red meat

Give Your Heart A Valentine

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How Can You Give Your Heart A Valentine?

Author: Dr. Stephen Chaney

Happy valentines day

Valentine’s Day is just around the corner. You have probably already selected Valentine Day cards and gifts for those nearest and dearest to you. But what about your heart. It’s your most trusted companion. Doesn’t it deserve a valentine?

The best Valentine’s gift you could give your heart would be a heart healthy diet. But what is a heart-healthy diet?

You may remember the nursery rhyme, “Jack Sprat could eat no fat. His wife could eat no lean…” You may know people who fit these extremes. And in terms of diets these extremes might represent the vegan and keto diets in today’s world.

The nursery rhyme assures us that, “…between them they licked the platter clean.” But were their diets equally heart-healthy? Which of them would have been more likely to live a long and healthy life, free of heart disease?

If you search Mr. Google – even with AI assist – you might be confused. That’s because AI bases its recommendations on the quantity of posts, not the accuracy of posts. And lots of media influencers recommend both diets, and just about every popular diet in between for heart health.

But what does good science say on the topic of heart healthy diets? Fortunately, a recent comprehensive review and meta-analysis (G. Riccardi et al, Cardiovascular Research, 118: 1118-1204, 2022) has answered that question.

How Was The Study Done?

clinical studyThe investigators reviewed 99 clinical studies with tens of thousands of participants that looked at the associations between foods or food groups and heart disease risk.

Most of the studies were “prospective cohort” studies in which:

  • Populations are divided into groups (cohorts) based on the foods they consume…
  • …and followed for a number of years (this is where the term “prospective” comes from)…
  • …and at the end of the study, the association between food and heart outcomes is measured.

However, the review also included several major randomized controlled clinical trials, including:

  • The DASH diet study.
  • The Lyon Diet Heart study.
  • The PREDIMED study.

Give Your Heart A Valentine

What is a heart-healthy diet? Here are the findings of the study. Most will sound very familiar. But you will note strong heartsome subtle differences based on recent data.

The overall summary was that for a healthy adult population:

  • Low consumption of salt and foods of animal origin…
  • …and increased intake of plant foods…
  • …are associated with reduced heart disease risk.

Of course, we have known that for years. It’s when they broke the data down further that it became more interesting.

Foods Of Animal Origin:

  • Processed meats increase heart disease risk. A single serving of processed meat is associated with a 27% to 44% increased risk of heart disease. This is not new.
  • Unprocessed red meat is also associated with increased risk of heart disease, but this association is not as consistent as for processed meats. The authors noted that some of this may be due to differences in saturated fat content or cooking methods of the red meats included in individual studies.

But this analysis also showed that the effect of red meat on heart disease risk may be dose dependent. For example:

    • The studies they reviewed suggested that consuming ≥3 servings per day of red meat is associated with a 27% increased risk of heart disease. However, consuming <3 servings per week may not increase risk, especially when consumed in the context of an otherwise heart-healthy diet.
  • White meat such as poultry does not appear to affect heart disease risk. This has been predicted by earlier reports, but this analysis strengthens those predictions.
  • Fish consumption decreases heart disease risk. This is not new. But this review added precision about recommended fish intake (2-4 servings/week) and a couple of caveats:
    • The heart benefits of fish may be due to their omega-3 content and may not apply equally to fish with lower omega-3 content.
    • The authors also expressed concerns about the sustainability of high-omega-3 fish populations. I would also add that our oceans are increasingly polluted, so contamination is another concern.
  • Egg consumption up to one egg/day does not appear to increase heart disease risk. This is consistent with the current American Heart Association recommendations.

However, the authors noted that the effect of eggs on serum cholesterol, and hence heart disease risk depends on several factors.

    • Genetics, obesity, and diabetes can make it more difficult to regulate serum cholesterol levels. For these individuals, eggs may need to be eaten only sparingly.
    • Diets low in saturated fat and high in fiber from plant foods help the body regulate serum cholesterol. Several studies suggest that eggs may decrease heart disease risk in the context of this type of a heart-healthy diet.
  • Dairy: Neither low-fat nor high-fat dairy foods appear to influence heart disease risk. This is different from the standard recommendation to consume low-fat dairy foods. But it is in line with the trend of recent research studies on dairy and heart disease.

Once again, there were a couple of caveats:

    • There is increasing evidence that fermented dairy foods may decrease heart disease risk which may explain why certain high-fat cheeses and other high-fat fermented dairy foods appear to have a neutral or slightly beneficial effect on heart disease risk.
    • As with eggs, the effect of high-fat dairy foods on heart disease risk may be influenced by genetics and diet context.

Vegan FoodsFoods Of Plant Origin: The effects of plant foods on heart health have been known for some time, and the most recent studies included in this analysis have not changed those conclusions.

  • Fruits and Vegetables consistently reduce heart disease risk in multiple studies. In each case, the optimal intake appears to be about 2 servings of each per day which provides an 18-21% risk reduction for vegetables and a 21-32% risk reduction for fruits.
  • Legumes (beans and peas) also consistently reduce heart disease risk in multiple studies. At the optimal intake of around 4 servings per week the risk reduction is around 14%.
  • Nuts also consistently reduce heart disease risk. At the optimal intake of around one serving (a handful) per day, the risk reduction is around 25%.
  • Cereals (grains) were divided into 3 categories:
    • Refined carbohydrates with a high glycemic index (e.g., white rice, white bread) are associated with increased heart disease risk in multiple studies probably due to their effect on blood sugar levels. And the increased risk is significant (Around 66% higher risk for every 2 servings).
    • Refined carbohydrates with a low glycemic index (e.g., pasta, corn tortillas) show an inconsistent effect on heart disease risk.
    • Whole grains are consistently associated with a lower heart disease risk. Two servings of whole grains per day are associated with a 25%-34% decreased risk.

Miscellaneous Foods:

  • Soft Drinks are associated with increased heart disease risk. One serving per day increases the risk by around 15-22% and recent evidence suggests that artificially sweetened soft drinks offer no heart health benefits compared to sugar sweetened soft drinks.
  • Coffee and Tea are both associated with decreased heart disease risk. For coffee the optimal benefit may occur at around 3 cups/day. Higher levels may have an adverse effect on heart disease risk.

Summary of Heart Health Recommendations

ScientistIf you think that was a lot of information, the authors provided a numerical summary of their recommendations for a heart-healthy diet. They are:

  • Two servings per day of vegetables, fresh fruits, and whole grains.
  • One serving per day of nuts and seeds, low-glycemic index refined cereals, extra-virgin olive oil or non-tropical vegetable oils, and yogurt.
  • Four servings per week of legumes and fish.
  • No more than 3 servings per week of white meat, eggs, cheese, and milk.
  • No more than 2 servings per week of high-glycemic index refined starchy foods, red meat, and butter.
  • Only occasional consumption of processed meats.

How Can You Give Your Heart A Valentine?

Of course, nobody wants to follow a “diet by the numbers”. If you are like most of us, you want flexibility and you Questionswant to be able to eat some of your favorite foods. So, let me put these recommendations into a more “user friendly” form.

If you want to give your heart a valentine:

  • Whole, unprocessed or minimally processed, plant foods are your heart’s best friends.
  • Your heart-healthy foundation should be fruits, vegetables, whole grains, nuts and seeds, healthy plant oils, and legumes.
    • Your heart-healthy foundation can also include fermented dairy foods and low-glycemic index refined grains.
    • Your “go-to” beverages should be water, tea (both caffeinated and herbal teas), and coffee. You should avoid soft drinks and other sugar-sweetened or artificially sweetened beverages.
  • Once you have achieved a heart-healthy foundation you can add a few servings per week of white meat, eggs, cheese, and dairy, even high-fat dairy.
    • If you have good adherence to the heart-healthy foundation described above and no genetic or health issues that increase your risk of heart disease, you can probably eat more of these foods.
    • Conversely, if your adherence to the heart-healthy foundation is poor and/or you are at high risk of heart disease, you may wish to consume less of these foods.
  • If you have good adherence to the heart-healthy foundation, you can also add up to 1-2 servings of high-glycemic index refined carbohydrates, red meat, or butter per week. With red meat, you may want to consider it as a garnish that adds flavor to a plant-based meal rather than the centerpiece of the meal.
    • You should eat processed meats seldom or never.

This would be the best Valentine’s gift you could possibly give your heart.

The Bottom Line

For those of you who might want to give your heart a valentine, a new comprehensive review and meta-analysis of 99 clinical studies with tens of thousands of participants has updated the correlation between foods and heart disease risk.

Many of the recommendations based on this analysis are identical to previous recommendations for a heart-healthy diet.

But there are some subtle changes to those recommendations based on the latest data.

For more details about this study and what a heart-healthy diet might look like for you, read the article above.

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

______________________________________________________________________________

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

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

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

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

______________________________________________________________________

About The Author 

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

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

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

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

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

 

 

 

 

Is The New Food Guide Pyramid Healthy?

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A Brief History Of USDA Food Guides

Author: Dr. Stephen Chaney

Unless you have cut yourself off from all outside media, you already know the USDA has just released new “Dietary Guidelines For Americans” and a new, upside down, food pyramid.

Both the AMA and AHA have endorsed the new guidelines with some reservations. But like everything else in today’s world they have become both political and controversial.

  • Some experts are saying, “The new guidelines are fantastic. They will make Americans much healthier. It’s about time the government caught up with the latest scientific advances.
  • Others are saying, “The new guidelines are terrible. They will set medicine back 20 years.”

As usual, the truth lies somewhere in the middle. I will explore that middle ground and discuss the pros and cons of the new dietary guidelines and food guide pyramid in this article.

But first we should start with something everyone can agree with, “What we are doing now isn’t working!” For example:

  • The percentage of Americans who are overweight or obese is approaching 70%.
  • The United States spends more on healthcare per person than any other country in the world. But we…
    • Rank 48th in life expectancy. We not only rank below every developed country, but we also rank below many 3rd world countries.
      • And we are losing ground. In 1990, we ranked 35th in life expectancy.
    • Rank 69th in health span (healthy life expectancy).
      • Again, we are losing ground. Our ranking was 42nd in 1990.
    • Rank dead last (183rd out of 183) in health span as a percentage of life expectancy.

In short, we are falling behind the rest of the world in terms of lifespan, health span, and percentage of healthy years.

And our deteriorating health is costly.

90% of our health care spending is for preventable diseases

A Brief History Of USDA Food Guides

The USDA introduced the first food guide pyramid in 1992 based on the best nutrition science of the time. You probably remember the mantra:

  • 2-3 servings of dairy, preferably low fat.
  • 2-3 servings in the protein category (lean meats, fish, dry beans, eggs, and nuts).
  • 2-4 servings of fruits and 3-5 servings of vegetables.
  • 6-11 servings of grains (bread, cereals, rice, and pasta).
  • Fats, oils, and sweets were at the top of the pyramid with the caption, “Use Sparingly”.

This pyramid and the accompanying dietary guidelines were publicized so much that practically everyone knew them by heart.

Ten years later the USDA did a nutrition survey to see if their guidelines had changed American’s eating behavior. The answer was a clear, “No”. Only 5% of Americans ate according to the food guide pyramid.

The Geniuses at the USDA concluded that the food guide pyramid must be too difficult for the average American, so they introduced a simpler version, My Pyramid in 2005.

Guess what! Only 5% of Americans followed those recommendations, so they went to the super simple My Plate. By now you have probably guessed that only 5% of Americans followed the My Plate recommendations.

It turns out Americans weren’t confused by the recommendations. The recommendations were just too different from the way they were used to eating.

So, one change you will see in the new food guide pyramid is it includes some of Americans favorite foods, such as red meat, butter, and full fat dairy. Is that sacrilege or is it smart? Only time will tell.

With that in mind, let’s discuss the new “Dietary Guidelines For Americans”.

#1: Eat Real Food

This is one recommendation that virtually everyone agrees with. The average American is getting 55% of their calories from highly processed foods. And the health consequences of that much processed food are devastating. Consumption of highly processed foods is linked to higher risk of:

  • Obesity.
  • Type 2 diabetes.
  • Heart attack.
  • Stroke.
  • Some cancers.
  • Depression and anxiety.
  • Dementia
  • Premature death.

If you are wondering how we got to this point, the answer is simple. It stems from the desire of Americans to eat a healthier diet without giving up their favorite foods and the willingness of Big Food Inc (the food industry) to give us exactly what we want. For example:

  • Some people want to eat a more plant-based diet, but don’t want to give up their favorite meats. Big Food Inc is only too happy to oblige. They mix some fat, salt, and a witch’s brew of chemicals to give us phony baloney, faken bacon, and everyone’s favorite, tofurkey.
  • Some people are convinced keto diets are healthy, but don’t want to give their favorite sweets. Again, Big Food Inc is only too happy to oblige. They mix up a witch’s brew of chemicals to give us keto cookies and keto pastries.

I’m being facetious, but you get my point.

Some representatives of Big Food Inc claim that the health risks of processed foods are unproven. They are lying!

If you would like to read my reviews of major studies showing the health risks of highly processed foods, just go to https://www.chaneyhealth.com/healthtips/ and put “processed foods” in the search box.

#2: Prioritize Protein Foods at Every Meal

protein foodsThis is one of the more controversial recommendations of the new food guide pyramid. The new USDA dietary guidelines increase the protein recommendation by 50-100% compared to previous versions…

  • From 0.36 grams of protein per pound of body weight to…
  • Between 0.54 and 0.72 grams of protein per pound of body weight.

[Note: If these numbers seem different from what you have seen, that is because the official recommendations are in grams of protein per kilogram of body weight. Since most Americans have no idea what their body weight is in kilograms, those numbers are useless.]

The main criticisms about the new protein recommendations are:

#1: “There isn’t solid evidence that most people need this much protein.”

My response is that anyone who makes that claim hasn’t kept up with the last two decades of protein research.

The old 0.36/pound standard is probably OK for the average middle-aged couch potato, but higher protein intakes are needed for people who are:

  • Active, especially if they are trying to increase muscle mass, strength, or endurance.
  • Over 50 and are trying to maintain muscle mass, strength, and mobility.
  • Trying to lose weight without losing muscle, especially if they are using GLP-1 drugs.
  • Trying to reduce the risk of type 2 diabetes and other chronic diseases.

In short, almost everyone except the couch potatoes will benefit from higher protein intakes. And, yes, the latest science shows that it is best to get at least 20 grams of protein with each meal.

You can find more information about the science behind increased protein recommendations by going to https://www.chaneyhealth.com/healthtips/ and putting “protein” in the search box.

#2: “The new guidelines don’t steer people towards plant proteins”. This is a subtle distinction. The new USDA dietary guidelines include plant protein sources. But they do not recommend that they replace some of the animal proteins in the diet, as did previous versions. This allows people to choose between animal and plant proteins based on their preferences.

Those of you who have been following my “Health Tips From the Professor” blog know that I am an advocate of primarily plant-based diets. I am fully in the “replace some animal protein with vegetable protein” camp.

  • But I acknowledge that is not the way most Americans eat. Perhaps it is time to make dietary recommendations that align more closely with the way people eat if we want to get above 5% acceptance.
  • It would also be difficult to meet the new protein guidelines with plant protein alone unless you add commercially available plant protein supplements.

#3: “Higher protein intakes may be harmful for some people”. Recent research has shown that this concern is overblown for most Americans. However, there are some people who should probably check with their doctor before they increase their protein intake.

  • People who have been diagnosed with kidney disease.
  • People with genetic conditions or diseases that predispose to kidney disease. One example would be poorly controlled diabetes. [Note: I do not mean to imply that higher protein intake is likely to cause kidney disease in these situations. I included this category because people in these situations may have undiagnosed kidney disease.]

In most of these cases, you have probably been warned by your doctor to be careful about excess protein intake. But if you are uncertain about your risk for kidney disease, it never hurts to check with your doctor before increasing your protein intake.

What About Red Meat?

SteakThe new dietary guidelines have been criticized for emphasizing red meat. That criticism is inaccurate. It’s a “tempest in a teapot”.

In fact, red meat is pictured in both the original and the most recent versions of the food guide pyramid. And red meat is mentioned as one source of protein in both the original and the latest versions of dietary guidelines. It is given no special emphasis over other protein sources in either version of the dietary guidelines.

However, I would like to share my perspective on red meat.

  • Diet context matters. As I have said in previous issues of “Health Tips From The Professor”, fruits, vegetables, whole grains, and beans are the antidotes to all the bad aspects of red meat.” And if you look at the new food guide pyramid, red meat and other proteins are in the same neighborhood as fruits and vegetables.
  • Amount matters. Think of red meat as a garnish – for example, 2-3 ounces of red meat as part of a steak salad or stir fry with lots of veggies rather than an 8-ounce steak with fries.

#3: Consume Dairy

dairy foodsThe new dietary guidelines differ from previous versions in both the amount and kind of dairy foods consumed. For example:

  • The old guidelines recommended 2-3 servings of dairy foods per day.
    • The new guidelines recommend 3 servings per day as part of a 2,000-calorie dietary pattern.
    • Since most Americans consume 3,600 to 3,800 calories per day that recommendation translates to at least 5 servings per day.
  • The old guidelines recommended choosing low fat dairy foods.
    • The new guidelines say, “When consuming dairy, include full-fat dairy with no added sugars.”

Since the full-fat dairy recommendation is the most controversial change, I will address it first.

Let me start by saying that I have been a traditionalist with respect to dairy foods. I have recommended low-fat dairy foods for years. But a good scientist must be willing to change their recommendations based on the latest research findings.

And new findings have clearly challenged our perspective on full-fat dairy foods. Several large, well-designed studies over the past decade have shown that full-fat dairy foods are just as healthy as low-fat dairy foods. I will make two comments about these studies.

  • I suspect that the studies may be skewed because much of the data on full-fat dairy comes from countries where most of full-fat dairy foods are fermented – and we know that fermented dairy foods are very healthy.
    • Admittedly, I have no data to back up my suspicion, but I recommend fermented dairy foods as part of your dairy intake. That’s a recommendation everyone can agree with!
  • One recent study has suggested that diet context is important. Specifically, the study suggests that the benefits of full-fat dairy foods are greatest in the context of a healthy, primarily plant-based diet.
    • Similar observations have been made for egg consumption. That suggests that full-fat dairy and eggs provide some important nutrients that may be missing in a vegetarian diet. But in a diet that is already high in saturated fat and cholesterol, the “bad” effects of full-fat dairy and eggs may outweigh the benefits.

You can find more information about full-fat dairy by going to https://www.chaneyhealth.com/healthtips/ and putting “dairy” in the search box.

As for the amount of dairy foods you should consume, I wouldn’t get hung up on the number of servings per day. I interpret the new guidelines as saying, “Don’t be afraid of dairy. It can be an important part of your diet.”

However, the servings of dairy products are more frequently determined by lactose intolerance or sensitivity to milk protein than by dietary guidelines. Many people, including myself, can only consume small, occasional servings of dairy without experiencing digestive distress.

#4: Eat Vegetables & Fruits Throughout The Day

Colorful fruits and vegetablesThe dietary guidelines say, “Eat a variety of colorful, nutrient-dense vegetables and fruits. Specifically, the recommendation is:

  • 3 servings/day of vegetables and 2 servings/day of fruits each day.
    • Once again, the number of servings are based on a 2,000-calorie diet.
    • When you take into account the actual caloric intake of Americans, the recommendations become 3-5 servings/day of vegetables and 2-4 servings/day of fruits.

These recommendations are not controversial. They are universally accepted.

#5: Incorporate Healthy Fats

The new dietary guidelines are:

  • “Healthy fats are plentiful in many whole foods, such as meats, poultry, eggs, omega-3 rich seafood, nuts, seeds, full-fat dairy, olives, and avocados.”
    • This recommendation is not controversial.
  • “When cooking with or adding fats to meals, prioritize oils with essential fatty acids, such as olive oil. Other options can include butter or beef tallow.”
    • This is the most controversial portion of the new dietary guidelines. The usual comment is something like, “How dare they include butter and lard as healthy fats!”

I’m not a fan of lard but let me make a couple of observations about butter.

  • Butter is a whole food. Its ingredient list is typically cream, milk, and salt. If you buy the unsalted version, the ingredient list is even shorter. Margarine and butter substitutes have much longer ingredient lists, often including some questionable ingredients.
  • The frequency of butter use is important. Let me share a personal example. We eat a whole food, primarily plant-based diet. We substitute almond butter for butter on toast and muffins. But there are certain foods like potatoes, winter squash, and corn on the cob that just aren’t the same without real butter. We buy 4 sticks of butter at a time, cut it into pats of butter, and freeze it. Four sticks of butter lasts us a year.

Finally, the critics who say that the new guidelines should not include foods that are high in saturated fat are ignoring the fact that the guidelines say, “Saturated fat consumption should not exceed 10% of total daily calories.” This statement has remained constant since the first food guide pyramid in 1992.

So, the new guidelines are not recommending that we eat more saturated fat as many critics have claimed. They are saying, “A little bit of saturated fat is OK in the context of a whole food diet with lots of fruits, vegetables, and whole grains.

#6: Focus On Whole Grains

The new dietary guidelines are:

  • “Prioritize fiber-rich whole grains.”
  • “Significantly reduce the consumption of highly processed, refined carbohydrates.”

These guidelines are unchanged from previous versions of the guidelines.

What is new is that the guidelines now recommend only 2-4 servings of whole grains per day. That’s a big change from the 6-11 servings per day recommended in the original food guide pyramid.

  • If the 6-11 servings per day were whole grains, the new recommendation would represent a significant decrease in fiber intake. But that’s not how most Americans eat.
  • Since most of the grains in a typical American’s diet are highly processed and refined, reducing the recommended intake to 2-4 servings per day is a step in the right direction.

#7: Limit Highly Processed Foods, Added Sugars, & Refined Carbohydrates

fast foodI call this, “Avoid the bad stuff”. Specifically:

  • Avoid highly processed foods with added sugar and sodium.
  • Limit foods and beverages that include artificial flavors, colors, preservatives, and sweeteners
  • Avoid sugar-sweetened and artificially sweetened beverages.

These recommendations are accepted by almost everyone except the food industry.

However, I should point out that there is also a slight difference in emphasis from previous versions of the USDA dietary guidelines:

  • The new guidelines are more restrictive for added sugars than previous versions of the dietary guidelines. For example, they say:
    • One meal should contain no more than 10 grams of added sugars.
    • Children under the age of 10 should not be given foods with added sugars (previous versions of the dietary guidelines recommend avoiding added sugars for children under the age of 2).

Given the wealth of evidence that added sugars are linked to increased risk of obesity and chronic diseases, these stricter restrictions on added sugars make good sense – especially because the USDA dietary guidelines form the basis for school lunch programs.

But these guidelines are very different from how the average American eats. I’m not sure how many Americans will follow them.

#8: Limit Alcoholic Beverages

The guidelines:

  • Say, “Consume less alcohol for better overall health”.
  • List people who should completely avoid alcohol.

The only controversy about this recommendation is that it is less specific than the previous guidelines that recommended no more than 1 alcoholic drink/day for women and no more than 2/day for men.

I recognize the desire for specificity. But alcohol tolerance depends on several factors such as body weight, genetics, and medication usage.

What Does This Mean For You?

Questioning WomanThe USDA just released a new version of the Food Guide Pyramid and accompanying “Dietary Guidelines For Americans”, and they are very different from previous versions. What do these changes mean for you?

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

To help you make sense of the article let me summarize the recommendations and criticisms by dividing the recommendations into 4 categories:

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

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

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

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

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

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

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

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

The Bottom Line

The USDA just released a new version of the Food Guide Pyramid and accompanying “Dietary Guidelines For Americans”.

While the AMA and AHA have both endorsed the new guidelines, they have been controversial.

In this article I describe the pros and cons of each dietary guideline and divide them into ones for which:

  • They are clearly an improvement over the previous guideline.
  • They are accepted by almost everyone.
  • The criticism is a “tempest in a teapot”.
  • The criticism is at least partially accurate.

For more information on the pros and cons of the new “Dietary Guidelines For Americans” and how these guidelines apply to you, read the article above.

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

 _____________________________________________________________________________

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

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

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

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

_______________________________________________________________________

About The Author 

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

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

For the past 55 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 Red Meat Be Good For You?

by

Everything You Wanted To Know About Red Meat 

Author: Dr. Stephen Chaney 

ArgumentNutrition is a bit like politics and religion. Everyone has an opinion, and there is not much grace for those with different opinions.

And everything is black or white. There is no middle ground. Red meat is a perfect example. Cardiologists tell us the saturated fat and cholesterol in red meat increases our risk of heart disease. Oncologists tell us red meat increases our risk of colon, breast, prostate, and pancreatic cancer.

The association with red meat consumption and colon cancer is so strong that the World Health Organization has classified red meat as a probable carcinogen.

  • Vegans and vegetarians tell you to avoid red meat at all costs and substitute plant proteins in its place.
  • Keto and carnivore diet enthusiasts tell you that red meat is healthy if you avoid any plant foods containing carbohydrates (which is most plant foods).

Who is right? Is red meat good for you or bad for you? As usual, the answer is somewhere in the middle. We also need to stop looking at individual foods and start looking at the overall diet. We need to ask how our overall diet alters the effect of red meat on our health.

But first, let’s explore:

  • Why red meat is good for us.
  • Why red meat is bad for us.
  • How diet can help us minimize the bad and maximize the good.

I call this section, “Everything You Wanted To Know About Red Meat”.

Everything You Wanted To Know About Red Meat

thumbs upWhy Red Meat Is Good For Us.

  • Red meat is an excellent source of protein, iron, and vitamin B12. Plus, the iron in red meat is primarily found in the heme molecule and heme iron is absorbed much more efficiently than other forms of iron.
  • Red meat contains creatine, which powers our muscles. You can think of creatine molecules as little power packs that are charged when we eat and release a burst of energy whenever we begin to exercise.
  • Red meat contains carnitine, which helps our muscles use fat as an energy source. This is particularly important for heart muscle.
  • But both creatine and carnitine also have a dark side, which I will discuss below.

Why Red Meat Is Bad For Us.thumbs down

When we think about heart disease:

  • The traditional view is that saturated fat and cholesterol are the problem, and we can reduce our risk of heart disease simply by choosing leaner cuts of meat.
  • Other experts feel the link between red meat and heart disease is more complicated. For example, some recent studies have suggested that the carnitine in red meat can be converted by gut bacteria to TMAO, and TMAO increases our risk of heart disease. I have discussed this in a previous issue of “Health Tips From the Professor”.

SteakWhen we think about cancer:

  • When fat and juices from the meat drip onto an open flame, carcinogenic polyaromatic hydrocarbons are formed that stick to the surface of the This can be reduced, but not eliminated, by lower fat meat choices.
  • When red meat is cooked at high temperatures, amino acids in the meat combine with creatine, which is found in all red meats, to form carcinogenic heterocyclic amines. This can be reduced, but not eliminated, by cooking the meat at lower
  • The nitrates and nitrites used as preservatives in many processed meats react with amino acids from the meat to form carcinogenic N-nitrosamines in our intestines.
  • Heme iron, which is found in all red meats, also combines with amino acids in the meat to form carcinogenic N-nitroso compounds in our intestines. This mechanism is inherent in all red meats and cannot be eliminated by choosing lower fat cuts or cooking at lower

Finally, diets high in red meat increase several markers of inflammation, and inflammation increases the risk of both heart disease and cancer.

How Can Diet Help Us Minimize The Bad And Maximize The Good?

Question MarkI’m going to start this section with a provocative statement: “Plant foods are the antidote to all the bad effects of red meat.” Let me explain.

Plant foods are an excellent source of:

  • Antioxidants
  • Polyphenols and other phytonutrients
  • Fiber
  • Plus, the fiber and phytonutrients found in plant foods support the growth of beneficial gut bacteria.

Here is where it gets very complex:

  • Beneficial gut bacteria convert some of the foods we eat into compounds that are absorbed into the bloodstream and improve blood sugar control, reduce cholesterol synthesis, and reduce inflammation.
  • Polyphenols support the growth of certain gut bacteria, and those gut bacteria can convert these polyphenols into compounds that can be absorbed from the intestine. This necessary for many polyphenols to exert their beneficial effects in the body.
  • And, as you might expect, the gut bacteria of meat eaters and vegetarians is very different.

With this in mind, let’s come back to the concept of plant foods being the antidote for red meat.

strong heartIn terms of heart health,

  • You may remember that I said above that the carnitine in red meat can be converted by gut bacteria into TMAO which increases the risk of heart disease. The operative wording here is “can be”. It turns out this only happens with the gut bacteria of habitual meat eaters. Here is the study that showed that:
    • When habitual meat eaters were fed an 8-ounce sirloin steak, both carnitine and TMAO increased in their blood and urine.
    • When vegans were fed the same 8-ounce steak, only carnitine increased. No TMAO was detected.
    • When the meat eaters were treated with an antibiotic that wiped out their gut bacteria prior to eating the steak, no TMAO was detected. This showed it was the gut bacteria in the meat eaters that were responsible for converting carnitine to TMAO.
  • Fiber from whole grains, fruits, and vegetables binds to cholesterol and flushes it out of the intestine, preventing its absorption into the bloodstream.
  • Plant-based diets are anti-inflammatory.

CancerIn terms of cancer,

  • The fiber found in fruits, vegetables and whole grains binds to polyaromatic hydrocarbons and heterocyclic amines and flushes them out through the intestines.
  • Polyaromatic hydrocarbons require activation by the liver before they become carcinogenic. Indoles and isothiocyanates found in broccoli, cabbage, and other cruciferous vegetables inhibit the enzymes that catalyze this activation.
  • Antioxidants found in fruits, vegetables and whole grains reduce the formation of N-nitroso compounds in the intestines.
  • A largely plant-based diet appears to favor a population of intestinal bacteria that is less likely to convert compounds in meat into cancer-causing chemicals. [Note: This is a new area of research, so the data supporting this mechanism of cancer prevention are less definitive than for the other three ]

These observations are based studies designed to identify the mechanisms by which plant-based diets negate the bad effects of red meat. For example, let me share a recent study (T Onali et al, Journal of Nutritional Biochemistry, 141, 109906, 2025) asking whether berries could negate the bad effects of adding red meat (pork) to a typical Finnish diet.

How Was This Study Done?

Clinical StudyThis study was conducted by a group of scientists at the University of Helsinki. They recruited 43 adults aged 20-68 and divided them into two groups. Each group was told to continue with their regular diet, except that consumption of any red meat or berries other than the foods they were provided with was prohibited.

  • Each group was given an extra 5 ounces of pork (minced pork, pulled pork, pork strips from fillet, cold cuts, sausages, and bacon) to eat each day.
  • One group was also given 1 cup of berries (bilberries, strawberries, cloudberries, raspberries, lingonberries, and blackcurrant) to eat each day.
    • Note: These are the foods most familiar to people from Finland in each category.
  • They were provided with these foods on a weekly basis.
  • This intervention portion of the study lasted four weeks.

Dietary intake was assessed in each group using 3-day food records (two weekdays and one weekend day) at the beginning and the end of the study.

Participants in the study collected stool samples on two consecutive days at the beginning and end of the study. These stool samples were analyzed in the following ways:

  • Bacterial DNA was extracted from the stool samples and used to determine which gut bacteria were present in the stools.
  • The stool samples were homogenized and filtered to:
    • Determine the polyphenols and polyphenol metabolites present in the stool samples.
    • Determine whether low molecular weight compounds present in the stool samples were able to inhibit the growth of human colon cancer cells in cell culture.

What Did The Study Show?

Questioning WomanThe dietary analysis found that total calories, protein, carbohydrate, fat, and saturated fat did not change significantly in either group. This indicates that the study participants likely substituted the pork they were given for other high-fat meats they were eating before the study.

However, in the group that was also given berries fiber, vitamin C, vitamin E, manganese, and several polyphenols increased significantly. This suggests that study participants likely substituted the berries for less healthy foods they were eating before the study.

The study found that:

  • In the red meat-only group the relative abundance of beneficial Roseburia and Fecalibacterium gut bacteria was decreased. This did not occur in the red meat + berries group.
  • In the red meat + berries group the concentration of several beneficial polyphenols and polyphenol metabolites was increased.
  • In the red meat + berries group, the filtrate obtained from stool samples inhibited the growth of several human colon cancer cell lines in cell culture experiments. These experiments did not identify which berry polyphenols were responsible for inhibiting the growth of cancer cells. It also did not determine whether the polyphenols came directly from the berries or were created when gut bacteria modified the polyphenol(s).

But these experiments did show that something from a high berry diet inhibited colon cancer cell growth.

The author’s concluded, “Berry supplementation to a diet high in red and processed meat led to berry-derived polyphenolic metabolites in the feces, beneficially modified gut microbiota, inhibited the viability of colon cancer cells, collectively suggesting potential in cancer prevention.

The difference seen in gut metabolism was probably induced by the higher intakes of dietary fiber, vitamin C and E, manganese, and polyphenols by the berry diet.”

Can Red Meat Be Good For You?

This study is one piece of the puzzle to help us understand the effect of diet on the benefits and risks of red meat consumption. Here is what I mean by that.

We can think of scientific investigations in terms of solving a large puzzle with lots of little pieces. If you are a puzzle enthusiast, you know the best way to solve a complicated puzzle is to put the edge pieces together first and then fill in the rest of the puzzle.

In this context, the studies showing that small amounts of red meat are not harmful in the context of healthy, primarily plant-based diets like the DASH and Mediterranean diets are the edge of the puzzle. Smaller studies that define the mechanisms of this effect and provide proof these mechanisms are accurate are the interior pieces that fill out the puzzle. This study is one of those interior pieces.

So, what does that mean for you? It means that diet context is important.

Most of the studies showing the bad effects of red meat have been done in the context of the typical American diet. That might consist of an 8 or 12-ounce steak with fries and either a soft drink or iced tea. Fruits and vegetables, if present at all, are minimal. Dessert usually consists of some sugary treats.

In this context, red meat is bad for you.

In contrast, consider the place red meat occupies in a primarily plant-based diet. Red meat becomes a condiment rather than the main course. Think of 2-3 ounces of red meat as part of a green salad or stir fry with a variety of greens and other vegetables. You might have beans, whole grains, or another vegetable to round out your plate. Dessert would be whatever fruit is in season. And your beverage might be water, milk, or herbal tea.

In this context, the bad effects of red meat disappear. In short, there are no bad foods, only bad diets.

I started this blog with the question, “Can red meat be good for you?”  You may be wondering if I have answered that question.

At the beginning of this article, I listed the good things about red meat, namely that it is a good source of protein, iron, vitamin B12, carnitine, and creatine.

If you remove the bad, only the good remains. So, the answer is, “Yes. In the right diet context red meat can be good for you”.

The Bottom Line

You have heard that red meat is bad for you. It increases your risk of heart disease and cancer. You should avoid it at all costs.

But is that true? In the article above I:

  • Describe both the benefits and risks of red meat.
  • Discuss how plant foods negate many of the bad effects of red meat.
  • Share a study providing proof of that concept.
  • Share how you can enjoy the benefits of red meat while avoiding the bad effects of red meat consumption.

For more details read the article above.

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

______________________________________________________________________________

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

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

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

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.

Eating For A Healthy Heart

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What Does This Mean For You?

Author: Dr. Stephen Chaney

You may remember the nursery rhyme, “Jack Sprat could eat no fat. His wife could eat no lean…” You may know people who fit these extremes. And in terms of diets these extremes might represent the vegan and keto diets in today’s world.

The nursery rhyme assures us that, “…between them they licked the platter clean.” But were their diets equally healthy? Which of them would have been more likely to live a long and healthy life?

And, since this is Heart Health Month, we might ask, “Which diet would have been better for their hearts?”

If you search Mr. Google – even with AI assist – you might be confused. That’s because AI bases its recommendations on the quantity of posts, not the accuracy of posts. And lots of media influencers recommend both diets, and just about every popular diet in between for heart health.

But what does good science say on the topic of heart healthy diets? Fortunately, a recent comprehensive review and meta-analysis (G. Riccardi et al, Cardiovascular Research, 118: 1118-1204, 2022) has answered that question.

How Was The Study Done?

clinical studyThe investigators reviewed 99 clinical studies with tens of thousands of participants that looked at the associations between foods or food groups and heart disease risk.

Most of the studies were “prospective cohort” studies in which:

  • Populations are divided into groups (cohorts) based on the foods they consume…
  • …and followed for a number of years (this is where the term “prospective” comes from)…
  • …and at the end of the study, the association between food and heart outcomes is measured.

However, the review also included several major randomized controlled clinical trials, including:

  • The DASH diet study.
  • The Lyon Diet Heart study.
  • The PREDIMED study.

Eating For A Healthy Heart

strong heartHere are the findings of the study. Most will sound very familiar. But you will note some subtle differences based on recent data.

The overall summary was that for a healthy adult population:

  • Low consumption of salt and foods of animal origin…
  • …and increased intake of plant foods…
  • …are associated with reduced heart disease risk.

Of course, we have known that for years. It’s when they broke the data down further that it became more interesting.

Foods Of Animal Origin:

  • Processed meats increase heart disease risk. A single serving of processed meat is associated with a 27% to 44% increased risk of heart disease. This is not new.
  • Unprocessed red meat is also associated with increased risk of heart disease, but this association is not as Steakconsistent as for processed meats. The authors noted that some of this may be due to differences in saturated fat content or cooking methods of the red meats included in individual studies.

But this analysis also showed that the effect of red meat on heart disease risk may be dose dependent. For example:

    • The studies they reviewed suggested that consuming ≥2 servings per day of red meat is associated with a 27% increased risk of heart disease. However, consuming <3 servings per week may not increase risk.
    • The idea that the effect of red meat on heart disease risk may be dose-dependent is novel. However, the authors said we also need to ask what replaces red meat in the diet. They postulated that when red meat consumption is decreased, it is often replaced with healthier protein sources.
  • White meat such as poultry does not appear to affect heart disease risk. This has been predicted by earlier reports, but this analysis strengthens those predictions.
  • Fish consumption decreases heart disease risk. This is not new. But this review added precision about recommended fish intake (2-4 servings/week) and a couple of caveats:
    • The heart benefits of fish may be due to their omega-3 content and may not apply equally to fish with lower omega-3 content.
    • The authors also expressed concerns about the sustainability of high-omega-3 fish populations. I would also add that our oceans are increasingly polluted, so contamination is another concern.
  • Egg consumption up to one egg/day does not appear to increase heart disease risk. This is consistent with the are eggs good for youcurrent American Heart Association recommendations.

However, the authors noted that the effect of eggs on serum cholesterol, and hence heart disease risk depends on several factors.

    • Genetics, obesity, and diabetes can make it more difficult to regulate serum cholesterol levels. For these individuals, eggs may need to be eaten only sparingly.
    • Diets low in saturated fat and high in fiber from plant foods help the body regulate serum cholesterol. Several studies suggest that eggs may decrease heart disease risk in the context of this type of diet.
  • Dairy: Neither low-fat nor high-fat dairy foods appear to influence heart disease risk. This is different from the standard recommendation to consume low-fat dairy foods. But it is in line with the trend of recent research studies on dairy and heart disease.

Once again, there were a couple of caveats:

    • There is increasing evidence that fermented dairy foods may decrease heart disease risk which may explain why certain high-fat cheeses and other high-fat fermented dairy foods appear to have a neutral or slightly beneficial effect on heart disease risk.
    • As with eggs the effect of high-fat dairy foods on heart disease risk may be influenced by genetics and diet context.

Foods Of Plant Origin: The effect of plant foods have been known for some time, and the most recent studies included in this analysis have not changed those conclusions.

  • Fruits and Vegetables consistently reduce heart disease risk in multiple studies. In each case, the optimal Vegan Foodsintake appears to be about 2 servings of each per day which provides an 18-21% risk reduction for vegetables and a 21-32% risk reduction for fruits.
  • Legumes (beans and peas) also consistently reduce heart disease risk in multiple studies. At the optimal intake of around 4 servings per week the risk reduction is around 14%.
  • Nuts also consistently reduce heart disease risk. At the optimal intake of around one serving (a handful) per day, the risk reduction is around 25%.
  • Cereals (grains) were divided into 3 categories:
    • Refined carbohydrates with a high glycemic index (e.g., white rice, white bread) are associated with increased heart disease risk in multiple studies probably due to their effect on blood sugar levels. And the increased risk is significant (Around 66% higher risk for every 2 servings).
    • Refined carbohydrates with a low glycemic index (e.g., pasta, corn tortillas) show an inconsistent effect on heart disease risk.
    • Whole grains are consistently associated with a lower heart disease risk. Two servings of whole grains per day are associated with a 25%-34% decreased risk.

Miscellaneous Foods:

  • Soft Drinks are associated with increased heart disease risk. One serving per day increases the risk by around 15-22% and recent evidence suggests that artificially sweetened soft drinks offer no heart health benefits compared to sugar sweetened soft drinks.
  • Coffee and Tea are both associated with decreased heart disease risk. For coffee the optimal benefit may occur at around 3 cups/day. Higher levels may have an adverse effect on heart disease risk.

Summary of Heart Health Recommendations

ScientistIf you are thinking that was a lot of information, the authors provided a numerical summary of their recommendations for a heart-healthy diet. They are:

  • Two servings per day of vegetables, fresh fruits, and whole grains.
  • One serving per day of nuts and seeds, low-glycemic index refined cereals, extra-virgin olive oil or non-tropical vegetable oils, and yogurt.
  • Four servings per week of legumes and fish.
  • No more than 3 servings per week of white meat, eggs, cheese, and milk.
  • No more than 2 servings per week of high-glycemic index refined starchy foods, red meat, and butter.
  • Only occasional consumption of processed meats.

What Does This Study Mean For You?

QuestionsOf course, nobody wants to follow a “diet by the numbers”. If you are like most of us, you want flexibility and you want to be able to eat some of your favorite foods. So, let me put these recommendations into a more “user friendly” form.

If you want a healthy heart:

  • Whole, unprocessed or minimally processed, plant foods are your friends.
  • Your heart-healthy foundation should be fruits, vegetables, whole grains, nuts and seeds, healthy plant oils, and legumes.
  • Your heart-healthy foundation can also include fermented dairy foods and low-glycemic index refined grains.
  • Your “go-to” beverages should be water, tea (both caffeinated and herbal teas), and coffee. You should avoid soft drinks and other sugar-sweetened or artificially sweetened beverages.
  • Once you have achieved a heart-healthy foundation you can add a few servings per week of white meat, eggs, cheese, and dairy, even high-fat dairy.
  • If you have good adherence to the heart-healthy foundation described above and no genetic or health issues that increase your risk of heart disease, you can probably eat more of these foods.
  • Conversely, if your adherence to the heart-healthy foundation is poor and/or you are at high risk of heart disease, you may wish to consume less of these foods.
  • If you have good adherence to the heart-healthy foundation, you can also add up to 1-2 servings of high-glycemic index refined carbohydrates, red meat, or butter per week. With red meat, you may want to consider it as a garnish that adds flavor to a plant-based meal rather than the centerpiece of the meal.
  • You should eat processed meats seldom or never.

The Bottom Line

A new comprehensive review and meta-analysis of 99 clinical studies with tens of thousands of participants has updated the correlation between foods and heart disease risk.

Many of the recommendations based on this analysis are identical to previous recommendations for a heart-healthy diet.

But there are some subtle changes to those recommendations based on the latest data.

For more details about this study and what a heart-healthy diet might look like 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.

Eat Green

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Can Diet Affect The Health Of Our Planet? 

Author: Dr. Stephen Chaney

Earth DayEarth Day was yesterday. So, it is time for my annual reminder that what you eat affects a lot more than just your health. It affects the health of our planet. Once again, it’s time to ask yourself, “Is my 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.

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.

Food 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.

Eat Green

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.

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

2) Reduce food losses and waste by at least 50%.

3) 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.

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

5) 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?

QuestionsIf 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.

______________________________________________________________________________

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 Diet Protect Your Mind?

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Which Diet Is Best?

Author: Dr. Stephen Chaney 

can diet prevent alzheimer'sAlzheimer’s is a scary disease. There is so much to look forward to in our golden years. We want to enjoy the fruits of our years of hard work. We want to enjoy our grandkids and perhaps even our great grandkids. More importantly, we want to be able to pass on our accumulated experiences and wisdom to future generations.

Alzheimer’s and other forms of dementia have the potential to rob us of everything that makes life worth living. What is the use of having a healthy body, family, and fortune if we can’t even recognize the people around us?

Alzheimer’s and other forms of dementia don’t happen overnight. The first symptoms of cognitive decline are things like forgetting names, where you left things, what you did last week. For most people it just keeps getting worse.

Can diet protect your mind? Recent studies have given us a ray of hope. For example, several meta-analyses have shown that adherence to the Mediterranean diet was associated with a 25-48% lower risk of cognitive decline and dementia.

However, there were several limitations to the studies included in these meta-analyses. For example:

  • For most of the studies the diet was assessed only at the beginning of the study. We have no idea whether the participants followed the same diet throughout the study. This means, we cannot answer questions like:
    • What is the effect of long-term adherence to a healthy diet?
    • Can you reduce your risk of cognitive decline if you switch from an unhealthy diet to a healthy diet?
  • These studies focused primarily on the Mediterranean diet. This leaves the question:
    • What about other healthy diets? Is there something unique about the Mediterranean diet, or do other healthy diets also reduce the risk of cognitive decline?

This study (C Yuan et al, American Journal of Clinical Nutrition, 115: 232-243, 2022) was designed to answer those questions.

How Was The Study Done?

clinical studyThe investigators utilized data from The Nurse’s Health Study. They followed 49,493 female nurses for 30 years from 1984 to 2014. The average age of the nurses in 1984 was 48 years, and none of them had symptoms of cognitive decline at the beginning of the study.

The nurse’s diets were analyzed in 1984, 1986, and every 4 years afterwards until 2006. Diets were not analyzed during the last 8 years of the study to eliminate something called “reverse causation”. Simply put, the investigators were trying to eliminate the possibility that participants in the study might change their diet because they were starting to notice symptoms of cognitive decline.

The data from the dietary analyses were used to calculate adherence to 3 different healthy diets:

  • The Mediterranean diet.
  • The DASH diet. The DASH diet was designed to reduce the risk of high blood pressure. But you can think of it as an Americanized version of the Mediterranean diet.
  • The diet recommended by the USDA. Adherence to this diet is evaluated by something called the Alternative Healthy Eating Index or AHEI.

Adherence to each diet was calculated by giving a positive score to foods that were recommended for the diet and a negative score for foods that were not recommended for the diet. For more details, read the article.

In 2012 and 2014 the nurses were asked to fill out questionnaires self-assessing the early stages of cognitive decline. They were asked if they had more trouble than usual:

  • Remembering recent events or remembering a short list of items like a grocery list (measuring memory).
  • Understanding things, following spoken instructions, following a group conversation, or following a plot in a TV program (measuring executive function).
  • Remembering things from one second to the next (measuring attention).
  • Finding ways around familiar streets (measuring visuospatial skills).

The extent of cognitive decline was calculated based on the number of yes answers to these questions.

Can Diet Protect Your Mind?

Vegan FoodsHere is what the investigators found when they analyzed the data:

At the beginning of the study in 1984 there were 49,493 female nurses with an average age of 48. None of them had symptoms of cognitive decline.

  • By 2012-2014 (average age = 76-78) 46.9% of them had cognitive decline and 12.3% of them had severe cognitive decline.

Using the data on dietary intake and the rating systems specific to each of the diets studied, the investigators divided the participants into thirds based on their adherence to each diet. The investigators then used these data to answer two important questions that no previous study had answered:

#1: What is the effect of long-term adherence to a healthy diet? To answer this question the investigators averaged the dietary data obtained every 4 years between 1984 and 2006 to obtain cumulative average scores for adherence to each diet. When the investigators compared participants with the highest adherence to various healthy diets for 30 years to participants with the lowest adherence to those diets, the risk of developing severe cognitive decline was decreased by:

  • 40% for the Mediterranean diet.
  • 32% for the DASH diet.
  • 20% for the USDA-recommended healthy diet (as measured by the AHEI score).

#2: Can you reduce your risk of cognitive decline if you switch from an unhealthy diet to a healthy diet? To answer this question, the investigators looked at participants who started with the lowest adherence to each diet and improved to the highest adherence by the end of the study. This study showed that improving from an unhealthy diet to a healthy diet over 30 years decreased the risk of developing severe cognitive decline by:

  • 20% for the Mediterranean diet.
  • 25% for the DASH diet.

There were a few other significant observations from this study.

  • The inverse association between healthy diets and risk of cognitive decline was greater for nurses who had high blood pressure.
    • This is an important finding because high blood pressure increases the risk of cognitive decline.
  • The inverse association between healthy diets and risk of cognitive decline was also greater for nurses who did not have the APOE-ɛ4 gene.
    • This illustrates the interaction of diet and genetics. The APOE-ɛ4 gene increases the risk of cognitive decline. Healthy diets reduced the risk of cognitive decline in nurse with the APOE-ɛ4 gene but not to the same extent as for nurses without the gene.

This study did not investigate the mechanism by which healthy diets reduced the risk of cognitive decline, but the investigators speculated it might be because these diets:

  • Were anti-inflammatory.
  • Supported the growth of healthy gut bacteria.

The investigators concluded, “Our findings support the beneficial roles of long-term adherence to the [Mediterranean, DASH, and USDA] dietary patterns for maintaining cognition in women…Further, among those with initially relatively low-quality diets, improvement in diet quality was associated with a lower likelihood of developing severe cognitive decline. These findings indicate that improvements in diet quality in midlife and later may have a role in maintenance of cognitive function among women.”

Which Diet Is Best?

Mediterranean Diet FoodsIn a sense this is a trick question. That’s because this study did not put the participants on different diets. It simply analyzed the diets the women were eating in different ways. And while the algorithms they were using were diet-specific, there was tremendous overlap between them. For more specifics on the algorithms used to estimate adherence to each diet, read the article.

That is why the investigators concluded that all three diets they analyzed reduced the risk of cognitive decline rather than highlighting a specific diet. However, based on this and numerous previous studies the evidence is strongest for the Mediterranean and DASH diets.

And I would be remiss if I didn’t also mention the MIND diet. While it was not included in this study, the MIND diet:

  • Was specifically designed to reduce cognitive decline.
  • Can be thought of as a combination of the Mediterranean and DASH diets.
  • Includes data from studies on the mind-benefits of individual foods. For example, it recommends berries rather than all fruits.

The MIND diet has not been as extensively studied as the Mediterranean and DASH diets, but there is some evidence that it may be more effective at reducing cognitive decline than either the Mediterranean or DASH diets alone.

Which Foods Are Best?

AwardThe authors of this study felt it was more important to focus on foods rather than diets. This is a better approach because we eat foods rather than diets. With that in mind they analyzed their data to identify the foods that prevented cognitive decline and the foods increased cognitive decline. This is what they found:

  • Fruits, fruit juices, vegetables, fish, nuts, legumes, low-fat dairy, and omega-3 fatty acids (fish oil) reduced the risk of cognitive decline.
  • Red and processed meats, omega-6 fatty acids (most vegetable oils), and trans fats increased the risk of cognitive decline.

While this study did not specifically look at the effect of processed foods on cognitive decline, diets high in the mind-healthy foods listed above are generally low in sodas, sweets, and highly processed foods.

What Does This Study Mean For You?

Question MarkThe question, “Can diet protect your mind”, is not a new one. Several previous studies have suggested that healthy diets reduce the risk of cognitive decline, but this study breaks new ground. It shows for the first time that:

  • Long-term adherence to a healthy diet can reduce your risk of cognitive decline by up to 40%.
    • This was a 30-year study, so we aren’t talking about “diet” in the traditional sense. We aren’t talking about short-term diets to drop a few pounds. We are talking about a life-long change in the foods we eat.
  • If you currently have a lousy diet, it’s not too late to change. You can reduce your risk of cognitive decline by switching to a healthier diet.
    • This is perhaps the best news to come out of this study.

Based on current evidence, the best diets for protecting against cognitive decline appear to be the Mediterranean, DASH, and MIND diets.

And if you don’t like restrictive diets, my advice is to:

  • Eat more fruits, fruit juices, vegetables, fish, nuts, legumes, low-fat dairy, and omega-3 fatty acids (fish oil).
  • Eat less red and processed meats, omega-6 fatty acids (most vegetable oils), and trans fats.
  • Eat more plant foods and less animal foods.
  • Eat more whole foods and less sodas, sweets, and processed foods.

And, of course, a holistic approach is always best. Other lifestyle factors that help reduce your risk of cognitive decline include:

  • Regular exercise.
  • Weight control.
  • Socialization.
  • Memory training (mental exercises).

The Bottom Line 

Alzheimer’s is a scary disease. What is the use of having a healthy body, family, and fortune if we can’t even recognize the people around us?

A recent study looked at the effect of diet on cognitive decline in women. The study started with middle-aged women (average age = 48) and followed them for 30 years. The investigators then used these data to answer two important questions that no previous study had answered:

#1: What is the effect of long-term adherence to a healthy diet? When the investigators compared participants with the highest adherence to various healthy diets for 30 years to participants with the lowest adherence to those diets, the risk of developing severe cognitive decline was decreased by:

  • 40% for the Mediterranean diet.
  • 32% for the DASH diet.
  • 20% for the USDA recommendations for a healthy diet.

#2: Can you reduce your risk of cognitive decline if you switch from an unhealthy diet to a healthy diet? This study showed that improving from an unhealthy diet to a healthy diet over 30 years decreased the risk of developing severe cognitive decline by:

  • 20% for the Mediterranean diet.
  • 25% for the DASH diet.

The investigators concluded, “Our findings support the beneficial roles of long-term adherence to the [Mediterranean, DASH, and USDA] dietary patterns for maintaining cognition in women…Further, among those with initially relatively low-quality diets, improvement in diet quality was associated with a lower likelihood of developing severe cognitive decline. These findings indicate that improvements in diet quality in midlife and later may have a role in maintenance of cognitive function among women.”

For more details on the study, which diets, and which foods are best for protecting your mind, and what this study means for you, read the article above.

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

Does Processed Food Give You Gas?

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Why Does Processed Food Give You Gas?

Author: Dr. Stephen Chaney 

Does it feel like a war is going on in your belly every time you eat? It could be IBD (inflammatory bowel disease). IBD can take several forms, but the two most common are Crohn’s disease and ulcerative colitis.

What do we know about IBD?

  • The symptoms of IBD can make you miserable. They include:
    • Abdominal pain and cramping.
    • Diarrhea with occasional bouts of constipation.
    • Gas and bloating.
    • Loss of appetite and/or unexpected weight loss.
  • There are about 1.6 million Americans with IBD and 70,000 new cases/year.
    • The prevalence of IBD in the United States has increased by 34% between 2006 and 2016.
  • As you might suspect from its name, IBD is a chronic inflammation of the gastrointestinal tract.
    • It is thought to be caused by “dysbiosis of the gastrointestinal track” (In layman’s terms that means damage to your intestine caused by too many bad bacteria and not enough good bacteria).
    • There is also a genetic component to the disease. Some people are much more susceptible to IBD than others.

If you watch TV, you know that there are drugs for treating IBD. The ads make them sound like miracle drugs. But if you listen carefully, you also know that these drugs have a long list of side effects. And some of the side effects are pretty scary.

Are There Natural Approaches For Controlling IBD?

BacteriaSo, if your belly is a bit rumbly, you might be wondering if there is a more natural approach you could take. We know that diet affects the balance between bad and good bacteria in our intestine. Could something as simple as changing your diet, quell the fire in your belly?

While the answer seems obvious, it has been hard to prove. The results of previous studies have been inconclusive. That is because previous studies:

  • Included too few people. 1.6 million people in the US with IBD may sound like a lot, but that represents only 0.4% of the population. Unless you have a really big study, there won’t be enough people who develop IBD to give you statistically significant results.
  • Were too short. IBD doesn’t develop overnight.
  • Did not include a diverse enough population. Previous studies were confined to individual countries or specific regions within a country.

This study (N Narula et al, British Medical Journal, 2021;374:n1554) was designed to overcome the limitations of previous studies. It also looked at the effect of diet on IBD from a different perspective than most previous studies.

  • It did not focus on the effect of individual foods on IBD. Since consumption of processed foods is known to affect the population of intestinal bacteria, the authors of this study asked whether processed food consumption might influence the likelihood of developing IBD.

How Was The Study Done?

Clinical StudyThe authors of this study used data collected from the PURE (Prospective Urban Rural Epidemiology) study between January 1, 2003, and December 31, 2016. The PURE study collected data from a very diverse population. Specifically, it collected data from 21 low-, middle-, and high-income countries across 7 geographical regions (Europe, North America, South America, Africa, Middle East, South Asia, Southeast Asia, and China).

  • This study followed 116,087 adults aged 35-70 years (average age 50, percent women = 60%) in the PURE study for an average of 9.7 years. During that time, 467 participants (0.4%) developed IBD.
  • All participants filled out a baseline food-frequency questionnaire that had been designed and validated for foods specific to their country.
  • Participants were asked if they had a diagnosis of Crohn’s disease or ulcerative colitis as part of an annual follow-up questionnaire. To assure the accuracy of these answers they were validated with medical records whenever possible.

Does Processed Food Give You Gas?

Does processed food give you gas? Does it give you abdominal pain, diarrhea, and bloating? In short, does it give you IBD? That is the question this study was designed to answer. Here are the results of the study:

  • When comparing those eating the most processed food (≥5 servings/day) to those consuming the least (≤1 serving/day), processed food consumption increased the risk of developing IBD by 1.82-fold. This finding was equally true for:
    • Both Crohn’s disease and ulcerative colitis.
    • Adults <50 and adults >50.
    • Every region of the world included in the PURE study.
  • When the investigators looked at different categories of processed foods:
    • Processed meat intake increased the risk of IBD by 2.07-fold.
    • Soft drink intake increased the risk of IBD by 1.94-fold.
    • Refined sweetened food intake increased the risk of IBD by 2.58-fold.
    • Salty food and snack intake increased the risk of IBD by 2.06-fold.
  • When the investigators looked at different categories of unprocessed foods:
    • White meat, red meat, dairy, starchy foods, fruits, vegetables, and legumes had no effect on the risk of developing IBD.
    • Sodium intake (as measured by urinary excretion of sodium) also had no effect on the risk of developing IBD.

Why Does Processed Food Give You Gas?

Question MarkYou may be wondering why does processed food give you gas – and other symptoms of IBD.

The simplest explanation is that whole grains, unprocessed fruits & vegetables, and legumes provide the fiber that supports the growth of friendly gut bacteria. Processed foods displace these foods from our diet.

But these investigators think something else about processed foods may be contributing to the increased risk of IBD. That is because in their study:

  • Processed meat increased the risk of IBD, but unprocessed white and red meat had no effect on IBD.
  • Processed sweetened foods increased the risk of IBD, but unprocessed starchy foods and naturally sweet fruits had no effect on IBD.
  • Processed salty foods and snacks increased the risk of IBD, but sodium intake had no effect on IBD.

The investigators also noted that in mouse studies:

  • Some food additives found in processed foods cause bacteria to stick to the epithelial lining of the intestine and/or cause leaky gut syndrome, both of which can lead to chronic inflammation of the intestine.

The investigators concluded, “In this study, higher ultra-processed food intake was associated with a higher risk of IBD.”

They went on to say, “As white meat, unprocessed red meat, dairy, starchy foods, fruits, vegetables, and legumes were not found to be associated with development of IBD, this study suggests that it may not be the food itself that confers this risk but rather the way the food is processed or ultra-processed…Further studies are needed to identify specific potential contributing factors among processed foods that might be responsible for the observed associations in our study.”

[Note: This is a fancy way of saying that the detrimental effects of processed foods may be due to more than the fact that they displace healthier foods from the diet. It may also be due to the effect of food additives on the risk of developing IBD.]

What Does This Study Mean For You?

Questioning WomanIBD is a rare disease (0.4% of the population). If you don’t have digestive issues, it would be easy to ignore this study and continue with a diet of highly processed foods.

However, I would remind you that in recent issues of “Health Tips From the Professor”, I have shared recent studies showing that highly processed foods increase your risk of:

And these studies are just the tip of the iceberg. We know that diets rich in whole grains and unprocessed fruits and vegetables decrease the risk of heart attack, stroke, and Alzheimer’s disease. And a diet rich in whole grains, fruits, and vegetables is the antithesis of a processed food diet.

The evidence is overwhelming. Highly processed foods may be convenient and tasty. But if you value your health, they are not your friends.

The Bottom Line 

A recent study looked at the effect of consuming processed foods on the risk of developing inflammatory bowel disease (IBD). The study found:

  • When comparing those eating the most processed food (≥5 servings/day) to those consuming the least (≤1 serving/day), processed food consumption increased the risk of developing IBD by 1.82-fold. This finding was equally true for:
    • Both Crohn’s disease and ulcerative colitis.
    • Adults <50 and adults >50.
    • Every region of the world included in the study.

The investigators concluded, “In this study, higher ultra-processed food intake was associated with a higher risk of IBD.”

They went on to say, “…This study suggests that it may not be the food itself that confers this risk but rather the way the food is processed or ultra-processed…Further studies are needed to identify specific potential contributing factors among processed foods that might be responsible for the observed associations in our study.”

[Note: This is a fancy way of saying that the detrimental effect of processed foods may be due to more than the fact that they displace healthier foods from the diet. It may also be due to the effect of food additives commonly found in processed foods on the risk of developing IBD.]

For more details on 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.

Does Red Meat Cause Frailty In Older Women?

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Which Proteins Are Best?

Author: Dr. Stephen Chaney

Fatty SteakThe ads from the meat lobby say, “Red meat does a body good”. Are the ads true?

If we consider the health consequences of regularly eating red meat, the answer appears to be a clear, “No”. Multiple studies have shown a link between red meat consumption and:

  • Coronary heart disease.
  • Stroke
  • Type 2 diabetes.
  • Colon cancer, prostate cancer, and breast cancer.

And, if we consider the environmental consequences of red meat production, the answer also appears to be, “No”. I have discussed this in a recent issue of “Health Tips From the Professor”.

But what about muscle mass and strength? Red meat is a rich source of protein, and we associate meat consumption with an increase in muscle mass. Surely, red meat consumption must help us build muscle mass and strength when we are young and preserve muscle mass and strength as we age.

This is why the recent headlines claiming that red meat consumption increases the risk of frailty in older women were so confusing. I, like you, found those headlines to be counterintuitive. So, I have investigated the study (EA Struijk et al, Journal of Cachexia, Sarcopenia and Muscle, 13: 210-219, 2022) behind the headlines. Here is what I found.

How Was The Study Done?

Clinical StudyThis study utilized data acquired from the Nurses’ Health Study (NHS). The NHS began in 1976 with 121,700 female nurses aged 30 to 55. This study followed 85,871 nurses in the NHS once they reached age 60 for an average of 14 years.

Dietary intake was assessed using a food frequency questionnaire that was administered to all participants in the study every four years between 1980 and 2010. The long-term intake of red meat and other protein sources was based on a cumulative average of all available diet questionnaires for each participant.

The participants also filled out a Medical Outcomes Short Report every four years between 1992 and 2014. Data from this survey was used to calculate something called the FRAIL scale, which includes the following frailty criteria:

  • Fatigue
  • Low muscle strength.
  • Reduced aerobic capacity.
  • Having ≥5 of the following chronic diseases:
    • Cancer
    • High blood pressure
    • Type 2 diabetes
    • Angina
    • Myocardial infarction (heart attack)
    • Congestive heart failure
    • Asthma
    • COPD (chronic obstructive pulmonary disease)
    • Arthritis
    • Parkinson’s disease
    • Kidney disease
    • Depression
  • Greater than ≥5% weight loss in two consecutive assessments.

Frailty was defined as having met 3 or more criteria in the FRAIL scale. The study looked at the effect of habitual consumption of red meat or other protein sources on the development of frailty during the 14-year follow-up period.

Does Red Meat Cause Frailty In Older Women?

The investigators separated the participants into 5 quintiles based on total red meat consumption, unprocessed red meat construction, or processed red meat consumption. The range of intakes was as follows.

Total red meat: 0.4 servings per day to 1.8 servings per day.

Unprocessed red meat: 0.3 servings per day to 1.3 servings per day.

Processed red meat: 0.04 servings per day to 0.6 servings per day.

Clearly none of the women in this study were consuming either vegan or keto diets. As might be expected from a cross-section of the American public, there was a fairly narrow range of daily meat consumption.

Here are the results of the study:

  • Each serving per day of total red meat increased frailty by 13%.
  • Each serving per day of unprocessed red meat increased frailty by 8%.
  • Each serving per day of processed red meat increased frailty by 26%.
  • When each component of the frailty index was examined individually, all of them were positively associated with red meat consumption except for weight loss.

This was perhaps the most unexpected finding of the study. Not only did red meat consumption increased the risk of chronic diseases in these women, which would be expected from many previous studies. But red meat consumption also made these women more tired, weaker, and shorter of breath.

The authors concluded, “Habitual consumption of any type of red meat was associated with a higher risk of frailty.”

Which Proteins Are Best?

Red Meat Vs White MeatThe investigators then asked if replacing one serving/day of red meat with other protein sources was associated with a significantly lower risk of frailty. Here is what they found:

  • Replacing one serving per day of unprocessed red meat with a serving of:
    • Fish reduced frailty risk by 22%.
    • Nuts reduced frailty risk by 14%.
  • Replacing one serving per day of processed red meat with a serving of:
    • Fish reduced frailty risk by 33%
    • Nuts reduced frailty risk by 26%
    • Low-fat dairy reduced frailty risk by 16%
    • Legumes reduced frailty risk by 13%.

The authors concluded, “Replacing red meat with another source of protein including fish, nuts, legumes, and low-fat dairy may be encouraged to reduce the risk of developing frailty syndrome. These findings are in line with dietary guidelines promoting diets that emphasize plant-based sources of protein.” [I would note that fish and low-fat dairy are hardly plant-based protein sources.]

What Does This Study Mean For You?

Questioning WomanI am not yet ready to jump on the “eating red meat causes frailty” bandwagon. This is a very large, well-designed study, but it is a single study. It needs to be replicated by future studies.

And, as a biochemist, I am skeptical about any study that does not offer a clear metabolic rationale for the results. As I said earlier, increased protein intake is usually associated with an increase in muscle mass when we are young and a preservation of muscle mass as we age. There is no obvious metabolic explanation for why an increase in red meat consumption in older women would cause a decrease in muscle mass and other symptoms of frailty.

On the other hand, there are plenty of well documented reasons for decreasing red meat intake. Consumption of red meat is bad for our health and bad for the health of the planet as I have discussed in an earlier issue of “Health Tips From the Professor”. And substituting other protein sources, especially plant proteins, is better for our health and the health of our planet.

Finally, we also need to consider the possibility that this study is correct and that future studies will confirm these findings. Stranger things have happened.

As we age, we begin to lose muscle mass, a process called sarcopenia. Increased protein intake and resistance exercise can help slow this process. While I am not ready to say that red meat causes decreased muscle mass, I do think this study should make us think about which protein sources we use to prevent sarcopenia. At the very least we should not use age-related muscle loss as an excuse to increase our red meat intake. That might just be counterproductive.

The Bottom Line

A recent study looked at the effect of red meat consumption on frailty in older women. It came to the unexpected conclusion that:

  • Each serving per day of total red meat increased frailty by 13%.
  • Each serving per day of unprocessed red meat increased frailty by 8%.
  • Each serving per day of processed red meat increased frailty by 26%.
  • The increase in frailty could be reduced by replacing one serving/day of red meat with a serving of fish, nuts, low-fat dairy, or legumes.

I am not yet ready to jump on the “eating red meat causes frailty” bandwagon. This is a very large, well-designed study, but it is a single study. It needs to be replicated by future studies. And, as a biochemist, I am skeptical about any study that does not offer a clear metabolic rationale for the results.

On the other hand, there are plenty of well documented reasons for decreasing red meat intake. Consumption of red meat is bad for our health and for the health of the planet.

Finally, we also need to consider the possibility that this study is correct and that future studies will confirm these findings. Stranger things have happened.

As we age, we begin to lose muscle mass, a process called sarcopenia. Increased protein intake and resistance exercise can help slow this process. This study should make us think about which protein sources we use to prevent sarcopenia. At the very least we should not use age-related muscle loss as an excuse to increase our red meat intake. That might just be counterproductive.

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

Can Diet Add Years To Your Life?

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Which Foods Have The Biggest Effect On Longevity? 

Author: Dr. Stephen Chaney

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

  • We want to look younger.
  • We want to feel younger.
  • We want the energy we had in our 20s.
  • We want to be rid of the diseases of aging.

The list goes on!

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

  • Should we train for marathons or bodybuilding contests?
  • Should we meditate or do yoga to relieve stress?
  • Should we get serious about losing weight?
  • Should we get more sleep?
  • Is there some miracle diet that can slow the aging process?

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

How Was This Study Done?

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

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

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

  • Typical Western Diet (TW). This diet was based on average consumption data from the United States and Europe. This was their baseline.
  • Optimal diet (OD). This diet is similar to a vegan or semi-vegetarian diet. However, it was not a purely vegan diet nor a purely semi-vegetarian diet. Instead, it represented the best diet people in this study were consuming.
  • Feasibility diet (FA). This diet recognizes that few people are willing to make the kind of changes required to attain an optimal diet. It is halfway between the Typical Western Diet and the Optimal Diet.

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

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

*1 serving = 1 handful of nuts

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

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

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

Can Diet Add Years To Your Life?

The results were impressive.

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

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

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

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

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

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

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

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

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

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

Which Foods Have The Biggest Effect On Longevity?

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

  • More legumes, whole grains, and nuts, and…
  • Less red and processed meat.

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

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

  • The quality of the individual studies with that food, and…
  • The difference in consumption of that food in going from a western diet to an optimal diet.

For example:

  • Legumes, whole grains, nuts, red & processed meat made the list because the quality of data was high and the difference in consumption between the typical western diet and optimal diet was significant.
  • The quality of data for an effect of fruits and vegetables was also high. For example, one major study concluded that consuming 10 servings a day of fruits and vegetables a day reduces premature death by 31% compared to consumption of less than 1 serving a day. However, the difference in consumption of fruits and vegetables between the western and optimal diets in this study was small, so fruits and vegetables didn’t make the list.
  • Eggs and white meat didn’t make the list because the quality of data was low for those foods. Simply put,  that means that there was a large variation in effect of those foods on longevity between studies.
  • Other foods didn’t make the list because the quality of data was only moderate and/or the difference in intake was small.

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

  • This study suggests that consuming more legumes, whole grains, and nuts and less red & processed meats has a significant beneficial effect on health and longevity.
  • Consuming more fruits and vegetables is likely to have a significant benefit on health and longevity, but you would need to consume more than people did in this study to achieve these benefits. In the words of the authors, “Fruits and vegetables also have a positive health impact, but, for these food groups, the intake in a typical Western diet is closer to the optimal intake than for the other food groups.”
  • Other foods may impact health and longevity, but the data in this study are not good enough to be confident of an effect.

What Does This Study Mean For You?

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

  • You can achieve significant benefit by switching to a more plant-based diet late in life. You get the biggest “bang for your buck” if you switch at age 20. But even making the switch at age 60 or 80 was beneficial.
  • You don’t need to be a “vegan purist”. While the biggest benefits were seen for people who came close to achieving a vegan or semi-vegetarian diet, people who only made half those changes saw significant benefits.

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

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

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

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

The Bottom Line

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

  • Changing to a healthier diet could add up to a decade to your lifespan.
  • The improvement in lifespan was greatest for those whose diets approached a vegan or semi-vegetarian diet, but a significant improvement in lifespan was seen for people who made only half those dietary improvements.
  • The improvement in lifespan was greatest for those who switched to a healthier diet in their 20’s, but significant improvements in lifespan were seen for people who didn’t change their diet until their 60’s or 80’s.

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

  • This study suggests that consuming more legumes, whole grains, and nuts and less red & processed meats has a significant beneficial effect on health and longevity.
  • Consuming more fruits and vegetables is likely to have a significant benefit on health and longevity, but you would need to consume more than people did in this study to achieve those benefits.
  • Other foods may impact health and longevity, but the data in this study are not good enough to be confident of an effect.

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

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

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

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

How Does Red Meat Cause Colon Cancer?

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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.

Health Tips From The Professor