Dr. Steve Chaney

Eating For A Healthy Planet

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Can Diet Affect The Health Of Our Planet? 

Author: Dr. Stephen Chaney 

Earth DayEarth Day is today. 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.

Eating For A Healthy Planet

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

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

  • It starts with a vegetarian diet. Vegetables, fruits, beans, nuts, soy foods, and whole grains are the foundation of the diet.
  • It allows the option of adding one serving of dairy a day (It turns out that cows produce much less greenhouse emissions per serving of dairy than per serving of beef. That’s because cows take several years to mature before they can be converted to meat, and they are emitting greenhouse gases the entire time).
  • It allows the option of adding one 3 oz serving of fish or poultry or one egg per day.
  • It allows the option of swapping seafood, poultry, or egg for a 3 oz serving of red meat no more than once a week. If you want a 12 oz steak, that would be no more than once a month.

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

  • “This would require greater than 50% reduction in consumption of unhealthy foods, such as red meat and sugar, and greater than 100% increase in the consumption of healthy foods, such as nuts, fruits, vegetables, and legumes”.
  • “In addition to the benefits for the environment, “dietary changes from current diets to healthy diets are likely to substantially benefit human health, averting about 10.8-11.6 million deaths per year globally.”

What Else Did The Commission Recommend?

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

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?

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

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

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

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

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

The Bottom Line

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

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

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

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

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

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.

 

 

 

The Soy Myth

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Why Is There So Much Confusion About Soy?

Author: Dr. Stephen Chaney

soyWhat is the truth about soy and breast cancer? Does it increase the risk of breast cancer, or is that just a myth? If you are a woman, particularly a woman with breast cancer, it is an important question.

Some experts say soy should be avoided at all costs. They say that soy will increase your risk of breast cancer. Other experts say soy is perfectly safe and may even reduce your risk of breast cancer. Who is right?

If you are a breast cancer survivor, the question of whether soy increases or decreases your risk of disease recurrence is even more crucial. You have already endured surgery, chemotherapy, and/or radiation. You never want to go through that again.

Why Is There So Much Confusion About Soy?

soy confusionSoy isoflavones decrease estrogen production, strengthen the immune system, inhibit cell proliferation, and reduce the production of reactive oxygen species. These are all effects that might reduce breast cancer risk.

On the other hand, soy isoflavones also bind to estrogen receptors and exhibit weak estrogenic activity. This effect has the potential to increase breast cancer risk.

Cell culture and animal studies have only confused the issue. Soy isoflavones stimulate the growth of breast cancer cells in a petri dish. Soy isoflavones also stimulate breast cancer growth in a special strain of mice lacking an immune system. However, in studies in both mice and rats with a functioning immune system, soy isoflavones decrease breast cancer risk.

The confusion has been amplified by claims and counterclaims on the internet. There are bloggers who are more interested in the spectacular than they are in accuracy (Today we call this fake news). They have taken the very weak evidence that soy isoflavones could possibly increase breast cancer risk and have blown it all out of proportion.

Their blogs claim that soy definitely increases breast cancer risk and should be avoided at all costs. Their claims have been picked up by other web sites and blogs. Eventually, the claims have been repeated so many times that people started to believe them. A “myth” has been created. I call it a myth because it was never based on convincing scientific evidence.

In the meantime, scientists looked at the cell culture and animal studies and took a more responsible approach. They said “If this is true, it is an important public health issue. We need to do clinical trials in humans to test this hypothesis.”

What Have Previous Clinical Studies Shown?

breast cancerThe question of whether soy consumption increased the risk of developing breast cancer was settled a long time ago. Some studies have shown no effect of soy consumption on breast cancer risk. Others have reported that soy consumption decreased breast cancer risk. A meta-analysis of 18 previous clinical studies found that soy slightly decreased the risk of developing breast cancer (J Natl Cancer Inst, 98: 459-471, 2006). None of those studies found any evidence that soy increased the risk of breast cancer.

What about recurrence of breast cancer in women who are breast cancer survivors? There have been five major clinical studies looking at the effects of soy consumption on breast cancer recurrence in both Chinese and American populations. Once again, the studies have shown either no effect of soy on breast cancer recurrence or a protective effect. None of them have shown any detrimental effects of soy consumption for breast cancer survivors.

A meta-analysis of all 5 studies was published in 2013 (Chi et al, Asian Pac J Cancer Prev., 14: 2407-2412, 2013). This study combined the data from 11,206 breast cancer survivors in the US and China. Those with the highest soy consumption had a 23% decrease in recurrence and a 15% decrease in mortality from breast cancer.

What Did The Most Recent Study Show?

Clinical StudyIn earlier clinical studies the protective effect of soy has been greater in Asian populations than in North American populations. This could have been because Asians consume more soy. However, it could be due to other population differences as well.

To better evaluate the effect of soy consumption on breast cancer survivors in the North America, a group of investigators correlated soy consumption with all-cause mortality in breast cancer survivors in the US and Canada (Zhang et al, Cancer, DOI: 10.1002/cncr.30615, March 2017).

The data were collected from The Breast Cancer Family Registry, an international research infrastructure established in 1995. The women enrolled in this registry either have been recently diagnosed with breast cancer or have a family history of breast cancer.

This study included 6235 breast cancer survivors from the registry who lived in the San Francisco Bay area and the province of Ontario in Canada. The women represented an ethnically diverse population and had a median age of 51.8 at enrollment. Soy consumption was assessed either at the time of enrollment or immediately following breast cancer diagnosis. The women were followed for 9.4 years, during which time 1224 of them died.

The results were as follows:

  • There was a 21% decrease in all-cause mortality for women who had the highest soy consumption compared to those with the lowest soy consumption.
  • The protective effect of soy was strongest for those women who had receptor negative breast cancer. This is significant because receptor-negative breast cancer is associated with poorer survival rates than hormone receptor-positive cases.
  • The protective effect was also greatest (35% reduction in all-cause mortality) for women with the highest soy consumption following breast cancer diagnosis. This suggests that soy may play an important role in breast cancer survival.
  • The authors concluded “In this large, ethnically diverse cohort of women with breast cancer, higher dietary intake of [soy] was associated with reduced total mortality.”

In an accompanying editorial, Omer Kucuk, MD, of the Winship Cancer Institute of Emory University, noted that the United States is the number 1 soy producer in the world and is in a great position to initiate changes in health policy by encouraging soy intake.  He said “We now have evidence that soy foods not only prevent breast cancer but also benefit women who have had breast cancer. Therefore, we can recommend women to consume soy foods because of soy’s many health benefits.”

The Soy Myth

Myth Versus FactsEvery clinical study has its limitations. If there were only one or two studies, the question of whether soy increases breast cancer risk might still be in doubt. However, multiple clinical studies have come to the same conclusion. Either soy has no effect on breast cancer risk and breast cancer recurrence, or it has a protective effect.

Not a single clinical study has found any evidence that soy increases breast cancer risk. It is clear that consumption of soy foods is safe, and may be beneficial, for women with breast cancer. The myth that soy increases breast cancer risk needs to be put to rest.

On the other hand, we should not think of soy as a miracle food. Breast cancer risk is also decreased by a diet that:

  • Contains lots of fruits and vegetables.
  • Is low in processed grains & sweets and high in whole grains.
  • Is low in saturated & trans fats and high in omega-3 and monounsaturated fats.
  • Is low in red & processed meats and high in beans, fish & chicken.

Furthermore, diet is just one component of a holistic approach for reducing the risk of breast cancer. In addition to a healthy diet, the American Cancer Society recommends that you:

  • Control your weight
  • Be physically active
  • Limit alcohol
  • Don’t smoke
  • Limit hormone replacement therapy unless absolutely necessary.
  • Reduce stress

The Bottom Line

1) It is time to put the myth that soy increases breast cancer risk to rest. This myth is based on cell culture and animal studies, and those studies were inconclusive.

2) Multiple clinical studies have shown that soy either has no effect on breast cancer risk, or that it reduces the risk.

3) Multiple clinical studies have also shown that soy either has no effect on breast cancer recurrence in women who are breast cancer survivors, or that it reduces recurrence.

4) The most recent clinical study is fully consistent with previous studies. It reports:

  • There was a 21% decrease in all-cause mortality for women who had the highest soy consumption compared to those with the lowest soy consumption.
  • The protective effect of soy was strongest for those women who had receptor negative breast cancer. This is significant because receptor-negative breast cancer is associated with poorer survival rates than hormone receptor-positive cases.
  • The protective effect was also greatest (35% reduction in all-cause mortality) for women with the highest soy consumption following breast cancer diagnosis. This suggests that soy may play an important role in breast cancer survival.
  • No clinical studies have provided any evidence to support the claim that soy increases either breast cancer risk or breast cancer recurrence.

For more information on this study and other things you can do to reduce the risk of breast 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.

 ______________________________________________________________________________

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

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

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

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

_______________________________________________________________________

About The Author 

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

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

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

 

 

 

The Low Carb Myth

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The “Goldilocks Effect”

Author: Dr. Stephen Chaney

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

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

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

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

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

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

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

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

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

And this study had two glaring weaknesses.

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

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

How Was The Second Study Done?

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

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

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

The Low Carb Myth

GravestoneThe results from the ARIC study were:

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

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

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

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

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

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

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

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

The “Goldilocks Effect”

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

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

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

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

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

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

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

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

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

What Does This Study Mean For You?

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

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

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

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

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

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

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

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

The Bottom Line

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

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

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

Specifically, this study reported:

  1. Moderate carbohydrate intake (50-55%) is healthiest. This is the carbohydrate intake found in healthy diets like the Mediterranean and DASH diets, and is the intake recommended by current nutritional guidelines.

2) All major studies agree that very high carbohydrate intake (60-70%) is unhealthy. It shortens the life expectancy of a 50-year-old by about a year.

3) All studies that cover the full range of carbohydrate intake agree that low carbohydrate intake (<26%) is also unhealthy. It shortens the life expectancy of a 50-year-old by about 4 years.

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

5) Meat-based low-carb diets decrease life expectancy compared to the typical American diet while plant-based low carb diets increase life expectancy. This is consistent with the results of previous studies.

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

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

For more details, read the article above.

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

______________________________________________________________________________

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

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

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

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

 ______________________________________________________________________

About The Author 

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

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

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

 

 

The Good Cholesterol Myth

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Is Everything You Knew About HDL Wrong?

Author: Dr. Stephen Chaney 

HDL CHolesterolOver the past couple of weeks” I have talked about one of the greatest strengths of the scientific method – namely that investigators constantly challenge, and occasionally disprove, existing paradigms. That allows us to discard old models of how things work and replace them with better ones.

Two weeks ago, I shared a study that disproved the myth that low to moderate alcohol consumption is healthier than total abstinence.

Last week I shared a study that disproved the myth about chocolate helping you lose weight weight.

This week I tackle the “good” cholesterol myth. I will share several studies that challenge the belief that HDL cholesterol is good for your heart.

The belief that HDL is good for your heart has all the hallmarks of a classic paradigm.

  • It is supported by multiple clinical studies.
  • Elaborate metabolic explanations have been proposed to support the paradigm.
  • It is the official position of most medical societies, scientific organizations, and health information sites on the web.
  • It is the recommendation of most health professionals.
  • It has been repeated so often by so many trusted sources that everyone assumes it must be true.

Once we accept the HDL/heart health paradigm as true, we can construct other hypotheses on that foundation. For example:

  • Raising your HDL levels naturally takes effort. Pharmaceutical companies have been pursuing the “magic pill” that raises HDL levels without any effort on your part.
  • Low carb diets like the Keto and Paleo diets are high in saturated fat. The low carb enthusiasts claim this is a good thing because saturated fat raises HDL levels, and HDL is good for your heart.

But what if the paradigm that HDL is good for your heart isn’t true? What if it is a myth? These hypotheses would be like the parable of a house built on a foundation of sand. They will be washed away as soon as the paradigm is critically tested.

Do Drugs That Increase HDL Levels Work?

The first hint that the HDL/heart health paradigm might be faulty happened when a pharmaceutical company developed a drug that selectively increased HDL levels.

The drug company thought they had found the goose that laid golden eggs. Just imagine. People wouldn’t have to lose weight, exercise, or change their diet. They could simply take a pill and dramatically decrease their heart disease risk. A drug like that would be worth billions of dollars.

The problem was that when they tested their drug (torcetrapib) in clinical trials, it had absolutely no effect on heart disease outcomes (AR Tall et al, Atherosclerosis, Thrombosis, and Vascular Biology 27:257-260, 2007).

The pharmaceutical company couldn’t believe it. Raising HDL levels just had to reduce heart disease risk. They concluded they didn’t have the right drug, and they continued to work on developing new drugs.

That was 18 years ago, and no HDL-increasing drug has made it to market. Have they just not found the right drug, or does this mean the HDL/heart health paradigm is incorrect?

Does Saturated Fat Decrease Heart Disease Risk?

Now let’s turn to two claims of low carb enthusiasts.

#1: Saturated fats decrease your risk of heart disease in the context of a low carb diet. I have debunked that claim in several previous issues of “Health Tips From The Professor”. But let me refer you to two articles here – one on saturated fat and heart disease risk and one on low-carb diets.

#2: Saturated fats decrease heart disease risk because they raise HDL levels. This is the one I will address today.

The idea that saturated fats decrease heart disease risk because they raise HDL levels is based on a simplistic concept of HDL particles. The reality is more complex. Several clinical studies have shown:

  • The type of fat determines the property of the HDL particles.
    • When polyunsaturated fats predominate, the HDL particles have an anti-inflammatory effect. When saturated fats predominate, the HDL particles have a pro-inflammatory effect.
  • Anti-inflammatory HDL particles relax the endothelial cells lining our blood vessels. That makes the lining of our blood vessels more pliable, which improves blood flow and reduces blood pressure.
    • Anti-inflammatory HDL particles also help reduce inflammation of the endothelial lining. This is important because an inflamed endothelial lining is more likely to accumulate fatty plaques and to trigger blood clot formation that can lead to heart attacks and strokes.

So, the question becomes, “What good is it to raise HDL levels if you are producing an unhealthy, pro-inflammatory HDL particle that may increase the risk of high blood pressure, heart attacks, and strokes?”

In short, these studies suggest it isn’t enough to just focus on HDL levels. You need to ask what kind of HDL particles you are creating.

So, let’s look at experiments that have challenged the HDL/heart health paradigm.

Is HDL Good For Your Heart?

strong heartOnce the studies were published showing that…

  • Drug-induced increase of HDL levels without any change in health habits is not sufficient to decrease heart attack risk, and…
  • Not all HDL particles are healthy. There are anti-inflammatory or pro-inflammatory HDL particles, which are likely to have opposite effects on heart attack risk…

…some people started to question the HDL/heart health paradigm. And one group came up with the perfect study to test the paradigm.

But before I describe the study, I need to review the term “confounding variables”. Here is a brief synopsis:

  • The studies supporting the HDL/heart health paradigm are association studies. Association studies measure the association between a single variable (in this case, increase in HDL levels) and an outcome (in this case, heart disease events, heart disease deaths, and total deaths).
  • Associations need to be corrected for other variables known to affect the same outcome (things like age, gender, smoking, and diabetes would be examples in this case).
  • Confounding variables are variables that also affect the outcome but are unknown or ignored. Thus, they are not used to correct the associations, which can bias the results.

The Good Cholesterol Myth

The authors of this study (M Briel et al, BMJ 2009:338.b92) observed that most interventions that increase HDL levels also lower LDL levels. Lowering LDL is known to decrease the risk of heart disease deaths. But this effect had been ignored in most studies looking at the association between HDL and heart disease deaths.

They hypothesized that the change in LDL levels was a confounding variable that had been ignored in previous studies and may have biased the results.

To test this hypothesis the authors searched the literature and identified 108 studies with 299,310 participants that:

  • Compared the effect of drugs, omega-3 fatty acids, or diet with either a placebo or usual care.
  • Measured both HDL and LDL levels.
  • Measured reduction in cardiovascular risk.
  • Had a randomized control design.
  • Lasted at least 6 months.

They found that every 10 mg/dl decrease in LDL levels in these studies was responsible for a:Heart Disease Study

  • 1% reduction in heart disease events (both heart disease deaths and non-fatal heart attacks).
  • 2% reduction in heart disease deaths.
  • 4% reduction in total deaths.

After correcting for the effect of decreased LDL levels on these heart disease outcomes, the increase in HDL levels had no statistically significant effect on any of the outcomes.

The authors concluded, “Available data suggest that simply increasing the amount of circulating HDL cholesterol does not reduce the risk of coronary heart disease events, coronary heart disease deaths, or total deaths. The results support reduction in LDL cholesterol as the primary goal for lipid modifying interventions.”

In other words, this study:

  • Supports the author’s hypothesis that LDL levels were a confounding variable that biased the studies supporting the HDL/heart health paradigm.
  • Concludes that increasing HDL levels has no effect on heart disease outcomes, thus invalidating the HDL/heart health paradigm.

In short, this study destroyed the “good” cholesterol myth.

Is Everything You Knew About HDL Wrong?

Peek Behind The CurtainDoes that mean that everything you knew about HDL is wrong? Not exactly. It just means that you may need to change your perspective.

Don’t focus on HDL levels. Peek behind the curtain and focus on what’s behind the HDL levels. For example:

  • Losing weight when overweight increases HDL levels. But the decrease in heart disease outcomes is more likely due to weight loss than to the increase in HDL levels.
  • Exercise increases HDL levels. But the decrease in heart disease outcomes is more likely due to exercise than to the increase in HDL levels.
  • Reversing pre-diabetes or type 2 diabetes increases HDL levels. But the decrease in heart disease outcomes is more likely due to the reversal of diabetes than to the increase in HDL levels.
  • High-dose omega-3 fatty acids increase HDL levels. But the decrease in heart disease outcomes is more likely due to the omega-3 fatty acids than to the increase in HDL levels.
  • The Mediterranean diet increases HDL levels. But the decrease in heart disease outcomes is more likely due to the diet than to the increase in HDL levels.

And if you want to go the drug route:

  • Statins and some other heart drugs increase HDL levels, but the reduction in heart disease outcomes is probably due to their effect on LDL levels rather than their effect on HDL levels.

On the other hand:

  • Saturated fats increase HDL levels. But saturated fats increase heart disease risk and create pro-inflammatory HDL particles. So, in this case the increase in HDL levels is not a good omen for your heart.
  • Drugs have been discovered that selectively increase HDL levels. However, there is nothing of value behind this increase in HDL levels, so the drugs have no effect on heart disease outcomes.

The Bottom Line 

In this article I discuss several studies that have challenged the good cholesterol myth – the belief that HDL is good for your heart.

For example, one group of investigators analyzed the studies underlying the HDL/heart health paradigm. They hypothesized that these studies were inaccurate because they failed to account for the effects of LDL levels on heart disease outcomes.

After correcting for the effect of decreased LDL levels on heart disease outcomes in the previous studies, the authors showed that increases in HDL levels had no significant effect on any heart disease outcome.

The authors concluded, “Available data suggest that simply increasing the amount of circulating HDL cholesterol does not reduce the risk of coronary heart disease events, coronary heart disease deaths, or total deaths. The results support reduction in LDL cholesterol as the primary goal for lipid modifying interventions.”

In other words, this study:

  • Supports the author’s hypothesis that LDL levels were a confounding variable that biased the studies supporting the HDL/heart health paradigm.
  • Concludes that increasing HDL levels has no effect on heart disease outcomes, thus invalidating the HDL/heart health paradigm.

Does that mean that everything you knew about HDL is wrong? Not exactly. It just means that you need to change your perspective. Don’t focus on HDL levels. Focus on what’s behind the HDL levels. For more information on that, read the article above.

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

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

_________________________________________________________________________________________________

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

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

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

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

________________________________________________________________________________________

About The Author 

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

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

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

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

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

The Chocolate Myth

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Can Chocolate Help You Lose Weight? 

Author: Dr. Stephen Chaney 

chocolateSometimes you come across news that just seems too good to be true. The claims that you can lose weight just by eating chocolate are a perfect example. Your first reaction when you heard that was probably “Sure, when pigs fly!”

But it’s such an enticing idea – one might even say a deliciously enticing idea. And, in today’s world enticing ideas like this quickly gain a life of their own. Two popular books have been written on the subject.

Chocolate diet plans are springing up right and left. A quick scan of the internet even revealed a web site saying that by investing a mere $1,250 in a training course you could become a “Certified Chocolate Weight Loss Coach” earning $50,000/year.

If you like chocolate as much as most people you are probably wondering, “Could it possibly be true, or is it just another myth?

Can Chocolate Help You Lose Weight?

Happy woman on scaleThe idea that chocolate could help you lose weight does have some support. There are actually three published clinical studies suggesting that chocolate consumption is associated with lower weight (European Journal of Clinical Nutrition, 62: 247-253, 2008; Nutrition Research, 31: 122-130, 2011; Archives of Internal Medicine, 172: 519-521, 2012).

While that sounds impressive, they were all cross-sectional studies. That means they looked at a cross section of the population and compared chocolate intake with BMI (a measure of obesity). Cross sectional studies have a couple of very important limitations:

1) Cross sectional studies merely measure associations. They don’t prove cause and effect. Was it chocolate that caused the lower weight, or was it something else that those populations were doing? We don’t really know.

2) Cross sectional studies don’t tell us why an association occurs. In many ways, this is the old chicken and egg conundrum. Which comes first? In this case the question is whether the people in the studies became obese because they ate less chocolate – or did they eat less chocolate because they were obese and were trying to control their calories? Again, we have no way of knowing.

The Chocolate Myth

Chocolate is relatively rich in fat and high in calories. It’s not your typical diet food. On the surface, it seems implausible that eating chocolate could actually help you lose weight.

Scientists love to poke holes in implausible hypotheses, so it is no surprise that a recent study (JA Greenberg and B Buijsse, PLOS ONE, 8(8) e70271) has poked some huge holes in the “chocolate causes weight loss” hypothesis.

This study analyzed data from over 12,000 participants in the Atherosclerosis Risk in Community (ARIC) Study. This was also a cross-sectional study, but it was a prospective, cross-sectional study (That’s just a fancy scientific term which means that the study followed a cross section of the population over time, rather than just asking what that population group looked like at a single time point).

The authors of the study assessed frequency of chocolate intake and weight for each individual in the study at two separate times 6 years apart. The results were very interesting:

  • When they looked at a cross section of the population at either time point, their results were the same as the previous three studies – namely those who consumed the most chocolate weighed less. So, the cross-sectional data were consistent. Overweight people consumed less chocolate. But that still doesn’t tell us why they consumed less chocolate.
  • However, when they followed the individuals in the study over 6 years, those who consumed the most chocolate gained the most weight. The chocolate eaters were skinnier than the non-chocolate eaters at the beginning of the study, but they gained more weight as the study progressed. And the more chocolate they consumed the more weight they gained over the next 6 years. [No surprise here. Calories still count.]
  • When they specifically looked at the population who had developed an obesity-related illness between the first and second time point, they found that by the end of the study those participants had:
    • Decreased chocolate intake by 37%
    • Decreased fat intake by 4.5%
    • Increased fruit intake by 20%
    • Increased vegetable intake by 17%
  • In short, this study is more consistent with the “obesity causes reduced chocolate intake” model than the “reduced chocolate intake causes obesity” model. Simply put, if you are trying to lose weight, sweets like chocolate are probably among the first things to go.

Of course, even prospective cross-sectional studies have their limitations. Double blind, placebo-controlled studies are clearly needed to resolve this question. The only published study of this type has reported a slight weight gain associated with 25 g/day of dark chocolate, but the study was too small and too short in duration to draw firm conclusions.

In summary, more studies are needed, but the current evidence does not support the “miracle diet food” claims for chocolate. This appears to be another food myth. Pigs are flying!

The Bottom Line: 

  • Pigs still haven’t learned how to fly. As enticing as it may sound, the weight of current evidence does not support the claims that chocolate is a miracle diet food or that eating chocolate every day is a sensible strategy for losing weight.
  • On the other hand, dark chocolate is probably one of the healthier dessert foods. There is no reason not to enjoy an occasional bite of chocolate as part of a healthy, calorie-controlled diet.

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.

 

The Alcohol Myth

by

How Were We Led Astray?

Author: Dr. Stephen Chaney 

You have probably heard that moderate alcohol consumption is healthier than complete abstinence from alcohol. It is certainly a popular viewpoint.

It is also a scientific paradigm. By that I mean:

  • It is supported by multiple clinical studies.
  • Elaborate metabolic explanations have been proposed to support this paradigm.
  • It is the official position of most medical societies, scientific organizations, and health information sites on the web.
  • It is the recommendation of most health professionals.
  • It has been repeated so often from so many trusted sources that everyone assumes it must be true.

But is it a myth? You may have been surprised when you saw recent headlines saying, “Having an alcoholic drink or two per day is not healthier than abstaining.”

Today I will review the study (J Zhao et al, JAMA Network Open, 6(3): e236185, 2023) behind the headlines and tell you what it means for you.

But first, I want to explain to you how the scientific method works. That’s because this study is a perfect example of the scientific method in action.

How Were We Lead Astray?

I have described the scientific method in detail in my books “Slaying The Food Myths” and “Slaying The Supplement Myths”, which you will find here.

Today, I will just give you a brief synopsis of the scientific method.

1) Most scientific studies are designed to disprove existing scientific paradigms. This is such a study.

  • In the scientific world, there is no glory in being the 10th person to prove that a scientific paradigm is correct. The glory comes from being the first person to disprove a scientific paradigm and create a new paradigm in the process.
  • This constant testing of existing paradigms is one of the most important strengths of the scientific method.

2) There is no perfect study. Every study has its flaws.

  • “Confounding variables” are flaws that can be the Achilles Heel of any association study.

Now let me explain the significance of these statements in the context of the current study:

  • All the studies supporting the current paradigm were association studies. Association studies measure the association between a selected variable and an outcome. For these studies, the selected variable was alcohol consumption, and the outcome was increased mortality.
  • Association studies try to statistically correct for other variables known to affect the outcome. For example, diseases like heart disease, diabetes, and cancer increase the risk of premature death. These are known variables that would be corrected for in any well-designed study of alcohol consumption and mortality.
  • “Confounding variables” are unknown variables that also affect the outcome of the study. But since they are unknown, they are not corrected for.

Let me give you a simplistic example of a confounding variable. Let’s say you were doing a study of dietary habits, and you found an association between ice cream consumption and mortality. You might conclude that ice cream consumption is bad for you. It increases your risk of dying.

But then you might remember that ice cream consumption increases during the summer. And then you might reason that people swim more during the summer, and there is a correlation between swimming and drowning deaths.

Swimming could be a confounding variable. To make sure that your initial conclusion that ice cream increases the risk of dying was correct, you would need to correct your data for swimming deaths during the summer and see if you still found a correlation between ice cream consumption and mortality.

Could The Current Paradigm Be Incorrect?

SkepticYou might be thinking, “What does this have to do with studies on the correlation between alcohol consumption and increased mortality?” Let me explain.

The baseline group for these comparisons was the abstainers – the group consuming no alcohol. Previous studies have compared the mortality risk associated with various amounts of alcohol consumption with the mortality risk of the abstainer group. This sounds like a reasonable approach.

But the investigators challenging the current paradigm noted that the “abstainer group” in previous studies included both lifetime abstainers and former drinkers who had become abstainers. They hypothesized that the “former drinkers” group may have become abstainers because of health issues related to excess alcohol consumption.

In short, they hypothesized that the “former drinkers” group was a confounding variable that biased the results of the previous studies. They hypothesized that the “lifetime abstainers” group was a more appropriate baseline group for this kind of study. They then set out to prove their hypothesis.

How Was This Study Done?

clinical studyThe investigators searched the literature and found 107 studies with 4.8 million participants published between 1980 and July 21, 2021, that:

  • Assessed the correlation between alcohol consumption and mortality.
  • Had data that allowed the investigators to separate lifetime abstainers from former drinkers who had become abstainers.

The investigators divided alcohol consumption into low, moderate, high, and very high categories based on the ounces of alcohol consumed per day. Since ounces of alcohol is not an easy measure for most of us, I have converted ounces/day to drinks/day based on the CDC definition of a drink (a 12-ounce beer, 5-ounce glass of wine, or 1.5 ounces of a distilled spirit like gin or vodka). And to make it even simpler, I have rounded to the nearest whole number. With that said, here are the classifications.

  • Low alcohol intake = 1-2 drinks/day.
  • Moderate alcohol intake = 2-3 drinks/day.
  • High alcohol intake = 3-4 drinks/day.
  • Very high alcohol intake = >4 drinks/day.

The risk of death associated with each of these intake levels was compared the risk of death of their preferred baseline group, the “lifetime abstainers”.

Finally, the data were corrected for other variables known to influence the correlation between alcohol consumption and mortality, namely age, sex, heart health, social status, race, diet, exercise, BMI, and smoking status. [These are known variables and had been adjusted for in most previous studies.]

The Alcohol Myth

Red WineWhen the investigators compared the mortality risk of former drinkers who had become abstainers with lifetime abstainers:

  • The former drinkers were 31% more likely to die, and this difference was highly significant.
  • This is consistent with their hypothesis that the “former drinkers” group was a confounding variable that may have biased the conclusions of previous studies.

When they compared the mortality risk of various levels of alcohol consumption with lifetime abstainers instead of all abstainers, they found:

  • The risk of mortality associated with low (1-2 drinks/day) and moderate (2-3 drinks/day) alcohol intake was statistically identical to the risk of mortality for lifetime abstainers.
  • The high alcohol intake group (3-4 drinks/day) was 24% more likely to die than the lifetime abstainers.
  • The very high alcohol intake group (>4 drinks/day) was 39% more likely to die than the lifetime abstainers.

In short, when lifetime abstainers were used as the baseline group, low to moderate alcohol intake did not reduce the risk of dying, as previous studies had suggested. This study suggests the idea that low to moderate alcohol consumption is good for us may not be accurate. It may be a myth.

Finally, there was a significant gender difference in the effect of alcohol consumption on mortality.

For women:

  • Even moderate alcohol consumption was associated with an increased risk of mortality. Only low alcohol consumption posed no increase in mortality.
  • The increased risk of mortality for women was significantly higher than for men with every level of alcohol consumption.

The authors concluded, “In this…meta-analysis, daily low or moderate alcohol intake was not significantly associated with all-cause mortality risk, while increased risk was evident at higher consumption levels, starting at lower levels for women than for men.”

Of course, this isn’t the end of the story. The scientific method will continue. Old paradigms don’t die easily. Other investigators will challenge the conclusions of this study. Stay tuned. I will give you updates as future studies are published.

What Does This Study Mean For You?

confusionIf you like to imbibe, there are two important takeaways from this study.

The bad news is that you can no longer claim that a drink or two a day is healthier than total abstinence from alcohol.

The good news is that this and every study preceding it have found that a drink or two a day is no less healthy than total abstinence. The studies found no increase in mortality associated with low to moderate alcohol intake.

[However, low to moderate alcohol intake may increase your risk of specific diseases. For example, many studies suggest that even low alcohol intake is associated with an increased risk of breast cancer.]

This study also agrees with previous studies that high alcohol intake increases your risk of death, and women are more susceptible to adverse effects of alcohol intake than men.

So, while this study challenges the existing paradigm that low to moderate alcohol intake is beneficial, it does not change the current recommendations on alcohol intake by most health organizations.

For example, the current CDC guidelines are:

  • Adults of legal drinking age should limit alcohol intake to 2 drinks or less per day for men and one drink or less per day for women.
  • Adults who do not drink alcohol should not start. [The current study strengthens this recommendation because it takes away the excuse that low to moderate alcohol consumption is healthier than abstinence.]
  • Drinking less is better than drinking more.

The CDC guidelines also note that the risk of some cancers increases even at very low levels of alcohol consumption.

Finally, the CDC recommends that some people never consume alcohol, including:

  • Women who are pregnant or might become pregnant.
  • Anyone younger than 21.
  • Anyone with medical conditions or medications that interact with alcohol.
  • Anyone recovering from an alcohol use disorder or who has trouble controlling the amount they drink.

The Bottom Line 

A recent study is a perfect example of the scientific method in action. Scientists are constantly challenging the existing scientific paradigms, and this is an important strength of the scientific method.

A group of scientists recently published a study challenging the paradigm that low to moderate alcohol intake is healthier than total abstinence from alcohol.

They hypothesized that previous studies supporting this paradigm had a common methodological flaw, corrected for the flaw, and reanalyzed the data from 104 studies with a total of 4.8 million participants.

The revised data showed no health benefit of low to moderate alcohol consumption compared to total abstinence. When you look at the data more closely, the current paradigm may be a myth.

  • This is a major change to the existing paradigm because it removes the justification for low to moderate alcohol consumption.

However, the revised data did not differ from previous studies in the following ways:

  • There is no health risk associated with low to moderate alcohol intake compared to total abstinence.
  • High alcohol intake (>3 drinks/day) is associated with increased mortality.
  • Women are more sensitive to the adverse effects of alcohol than men.

So, this study does not change current guidelines for alcohol consumption.

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

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

_________________________________________________________________________________________________

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

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

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

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

_______________________________________________________________________________________

About The Author

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

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

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

Do Omega-3s Benefit Athletes?

by

What Do These Recommendations Mean For Non-Athletes?

Author: Dr. Stephen Chaney

fish and fish oilI have been following the research on omega-3s for athletes. But I have been reluctant to review that research in “Health Tips From the Professor” because:

  • Most of the studies are small.
  • Each study measures the effect of omega-3 supplementation on different aspects of exercise and fitness.
  • The dose of omega-3s used in the studies varies widely.
  • To the casual observer, the studies appear to come to conflicting conclusions.

I have been waiting for a respected organization to do an in-depth analysis of the published studies before commenting. The International Society of Sports Nutrition (ISSN) has just published such a study (R Jager et al, Journal of the International Society of Sports Nutrition, Issue 22 (1), 2441775, 2025) and have provided a position statement on the use of omega-3 supplements by athletes and active adults.

I would add that the ISSN is regarded as a trusted source of nutrition information for athletes.

Do Omega-3s Benefit Athletes?

Question MarkThe position of the ISSN is summarized below. What I like is they give the best recommendations based on current data and summarize the strength of the data behind each recommendation.

Statement 1: Athletes may be at higher risk of omega-3 insufficiency, and diets rich in omega-3s, including supplements, are effective for increasing omega-3 levels. In this category, they reported three key findings:

  • Omega-3s (ie EPA and DHA) are conditionally essential nutrients.
  • Fatty fish and omega-3 supplements are both effective in raising omega-3 levels.
  • Athletes belong to the groups at higher risk of omega-3 inadequacy.

My Comments:

    • This conclusion was primarily based on studies with Division I college football players. More research is needed for high-level athletes in other sports.
    • The reason for this omega-3 insufficiency was not discussed. However, I suspect it has to do with the recognition that high-level athletes need extra protein, and that fish is not usually included as a recommended source of additional protein for athletes.
    • The average Omega-3 Index for the football players was 4.4% which is considered at high risk for heart disease. The authors of the ISSN report noted that previous studies have shown that around 1.4 g/day of EPA + DHA is recommended to increase the Omega-3 Index to an optimal 8%.

Statement 2: Omega-3 supplementation, particularly EPA and DHA, has been shown to enhance Sprinterendurance capacity and cardiovascular function during aerobic-type exercise. In this category, they reported three key findings:

  • Omega-3s can improve cardiovascular dynamics during and after exercise as evidenced by enhanced red blood cell deformability, endothelial function, and heart rate recovery after exercise.
  • The incorporation of omega-3s into skeletal muscle membranes has been found to result in changes in muscle omega-3 composition, particularly in the sarcolemma, which is essential for muscle remodeling and/or regeneration after endurance exercise.
  • While these changes may help the heart pump more efficiently during exercise and muscle recover quicker after exercise, their direct impact on endurance performance remains inconsistent. More studies are needed.

My Comments:

    • These studies should be interpreted through the lens of your desired outcome. High-intensity exercise is hard on the heart.
    • If your goal is increased endurance the role of omega-3s is uncertain.
    • If your goal is to have your heart operate more efficiently during aerobic exercise, omega-3 supplementation may be beneficial.

Weight TrainingStatement 3: Omega-3 supplementation in combination with resistance training may improve strength in a dose- and duration-dependent manner. Specifically, they reported.

  • The incorporation of omega-3s into muscle cells may take a minimum of four weeks, and this is dose-dependent. It takes longer to optimize the omega-3 content in muscle cells at lower doses.
  • Once the omega-3 content of muscle cells has been optimized, it may take another three to six months until the improvement in strength plateaus.

My Comment:

    • In short, don’t expect immediate results, but omega-3 supplementation may help increase muscle strength over the long haul.

Statement 4: Omega-3 supplementation may not confer a hypertrophic benefit in young adults. [In plain English they are saying that omega-3s may not stimulate any increase in muscle mass beyond that due to exercise alone for young adults.] They went on to say:

  • More high-quality research is warranted to investigate the effects of omega-3 supplementation on body composition.

My Comments:

    • We need to remember that the ISSN recommendations are for serious athletes and may not apply to the rest of us.
    • For example, the authors state that omega-3 supplementation may enhance an increase in muscle mass…
      • When protein intake is suboptimal.
      • For older adults who are experiencing age-related loss of muscle mass.
      • For people who have previous been inactive and are just beginning an exercise program.
    • In other words, omega-3 supplements may help a lot of us non-athletes who are exercising to retain or increase muscle mass and strength.

Inflammed HeelStatement 5: Omega-3 supplementation may decrease subjective measures of muscle soreness following intensive exercise. In this category, they reported three key findings:

  • Omega-3 supplementation may attenuate indirect measures of muscle damage following intense exercise.
    • For example, when muscles are damaged, they release muscle-specific enzymes such as creatine kinase and lactate dehydrogenase into the blood. Some studies have shown that omega-3s reduce the release of these muscle enzymes following intense exercise.
  • Omega-3 supplementation is equivocal in decreasing subjective measures of muscle soreness following intense exercise.
  • Omega-3 supplementation does not decrease measures of inflammation following exercise-induced muscle damage.

My Comments:

    • Don’t count on omega-3 supplementation for reducing muscle soreness. But if you experience a decrease in muscle soreness, count it as an unexpected side benefit.
    • The lack of an effect of omega-3s at reducing inflammation post exercise may be a good thing. Some experts think that the inflammatory response plays a role in stimulating muscle repair following exercise.

Statement 6: Omega-3 supplementation can positively affect various immune cell responses in athletic populations. In this category, they reported three key findings:

  • Many athletes develop a compromised immune system due to the stress of high training volumes, which can increase the likelihood of developing acute respiratory infections that negatively impact their ability to train and compete.
  • Omega-3 supplementation can affect various immune cell responses in non-athlete, clinical, and athletic populations.
  • Many clinical studies conducted in athletic populations have indicated that omega-3 supplementation can influence the production and regulation of various inflammatory cytokines, which may lead to physiological benefits for the athletes [An example would be a reduction in exercise-induced asthma].

My Comments:

    • These recommendations are based on the effect of omega-3s on blood markers of immune health and inflammation. Clinical studies looking at the effect of omega-3s on exercise-induced respiratory infections or asthma are either nonexistent or conflicting.
    • So, if you experience decreased respiratory infections or exercise induced asthma when you add omega-3s to your exercise regimen, consider it an unexpected side benefit.

Statement 7: Omega-3 supplementation may offer neuroprotective benefits in athletes exposed to repeated head impacts. In this category, they reported three key findings:

  • Omega-3s are crucial for optimal brain development and functioning.
  • Omega-3 supplementation can increase membrane fluidity, neurotransmitter synthesis and release, and cerebral blood flow.
  • In humans, a limited amount of evidence suggests that omega-3 supplementation may offer neuroprotective benefits in athletes following repeated head impacts.

My Comments:

  • This is an important recommendation. Long-term cognitive decline, associated with repetitive traumatic brain injuries, is a serious concern for many high-impact sports. And there are no established protocols to prevent cognitive decline from occurring.
  • I have covered this in more detail in a previous issue of “Health Tips From the Professor”.

Statement 8: Omega-3 supplementation is associated with improved sleep quality. In this category, they reported three key findings:

  • Omega-3 supplementation has been linked to improved sleep quality in some studies.
  • Omega-3 supplementation may help sleep quality due to anti-inflammatory properties and effects on neurotransmitters like dopamine and serotonin, a precursor of melatonin, which helps regulate sleep-wake cycles.
  • However, inconsistency of results indicates more research is needed to fully understand the relationship between omega-3 supplementation and sleep.

My Comment:

  • If you experience improved sleep when you add omega-3s to your exercise regimen, consider it an unexpected side benefit.

Summary Of ISSN Recommendations

A strength of the ISSN recommendations is that they acknowledge where there is good agreement in the studies supporting their recommendations and where the data are scanty or conflicting. Based on the studies behind each recommendation, I would divide their recommendations into three categories.

#1: Recommendations backed by a limited number of strong studies. Confidence in these recommendations can be improved with more studies, but the recommendations are strong. These include:

  • Statement 1: Athletes are at higher risk of omega-3 insufficiency, and diets rich in omega-3s, including supplements, are effective for increasing omega-3 levels.
  • Statement 4: Omega-3 supplementation in combination with resistance training may improve strength in a dose- and duration-dependent manner.

#2: Recommendations where the evidence is weak for athletes, but valuable for non-athletes. I will discuss those in more detail below. These include:

  • Statement 2: Omega-3 supplementation has been shown to enhance endurance capacity and cardiovascular function during aerobic-type exercise.
  • Statement 3: Omega-3 supplementation may not confer a muscle hypertrophic benefit [increase in muscle mass] in young adults.

#3: Recommendations that are weak and/or conflicting. These fall in the category of “don’t count on it. But if you do experience it, consider it an unexpected side-benefit of omega-3 supplementation”. These include”

  • Statement 5: Omega-3 supplementation may decrease subjective measures of muscle soreness following intense exercise.
  • Statement 6: Omega-3 supplementation can positively affect various immune cell responses in athletic populations.
  • Statement 8: Omega-3 supplementation is associated with improved sleep quality.

Finally, the effect of omega-3 supplementation on preventing the cognitive consequences of repeated head trauma (Statement 7) is a very important topic. I have covered this in more detail in a previous issue of “Health Tips From the Professor”.

What Do These Recommendations Mean For Non-Athletes?

confusionAs their name (International Society of Sports Nutrition) suggests, their recommendations are meant primarily for athletes. But what about those of us who are not athletes but work out on a regular basis for fitness, weight management, maintaining muscle mass as we age, or other reasons?

In general, the recommendations apply equally well for athletes and non-athletes with a couple of caveats:

1) Dosage: Some of the studies with athletes were done with 3 to 6 grams/day of omega-3s. However, in most cases similar results were obtained 1-2 grams/day. Since 1-2 grams/day is enough to increase omega-3 levels to optimal for 90% of the population, I would recommend this dosage rather than the higher doses used in some of the studies with athletes.

2) Different Priorities for athletes and non-athletes: As I described earlier, this applies to two of the ISSN recommendations, namely:

  • Statement 2: Omega-3 supplementation has been shown to enhance endurance capacity and cardiovascular function during aerobic-type exercise. As I said above:
    • Young athletes are primarily interested in endurance, and the evidence for an endurance benefit for omega-3 supplementation is weak.
    • However, the rest of us are more interested in how efficiently our heart is functioning during high-intensity exercise, especially as we age. And the evidence for that benefit is strong.
  • Statement 3: Omega-3 supplementation may not confer a hypertrophic muscle benefit [increase in muscle mass] in young adults.
    • That is a true statement for young, high-performance athletes who are consuming high protein diets. For the rest of us, we need to remember the authors of the ISSN report stated that omega-3 supplementation may enhance an increase in muscle mass:
      • When protein intake is suboptimal.
      • For older adults who are experiencing age-related loss of muscle mass.
      • For people who have previous been inactive and are just beginning an exercise program.

The Bottom Line

The International Society For Sports Nutrition (ISSN) is recognized as a trusted source of nutrition advice for athletes. They recently reviewed the literature on the value of omega-3 supplementation for athletes and released a position paper with eight statements (recommendations).

I have divided these recommendations into 3 categories:

  • Recommendations backed by strong data.
  • Recommendations backed by weak data.
  • Recommendations that have different significance for high-performing athletes and the rest of us.

For more details about the ISSN recommendations and what they mean for you, read the article above.

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

______________________________________________________________________________

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

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

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

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

_______________________________________________________________________

About The Author 

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

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

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

 

Why Is Keeping Weight Off So Hard?

by

Can You Achieve Permanent Weight Loss? 

Author: Dr. Stephen Chaney 

Why is the dreaded yo-yo rearing its ugly head again? You tried a new diet this year, and it worked really well. The weight came off easily. But the diet is over, and the pounds are starting to creep up once again.

You are beginning to wonder if this diet was just like all the other yo-yo diets you’ve tried in the past. You are wondering whether those pounds you lost will come back and bring their friends with them. If so, you’ll be like 156 million Americans who lose weight and gain it all back each year.

And it’s so frustrating. You are trying to be good. You are still exercising and trying to eat healthily. Why isn’t it working?

Could it be that your fat cells have a memory? Could it be they like to be big and bulky with lots of stored fat? While that description is a bit fanciful, a new study (LC Hinte et al, Nature Online, 2024) suggests your fat cells may have a memory, which could explain why it is so hard to keep the weight off.

This is a highly technical study. So, before I discuss how the study was done, I should perhaps review a little bit of Biochemistry 101.

Biochemistry101: Epigenetics and Gene Activity

EpigeneticsWhat Is Epigenetics? When I was a young graduate student (which is more than just a few years ago), I was taught that all genetic information resided in our DNA. During conception, we picked up some DNA from our dad and some from our mom, and that DNA was what made us a unique individual.

In recent years, the hype has centered on DNA sequencing. It seems like everyone is offering to sequence your genome and tell you what kind of diet is best for you, what foods to eat, and what supplements to take. But can DNA sequencing fulfill those promises?

The problem is that DNA sequencing only tells you what genes you have. It doesn’t tell you whether those genes are active. Simply put, it doesn’t tell you whether those genes are turned on or turned off.

This is where epigenetics comes in. Epigenetics is the science of modifications that alter gene expression. In simple terms, both DNA and the proteins that bind to DNA can be modified. This does not change the DNA sequence. But these modifications can determine whether a gene is active (turned on) or inactive (turned off).

This sounds simple enough, but here is where it really gets interesting. These modifications are affected by our diet, our lifestyle (body weight and exercise, for example), our microbiome (gut bacteria), and our environment.

And if that weren’t complicated enough, some of these epigenetic changes (DNA modifications) can be transitory and others are long-lasting.

The authors of this study hypothesized that obesity causes long-lasting epigenetic changes to certain critical genes in our fat cells that slow metabolism and promote fat accumulation, even after we have lost weight. In other words, these epigenetic changes “prime” our fat cells to regain all the weight we’ve lost.

How Do You Measure the Effect of Epigenetic Changes? As you might expect this study measured epigenetic modifications to critical genes in fat cells. But that’s only part of the story. Epigenetic modification can turn genes on, turn them off, or have no effect on gene activity.

So, the investigators also needed to monitor the activity of the genes to determine the effect of the epigenetic modifications. Fortunately, one fact you may have learned in high school or college biology is mostly unchanged by the passage of time.

It is that the genetic sequence of DNA is translated into messenger RNA and that messenger RNA is used to code for proteins. If epigenetic modifications turned on a gene, we would expect higher levels of the corresponding messenger RNA and corresponding protein in those cells. Conversely, if epigenetic modifications turned off a gene, we would expect the opposite.

It turns out that it is much easier to measure changes in messenger RNA levels than individual protein levels that correspond to specific genes. So, the investigators used cellular messenger levels to measure the effect of epigenetic modifications on gene activity.

How Was This Study Done?

clinical studyThe investigators measured the effect of obesity and subsequent weight loss on fat cell gene expression in a limited set of human subjects and supplemented those results with a more expansive set of experiments with mice.

I don’t normally report on animal studies or very small human studies because these studies often lead to misleading results that are not supported by subsequent long-term, large clinical studies.

However, I am making an exception for this study because it leads to an interesting paradigm shift which, if true, changes the way we think about how to keep weight off long term.

Human Study: The investigators determined messenger RNA levels for key genes in fat cells from human volunteers who were:

  • At a healthy weight.
  • Obese both before and 2 years after bariatric surgery that resulted in at least 25% weight loss.

The groups were small (10-16 total), in part because obtaining fat cell samples is an invasive and painful procedure.

Mouse study: The investigators determined both messenger RNA levels and epigenic modifications for key genes in fat cells from 6-week-old male mice who were:

  • Fed either a low-fat or high-fat chow diet for 25 weeks. As expected, the mice fed the low-fat diet remained lean and the mice fed the high-fat diet became obese.
  • Subsequently, the obese mice were put on low-fat chow for 8 weeks during which time their weight returned to normal.
  • Finally, both the ‘always lean’ and ‘formerly obese’ mice were put on high-fat chow to compare how rapidly they gained weight.

What Happens To Fat Cells During Obesity And Weight Loss?

This study is best viewed as a story of what happens to fat cells during obesity and subsequent weight loss. There are two parts – what happens to human fat cells and what happens to mouse fat cells:

 Human Fat Cells: When obese individuals were compared to lean individuals:

  • Genes coding for fat storage and inflammation (which is known to be associated with obesity) were more active.
  • Fat-burning genes were less active.
  • These changes in gene expression were retained even after the obese individuals lost substantial weight through bariatric surgery.

[Note: The measurements of gene expression were based on the amount of messenger RNA produced by those genes.]

The human study had a couple of important limitations, which is why the investigators also did a similar study with mice.

#1: Because the study did not include a habitually lean group who became obese after going on a high-fat diet (no clinical review board would approve such a study), it could not determine whether the differences in gene expression were caused by the onset of obesity or whether they caused obesity.

Simply put, we know some individuals are genetically predisposed to obesity. The differences in gene expression between lean and obese individuals could have simply represented a genetic predisposition to obesity.

The mouse experiments did not suffer from that limitation because it was possible to put lean mice on a high fat diet until they became obese.

#2: The study did not measure epigenetic changes that may have caused the changes in gene expression. That is because humans are genetically heterogeneous. Consequently, you need population studies with hundreds of individuals to reliably determine epigenetic differences between groups.

The mouse experiments did not suffer from that limitation because laboratory mice are genetically homogeneous.

Mouse Fat Cells:

When the investigators looked at the physical effects of obesity:

  • When mice became obese on a high-fat diet:
    • Blood glucose levels rose.
    • Insulin levels rose, indicating the mice had become insulin resistant.
    • Fat accumulated in their livers.
  • When the obese mice lost the excess weight on a low-fat diet all these parameters returned to normal.
  • When the ‘always lean’ and ‘previously obese’ mice were put back on a high fat diet at the end of the study, the previously obese mice gained weight more quickly than the always lean mice.

In other words, mice responded to obesity in the same way that humans do except none of these effects could be explained by genetics. This strain of mice was genetically homogeneous.

When the investigators compared gene expression (as measured by messenger RNA levels) in mice who had become obese to ‘always lean’ mice:

  • Genes coding for fat storage and inflammation were more active.
  • Fat-burning genes were less active.
  • These changes in gene expression were retained even after the obese mice lost weight.

In other words, mice responded to obesity in the same ways as humans with respect to gene expression. However, in this case it was clear that obesity caused the changes in gene expression.

When the investigators looked at epigenetic modifications:

  • They identified epigenetic modifications to the regulatory regions of genes whose activity was increased or decreased when the mice became obese.
  • These epigenetic modifications were retained even after the mice lost weight.

These data suggest, but do not prove, that the epigenetic modifications were responsible for the changes in gene activity.

The authors concluded, “We show that both human and mouse adipose tissues retain transcriptional changes after appreciable weight loss.

Furthermore, we find persistent obesity induced alterations in the epigenome of mouse adipocytes that negatively affect their function and response to metabolic stimuli. Mice carrying this obesogenic memory show accelerated rebound weight gain…in response to high-fat diet feeding.

In summary, our findings indicate the existence of an obesogenic memory, largely on the basis of stable epigenetic changes, in mouse adipocytes and probably other cell types. These changes seem to prime cells for pathological response [weight gain] in an obesogenic environment, contributing to the problematic ‘yo-yo’ effect often seen with dieting.”

More simply put, the investigators concluded that obesity causes epigenetic modifications to the DNA of fat cells that prime them to regain their fat stores. They said that this may contribute to the ‘yo-yo’ effect often seen with dieting and explain why keeping weight off is so hard.

Why Is Keeping Weight Off So Hard?

Question MarkYou are not alone. You are like millions of other Americans. You lose weight effectively, but you struggle to keep it off. You just look at a donut and the fat jumps from the donut to your hips. You try to eat right, but the pounds keep creeping back on.

Experts have told us for years that our fat cells (and perhaps other cells in our body) are the culprit. Those cells have switched from a fat burning mode to a fat storage mode. There have been lots of attempts to explain that phenomenon, but my favorite is one that hypothesizes that our metabolism was designed for paleolithic times when it was either feast or famine.

Simply put, the theory is that our bodies were designed to store energy reserves in times of plenty and hold on to those energy reserves as long as possible in times of famine. Holding on to energy reserves was essential for prehistoric man to survive cold winters when food was hard to come by. And our number one energy reserve is, you guessed it, fat.

That is an appealing hypothesis, but it doesn’t tell us how our bodies manage to do that.

That’s what makes this study so intriguing. It may be wrong. It needs to be substantiated by large scale clinical trials. But the idea that epigenic changes occur during obesity and persist after substantial weight loss is novel. More importantly, it may explain the “feast or famine” response and why it is so hard to keep weight off after substantial weight loss.

Can You Achieve Permanent Weight Loss?

By now you may be thinking, “I thought my weight loss woes were due to my genetics. Now you’re telling me that they could be due to my epigenetics. Am I doubly cursed? Is there nothing I can do to keep my weight off?”

I can tell you science doesn’t have a simple answer, but there are two big clues that offer hope.

#1: Slow and steady wins the race. Obesity experts have known for years that slow weight loss often results in permanent weight loss.

  • If you are counting calories, that means a reduction of around 500 calories per week (That’s 71 calories per day, which is equivalent to one small apple, one hard-boiled egg, or 1.5 ounces of chicken breast). And a 500-calorie deficit maintained each week for a year can lead to a 20-25 pound weight loss.
  • If you are thinking of diets, it could amount to switching to a diet of unprocessed or minimally processed foods consisting of fruits, vegetables, whole grains, and primarily plant-based proteins without worrying about calories or serving sizes. Again, clinical studies show that switching from the typical American diet to this kind of diet can lead to substantial weight loss over a period of years.

Neither approach is popular in the weight loss world, but they work. Why do they work? It could be because the daily reduction in calories is so small that it never triggers the famine response.

If we look at the two parts of the study I reported on above:

  • In the human study weight loss was achieved through bariatric surgery which causes a huge reduction in caloric intake and rapid weight loss.
  • In the mouse study going from high-fat chow to low-fat chow represented a large decrease in calories. And again, weight loss was very rapid. It took the mice 25 weeks to become obese and only 4-8 weeks to lose the weight they had gained.

When viewed from this perspective, the epigenetic modifications observed after weight loss in this study may have been due to the famine response rather than a retention of the modifications observed during obesity.

And when you think about it, most popular diets feature major restrictions (calories, fats, carbs, forbidden foods, time of eating) and cause rapid weight loss. They are likely to trigger a famine response as well.

#2: The secrets of the National Weight Control Registry. There are some people who manage to keep their weight off and avoid the yo-yo effect. They don’t have any genetic or epigenetic advantage over the rest of us. They have lost weight on every diet imaginable – including rapid weight loss fad diets.

Yet they have managed to keep the weight off. What are their secrets? How did they avoid regaining their weight? How did they avoid the yo-yo diet effect?

An organization called the National Weight Control Registry was established to answer that question. It has enrolled more than 10,000 people who have lost weight and kept it off. On average people in this group have lost 66 pounds and kept it off for at least 5 years.

The National Weight Control Registry kept track of what they did to keep the weight off. Everyone’s approach was a little different, but the National Weight Control Registry summarized the ones that were most frequently mentioned. Here is what they do that you may not be doing:

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

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

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

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

#5: They eat breakfast on a regular basis.

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

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

The good news is that participants in the National Weight Control Registry reported that while maintaining weight loss was difficult at first, it became easy after 2 years.

Of course, we don’t know whether is due to epigenic modifications being reset to “lean” by these behaviors or whether the new behaviors became automatic and overrode epigenetics.

It doesn’t matter. It means you can end the ‘yo-yo’ cycle forever. You can keep weight off, and you know how to do it.

The Bottom Line

A recent study in both humans and mice suggests that epigenetic modifications to key genes in your fat cells make it hard to keep weight off. These epigenetic changes may explain why so many people struggle with yo-yo dieting.

 

For more details on this study and how you may be able to override these epigenetic modifications and prevent weight regain 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.

Maternal Mortality In The United States

by

Leading Causes Of Maternal Deaths

Author: Carolyn Curtis, MSN, CNM, RN, FACNM, FAAN

Editor: Dr. Steve Chaney

Maternal Mortality In The United States

Between 2018 and 2021, the maternal mortality (death) rate in the United States nearly doubled, placing the country last among developed nations in maternal health outcomes.  The maternal mortality ratio (MMR) is a key indicator of a nation’s overall health, making this rapid increase a cause for serious concern.

Understanding Maternal Mortality

Maternal mortality refers to the number of women who die during pregnancy or within 42 days (six weeks) after childbirth for every 100,000 live births. As per the Government Accounting Office, 25% of the increase in maternal mortality from 2020 to 2021 was due to Covid-19, which contributed to the doubling of the maternal mortality ratioi.

The maternal mortality ratio is used globally to assess the state of a country’s health. A rising MMR signals the need for urgent action.

In 2022, the U.S. recorded an overall maternal mortality ratio 22.3 deaths per 100,000 live birthsii. This decreased by about 10 deaths per 100,000 from 2021 (32 deaths per 100,000 live births in 2021). However, stark racial disparities continued to exist as demonstrated through 2018 to 2021.

  • Black women: 49.5 deaths per 100,000 live births (more than 2.5 times the rate for white women)
  • White women: 19.0 deaths per 100,000 live births
  • Hispanic women: 16.9 deaths per 100,000 live births
  • Asian women: 13.2 deaths per 100,000 live births

Maternal Mortality versus Pregnancy Related Deaths

What Is The Difference?

While maternal mortality measures deaths that occur from the onset of pregnancy to six weeks post-delivery, pregnancy-related deaths extend further.  Pregnancy-related deaths are the number of deaths per 100,000 live births up to 12 months (one year) after birth or the first birthday.

Does The Age Of The Mother Make A Difference?

The age of the mother significantly affects the risk of dying during pregnancy. The ratio of deaths among women younger than 25 years of age is 14.4 deaths per 100,000 live births. Women aged 25 to 39 have a rate of 21.1/100,000 live births, while those aged 40 and older face a staggering 87.1 deaths per 100,000 live birthsiii. This means that women over 40 are dying at six times the rate of those under 25 and four times the rate of women aged 25 to 29iv.

When Are The Deaths Occurring?

Surprisingly, a little under half (47%) of maternal deaths occur during pregnancy or within the first week postpartum (Maternal Mortality).  And a little over half (53%) happen between one week and one year after childbirth or the baby’s first birthday (Pregnancy-Related Deaths).

Leading Causes Of Maternal Deaths

The primary causes of maternal mortality in the U.S. are largely preventablev. The six main causes of maternal death include:

  • Mental Health Conditions (23%) – Suicide, overdose, and substance-related poisoning are the leading causes, this affects White and Hispanic women more than Black or Asian women.
  • Hemorrhage (14%) – Severe postpartum bleeding remains one of the top causes of maternal deaths not only in the Unites States but throughout the world with Asian women being more susceptible. Hemorrhage is defined as bleeding about one half quart of blood.
  • Cardiac Conditions (13%) – Heart disease disproportionately affects Black women.
  • Blood Clots (9%) – A major contributor to maternal deaths.
  • Cardiomyopathy (9%) – A condition affecting the heart muscle, making it harder to pump blood efficiently.
  • Hypertensive Disorders of Pregnancy (7%) – relating to high blood pressure

Contributors to maternal death include familial, societal, health care system issues and one’s personal health. it is possible to reduce the risks of maternal death by understanding one’s personal health history and your family’s health history.

This information informs nutritional, behavioral and lifestyle changes that can be made prior to and during pregnancy to reduce health risks, enabling a healthier pregnancy outcome.

The Bottom Line

  • The United States has the highest maternal mortality rate amongst all developed countries in the world.
  • The maternal mortality rate in the U.S. has nearly doubled between 2018 and 2021; Covid-19 caused a 25% increase of maternal deaths from 2020 to 2021 which contributed to the doubling of maternal deaths. Black women have been disproportionately affected, with mortality rates 2.5x that of White women.
  • Women aged 40 and over die at four times the rate of women ages 25 to 39 and six times more than women under 25 years of age.
  • The leading causes of maternal deaths include mental health conditions, hemorrhage, cardiac conditions, blood clots, and cardiomyopathy— most of which are preventable.
  • Almost half of maternal deaths occur throughout pregnancy and the first week after childbirth. A little more than half of maternal deaths occur from the first week following birth up to the first year after birth.  It’s important to continue monitoring mothers with home visits once they return home from the hospital and up until one year after birth.

References

i General Accounting Office, Maternal Health: Outcomes Worsened and Disparities Persisted During the Pandemic.  Oct, 2022.

ii Hoyert DL.  Maternal mortality rates in the United States, 2022.  NCHS Health E-Stats.  2024.  DOI:https://dx.doi.org/10.15620/cdc/152992.

iii Ibid

iv Ibid.

vFour in five pregnancy related deaths in the US are preventable – https://www.cdc.gov/media/releases/2022/p0919-pregnancy-related-deaths.html.

For More Information

Feel free to visit my website, subscribe to my YouTube channel and learn more about my online coaching program, “Mastering Pregnancy and Birth”.

You-Tube Channel – Over 80 videos exploring pregnancy, labor, birth, postpartum and contraception

www.thecarabcompany.com – Website with free downloadable pregnancy and birth information

Mastering Pregnancy and Birth Coaching Program –  A program that prepares Dads and Mom’s-to-be for a healthier pregnancy and safer birth.  This course also provides information for Doulas to provide enhanced support to families.

Carolyn Curtis

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.

About The Author

Carolyn Curtis, MSN, CNM, RN, FACNM, FAAN, has:

 

  • More than 40 years’ experience in the oversight of domestic and international programs and the provision of nursing and midwifery integrated service delivery in maternal child health, family planning, reproductive and women’s health care.

 

  • Twenty years’ experience in teaching, mentoring, and providing clinical oversight to undergraduate and graduate public health, medical, nursing and midwifery students.

 

About The Editor

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

by

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.

Health Tips From The Professor