, blood sugar, and blood pressure). It sounds so convincing.

Before you fall for Dr. Strangelove’s latest “magic” diet, let me share two things that may blow your mind:

The studies are all short-term (usually 3 months or less).

When you rely on short-term studies, the very low-fat Vegan diet and very low-carb Keto diet give you virtually identical weight loss and improvement in health parameters!

Those two diets are as different as any two diets could be. That means we can forget all the scientific-sounding mumbo-jumbo as to why each of those diets work. Instead, we should ask what these two diets have in common.

The answer is simple:

#1: The clinical studies are comparing “magic” diets to the typical American diet. Anything is better than the typical American diet! It is high in sugar, refined carbohydrates, saturated fat, and highly processed foods. No wonder the “magic” diets look so good.

#2: The diets are whole food diets. Anytime you eliminate sodas, fast foods, and highly processed foods, you will lose weight.

#3: The diets eliminate one or more food groups. Whenever you eliminate some of your favorite foods from your diet, you tend to lose weight without thinking about it. I call this the cream cheese and bagel phenomenon.

If you are following a low-fat diet, it sounds great to say you can eat all the bagels you want. But without cream cheese to go with the bagels, you tend to eat fewer bagels.

If you are following a low-carb diet, it sounds great to say you can eat as much cream cheese as you want, but without bagels to go with your cream cheese, you tend to eat less cream cheese.

#4: Because they eliminate many of your favorite foods, “magic” diets make you focus on what you eat. Whenever you focus on what you eat, you tend to lose weight. That is why food journals and calorie counters are effective.

#5: Finally, whenever you lose weight, your health parameters (cholesterol, triglycerides, blood sugar, and blood pressure) improve.

Tips For Successful Weight Loss

What should you look for in choosing a healthy weight loss diet? Here are my top 6 tips.

1. Choose whole food diets. Avoid sodas, fast foods, and highly processed foods.

2) Choose primarily plant-based diets. These can range from Vegan through semi-vegetarian, Mediterranean, DASH, and Nordic. All are healthy diets. I have discussed the evidence for this recommendation in my book “Slaying The Food Myths”. Here is a brief summary.

When we look at long term (10-20 year) studies:

Vegetarians weigh less and are healthier than people consuming the typical American diet.

People consuming semi-vegetarian, Mediterranean, and DASH diets are healthier than people consuming the typical American diet.

When we look at low-carb diets:

People consuming plant-based low-carb diets weigh less and are healthier than people consuming the typical American diet.

People consuming meat-based low-carb diets are just as fat and unhealthy as people consuming the typical American diet.

The Atkins low-carb diet has been around for more than 50 years, and there is no evidence it is healthy long-term.

3) Choose diets that include a variety of foods from all 5 food groups. I have discussed the rationale for that recommendation above.

4) Choose diets that consider meat as a garnish, not a main course.

5) Choose diets that feature healthy carbs and healthy fats rather than low-carb or low-fat diets.

6) Think lifestyle, not diet. If you choose a restrictive diet so you can achieve quick weight loss, you will probably be just as fat and unhealthy next December 31^st as you are this year. Instead, choose diets that teach healthy eating and lifestyle changes that you can make a permanent part of your life.

Tips For Keeping The Weight Off

You know the brutal truth. Around 95% of dieters regain everything they lost and then some within a few years. You have probably gone through one or more cycles of weight loss and regain yourself – something called “yo-yo dieting”. You may even be asking yourself if it is worth bothering to try to lose weight this year.

Rather focusing on the negative statistics of weight loss, let’s look at the good news. There are people who lose the weight and keep it off. What do they do?

There is an organization called the National Weight Control Registry that has enrolled more than 10,000 people who have lost weight and kept it off. The people in this group lost weight on almost every diet imaginable. However, here is the important statistic: On average people in this group have lost 66 pounds and kept it off for at least 5 years.

The National Weight Control Registry has kept track of what they have done to keep the weight off. Here is what they do that you may not be doing:

1. They consume a reduced calorie, whole food diet.

2) They get lots of exercise (around 1 hour/day).

3) They have internalized their eating patterns. In short, this is no longer a diet. It has become a permanent part of their lifestyle. This is the way they eat without even thinking about it.

4) They monitor their weight regularly. When they gain a few pounds, they modify their diet until they are back at their target weight.

5) They eat breakfast on a regular basis.

6) They watch less than 10 hours of TV/week.

7) They are consistent (no planned cheat days).

Which Diet Is Best?

Now it is time to get back to the question you are asking right now, “Which diet is best?” I have covered a lot of ground in this article. Let me summarize it for you.

If you are thinking about popular diets:

Primarily plant-based diets ranging from Vegan to Mediterranean and Dash are associated with a healthier weight and better health long term.

- If want to lose weight quickly, you may want to start with the more restrictive plant-based diets, like Vegan, Ornish, Pritikin or semi-vegetarian.

- If you do better with a low-carb diet, my recommendation is the lower-carb version of the Mediterranean diet called Med-Plus. It is a whole food version of the Mediterranean diet that minimizes added sugar and refined grains (I will be talking more about it in next week’s “Health Tips From the Professor”).

- If your primary goal is rapid weight loss, you could also start with one of the healthier of the restrictive low-carb diets, like the Paleo or the 360 diet. I do not recommend the Keto diet.

No matter what diet you start with, plan to transition to the primarily plant-based diet that best fits your lifestyle and food preferences. This is the diet you will want to stick with to maintain your weight loss and achieve better health long term.

Plan on permanent lifestyle change rather than a short-term diet. Otherwise, you are just wasting your time.

Eat whole foods. Big Food keeps up with America’s favorite diets and is only too happy to sell you highly processed foods that match your favorite diet. Avoid those like the plague.

If you are thinking about commercial diets featuring meal replacement products:

Look for meal replacement products that:

- Do not contain artificial sweeteners, flavors, or preservatives.

- Use non-GMO protein. A non-GMO certification for the other ingredients is not necessary. For a more detailed explanation of when non-GMO certification is important and when it is unnecessary, see my article in “Health Tips From the Professor”.

- Have stringent quality controls in place to assure purity. “Organic” and/or “non-GMO” on the label do not assure purity.

Look for programs that can provide clinical studies showing their diet plan is effective for weight loss and for keeping the weight off. Many programs have short-term clinical studies showing they are effective for weight loss, but very few have longer-term studies showing the weight stays off.

Finally, look for programs that teach permanent lifestyle change. This should include guidance on exercise and healthy eating.

I do not recommend most commercial diets that feature prepared low-calorie foods “shipped right to your door” as a major part of their program. The foods are highly processed. Plus, they include all your favorite unhealthy foods as part of the program. Even if they include lifestyle change as part of their program, they are undermining their message with the foods they are providing you.

I would be remiss if I didn’t mention that Weight Watchers is highly recommended by most experts in the field. Weight Watchers emphasizes journaling and counting calories, which is a plus because it makes you focus on what you are eating. They also have a good lifestyle program and support that can help you transition to permanent lifestyle change if you are willing to put in the effort. However, I don’t recommend their prepared low-calorie foods. They are no better than foods provided by the other commercial diet programs.

The Bottom Line

Weight loss season is upon us. If you plan to lose weight and/or adopt a healthier diet this year, you are probably asking, “Which Diet Is Best?” In this issue of “Health Tips From The Professor” I give you:

4 tips on mistakes to avoid when selecting the diet that is best for you.

6 tips on how to choose the best diet.

5 tips on what to look for when selecting a diet featuring meal replacement products.

7 tips on how to keep the weight off.

Then I put all this information together to help you choose the best diet, the best meal replacement product, and/or the best commercial diet program.

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.

Eating For A Healthy Planet

April 26, 2022 by Dr. Steve Chaney

Can Diet Affect The Health Of Our Planet?

Author: Dr. Stephen Chaney

Earth Day has come and gone. You have recommitted to saving the planet. You plan to recycle, conserve energy, and turn in your gas guzzler for an energy efficient car. But what about your diet? Is your diet destroying the planet?

This is not a new question, but a recent commission of international scientists has conducted a comprehensive study into our diet and its effect on our health and our environment. Their report (W. Willet et al, The Lancet, 393, issue 10170, 447-492, 2019) serves as a dire warning of what will happen if we don’t change our ways. I touched on this report briefly in a previous issue of “Health Tips From The Professor”, but this topic is important enough that it deserves an issue all its own.

The commission carefully evaluated diet and food production methods and asked three questions:

Are they good for us?

Are they good for the planet?

Are they sustainable? Will they be able to meet the needs of the projected population of 10 billion people in 2050 without degrading our environment.

The commission described the typical American diet as a “lose-lose-lose diet”. It is bad for our health. It is bad for the planet. And it is not sustainable.

In its place they carefully designed their version of a primarily plant-based diet they called a “win-win-win diet”. It is good for our health. It is good for the planet. And it is sustainable.

In their publication they refer to their diet as the “universal healthy reference diet” (What else would you expect from a committee?). However, it has become popularly known as the “Planetary Diet”.

I have spoken before about the importance of a primarily plant-based diet for our health. In that context it is a personal choice. It is optional.

However, this report is a wake-up call. It puts a primarily plant-based diet in an entirely different context. It is essential for the survival of our planet. It is no longer optional.

If you care about our environment…If you care about saving our planet, there is no other choice.

How Was The Study Done?

The publication (W. Willet et al, The Lancet, 393, issue 10170, 447-492, 2019) was the report of the EAT-Lancet Commission on Healthy Diets from Sustainable Food Systems. This Commission convened 30 of the top experts from across the globe to prepare a science-based evaluation of the effect of diet on both health and sustainable food production through the year 2050. The Commission included world class experts on healthy diets, agricultural methods, climate change, and earth sciences. The Commission reviewed 356 published studies in preparing their report.

Can Diet Affect The Health Of Our Planet?

When they looked at the effect of food production on the environment, the Commission concluded:

“Strong evidence indicates that food production is among the largest drivers of global environmental change.” Specifically, the commission reported:

- Agriculture occupies 40% of global land (58% of that is for pasture use).

- Food production is responsible for 30% of global greenhouse gas emissions and 70% of freshwater use.

- Conversion of natural ecosystems to croplands and pastures is the largest factor causing species to be threatened with extinction. Specifically, 80% of extinction threats to mammals and bird species are due to agricultural practices.

- Overuse and misuse of nitrogen and phosphorous in fertilizers causes eutrophication. In case you are wondering, eutrophication is defined as the process by which a body of water becomes enriched in dissolved nutrients (such as phosphates from commercial fertilizer) that stimulate the growth of algae and other aquatic plant life, usually resulting in the depletion of dissolved oxygen. This creates dead zones in lakes and coastal regions where fish and other marine organisms cannot survive.

- About 60% of world fish stocks are fully fished and more than 30% are overfished. Because of this, catch by global marine fisheries has been declining since 1996.

“Reaching the Paris Agreement of limiting global warming…is not possible by only decarbonizing the global energy systems. Transformation to healthy diets from sustainable food systems is essential to achieving the Paris Agreement.”

The world’s population is expected to increase to 10 billion by 2050. The current system of food production is unsustainable.

When they looked at the effect of the foods we eat on the environment, the Commission concluded:

Beef and lamb are the biggest contributors to greenhouse gas emissions and land use.

- The concern about land use is obvious because of the large amount of pastureland required to raise cattle and sheep.

- The concern about greenhouse gas emissions is because cattle and sheep are ruminants. They not only breathe out CO₂, but they also release methane into the atmosphere from fermentation in their rumens of the food they eat. Methane is a potent greenhouse gas, and it persists in the atmosphere 25 times longer than CO₂.

The single most important thing we can do as individuals to reduce greenhouse gas emissions is to eat less beef and lamb. [Note: grass fed cattle produce more greenhouse gas emissions than cattle raised on corn because they require 3 years to bring to market rather than 2 years.]

- In contrast, plant crops reduce greenhouse gas emissions by removing CO₂ from the atmosphere.

In terms of energy use beef, lamb, pork, chicken, dairy, and eggs all require much more energy to produce than any of the plant foods.

In terms of eutrophication of our lakes and oceans, beef, lamb, and pork, all cause much more eutrophication than any plant food. Dairy and eggs cause more eutrophication than any plant food except fruits.

Eating For A Healthier Planet

In the words of the Commission: “[The Planetary Diet] largely consists of vegetables, fruits, whole grains, legumes, nuts, and unsaturated oils. It includes a low to moderate amount of seafood, poultry, and eggs. It includes no or a very low amount of red meat, processed meat, sugar, refined grains, and starchy vegetables.”

When described in that fashion it sounds very much like other healthy diets such as semi-vegetarian, Mediterranean, DASH, and Flexitarian. However, what truly distinguishes it from the other diets is the restrictions placed on the non-plant portion of the diet to make it both environmentally friendly and sustainable. Here is a more detailed description of the diet:

It starts with a vegetarian diet. Vegetables, fruits, beans, nuts, soy foods, and whole grains are the foundation of the diet.

It allows the option of adding one serving of dairy a day (It turns out that cows produce much less greenhouse emissions per serving of dairy than per serving of beef. That’s because cows take several years to mature before they can be converted to meat, and they are emitting greenhouse gases the entire time).

It allows the option of adding one 3 oz serving of fish or poultry or one egg per day.

It allows the option of swapping seafood, poultry, or egg for a 3 oz serving of red meat no more than once a week. If you want a 12 oz steak, that would be no more than once a month.

This is obviously very different from the way most Americans currently eat. According to the Commission:

“This would require greater than 50% reduction in consumption of unhealthy foods, such as red meat and sugar, and greater than 100% increase in the consumption of healthy foods, such as nuts, fruits, vegetables, and legumes”.

“In addition to the benefits for the environment, “dietary changes from current diets to healthy diets are likely to substantially benefit human health, averting about 10.8-11.6 million deaths per year globally.”

What Else Did The Commission Recommend?

In addition to changes in our diets, the Commission also recommended several changes in the way food is produced. Here are a few of them.

Reduce greenhouse gas emissions from the fuel used to transport food to market.

Reduce food losses and waste by at least 50%.

Make radical improvements in the efficiency of fertilizer and water use. In terms of fertilizer, the change would be two-fold:

- In developed countries, reduce fertilizer use and put in place systems to capture runoff and recycle the phosphorous.

- In third world countries, make fertilizer more available so that crop yields can be increased, something the Commission refer to as eliminating the “yield gap” between third world and developed countries.

Stop the expansion of new agricultural land use into natural ecosystems and put in place policies aimed at restoring and re-foresting degraded land.

Manage the world’s oceans effectively to ensure that fish stocks are used responsibly and global aquaculture (fish farm) production is expanded sustainability.

What we can do: While most of these are government level policies, we can contribute to the first three by reducing personal food waste and purchasing organic produce locally whenever possible.

What Does This Mean For You?

If you are a vegan, you are probably asking why the Commission did not recommend a completely plant-based diet. The answer is that a vegan diet is perfect for the health of our planet. However, the Commission wanted to make a diet that was as consumer friendly as possible and still meet their goals of a healthy, environmentally friendly, and sustainable diet.

If you are eating a typical American diet or one of the fad diets that encourage meat consumption, you are probably wondering how you can ever make such drastic changes to your diet. The answer is “one step at a time”. If you have read the Forward to my books “Slaying The Food Myths” or “Slaying the Supplement Myths”, you know that my wife and I did not change our diet overnight. Our diet evolved to something very close to the Planetary Diet over a period of years.

The Commission also purposely designed the Planetary Diet so that you “never have to say never” to your favorite foods. Three ounces of red meat a week does not sound like much, but it allows you a juicy steak once a month.

Sometimes you just need to develop a new mindset. As I shared in my books, my father prided himself on grilling the perfect steak. I love steaks, but I decided to set a few parameters. I don’t waste my red meat calories on anything besides filet mignon at a fine restaurant. It must be a special occasion, and someone else must be buying. That limits it to 2-3 times a year. I still get to enjoy good steak, and I stay well within the parameters of the Planetary diet.

Develop your strategy for enjoying some of your favorite foods within the parameters of the Planetary Diet and have fun with it.

The Bottom Line

Is your diet destroying the planet? This is not a new question, but a recent commission of international scientists has conducted a comprehensive study into our diet and its effect on our health and our environment. Their report serves as a dire warning of what will happen to us and our planet if we don’t change our ways.

The Commission carefully evaluated diet and food production methods and asked three questions:

Are they good for us?

Are they good for the planet?

Are they sustainable? Will they be able to meet the needs of the projected population of 10 billion people in 2050 without degrading our environment.

The Commission described the typical American diet as a “lose-lose-lose diet”. It is bad for our health. It is bad for the planet. And it is not sustainable.

In its place they carefully designed their version of a primarily plant-based diet they called a “win-win-win diet”. It is good for our health. It is good for the planet. And, it is sustainable.

The Planetary Diet is similar to other healthy diets such as semi-vegetarian, Mediterranean, DASH, and Flexitarian. However, what truly distinguishes it from the other diets is the restrictions placed on the non-plant portion of the diet to make it both environmentally friendly and sustainable (for details, read the article above).

I have spoken before about the importance of a primarily plant-based diet for our health. In that context it is a personal choice. It is optional.

However, this report is a wake-up call. It puts a primarily plant-based diet in an entirely different context. It is essential for the survival of our planet. It is no longer optional.

If you care about global warming…If you care about saving our planet, there is no other choice.

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.

Can Diet Add Years To Your Life?

April 5, 2022 by Dr. Steve Chaney

Which Foods Have The Biggest Effect On Longevity?

Author: Dr. Stephen Chaney

Everyone over 50 is searching for the elusive “Fountain Of Youth”.

We want to look younger.

We want to feel younger.

We want the energy we had in our 20s.

We want to be rid of the diseases of aging.

The list goes on!

But how do we do that? Pills and potions abound that claim to reverse the aging process. Most just reverse your wallet.

Should we train for marathons or bodybuilding contests?

Should we meditate or do yoga to relieve stress?

Should we get serious about losing weight?

Should we get more sleep?

Is there some miracle diet that can slow the aging process?

All the above probably slow the aging process, but the evidence is best for the effect of diet on aging. Several recent meta-analyses have looked at the effect of diet on the risk of premature deaths. In this issue of “Health Tips From the Professor” I review a study (LT Fadnes et al, PLoS Medicine, February 8, 2022) that combines the best of these meta-analyses into a single database and provides a provocative insight into the effect of diet on longevity.

How Was This Study Done?

This study combined data from recent meta-analyses looking at the impact of various food groups on the risk of premature deaths with the Global Burden of Disease Study which provides population-level estimates of life years lost due to dietary risk factors.

The authors then developed a new algorithm that allowed them to estimate how different diets affect sex- and age-specific life expectancy.

They divided the population into three different diet categories based on their intake of whole grains, vegetables, fruits, nuts, legumes, fish, eggs, dairy, refined grains, red meat, processed meat, white meat, sugar-sweetened beverages, and added plant oils. The diet categories were:

Typical Western Diet (TW). This diet was based on average consumption data from the United States and Europe. This was their baseline.

Optimal diet (OD). This diet is similar to a vegan or semi-vegetarian diet. However, it was not a purely vegan diet nor a purely semi-vegetarian diet. Instead, it represented the best diet people in this study were consuming.

Feasibility diet (FA). This diet recognizes that few people are willing to make the kind of changes required to attain an optimal diet. It is halfway between the Typical Western Diet and the Optimal Diet.

To help you understand these diets based on the foods the study participants were eating, here are the comparisons in terms of daily servings:

Food	TW Diet	FA Diet	OD Diet
Whole grains	1.5 servings	4.3 servings	7 servings
Vegetables	3 servings	4 servings	5 servings
Fruits	2.5 servings	3.75 servings	5 servings
Nuts	0 serving*	0.5 serving*	1 serving*
Legumes	0 serving**	0.5 serving**	1 serving**
Fish	0.25 serving	0.5 serving	1 serving
Eggs	1 egg	0.75 egg	0.5 egg
Dairy	1.5 servings	1.25 servings	1 serving
Refined grains	3 servings	2 servings	1 serving
Red meat	1 serving	0.5 serving	0 serving
Processed meat	2 servings	1 serving	0 serving
White meat	0.75 serving	0.6 serving	0 serving
Sugar-sweetened beverages	17 oz	8.5 oz	0 oz
Added plant oils	2 tsp	2 tsp	2 tsp

*1 serving = 1 handful of nuts

**1 serving = 1 cup of beans, lentils, or peas

Using their algorithm, the authors asked what the effect on longevity would be if people changed from a typical western diet to one of the other diets at age 20, 60, or 80 and maintained the new diet for at least 10 years. The 10-year requirement is based on previous studies showing that it takes around 10 years for dietary changes to affect the major killer diseases like heart disease, cancer, or diabetes.

Finally, the authors improved the accuracy of their estimates of the effect of diet on longevity by taking into account the quality of each study included in their analysis. I will discuss the importance of this below.

Can Diet Add Years To Your Life?

The results were impressive.

The authors estimated that if people in the United States were to change from a typical western diet to an “optimal diet” and maintain it for at least 10 years,

…starting at age 20, men would live 13 years longer and women would live 10.7 years longer.

…starting at age 60, men would live 8.8 years longer and women would live 8 years longer.

…starting at age 80, both men and women would live 3.4 years longer.

But what if you weren’t a vegan purist? What if you only made half the changes you would need to make to optimize your diet? The news was still good.

The authors estimated that people in the United States were to change from a typical western diet to a “feasibility diet” and maintain it for at least 10 years,

…starting at age 20, men would live 7.3 years longer and women would live 6.2 years longer.

…starting at age 60, men would live 4.8 years longer and women would live 4.5 years longer.

…starting at age 80, both men and women would live ~2 years longer.

The authors concluded, “A sustained dietary change may give substantial health gains for people of all ages for both optimized and feasible [diet] changes. [These health gains] could translate into an increase in life expectancy of more than 10 years. Gains are predicted to be larger the earlier the dietary changes are initiated in life.”

Which Foods Have The Biggest Effect On Longevity?

The algorithm the authors developed also allowed them to look at which foods have the biggest effect on longevity. The authors estimated when changing from a typical western diet to an optimal diet, the greatest gains in longevity were made by eating:

More legumes, whole grains, and nuts, and…

Less red and processed meat.

The authors concluded, “An increase in the intake of legumes, whole grains, and nuts, and a reduction in the intake of red meat and processed meats, contributed most to these gains [in longevity].”

However, this conclusion needs to be interpreted with caution. We also need to recognize that an “optimal diet” was defined as the best diet people in this study were eating. In addition, the effect of different foods on longevity depends on:

The quality of the individual studies with that food, and…

The difference in consumption of that food in going from a western diet to an optimal diet.

For example:

Legumes, whole grains, nuts, red & processed meat made the list because the quality of data was high and the difference in consumption between the typical western diet and optimal diet was significant.

The quality of data for an effect of fruits and vegetables was also high. For example, one major study concluded that consuming 10 servings a day of fruits and vegetables a day reduces premature death by 31% compared to consumption of less than 1 serving a day. However, the difference in consumption of fruits and vegetables between the western and optimal diets in this study was small, so fruits and vegetables didn’t make the list.

Eggs and white meat didn’t make the list because the quality of data was low for those foods. Simply put, that means that there was a large variation in effect of those foods on longevity between studies.

Other foods didn’t make the list because the quality of data was only moderate and/or the difference in intake was small.

So, the best way to interpret this these data is:

This study suggests that consuming more legumes, whole grains, and nuts and less red & processed meats has a significant beneficial effect on health and longevity.

Consuming more fruits and vegetables is likely to have a significant benefit on health and longevity, but you would need to consume more than people did in this study to achieve these benefits. In the words of the authors, “Fruits and vegetables also have a positive health impact, but, for these food groups, the intake in a typical Western diet is closer to the optimal intake than for the other food groups.”

Other foods may impact health and longevity, but the data in this study are not good enough to be confident of an effect.

What Does This Study Mean For You?

This study is the best of many studies showing the benefit of a more plant-based diet on health and longevity. It particularly encouraging because it shows:

You can achieve significant benefit by switching to a more plant-based diet late in life. You get the biggest “bang for your buck” if you switch at age 20. But even making the switch at age 60 or 80 was beneficial.

You don’t need to be a “vegan purist”. While the biggest benefits were seen for people who came close to achieving a vegan or semi-vegetarian diet, people who only made half those changes saw significant benefits.

As I said above, this is a very strong study. However, the underlying data come from association studies, which can have confounding variables that influence the results.

For example, people who eat more plant-based diets tend to weigh less and exercise more. And both of those variables can influence longevity. Each study attempted to statistically correct for those variables, but they still might have a slight influence on the results.

However, I don’t see that as a problem because, in my view, a holistic approach is always best. As illustrated on the right, we should be seeking a lifestyle that includes a healthy diet, weight control, and exercise.

As for supplementation, both the vegan and semi-vegetarian diets tend to leave out whole food groups. Unless you are married to a dietitian, that means your diet is likely to be missing important nutrients.

The Bottom Line

A recent study asked whether changing from the typical western diet to a healthier, more plant-based diet could influence longevity. The results were very encouraging. The study showed that:

Changing to a healthier diet could add up to a decade to your lifespan.

The improvement in lifespan was greatest for those whose diets approached a vegan or semi-vegetarian diet, but a significant improvement in lifespan was seen for people who made only half those dietary improvements.

The improvement in lifespan was greatest for those who switched to a healthier diet in their 20’s, but significant improvements in lifespan were seen for people who didn’t change their diet until their 60’s or 80’s.

In terms of the foods that have the biggest effect on longevity.

This study suggests that consuming more legumes, whole grains, and nuts and less red & processed meats has a significant beneficial effect on health and longevity.

Consuming more fruits and vegetables is likely to have a significant benefit on health and longevity, but you would need to consume more than people did in this study to achieve those benefits.

Other foods may impact health and longevity, but the data in this study are not good enough to be confident of an effect.

An increase in the intake of legumes, whole grains, and nuts, and a reduction in the intake of red meat and processed meats, contributed most to these gains. Fruits and vegetables also have a positive health impact, but, for these food groups, the intake in a typical Western diet is closer to the optimal intake than for the other food groups.”

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.