Is The Blood Type Diet A Myth?

What Does This Study Mean For You? 

Author: Dr. Stephen Chaney 

Blood TypesIn 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? 

clinical studyThe 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? 

SkepticThe 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.

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.”

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? 

Questioning WomanFirst 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.

_____________________________________________________________________________

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

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

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

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

About The Author 

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

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

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

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

What Kind Of Protein Is Best For Strength?

What Kind Of Protein Is Best For You?

Author: Dr. Stephen Chaney 

Sport DrinkEvery bodybuilder “knows” that whey is the best protein for building strong muscles. After all, it:

  • Is absorbed more rapidly than some other proteins.
  • Contains all nine essential amino acids.
  • Is naturally rich in leucine, a branched chain amino acid that stimulates increased muscle mass.

However, as someone who is not a vegan but who follows the vegan literature, I frequently come across testimonials from bodybuilders and elite athletes who say they get all the strength and muscle mass they need from plant proteins.

I’ve always assumed they must have dietitians designing the perfect plant protein diet for them. But a recent study surprised me. It challenged that assumption.

Before I talk about this study, let me change our focus. Most of us will never be bodybuilders or elite athletes, but all of us face a common challenge. We all tend to lose muscle mass as we age, something referred to as sarcopenia. I have discussed this in a previous issue of “Health Tips From the Professor”.

Simply put, sarcopenia results in:

  • Loss of muscle strength. Even the simple act of picking up a grandchild or a bag of groceries can become problematic.
  • Increased risk of falls and fractures.
  • Lower quality of life.

Sarcopenia is a major health issue for those of us in our golden years. If you are younger, it is a concern for your parents or grandparents. Sarcopenia is a health issue that affects everyone.

In my previous article I discussed the role of adequate protein intake and exercise in preventing age-related sarcopenia. But I did not discuss what kind of protein was best for preventing muscle loss, and the frailty that comes with it, as we age.

The article (EA Struijk et al, Journal of Cachexia, Sarcopenia and Muscle, 13: 1752-1761, 2022) I will discuss today suggests that plant protein is best for preventing frailty in women as they age. It’s a surprising conclusion, so join me as I evaluate this study.

How Was This Study Done?

Clinical StudyThe data for this study came from the Nurses Health Study which started in 1976 with 121,700 women nurses and is still ongoing. This study followed 85, 871 female nurses for an average of 22 years starting when they were 60.

Food frequency questionnaires were administered to the participants in the study every four years starting in 1980. The questionnaires were used to calculate:

  • Total calories consumed.
  • Percent of calories from protein, carbohydrate, and fat.
  • Percent of calories from different kinds of protein.
  • The overall quality of the diet.
  • Saturated fat, polyunsaturated fat, cholesterol, and alcohol intake.

For this study the investigators used the cumulative average values from all questionnaires completed by participants in the study from age 60 until the onset of frailty.

Frailty was assessed every four years starting in 1992 using something called the FRAIL scale. The FRAIL scale defines frailty based on five self-reported criteria: fatigue, low strength, reduced aerobic capacity, having 5 or more chronic illnesses, and recent significant unintentional weight loss.

  • It is important to note that strength is only one of the five criteria used to identify frailty, although decreased muscle mass can contribute to lack of energy and reduced aerobic activity.
  • It is also worth pointing out that multiple studies have shown that primarily plant-based diets are associated with a decrease in chronic diseases.

I will come back to both of these points when I discuss the results of this study.

What Kind Of Protein Is Best For Strength? 

I will start with the “big picture” results from this study and then cover some of the important details.

Average intake of:

  • Total protein was 18.3% of calories consumed.
  • Animal protein was 13.3% of calories consumed.
  • Plant protein was 5.0% of calories consumed.
  • Dairy protein was 3.8% of calories consumed.

When protein intake was divided into quintiles (5 equal parts) and women consuming the most protein were compared to those consuming the least protein for an average of 22 years:

  • Those consuming the most total protein had a 7% increased risk of developing frailty.
  • Those consuming the most animal protein had a 7% increased risk of developing frailty. (It is perhaps not surprising that the results were essentially the same for total and animal protein since animal protein was 73% of the total protein consumed by women in this study.)
  • Those consuming the most plant protein had a 14% decreased risk of developing frailty.
  • Consumption of dairy protein did not affect frailty.

Substituting as little as 5% of calories of plant protein for:

  • Dairy protein decreased the risk of developing frailty by 32%.
  • Animal protein decreased the risk of developing frailty by 38%.
  • Non-dairy animal protein (meat, fish, and eggs) decreased the risk of developing frailty by 42%.

In addition, substituting as little as 5% of calories of dairy protein for non-dairy animal protein decreased the risk of developing frailty by 14%.

But, as I said above, the frailty scale used in this study included the criteria of developing 5 or more chronic illnesses, and long-term consumption of plant protein is known to reduce the risk of developing chronic illnesses. So, it is important to break the study down into its component parts. When that was done the statistically significant results were:

  • Those consuming the most total protein had a 7% increased risk of low strength and a 25% increased risk of developing 5 or more chronic diseases.
  • Those consuming the most animal protein had a 9% increased risk of low strength and a 35% increased risk of developing 5 or more chronic diseases.
  • Those consuming the most plant protein had an 18% decreased risk of low strength. (It is interesting to note that plant protein consumption did not have a statistically significant effect on the development of chronic diseases in this study. That suggests that the “protective” effect of plant protein may simply be due to the absence of animal protein from the diet.)
  • Consumption of dairy protein did not affect any of the frailty criteria.

Finally, prevention of strength loss due to age-related sarcopenia is known to require exercise as well as adequate protein intake.

So, it was somewhat surprising that no difference in the association between protein intake and frailty was seen in women with high physical activity compared with those with lower physical activity levels. However, this may be because the range in activity level between the women in this study was relatively small. There didn’t appear to be a significant number of “gym rats” among the women in this study.

What Kind Of Protein Is Best For You?

Questioning WomanOne take-away from this study is clear. If you are a woman and want to minimize sarcopenia (loss of muscle mass and strength as you age), plant protein is an excellent choice.

  • A variety of plant proteins is best, so you get all the essential amino acids.
  • You don’t need to become a vegan. This study showed that replacing as little as 5% of your calories from animal protein with plant protein can have a significant benefit. Any healthy primarily plant-based diet will do.
  • This study enrolled only women aged 60 or above, so we don’t know whether the results apply to men or to younger women.

We don’t know why plant protein is better than animal protein at preventing age-related sarcopenia.

  • It could be because primarily plant-based diets are anti-inflammatory, and inflammation plays a role in sarcopenia.
  • Or it could be because primarily plant-based diets reduced the risk of chronic diseases, and chronic diseases can lead to loss of strength.

To be clear, this is a study that focuses on the type of protein that is best for long-term health and strength as we age. This is not a study of the best protein for increasing muscle mass following a workout.

  • Multiple studies show that whey protein can be a good post-workout choice.
  • However, other studies show that plant protein can also be a good post-workout choice if extra leucine is added to make it equivalent to whey protein in terms of leucine content.

The Bottom Line

You have probably heard that it is all downhill after age 30. But it doesn’t have to be.

One of the downhill slopes we all face is something called sarcopenia (age-related muscle loss). The resulting loss of strength and agility can severely impact our quality of life in our golden years.

We can prevent sarcopenia with the combination of a high protein diet and resistance training (weight bearing exercise).

But what kind of protein is best? In this issue of “Health Tips From the Professor” I review a large, well-designed study that suggests plant protein is the best choice for women if they wish to reduce age-related muscle loss and the weakness that comes with it.

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

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

 ______________________________________________________________________________

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

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

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

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

 _____________________________________________________________________

About The Author

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

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

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

Can Healthy Eating Help You Lose Weight?

Who Benefits Most From A Healthy Diet?

Author: Dr. Stephen Chaney 

fad dietsFad diets abound. High protein, low carb, low fat, vegan, keto, paleo – the list is endless. They all claim to be backed by scientific studies showing that you lose weight, lower your cholesterol and triglycerides, lower your blood pressure, and smooth out your blood sugar swings.

They all claim to be the best. But any reasonable person knows they can’t all be the best. Someone must be lying.

My take on this is that fad diet proponents are relying on “smoke and mirrors” to make their diet look like the best. I have written about this before, but here is a brief synopsis:

  • They compare their diet with the typical American diet.
    • Anything looks good compared to the typical American diet.
    • Instead, they should be comparing their diet with other weight loss diets. That is the only way we can learn which diet is best.
  • They are all restrictive diets.
    • Any restrictive diet will cause you to eat fewer calories and to lose weight.
    • As little as 5% weight loss results in lower cholesterol & triglycerides, lower blood pressure, and better control of blood sugar levels.

Simply put, any restrictive diet will give you short-term weight loss and improvement in blood parameters linked to heart disease, stroke, and diabetes. But are these diets healthy long term? For some of them, the answer is a clear no. Others are unlikely to be healthy but have not been studied long term. So, we don’t know whether they are healthy or not.

What if you started from the opposite perspective? Instead of asking, “Is a diet that helps you lose weight healthy long term?”, what if you asked, “Can healthy eating help you lose weight?” The study (S Schutte et al, American Journal of Clinical Nutrition, 115: 1-18, 2022) I will review this week asked that question.

More importantly, it was an excellent study. It compared a healthy diet to an unhealthy diet with exactly the same degree of caloric restriction. And it compared both diets to the habitual diet of people in that area. This study was performed in the Netherlands, so both weight loss diets were compared to the habitual Dutch diet.

How Was The Study Done?

clinical studyThis was a randomized controlled trial, the gold standard of clinical studies. The investigators recruited 100 healthy, abdominally obese men and women aged 40-70. At the time of entry into the study none of the participants:

  • Had diabetes.
  • Smoked
  • Had a diagnosed medical condition.
  • Were on a medication that interfered with blood sugar control.
  • Were on a vegetarian diet.

The participants were randomly assigned to:

  • A high-nutrient quality diet that restricted calories by 25%.
  • A low-nutrient-quality diet that restricted calories by 25%.
  • Continue with their habitual diet.

The study lasted 12 weeks. The participants met with a dietitian on a weekly basis. The dietitian gave them the foods for the next week and monitored their adherence to their assigned diet. They were advised not to change their exercise regimen during the study.

At the beginning and end of the study the participants were weighed, and cholesterol, triglycerides, and blood pressure were measured.

Can Healthy Eating Help You Lose Weight?

Vegetarian DietTo put this study into context, these were not healthy and unhealthy diets in the traditional sense.

  • Both were whole food diets.
  • Both included fruits, vegetables, low-fat dairy, and lean meats.
  • Both restricted calories by 25%.

The diets were designed so that the “high-nutrient quality” diet had significantly more plant protein (in the form of soy protein), fiber, healthy fats (monounsaturated and omega-3 fats), and significantly less fructose and other simple sugars than the “low-nutrient-quality” diet.

At the end of 12 weeks:

  • Participants lost significant weight on both calorie-restricted diets compared to the group that continued to eat their habitual diet.
    • That is not surprising. Any diet that successfully restricts calories will result in weight loss.
  • Participants on the high-nutrient quality diet lost 33% more weight than participants on the low-nutrient-quality diet (18.5 pounds compared to 13.9 pounds).
  • Participants on the high-nutrient quality diet lost 50% more inches in waist circumference than participants on the low-nutrient-quality diet (1.8 inches compared to 1.2 inches).
    • This is a direct measure of abdominal obesity.

When the investigators measured blood pressure, fasting total cholesterol levels, and triglyceride levels:Heart Healthy Diet

  • These cardiovascular risk factors were significantly improved on both diets.
    • Again, this would be expected. Any diet that causes weight loss results in an improvement in these parameters.
  • The reduction in total serum cholesterol was 2.5-fold greater and the reduction in triglycerides was 2-fold greater in the high-nutrient quality diet group than in the low-nutrient-quality diet group.
  • The reduction in systolic blood pressure was 2-fold greater and the reduction in diastolic blood pressure was 1.67-fold greater in the high-nutrient quality diet group than in the low-nutrient-quality diet group.

The authors concluded, “Our results demonstrate that the nutrient composition of an energy-restricted diet is of great importance for improvements of metabolic health in an overweight, middle-aged population. A high-nutrient quality energy-restricted diet enriched with soy protein, fiber, monounsaturated fats, omega-3 fats, and reduced in fructose provided additional health benefits over a low-nutrient quality energy-restricted diet, resulting in greater weight loss…and promoting an antiatherogenic blood lipid profile.”

In short, participants in this study lost more weight and had a better improvement in risk factors for heart disease on a high-nutrient-quality diet than on a low-nutrient-quality diet. Put another way, healthy eating helped them lose weight and improved their health.

Who Benefits Most From A Healthy Diet?

None of the participants in this study had been diagnosed with diabetes when the study began. However, all of them were middle-aged, overweight, and had abdominal obesity. That means many of them likely had some degree of insulin resistance.

Because of some complex metabolic studies that I did not describe, the investigators suspected that insulin resistance might influence the relative effectiveness of the two energy-restricted diets.

To test this hypothesis, they used an assay called HOMA-IR (homeostatic model assessment of insulin resistance). Simply put, this assay measures how much insulin is required to keep your blood sugar under control.

They used a HOMA-IR score of 2.5 to categorize insulin resistance among the participants.

  • Participants with a HOMA-IR score >2.5 were categorized as insulin-resistant. This was 55% of the participants.
  • Participants with a HOMA-IR score ≤2.5 were categorized as insulin-sensitive. This was 45% of the participants.

When they used this method to categorize participants they found:

  • Insulin-resistant individual lost about the same amount of weight on both diets.
  • Insulin-sensitive individuals lost 66% more weight on the high-nutrient-quality diet than the low-nutrient-quality diet (21.6 pounds compared to 13.0 pounds).

The investigators concluded, “Overweight, insulin-sensitive subjects may benefit more from a high- than a low-nutrient-quality energy-restricted diet with respect to weight loss…”

What Does This Study Mean For You?

Questioning WomanSimply put this study confirms that:

  • Caloric restriction leads to weight loss, and…
  • Weight loss leads to improvement in cardiovascular risk factors like total cholesterol, triglycerides, and blood pressure.
    • This is not new.
    • This is true for any diet that results in caloric restriction.

This study breaks new ground in that a high-nutrient quality diet results in significantly better:

  • Weight loss and…
  • Reduction in cardiovascular risk factors…

…than a low-nutrient quality diet. As I said above, the distinction between a “high-nutrient-quality” diet and a “low-nutrient-quality” diet may not be what you might have expected.

  • Both diets were whole food diets. Neither diet allowed sodas, sweets, and highly processed foods.
  • Both included fruits, vegetables, grains, and lean meats.
  • Both reduced caloric intake by 25%.
    • If you want to get the most out of your weight loss diet, this is a good place to start.

In this study the investigators designed their “high-nutrient-quality” diet so that it contained:

  • More plant protein in the form of soy protein.
    • In this study they did not reduce the amount of animal protein in the “high-nutrient-quality” diet. They simply added soy protein foods to the diet. I would recommend substituting soy protein for some of the animal protein in the diet.
  • More fiber.
    • The additional fiber came from substituting whole grain breads and brown rice for refined grain breads and white rice, adding soy protein foods, and adding an additional serving of fruit.
  • More healthy fats (monounsaturated and omega-3 fats).
    • The additional omega-3s came from adding a fish oil capsule providing 700mg of EPA and DHA.
  • Less simple sugars. While this study focused on fructose, their high-nutrient-quality diet was lower in all simple sugars.

ProfessorAll these changes make great sense if you are trying to lose weight. I would distill them into these 7 recommendations.

  • Follow a whole food diet. Avoid sodas, sweets, and highly processed foods.
  • Include all 5 food groups in your weight loss diet. Fruits, vegetables, whole grains, dairy, and lean proteins all play an important role in your long-term health.
  • Eat a primarily plant-based diet. My recommendation is to substitute plant proteins for at least half of your high-fat animal proteins. And this study reminds us that soy protein foods are a convenient and effective way to achieve this goal.
  • Eat a diet high in natural fibers. Including fruits, vegetables, whole grains, beans, nuts, seeds, and soy foods in your diet is the best way to achieve this goal.
  • Substitute healthy fats (monounsaturated and omega-3 fats) for unhealthy fats (saturated and trans fats) in your diet. And this study reminds us that it is hard to get enough omega-3s in your diet without an omega-3 supplement.
  • Reduce the amount of added sugar, especially fructose, from your diet. That is best achieved by eliminating sodas, sweets, and highly processed foods from the diet. I should add that fructose in fruits and some healthy foods is not a problem. For more information on that topic, I refer you to a previous “Health Tips” article .
  • Finally, I would like to remind you of the obvious. No diet, no matter how healthy, will help you lose weight unless you cut back on calories. Fad diets achieve that by restricting the foods you can eat. In the case of a healthy diet, the best way to do it is to cut back on portion sizes and choose foods with low caloric density.

I should touch briefly on the third major conclusion of this study, namely that the “high-nutrient quality diet” was not more effective than the “low-nutrient-quality” diet for people who were insulin resistant. In one sense, this was not news. Previous studies have suggested that insulin-resistant individuals have more difficulty losing weight. That’s the bad news.

However, there was a silver lining to this finding as well:

  • Only around half of the overweight, abdominally obese adults in this study were highly insulin resistant.
    • That means there is a ~50% chance that you will lose more weight on a healthy diet.
  • Because both diets restricted calories by 25%, insulin-resistant individuals lost weight on both diets.
    • That means you can lose weight on any diet that successfully reduces your caloric intake. That’s the good news.
    • However, my recommendation would still be to choose a high-nutrient quality diet that is designed to reduce caloric intake, because that diet is more likely to be healthy long term.

The Bottom Line 

A recent study asked, “Can healthy eating help you lose weight?” This study was a randomized controlled study, the gold standard of clinical studies. The participants were randomly assigned to:

  • A high-nutrient quality diet that restricted calories by 25%.
  • A low-nutrient-quality diet that restricted calories by 25%.
  • Continue with their habitual diet.

These were not healthy and unhealthy diets in the traditional sense.

  • Both were whole food diets.
  • Both included fruits, vegetables, low-fat dairy, and lean meats.
  • Both restricted calories by 25%.

The diets were designed so that the “high-nutrient quality” diet had significantly more plant protein (in the form of soy protein), fiber, healthy fats (monounsaturated and omega-3 fats), and significantly less fructose and other simple sugars than the “low-nutrient-quality” diet.

At the end of 12 weeks:

  • Participants on the high-nutrient quality diet lost 33% more weight than participants on the low-nutrient-quality diet (18.5 pounds compared to 13.9 pounds).

When the investigators measured cardiovascular risk factors at the end of 12 weeks:

  • The reduction in total serum cholesterol was 2.5-fold greater and the reduction in triglycerides was 2-fold greater in the high-nutrient quality diet group than in the low-nutrient-quality diet group.
  • The reduction in systolic blood pressure was 2-fold greater and the reduction in diastolic blood pressure was 1.67-fold greater in the high-nutrient quality diet group than in the low-nutrient-quality diet group.

The authors concluded, “Our results demonstrate that the nutrient composition of an energy-restricted diet is of great importance for improvements of metabolic health in an overweight, middle-aged population. A high-nutrient quality energy-restricted diet enriched with soy protein, fiber, monounsaturated fats, omega-3 fats, and reduced in fructose provided additional health benefits over a low-nutrient quality energy-restricted diet, resulting in greater weight loss…and promoting an antiatherogenic blood lipid profile.”

In short, participants in this study lost more weight and had a better improvement in risk factors for heart disease on a high-nutrient-quality diet than on a low-nutrient-quality diet. Put another way, healthy eating helped them lose weight and improved their health.

For more details on this study, what this study means for you, and my 7 recommendations for a healthy weight loss diet, read the article above.

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

Eating For A Healthy Planet

Can Diet Affect The Health Of Our Planet?

Author: Dr. Stephen Chaney

Earth DayEarth 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?

Factory FarmWhen 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.

healthy vs Unhealthy ChoicesWhen 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

Planetary DietIn 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?

confusionIf 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.

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”.

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.

Eating Of The Green

Why Is Eating Green Good For Your Heart? 

Author: Dr. Stephen Chaney

You may be one of the millions of Americans who celebrated St. Patrick’s Day a couple of weeks ago. If so, you may have sung the famous Irish folk song “The Wearing of the Green”. If you are Irish, that song has special meaning for you. However, when I hear that song, I think of “Eating of the Green.”

And when I think of eating green, I don’t mean that everything we eat should be green. I am thinking of whole fruits and vegetables in a variety of colors. We have known for years that fruits and vegetables are good for our health. Consumption of fruits and vegetables is associated a lower risk of high blood pressure, heart disease, cancer, inflammatory diseases, and much more.

For today’s health tip, I am going to focus on heart health and an unexpected explanation for how fruits and vegetables reduce our risk of heart disease.

Why Is Eating Green Good For Your Heart?

health benefits of beetroot juiceWe have assumed that whole fruits and vegetables lower our risk of heart disease because they are low in saturated fats and provide heart-healthy nutrients, phytonutrients, and fiber. All of that is true. But could there be more?

Recent research has suggested that the nitrates found naturally in fruits and vegetables may also play a role in protecting our hearts. Here is what recent research shows:

  • The nitrates from fruits and vegetables are converted to nitrite by bacteria in our mouth and intestines.
    • Fruits and vegetables account for 80% of the nitrate in our diet. The rest comes from a variety of sources including the nitrate added as a preservative to processed meats.
    • Although all fruits and vegetables contain nitrates, the best sources are green leafy vegetables and beetroot. [Beet greens are delicious and also a good source of nitrate, but beetroot is the part of the beet we usually consume.]
  • Nitrite is absorbed from our intestine and converted to nitric oxide by a variety of enzymes in our tissues.
  • Both reactions require antioxidants like vitamin C, which are also found in fruits and vegetables.

Nitric oxide has several heart healthy benefits. For example:

  • It helps reduce inflammation in the lining of blood vessels. Inflammation stimulates atherosclerosis, blood clot formation, and is associated with an increased risk of heart disease.
  • It relaxes the smooth muscle cells that surround our blood vessels. This makes the blood vessels more flexible and helps reduce blood pressure.
  • It prevents smooth muscle cells from proliferating, which prevents them from invading and constricting our arteries. This, in turn, has the potential to reduce the risk of atherosclerosis.
  • It prevents platelet aggregation. This, in turn, has the potential to reduce the risk of heart attack and stroke due to blood clots that block the flow of blood to our heart or brain.

It is well established that nitrates from fruits and vegetables reduce blood pressure. More importantly, they can help slow the gradual increase in blood pressure as we age.

However, few studies have asked whether this reduction in blood pressure translates into improved cardiovascular outcomes. This study (CP Bondonno et al, European Journal of Epidemiology, 36: 813-825, 2021) was designed to answer that question.

How Was This Study Done?

Clinical StudyThis study made use of data from the Danish Diet, Cancer, and Health Program. That program enrolled 53,150 participants from Copenhagen and Aarhus between 1993 and 1997 and followed them for an average of 21 years. None of the participants had a diagnosis of cancer or heart disease at the beginning of the study.

Other characteristics of the participants at the time they were enrolled in the study were:

  • 46% male
  • Average age = 56
  • BMI = 26 (>20% overweight)
  • Average systolic blood pressure = 140 mg Hg
  • Average diastolic blood pressure = 84 mg Hg

At the beginning of the study, participants filled out a 192-item food frequency questionnaire that assessed their average intake of various food and beverage items over the previous 12 months. The vegetable nitrate content of their diets was analyzed using a comprehensive database of the nitrate content of 178 vegetables. For those vegetables not consumed raw, the nitrate content was reduced by 50% to account for the nitrate loss during cooking.

Blood pressure was measured at the beginning of the study. Data on the incidence (first diagnosis) of heart disease during the study was obtained from the Danish National Patient Registry. Data were collected on diagnosis of the following heart health parameters:

  • Cardiovascular disease (all diseases of the circulatory system).
  • Ischemic heart disease (lack of sufficient blood flow to the heart). The symptoms of ischemic heart disease range from angina to myocardial infarction (heart attack).
  • Ischemic stroke (lack of sufficient blood flow to the brain).
  • Hemorrhagic stroke (bleeding in brain).
  • Heart failure.
  • Peripheral artery disease (lack of sufficient blood flow to the extremities).

Is Nitrate From Vegetables Good For Your Heart?

strong heartIntake of nitrate from vegetables ranged from 18 mg/day (<1/3 serving of nitrate-rich vegetables per day) to 168 mg (almost 3 servings of nitrate-rich vegetables per day). The participants were grouped into quintiles based on their vegetable nitrate intake. When the group with the highest vegetable nitrate intake was compared to the group with the lowest vegetable nitrate intake:

  • Systolic blood pressure was reduced by 2.58 mg Hg.
  • Diastolic blood pressure was reduced by 1.38 mg Hg.
  • Risk of cardiovascular disease was reduced by 14%.
  • Risk of ischemic heart disease (angina and heart attack) was reduced by 13%.
  • Risk of ischemic stroke (stroke caused by lack of blood flow to the brain) was reduced by 14%.
  • Risk of heart failure was reduced by 17%.
  • Risk of peripheral artery disease was reduced by 31%.
  • Risk of hemorrhagic stroke (bleeding in the brain) was not significantly reduced.

Two other observations were of interest:

  • Blood pressure and risk of peripheral artery disease decreased with increasing vegetable nitrate intake in a relatively linear fashion. However, the other parameters of heart disease plateaued at a modest intake of vegetable nitrate intake (around one cup of nitrate-rich vegetables per day). This suggests that as little as one serving of nitrate-rich vegetables a day is enough to provide some heart health benefits.
  • Only about 21.9% of the improvement in heart health could be explained by the decrease in blood pressure. This is not surprising when you consider the other beneficial effects of nitric oxide described above.

The authors concluded, “Consumption of at least ~60 mg/day of vegetable nitrate (~ one serving of green leafy vegetables or beets) may mitigate risk of cardiovascular disease.”

Are Nitrates Good For You Or Bad For You?

questionsYou are probably thinking, “Wait a minute. I thought nitrates and nitrites were supposed to be bad for me. Which is it? Are nitrates good for me or bad for me?”

It turns out that nitrates and nitrites are kind of like Dr. Jekyll and Mr. Hyde. They can be either good or bad. It depends on the food they are in and your overall diet.

Remember the beginning of this article when I said that the conversion of nitrates to nitric oxide depended on the presence of antioxidants? Vegetables are great sources of antioxidants. So, when we get our nitrate from vegetables, most of it is converted to nitric oxide. And, as I discussed above, nitric oxide is good for us.

However, when nitrates and nitrites are added to processed meats as a preservative, the story is much different. Processed meats have zero antioxidants. And the protein in the meats is broken down to amino acids in our intestine. The amino acids combine with nitrate to form nitrosamines, which are cancer-causing chemicals. Nitrosamines are bad for us.

Of course, we don’t eat individual foods by themselves. We eat them in the context of a meal. If you eat small amounts of nitrate-preserved processed meats in the context of a meal with antioxidant-rich fruits and vegetables, some of the nitrate will be converted to nitric oxide rather than nitrosamines. The processed meat won’t be as bad for you.

Eating Of The Green

spinachYour mother was right. You should eat your fruits and vegetables!

  • The USDA recommends at least 3 servings of vegetables and 2 servings of fruit a day.
  • Based on this study, at least one of those servings should be nitrate-rich vegetables like green leafy vegetables and beets.
  • If you don’t like any of those, radishes, turnips, watercress, Bok choy, Chinese cabbage, kohlrabi, chicory leaf, onion, and fresh garlic are also excellent sources of nitrate.
  • The good news is that you may not need to eat green leafy vegetables and beets with every meal. If this study is correct, one serving per day may have heart health benefits. That means you can enjoy a wide variety of fresh fruits and vegetables as you try to meet the USDA recommendations.

Finally, if you don’t like any of those foods, you may be asking, “Can’t I just take a nitrate supplement?”

  • For blood pressure, there are dozens of clinical trials, and the answer seems to be yes – especially when the nitrate comes from vegetable sources and the supplement also contains an antioxidant like vitamin C.
  • For heart health benefits, the answer is likely to be yes, but clinical trials to confirm that would take decades. Double blind, placebo-controlled trials of that duration are not feasible, so we will never know for sure.
  • Moreover, you would not be getting all the other health benefits of a diet full of fresh fruits and vegetables. Supplementation has its benefits, but it is not meant to replace a healthy diet.

The Bottom Line

We have known for years that fruits and vegetables are good for our hearts. We have assumed that was because whole fruits and vegetables are low in saturated fats and provide heart-healthy nutrients, phytonutrients, and fiber. But could there be more?

It is well established that nitrates from fruits and vegetables reduce blood pressure. More importantly, they can help slow the gradual increase in blood pressure as we age.

However, few studies have asked whether this reduction in blood pressure translates into improved cardiovascular outcomes. A recent study was designed to answer that question.

When the study compared people with the highest vegetable nitrate intake to people with the lowest vegetable nitrate intake:

  • Blood pressure was significantly reduced.
  • The risk of cardiovascular disease was reduced by 14%.
  • Risk of ischemic heart disease (angina and heart attack) was reduced by 13%.
  • Risk of ischemic stroke (stroke caused by lack of blood flow to the brain) was reduced by 14%.
  • Risk of heart failure was reduced by 17%.
  • Risk of peripheral artery disease was reduced by 31%.
  • Blood pressure and risk of peripheral artery disease decreased with increasing vegetable nitrate intake in a relatively linear fashion.
  • However, the other parameters of heart disease plateaued at a modest intake of vegetable nitrate intake (around one cup of nitrate-rich vegetables per day). This suggests that as little as one serving of nitrate-rich vegetables a day is enough to provide some heart health benefits.

The authors concluded, “Consumption of at least ~60 mg/day of vegetable nitrate (~ one serving of green leafy vegetables or beets) may mitigate risk of cardiovascular disease.”

Of course, you may have heard that nitrates and nitrites are bad for you. I discuss that in the article above.

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.

Which Diet Is Best?

Tips For Loosing Weight And Keeping It Off

Author: Dr. Stephen Chaney

Diet season starts in just a few days! Like millions of Americans, you will probably be setting 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 what to avoid and…
  • 6 tips on what to look for…

…when you are choosing the best diet for you.

What Should You Avoid When Choosing The Best Diet?

AvoidEndorsements.

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 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.

MagicI 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.

What Should You Look For In Choosing The Best Diet?

Skeptic1) 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.

If you 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 31st 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 Losing Weight And Keeping It 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 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, low fat 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 low-carb version of the Mediterranean diet.
    • 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 in the coming year, you are probably asking, “Which Diet Is Best?” In this issue of “Health Tips From The Professor” I give you:

  • 4 tips on what 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.

 

 

How Does Red Meat Cause Colon Cancer?

How Can You Decrease Your Risk Of Colon Cancer? 

Author: Dr. Stephen Chaney

Grilled HamburgersBoth red meat and processed meat consumption are associated with increased risk of colon cancer. But the strength of that association differs between the two.

Processed meat has been classified as a carcinogen by the IARC*, indicating the evidence that processed meat causes colon cancer is definitive. Red meat, on the other hand, has been classified as a probable carcinogen by the IARC*. That means the evidence that red meat causes colon cancer is strong, but not definitive.

*[In case you were wondering, the IARC (International Agency for Research on Cancer) is an international agency charged by the WHO to, among other things, determine the risk of cancer from various foods, industrial chemicals, and environmental pollutants.]

As I said above, red meat consumption is associated with increased risk of colon cancer. But…

  • Not all studies agree (more about that later), and…
  • Association doesn’t prove cause and effect. It could be some other characteristic of red meat eaters that increases their risk of colon cancer.
  • Until recently we had no clear idea of how red meat might cause colon cancer.

Several mechanisms have been proposed. I will discuss each mechanism and ways to reduce the risk of colon cancer by that mechanism:

#1: When fat and juices from the meat drip onto an open flame, carcinogenic polyaromatic hydrocarbons (PAHs) Barbecue Gatheringare formed that stick to the surface of the meat. PAHs can be metabolized to cancer causing chemicals in our body.

  • PAH formation can be reduced by marinating the meat prior to cooking or by using cooking techniques that don’t involve an open flame.
  • PAH formation can be reduced, but not eliminated, by lower fat meat choices, such as grass-fed beef.
  • High fiber diets reduce exposure to PAHs by binding to them and flushing them through the intestine.
  • Cruciferous vegetables block the conversion of PAHs to cancer causing chemicals in our body.

#2: When red meats are cooked at high temperatures, amino acids in the meat combine with creatine, which is found in all red meats, to form heterocyclic amines (HCAs). HCAs can also be metabolized to cancer causing chemicals in our body.

  • HCA formation can be reduced by cooking the meat at lower temperatures.
  • Grass-fed beef does not reduce HCA formation because this mechanism is not dependent on the fat content of the meat.
  • High fiber diets and cruciferous vegetables reduce the danger of HCAs by the same mechanisms as for PAHs.

#3: The nitrates and nitrites used as preservatives in many processed meats react with amino acids from the meat to form carcinogenic N-nitrosamines in our intestines.

  • Antioxidant-rich fruits and vegetables can divert nitrates and nitrites into an alternative pathway that coverts them into nitric oxide, which is beneficial to our bodies. I have discussed this in a previous issue of “Health Tips From the Professor”.

#4: Heme, which is found in all red meats, combines with amino acids in the meat to form carcinogenic N-nitrosamines and similar N-nitroso compounds in our intestines.

  • This mechanism is inherent in all red meats and cannot be eliminated by choosing grass-fed beef or cooking at lower temperatures.
  • The formation of N-nitroso compounds from red meat appears to be carried out by gut bacteria. We know that meat eaters and vegetarians have very different populations of gut bacteria, but we don’t know whether this influences N-nitroso formation.

Mechanism #4 (formation of N-nitroso compounds from heme-containing red meat in our intestines) is the one I will be discussing in this article. But first, it’s time for Metabolism 101.

Metabolism 101: Why Should We Fear N-Nitroso Compounds?

ProfessorSimply put, N-nitroso compounds react with our DNA. They transfer methyl and ethyl groups to the nucleotides that make up our DNA sequence. The general term for these reactions is alkylation of the DNA.

  • In some cases, this causes the alkylated nucleotides to miscode during DNA replication. This can lead to cancer causing mutations.
  • In other cases, this causes genes to be permanently turned on or off.

To understand why this is a problem, you need to know a bit about cancer cell biology.

  • We have certain genes called “oncogenes”. These are genes that turn on processes like cell division. Normally these genes are tightly regulated so that cell division only occurs when it is needed. When these genes are permanently turned on, unregulated, continuous cell division occurs. In short, the cell becomes a cancer cell.
  • We have other genes called “tumor suppressor genes”. These are genes that do things like shutting down cell division when it is not needed. When these genes are permanently turned off, unregulated cell division can occur.

With this in mind, let us review what we know about red meat and colon cancer:

  • Red meat consumption is associated with increased risk of colon cancer.
  • Red meat consumption is also associated with increased concentrations of N-nitroso compounds in the colon. Studies also show:
  • The formation of N-nitroso compounds correlates with the heme content of the meat.
  • The formation of N-nitroso compounds in the colon is dependent on certain strains of gut bacteria.
  • The formation of N-nitroso compounds is reduced by diets high in fiber. It is likely this is because high fiber diets influence the types of bacteria in the colon, but that has not been proven yet.

What is missing is evidence that colon cancer cells contain the kind of DNA modifications (DNA alkylation) caused by N-nitroso compounds. That is what the current study (C Gurjao et al, Cancer Discovery, published online June 17, 2021) was designed to test.

How Was This Study Done?

Clinical StudyOne reason previous studies had not been able to demonstrate a clear correlation between red meat consumption and DNA modifications was that the studies were too small to obtain statistically significant results.

So, the authors of this study combined data from women in the Nurses’ Health Study, the Nurses’ Health Study II, and men in the Health Professionals Follow-Up Study. There were over 238,130 women and 51,529 men in these three studies.

None of the participants had cancer at the time they entered the studies. The participants were followed for at least 27 years. During that time 4855 participants developed colon cancer.

At the beginning of each study and every 4 years later the participants were asked to fill out a food frequency questionnaire to collect information about their usual diet over the past year. Validation studies showed that the diets of the participants changed little over the interval of the studies.

The participants in these studies were sent follow-up questionnaires every two years to collect information on lifestyle and newly diagnosed diseases like colon cancer.

For those who developed colon cancer, their medical records were reviewed to collect data on tumor size, tumor location, and disease stage.

The diagnoses of colon cancer often involves removing tissue from the cancer and from surrounding normal tissue and putting it in formalin-fixed paraffin-embedded tissue blocks. These were collected, and the DNA was extracted and sequenced to determine the extent and genetic location of alkylated DNA sequences.

How Does Red Meat Cause Colon Cancer?

colon cancerThis study measured the effect of red meat consumption on the extent and location of what the authors called “alkylation signatures”, which refers to the kinds of DNA modifications caused by N-nitroso compounds. Here is what they found:

  • Red meat consumption was positively associated with an increase in alkylation signatures caused by N-nitroso compounds in tumor tissue from patients with colon cancer.
    • This was true for both processed and unprocessed red meat.
    • There was no difference between men and women after adjusting for differences in red meat intake.
    • White meat (chicken and fish) did not cause an increase in alkylation damage in colon cells.
  • More importantly, there was an inverse association between alkylation damage in the tumor tissue and patient survival. Simply put, high levels of alkylation damage were associated with short survival times.

Previous studies have shown that processed red meat consumption was associated with increased levels of N-nitroso compounds and an increased risk of colon cancer in the distal colon.

  • This study showed colon cancer patients who had been consuming processed red meats had higher alkylation damage in tumors in the distal colon.

Previous studies have shown that certain oncogenes (genes that drive the conversion of normal cells to cancer cells) are activated in colon cancer cells and this activation is associated with alkylation damage to their DNA.

  • This study showed that tumors with activated oncogenes were enriched with the alkylation signature characteristic of N-nitroso compounds.

I realize this study is highly technical. It is not easy to understand, so let me simplify it.

  • Previous studies have shown that red meat consumption is associated with an increased risk of colon cancer.
  • Previous studies have also shown that red meat consumption is associated with an increased concentration of carcinogenic N-nitroso compounds in the colon.
  • This study shows that red meat consumption is associated with the kind of DNA damage caused by N-nitroso compounds in colon tumor cells. More importantly, this is the kind of damage that can lead to cancer-causing mutations. In addition:
    • The DNA damage occurs in the exact location of the colon predicted from earlier studies.
    • The DNA damage occurs in genes known to drive the conversion of normal colon cells to cancer cells.

In short, this study provides a plausible mechanism for the effect of red meat consumption on increased risk of colon cancer. It shows how red meat can cause colon cancer.

“In the words of the authors, “Our study has leveraged a comprehensive dataset with repeated dietary measures over years…and [DNA sequencing] on a large collection of colorectal tumors. It provides unique evidence supporting the direct impact of dietary behaviors on colorectal carcinogenesis…”

How Can You Decrease Your Risk Of Colon Cancer?

Steak SaladWhen this study is combined with previous studies, it provides a clear explanation of how red and processed meats can cause colon cancer. And, unfortunately, grass-fed beef is not a “Get Out Of Jail Free” card. This mechanism is equally applicable to grass-fed beef and conventionally raised beef.

Does this mean you need to become a vegan? While I have nothing against veganism, the answer appears to be no. As I discussed above whole, unprocessed plant foods are the antidote to the carcinogenic compounds formed from red meat. This is due to:

  • Their fiber, which sweeps some carcinogens out of the intestine before they can be absorbed.
  • Their antioxidants, which prevent some carcinogens from being formed.
  • Their phytonutrients, which block the activation of some carcinogens.
  • The friendly gut bacteria they support, which displace the bad bacteria that form some carcinogen precursors in the intestine.

The good news is that some red meat may be OK in the context of a primarily plant-based diet. For example, 3 ounces of red meat in a green salad or stir fry is less likely to increase your risk of colon cancer than an 8-ounce steak and fries.

The bad news is this is why not all studies have shown an association of red meat consumption and increased risk of colon cancer. Unfortunately, far too many of these studies have ignored other components of the diet.

The Bottom Line

A recent study looked at the effect of red meat consumption on DNA modifications in colon cells that are associated with the conversion of normal cells to cancer cells. It is a highly technical study, but the simplified version is:

  • Previous studies have shown that red meat consumption is associated with an increased risk of colon cancer.
  • Studies have also shown that red meat consumption is associated with an increased concentration of carcinogenic N-nitroso compounds in the colon.
  • This study shows that red meat consumption is associated with the kind of DNA damage caused by N-nitroso compounds in colon tumor cells – the kind of damage that can lead to cancer-causing mutations. In addition:
    • The DNA damage occurs in the exact location of the colon predicted from earlier studies.
    • The DNA damage occurs in genes known to drive the conversion of normal colon cells to cancer cells.

In short, this study provides a plausible mechanism for the effect of red meat consumption on increased risk of colon cancer. It shows how red meat can cause colon cancer.

“In the words of the authors, “Our study has leveraged a comprehensive dataset with repeated dietary measures over years…and [DNA sequencing] on a large collection of colorectal tumors. It provides unique evidence supporting the direct impact of dietary behaviors on colorectal carcinogenesis…”

For more details about this study and how you can eat red meat and still reduce your risk of colon cancer, read the article above.

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

Is It Too Late To Change Your Diet?

You Can Improve Your Health At Any Age

Author: Dr. Stephen Chaney

Fast Food ExamplesIf you are like most Americans, your dietary preferences as an adult are based on the foods your family ate while you were growing up.

  • Your favorite foods…
  • Your comfort foods…
  • The foods you always avoid…

…are based on your family heritage, not on your genes. And if you are like most Americans, your diet isn’t healthy.

  • It’s high in fat and cholesterol…
  • It’s high in sugar and refined carbohydrates…
  • It’s high in processed foods…
  • It’s low in whole, unprocessed foods…
  • It’s high in calories, so your waistline keeps growing.

You know your diet isn’t healthy, but you keep coasting along through your 30’s and 40’s until…the unthinkable happens. You are diagnosed with a deadly disease, like heart disease, high blood pressure, or diabetes, and your doctor says that unless you change your diet, you are doomed to a short unhealthy life. You have reached a fork in Food Choicesthe road.

Changing the diet you grew up with, the diet you love, is a daunting task. It’s tempting to think, “Why bother…

  • It’s probably too late to change my diet…
  • The damage has already been done…
  • I can’t reverse it now.”

If this scenario describes you or someone you love, you aren’t alone. There are millions of Americans just like you. You want to know whether changing your diet is worth the trouble. You want to know whether it is too late, or whether you can still change your health for the better.

Most clinical studies don’t answer this question. Most clinical studies do a diet assessment at the beginning of the study and look at health outcomes 20 or 30 years later. If they do more than one diet assessment during the study, the purpose of these assessments is to show that most people stick to the same diet throughout the study.

These studies measure the effect of habitual diets on health outcomes. They tell you that good diets lead to good health outcomes, and bad diets lead to bad health outcomes. But they don’t tell you whether changing your diet from bad to good in your 30’s or 40’s can have a significant effect on your health.

Fortunately, a recent study has answered this question. This study (Y Choi et al, Journal of The American Heart Association, 10e020718, 2021) started with people in their mid-20s. It looked at whether changing their diet from bad to good in their 30s and 40s had any effect on their risk of developing heart disease in their 50s and 60s.

How Was This Study Done?

Clinical StudyThe data for this study were obtained from the CARDIA study (Coronary Artery Risk Development in Young Adults). The study enrolled 4946 young adults (average age = 25, 55% female and 45% male, 50% black and 50% white) and followed them for 32 years (average age of participants at the end of the study = 57).

Diet was assessed by a trained interviewer at year 0, year 7 (average age of participants = 32), and year 20 (average age of participants = 45).

Adherence of the participants to a healthy, plant-centered diet was assessed using an analytical tool called APDQS that divided the foods eaten by the participants into 3 groups based on their known influence on heart disease:

1) Beneficial.

    • These foods included fruit, avocado, beans/legumes, green vegetables, yellow vegetables, tomatoes, other vegetables, nuts and seeds, soy products, whole grains, vegetable oil, fatty fish, lean fish, poultry, moderate alcohol, coffee, tea, and low-fat milk/cheese/yogurt.
    • This is what the investigators considered a plant-centered diet. It encompasses diets ranging from vegan to Mediterranean and DASH.

2) Adverse.

    • These foods included fried potatoes, refined grain desserts, salty snacks, pastries, sweets, high-fat red meats, processed meats, organ meats, fried fish/poultry, sauces, soft drinks, whole fat milk/cheese/yogurt, and butter.
    • This could be considered a typical American diet.

3) Neutral.

    • These foods included potatoes, refined grains, margarine, chocolate, meal replacements, pickled foods, lean meats, shellfish, eggs, soups, and fruit juices.
    • These foods are not the healthiest, but the evidence that they have a negative effect on health disease risk is inconclusive.

The participants were divided into 5 quintiles based on adherence to a plant-centered diet, with quintile 1 having the lowest adherence and quintile 5 having the highest adherence to a plant-centered diet.

The effect of diet on heart disease was measured in two ways:

1) The dietary data from years 0, 7 and 20 were averaged and the effect of average adherence to a plant-centered diet on the risk of developing heart disease by the time the participants were 57 was measured. This is similar to the design of most other studies looking at the effect of diet and heart disease.

2) The effect of an improvement in adherence to a plant-centered diet between ages of 32 and 45 on the risk of developing heart disease by age 57 was also measured. This is what makes this study unique. Basically, the investigators were asking if you could eat a bad diet for 30 years or more and still reduce your risk of heart disease by switching to a good diet by the age of 45. That is the question that millions of American are asking themselves right now.

Is It Too Late To Change Your Diet?

Heart Healthy DietAs I described above this study asked two distinct questions:

1) What effect does your habitual diet have on your risk of developing heart disease?

For this portion of the study, the investigators averaged the dietary data collected in years 0, 7, and 20 of the study and ranked the participants diet from 1 to 5 based on their adherence to a plant-centered diet. When they compared the group with best adherence (group 5) with the group with worst adherence (group 1):

    • Adherence to a plant-centered diet reduced their risk of developing heart disease by 48%.
    • This is consistent with previous studies looking at the beneficial effects of plant-centered diets on heart disease.

2) What effect does changing your diet from bad to good when you are in your 30s or 40s have on your risk of developing heart disease? 

For this portion of the study, the investigators compared the dietary data collected at years 7 and 20 (corresponding to average ages 32 and 45 for the participants) and ranked the participants from 1 to 5 based on improved adherence to a plant-centered diet. When they compared the group with best improvement in adherence (group 5) with the group with worst improvement in adherence (group 1):

    • Improved adherence to a plant-centered diet reduced the risk of developing heart disease by 39%.
    • This answers the questions I posed at the beginning of this article. In short, it is never too late to change your diet for the better.

The authors concluded, “In summary, our study shows that long-term consumption of a nutritionally rich plant-centered diet is associated with a lower risk of heart disease. Furthermore, increased [adherence to a] plant-centered diet in young adulthood is associated with a lower subsequent risk of heart disease throughout middle age, independent of the earlier diet quality” [In short, they are saying that changing to a more plant-centered diet in your 30s and 40s reduces your risk of heart disease.]

You Can Improve Your Health At Any Age

I titled this section, “You Can Improve Your Health At Any Age” for a reason. I wanted to make the point that it is never too late to change your diet, and your health, for the better.

Yes, I realize that the study I described above only shows:

  • The effect of changing to a more plant-centered diet in your 30s and 40s.
  • The benefit of changing to a more plant-centered diet on heart disease outcomes.

However, we have ample evidence that changing to a more plant-based diet at any age is likely to reduce the risk of many diseases. For example:

  • There are multiple reports in the literature of people in their 60s and 70s who had a health scare, changed to a more plant-centered diet, and dramatically improved their health.

While neither type of study can be considered definitive by itself, together they suggest it is never too late to change your diet for the better.

But what changes should you make? As I said above, anything from Vegan to Mediterranean or DASH fits the definition of a plant-centered diet (something I have previously referred to as a primarily plant-based diet).

You could choose the plant-centered diet that best fits your preferences and lifestyle and read books or go online to find details and recipes that will help you transition to that diet…or you could simply:

  • Eat more fruit, avocado, beans/legumes, green vegetables, yellow vegetables, tomatoes, other vegetables, nuts and seeds, soy products, whole grains, vegetable oil, fatty fish, lean fish, poultry, moderate alcohol, coffee, tea, and low-fat milk/cheese/yogurt.
  • Eat less fried potatoes, refined grain desserts, salty snacks, pastries, sweets, high-fat red meats, processed meats, organ meats, fried fish/poultry, sauces, soft drinks, whole fat milk/cheese/yogurt, and butter.
  • Eat these foods in moderation: potatoes, refined grains, margarine, chocolate, meal replacements, pickled foods, lean meats, shellfish, eggs, soups, and fruit juices.

The Bottom Line

If you are like most Americans, you know your diet is unhealthy. But it is the diet you grew up with. It’s the diet you love. So, you keep eating it anyway.

Then you have a wake-up call. You find yourself in your doctor’s office, and your doctor is advising you to change your diet. But giving up the diet you love is difficult, and you wonder if it is worth it. Can you really improve your health significantly by changing your diet now, or is it too late? Has the damage already been done?

Fortunately, a recent study has answered these questions. This study started with people in their mid-20s. And it looked at whether changing their diet from bad to good in their 30s and 40s had any effect on their health in their 50s and 60s. This is what the study found.

  • Improved adherence to a plant-centered diet in their 30s and 40s reduced their risk of developing heart disease in their 50s and 60s by 39%.

While this study was very specific in terms of age and disease, I have discussed in the article above why changing to a more plant-based diet at any age is likely to reduce your risk of multiple diseases. In short, it is never too late to change your diet, and your health, for the better.

For more details about this study and how to change your diet for the better, 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.

A Diet To Die For

Which Diet Is Best? 

Author: Dr. Stephen Chaney

Heart AttackMany clinical studies focus on the benefits or risks associated with individual components of our diet. For example, we have been told:

  • Saturated and trans fats are bad for us and monounsaturated and omega-3 fats are good for us.
  • Sugar and refined carbohydrates are bad for us, but complex carbohydrates are good for us.

However, we don’t eat saturated fats or sugars in isolation. They are part of a diet with many other foods. Do other foods in our diet affect the risks we associate with saturated fat or sugar? We don’t know.

Simply put, we don’t eat foods, we eat diets. We don’t eat saturated fats, we eat diets. It would be more helpful for the average person if research focused on which diets are good and bad for us instead of which foods are good and bad for us.

One recent study (JM Shikany et al, Journal of the American Heart Association, 10:e019158, 2021) did just that. It evaluated the effect of 6 different dietary patterns on the risk of sudden cardiac death (dropping dead from a stroke or heart attack).

  • It turns out that one of the diets significantly increases your risk of sudden cardiac death. I call that one, “A diet to die for”.
  • Another diet significantly decreases your risk of sudden cardiac death. I call that one, “A diet to live for”.
  • The other diets had no significant effect on the risk of sudden cardiac death.

You are probably wondering, “What were the diets?”; “Which diet is best?”; and “Which diet is worst?” I cover that below, but first we should look at how the study was designed.

How Was The Study Designed?

Clinical StudyThe study involved 21,069 participants in the REGARDS (Reasons for Geographical and Racial Differences in Stroke) clinical trial who were followed for an average of 10 years. This clinical trial enrolled:

  • 30% of its participants from what is called the “the stroke belt” (North Carolina, South Carolina, Georgia, Tennessee, Alabama, Mississippi, Arkansas, and Louisiana).
  • 20% of its participants from what is called “the stroke buckle” (the coastal plain of North Carolina, South Carolina, and Georgia).
  • 50% of its participants from elsewhere in the continental United States.

At the beginning of the study, participants were given a medical exam and filled out an extensive questionnaire on diet.

Based on the diet analysis, the participants were ranked for adherence to six dietary patterns.

#1: The Convenience Pattern. This dietary pattern relied heavily on pre-packaged or restaurant meals, pasta dishes, pizza, Mexican food, and Chinese food.

#2: The Plant-Based Pattern. This dietary pattern relied heavily on vegetables, fruits, fruit juice, cereal, beans, fish, poultry, and yogurt.

#3: The Sweets Pattern. This dietary pattern relied heavily on added sugars, desserts, chocolate, candy, and sweetened breakfast foods.

#4: The Southern Pattern. This dietary pattern relied heavily on added fats, fried food, eggs and egg dishes, organ meats, processed meats, and sugar-sweetened beverages.

#5: The Alcohol and Salad Pattern. This dietary pattern relied heavily on beer, wine, liquor, green leafy vegetables, tomatoes, and salad dressing.

#6: The Mediterranean Pattern. Adherence to the Mediterranean dietary pattern was based on the well-established Mediterranean Diet Score.

  • Points are added for beneficial foods (vegetables, fruits, legumes, whole grain cereals, nuts, and fish).
  • Points are subtracted for detrimental foods (meat and dairy).
  • Points are added for a high ratio of monounsaturated fats to saturated fats (think diets rich in olive oil).
  • One point is added for moderate alcohol consumption, Zero or excess alcohol consumption is assigned 0 points.

The study looked at the correlation of these dietary patterns with the incidence of sudden cardiac death during the 10-year study.

A Diet To Die For

deadThe results were striking.

  • The Southern Diet increased the 10-year risk of sudden cardiac death 2.2-fold. Basically, it doubled the risk.
    • In people with no previous history of heart disease at the beginning of the 10-year study, the Southern Diet increased the risk of sudden cardiac death by 2.3-fold.
    • In people with a previous history of heart disease at the beginning of the 10-year study, the Southern Diet increased the risk of sudden cardiac death by 2-fold.
  • The Mediterranean Diet decreased the 10-year risk of sudden cardiac death 41%.
    • In people with no previous history of heart disease at the beginning of the 10-year study, the Mediterranean Diet decreased the risk of sudden cardiac death by 51%. Basically, it cut the risk in half.
    • In people with a previous history of heart disease at the beginning of the 10-year study, the Mediterranean Diet decreased the risk of sudden cardiac death by 23%, but that decrease was not statistically significant.
  • None of the other diets had a significant effect on the 10-year risk of sudden cardiac death.

In the words of the authors, “We identified a trend towards an inverse association of the Mediterranean diet score and a positive association of adherence to the Southern dietary pattern with risk of sudden cardiac death.” [That is a fancy way of saying the Mediterranean diet decreased the risk of sudden cardiac death, and the Southern dietary pattern increased the risk of sudden cardiac death.]

Which Diet Is Best?

AwardThe Mediterranean Diet Is Best: In this analysis of the effects of 6 different dietary patterns on the risk of sudden cardiac death, it is obvious that the Mediterranean diet is best. It cut the risk of sudden cardiac death in half.

This should come as no surprise:

  • I have reported on a previous study showing that the Mediterranean diet decreases the risk of heart disease by 47%.
  • In the Woman’s Health Study the Mediterranean diet decreased the risk of sudden cardiac death by 36%.
  • In the Nurses’ Health Study there was an inverse association between the Mediterranean Diet Score and sudden cardiac death.

The Southern Dietary Pattern Was Worst. It doubled the risk of sudden cardiac death. As someone who grew up in the South, this comes as no surprise to me. Let me count the ways:

  • It starts with a breakfast of fried eggs, grits with “red-eye gravy” (a mixture of ham drippings and coffee), ham or sausage, and biscuits made with lots of lard and sugar.
  • When I was growing up, a snack might be an RC cola and moon pies (look that one up).
  • Dinner might be fried chicken and hushpuppies or fried fish and hushpuppies.
  • Instead of picnics we have pig pickins (which is pretty much what it sounds like).
  • And we boil our vegetables with fatback (pig fat) and sugar.

I could go on, but you get the picture. Don’t get me wrong, I have fond memories of the foods I ate while growing up in the South. I just don’t eat them much anymore.

Why Didn’t The Plant-Based Dietary Pattern Score Better? One of the surprises from this study was that the Plant-Based Dietary Pattern didn’t score better. After all, numerous studies have shown that mostly plant-based diets reduce the risk of heart disease. Why did it strike out in this study?Vegan Foods

My feeling is that the study did not adequately describe a true Plant-Based Dietary Pattern. As I described above, participants following the Plant-Based Dietary Pattern were identified as having above average consumption of vegetables, fruits, fruit juice, cereal, beans, fish, poultry, and yogurt compared to others in this study. I have two concerns with this classification.

  • As described, this is a semi-vegetarian diet, while the best results for reducing heart disease risk are seen with strict vegetarian and lacto-ovo-vegetarian diets.
  • However, my biggest concern is that we don’t know what other foods they were consuming. Were they also consuming convenience foods? Were they consuming sweets? We don’t know.

That is very different from the two dietary patterns that stood out in this study.

  • 50% of the participants in this study came the Southeastern region of the United States. So, when the study identified participants as following a Southern Dietary Pattern based on a few southern foods, it is likely that those participants ate many other southern foods as well.

If 50% of the participants in the study had come from the Loma Linda area of California where vegetarianism is much more common, the study might have done a better job of identifying participants consuming a plant-based diet.

  • While participants consuming the Mediterranean diet were more scattered geographically, the Mediterranean Diet Score used to identify people consuming a Mediterranean diet is much more detailed and has been validated in numerous previous studies.

In short, the Southern and Mediterranean Dietary Patterns may have stood out in this study because they provided a more precise distinction between those consuming a Southern or Mediterranean diet and those following other dietary patterns. If the Plant-Based Dietary Pattern had been more precisely described, it might have shown a statistically significant benefit as well.

The Bottom Line

Many clinical studies focus on the benefits or risks associated with individual components of our diet.

However, we don’t eat foods, we eat diets. It would be more helpful for the average person if research focused on which diets are good and bad for us instead of which foods are good and bad for us.

One recent study did just that. It evaluated the effect of 6 different dietary patterns on the risk of sudden cardiac death (dropping dead from a stroke or heart attack).

  • It turns out that the Southern diet doubles your risk of sudden cardiac death. I call that one, “A diet to die for”.
  • In contrast, the Mediterranean diet cuts your risk of sudden cardiac death in half. I call that one, “A diet to live for”.
  • The other diets had no significant effect on the risk of sudden cardiac death.

For more details on the study, why the Southern diet is so bad for us, and why the Mediterranean diet is so good for us, 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.

Health Tips From The Professor