Is Sorbitol Dangerous?

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Should You Avoid Foods Containing Sorbitol?

Author: Dr. Stephen Chaney

Sorbitol is in the news. And the news doesn’t seem to be good. Social media influencers are telling you:

  • Sorbitol can cause gastrointestinal distress (cramping, bloating, cramping, and diarrhea).
  • Sorbitol can cause heart attacks and strokes.
  • Sorbitol can cause liver disease.

They are telling you to scan every label and avoid anything with sorbitol in it. Should you listen to them, or are they promoting food myths to get more followers and clicks?

After all, sorbitol is found in lots of healthy foods such as peaches, pears, apples, nectarines, apricots, cherries, sweet corn, white cabbage, and eggplant. Should you give up those as well?

And our body produces sorbitol from other sugars, so we always have some sorbitol circulating through our bloodstream.

In short, sorbitol is not a foreign substance. It’s not an artificial sweetener. Our body knows how to handle it safely.

But every food myth starts with a kernel of truth. So, let me discuss each of these claims and separate the kernel of truth from the myth.

Can Sorbitol Cause Gastrointestinal Distress?

This claim is true, but:

  • It is true for every sugar alcohol.
  • It is a matter of dose.
  • It is also true for the sugar alcohols found in healthy foods.

Let’s examine those last two points in more detail.

For most people, the small amount of sugar alcohols found in the foods they eat cause no problem. It’s only when they consume large amounts that they experience gastrointestinal distress. [Note: I said most people. If you have Irritable Bowel Syndrome (IBS) or Small Intestinal Bacterial Overgrowth (SIBO), you may be sensitive to even small amounts of sugar alcohols – and many other things.]

And the gastrointestinal effects of large amounts of sugar alcohols are not limited to processed foods. They can also be associated with consumption of healthy foods. Let me share my personal experiences, and you can see if you have had similar experiences.

Years ago, I had a strawberry patch and several fig bushes. At the height of their seasons, it was tempting to eat lots of strawberries and lots of figs. After all, why let those delicious fruits go to waste?

I quickly discovered that 8-10 strawberries on my breakfast cereal was a treat, but 30 strawberries at a sitting was a BIG problem. Similarly, 2-3 figs for dessert were the perfect ending to a meal, but 10 figs at a time was a BIG problem.

The take-home lesson was clear. Small amounts of sorbitol and other sugar alcohols in healthy foods and supplements are no problem. Our body knows how to handle them. But large amounts of sorbitol and other sugar alcohols can cause gastrointestinal distress. And it doesn’t matter if those large amounts come from healthy foods or unhealthy processed foods. 

Can Sorbitol Cause Heart Attacks And Strokes?

Human heart attack time bomb as a symbol of urgent health problems due to poor cholesterol levels and bad diet eating fatty greasy junk food.

This claim is mostly false. In the first place, the study on which this claim is based was done with erythritol, not sorbitol. More importantly, the study was deeply flawed.

I have described the flaws in a recent issue of “Health Tips From the Professor”.

In addition to its many flaws the study only found an association between erythritol and heart disease at very high intakes of erythritol. Specifically:

  • There was no association between erythritol and heart disease at low to moderate intakes of erythritol. As with sorbitol, erythritol is found in many healthy foods and our bodies know how to handle the amount of erythritol found in healthy foods and supplements.
  • The association between erythritol and heart disease was only seen at intakes of 30 grams/day or above. The only way you could get that much erythritol daily would be to consume a diet with lots of erythritol-sweetened highly processed foods. And we already know a diet of highly processed foods is associated with an increased risk of heart attack and stroke.

After reviewing the study and analyzing its flaws, I concluded,” Clearly, it doesn’t matter what sweetener we are talking about. Large intake of any natural sweetener in the context of a diet rich in highly processed foods appears to have an adverse effect on our health. And we don’t know whether these adverse health effects are caused by the sweetener or some other components of the highly processed foods.

If you want to improve your health, the best solution is to decrease your intake of highly processed foods. That will automatically reduce your intake of sweeteners and other unhealthy components of highly processed foods and increase your intake of healthy components from the whole foods you will be eating instead”

Many other experts have come to a similar conclusion after reviewing that study.

However, that hasn’t kept social media influencers from warning you to read labels and avoid everything with sorbitol in it because it increases your risk of heart attack and stroke. And, unfortunately, some respectable web sites have repeated that claim without examining the study behind the claim.

Can Sorbitol Increase The Risk Of Liver Disease?

fatty liver disease causesThis claim is also mostly false. The study behind this claim was done in zebrafish, not humans. And the zebrafish were put on antibiotics that wiped out their intestinal bacteria. Under these conditions, when the zebrafish were fed glucose, they developed fatty liver disease.

I realize that description of the experimental protocol has probably left you confused. So, let me walk you through the metabolic rationale for the study.

  • In zebrafish, like in humans, a small amount of dietary glucose is converted to sorbitol by intestinal mucosal cells.
  • In zebrafish and humans, the small amount of sorbitol produced in the intestine is degraded by intestinal bacteria. No harm, no foul.
  • However, when the intestinal bacteria are wiped out, sorbitol accumulates and is absorbed into the bloodstream. Simply put, this was way to create very high blood levels of sorbitol in zebrafish.
  • Zebrafish and humans are both able to metabolize small amounts of sorbitol. But when the blood levels of sorbitol are high enough, the normal metabolic pathways are overwhelmed.
  • Under these conditions, sorbitol goes to the liver where it is converted to fructose.
  • Previous studies have shown that excess fructose in the liver can cause fatty liver disease.

The authors of this study concluded, “These results indicate that sorbitol is derived from glucose in the zebrafish intestine, implicate gut microbiota [gut bacteria] in protecting against sorbitol-induced steatosis [abnormal accumulation of fat], and suggest that dietary sorbitol, which is used as a sugar substitute, may increase the risk of developing steatotic liver disease [fatty liver disease].”

This is the message you have probably seen from social media influencers and some websites. Of course, they consider “fatty liver disease” to be too complicated, so their warnings are usually that sorbitol can cause liver disease or liver “danger”.

It sounds scary, but this claim ignores the flaws in this study. In the first place, the study was conducted with zebrafish with no intestinal bacteria. We don’t know whether this is true for humans under normal conditions. And if it is true, it required high blood levels of sorbitol which can only be attained in humans by eating lots of highly processed sorbitol-sweetened foods.

And to put this in proper perspective we also need to investigate the link between fructose and fatty liver disease, as I have done in previous issues of “Health Tips From the Professor”.

  • Fructose or “fruit sugar” is, as the name suggests, found in almost all fruits.
  • Fructose in fruits is present in small amounts and is encased with fiber, so it is absorbed slowly.
  • Our bodies are designed to handle the fructose found in fruits. It is slowly converted to glucose, avoiding the blood sugar spikes associated with sucrose (table sugar) and glucose consumption.
  • Fructose in highly processed foods is present in much larger amounts with no fiber to slow its absorption into the bloodstream.
  • Under these conditions, our normal metabolic pathways for dealing with dietary fructose are overwhelmed. Fructose accumulates in the liver, where it is converted to fat.
  • If we consume highly processed fructose-containing foods long enough, we develop fatty liver disease.

Is this starting to sound familiar? In short, fructose, erythritol, sorbitol, and other sugar alcohols are not a problem in the small doses found in supplements and healthy foods. They only become a problem when we consume lots of processed foods that use them as sweeteners.

Is Sorbitol Dangerous?

danger symbolThe short answer is, “No”. You can ignore the dire warnings about the dangers of sorbitol. They are food myths! You don’t need to become a label reader and avoid every supplement and food with sorbitol on the label.

Here is the truth about sorbitol:

#1: It can cause gastrointestinal distress (cramping, bloating, cramping, and diarrhea) if you eat too much sorbitol-containing foods at one time. Other studies suggest that this occurs for most people at doses of 10-15 grams of sorbitol. This can occur with excess consumption of both healthy foods and processed foods that are high in sorbitol.

And most of us figure out pretty quickly which foods are a problem for us. That doesn’t require label reading. It just requires paying attention to our symptoms.

#2: The claims about increased risk of heart disease and liver disease are mostly false.

  • The claim that sorbitol increases the risk of heart disease was based on a study with erythritol, not sorbitol, and the study was highly flawed.
  • The claim that sorbitol increases the risk of liver disease was done with zebrafish, not humans.
  • If those studies tell us anything, it is that health issues associated with sorbitol consumption only occur at high doses which can only be achieved by eating lots of sorbitol-sweetened highly processed foods.
  • There is no evidence of health issues associated with the small amounts of sorbitol found in some supplements and healthy foods. Our bodies are designed to handle small amounts of sorbitol because they occur naturally in a healthy diet containing fruits and vegetables.

I suppose you could read the labels of processed foods and avoid the ones containing sorbitol. However, there are lots of health concerns with highly processed foods. Sorbitol is the least of the concerns.

A better choice would be to avoid highly processed foods. You don’t need to read their labels to know they are bad for you. 

The Bottom Line

We are constantly bombarded with new food ingredients we need to avoid. Social media influencers are telling us to scan food and supplement labels, so we know which ones we shouldn’t eat.

The latest warnings are about sorbitol, a sugar alcohol that occurs naturally in healthy foods and is also added to processed foods. We are being told that:

  • Sorbitol can cause gastrointestinal distress (cramping, bloating, cramping, and diarrhea).
  • Sorbitol can cause heart attacks and strokes.
  • Sorbitol can cause liver disease.

are telling you to scan every label and avoid anything with sorbitol in it. Should you listen to them, or are they promoting food myths to get more followers and clicks?

Here is the truth about sorbitol:

  • The claim that high levels of sorbitol can cause gastrointestinal distress are mostly true, but they are equally true for healthy foods and processed foods that are high in sorbitol.

And most of us figure out pretty quickly which foods are a problem for us. That doesn’t require label reading. It just requires paying attention to our symptoms.

  • The claims that sorbitol increases our risk heart and liver disease are mostly false. They are based on flawed studies that were not done with sorbitol in humans.
    • If those studies tell us anything, it is that health issues associated with sorbitol consumption only occur at high doses which can only be achieved by eating lots of sorbitol-sweetened highly processed foods.
    • There is no evidence of health issues associated with the small amounts of sorbitol found in some supplements and healthy foods. Our bodies are designed to handle small amounts of sorbitol because they occur naturally in a healthy diet containing fruits and vegetables.

I suppose you could read the labels of processed foods and avoid the ones containing sorbitol. However, there are lots of health concerns with highly processed foods. Sorbitol is the least of the concerns.

A better choice would be to avoid highly processed foods. You don’t need to read their labels to know they are bad for you.

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 Erythritol Myth

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Who Should Be Concerned About Erythritol Intake?

Author: Dr. Stephen Chaney 

darts hit the target

Everyone is searching for the perfect sweetener. And if you were in the marketing department of Big Food Inc, the perfect sweetener would be defined as:

  • Natural, meaning that it is found in fruits, vegetables, or other plant foods.
  • Low in calories. Of course, a perfect sweetener would have zero calories because it is not metabolized in our bodies.
  • Low glycemic, meaning that it would have a minimal effect on blood sugar levels. Once again, a perfect sweetener would have zero effect on blood sugar levels.
  • Safe, meaning that it has no adverse effects on our health.

Sugar alcohols appear to meet all these criteria, so they have become the sweetener of choice for lots of highly processed foods. This is especially true for the sugar alcohol, erythritol, since it is currently the least expensive of the sugar alcohols.

So, a recent study (M Witowski et al, Nature Medicine) suggesting that erythritol might increase the risk of heart disease was quite surprising.

This is the first study to suggest a link between erythritol and heart disease, and it was a flawed study (I will discuss the flaws below).

Reputable scientists don’t put much credence in a weak first study like this one. We generally consider the conclusions of a first study like this one to be an unproven hypothesis at this point.

But we are cautious. There will be many follow-up, better designed studies, to test this hypothesis. Once these studies have been published, the scientific community will look at all the evidence and either issue a warning or conclude that there is no reason for concern.

But that doesn’t stop the Dr. Strangeloves of the world from warning you of the “dangers” of erythritol and telling you to avoid it at all costs.

For that reason, I felt it was appropriate to address this issue. I will:

  • Describe the study and its flaws.
  • Put the study into the broader perspective of what we know about sweeteners.
  • Identify the two population groups who should be most concerned about erythritol.

How Was The Study Done And What Did It Show?

This study can be divided into three parts.

Human heart attack time bomb as a symbol of urgent health problems due to poor cholesterol levels and bad diet eating fatty greasy junk food.

#1: An Association Between Erythritol Blood Levels And Heart Disease.

There were three separate experiments included in this section of the study. In each experiment patients were recruited after visiting cardiac clinics for diagnostic procedures. The average age of these patients was 67 and 45% of them already had experienced a non-fatal heart attack prior to the study. In other words, these were all older patients with pre-existing heart disease who were at high risk of heart attack or stroke in the near future.

The first study was a metabolomic study. In simple terms this means that high-tech equipment and computing were used to measure hundreds of metabolites in the blood of the patients and, in this case, correlate each of them with the occurrence of heart attacks and strokes over the next three years.

  • This experiment identified 16 sugar alcohols and related metabolites in the blood of these patients that were associated with an increased risk of heart attack and stroke. (I will discuss the significance of this observation in more detail later.)

Because erythritol was among the top 6 compounds in terms of association with increased heart attack and stroke risk, and erythritol is the most commonly used sugar alcohol in processed foods, the next two studies focused on the association between blood levels of erythritol and heart attack/stroke risk. Their results were predictable.

  • High blood levels of erythritol were associated with an increased risk of heart attack and stroke over the next three years.

Flaws In This Portion Of The Study:

  • As the authors of the study pointed out, these studies were done with older patients with pre-existing heartthumbs down symbol disease who were at high risk of heart attack or stroke. They acknowledged that it is not known whether these associations exist with younger, healthier patients.
  • As the authors also pointed out, these are associations. They do not prove cause and effect. In particular, the studies did not measure the diet, exercise habits, and other lifestyle factors of these patients that may have contributed to their increased risk of heart attack and stroke.
  • When you look closely at the data, it is clear that the association is only seen at the highest blood levels of erythritol. Specifically, the blood levels of erythritol in these patients were divided into quartiles. The risk of heart attack and stroke in the first three quartiles (low to moderate blood levels of erythritol) were identical to the control. However, the fourth quartile (highest blood levels of erythritol) was associated with a dramatically increased risk of heart attack and stroke. That raises three important questions:
    • “How much erythritol were patients in the fourth quartile consuming?”
      • The authors did not look at dietary intake of erythritol but did note a previous study estimated that Americans consume up to 30 grams of erythritol a day.
    • 30 grams of erythritol a day is a huge amount of erythritol. Where does that erythritol come from?
      • Much of it comes from erythritol-containing highly processed foods like zero calorie sugar substitutes (either erythritol alone or erythritol mixed with artificial sweeteners to improve the taste); reduced- and low-calorie carbonated and non-carbonated beverages; hard candy and cough drops, cookies, cakes, pastries, and bars; puddings and pie fillings; soft candies; syrups and toppings; ready to eat cereals; fruit novelty snacks; and frozen desserts.
      • But it is also found in foods you might not suspect, such as plant-based “milk” substitutes; chocolate and flavored milks; barbecue and tomato sauce, fruit-based smoothies, the syrup used in canned fruits, yoghurt; low calorie salad dressings; and even salty snacks.
      • In other words, the only way anyone can consume 30 grams of erythritol in a day is to consume large quantities of erythritol-containing highly processed foods (I will discuss the significance of this observation later).
    • “What else was different about patients in the fourth quartile?”
      • When you look carefully at the data, the patients in the fourth quartile were significantly older, with a higher incidence of diabetes, pre-existing coronary artery disease, previous non-fatal heart attacks, congestive heart failure, and greater triglycerides – all of which significantly increase their risk of heart attack and stroke.

#2: Mechanistic Studies:

Next the authors did in vitro and animal studies looking at the effect of high levels of erythritol on blood clotting.

  • These studies showed that high levels of erythritol promoted blood clotting both in vitro and in mice. The authors concluded that these studies provided a plausible mechanism for a link between high erythritol blood levels and increased risk of heart attack and stroke.

Flaws In This Portion Of The Study:thumbs down symbol

  • Other critics have pointed out that the assays used were not accurate models of blood clotting in humans. This particular critique is beyond my expertise, so I won’t comment further. However:
    • As someone who was involved in cancer drug development for over 30 years, I know that in vitro and animal models are poor indicators of how things work in humans.
    • And as a biochemist, I have two concerns:
      • The authors provided no mechanistic rationale for why erythritol would enhance blood clotting.
      • The authors made no effort to show that the effect of erythritol was unique. Would high levels of other sugar alcohols or other naturally occurring sugars have the same effect on blood clotting in their assays? We don’t know.

#3: Blood Levels Of Erythritol After Oral Intake.

Finally, the authors gave subjects 30 grams of erythritol and measured blood levels over the next several days.

  • This experiment showed that very high blood levels of erythritol were attained and maintained for at least two days before gradually decreasing to baseline. The authors concluded this experiment showed that it was feasible to attain and maintain high blood levels of erythritol for several days following a single ingestion of 30 grams of erythritol.

Flaws In This Portion Of The Study:thumbs down symbol

  • I have already pointed out that 30 grams per day is a huge amount of erythritol. Furthermore, erythritol from foods in the diet will come from a variety of foods, many of which will contain components (fiber etc.) that slow the absorption of erythritol.
  • In contrast, the subjects in this experiment were given 300 ml of liquid containing 30 grams of erythritol and told to drink it in two minutes!
  • In other words, these subjects were consuming 30 grams of erythritol in 2 minutes rather than 24 hours, and they were consuming it in the most easily absorbable form. For a study like this, that makes the effective dose orders of magnitude greater than the amount of erythritol that anyone consumes from their diet over a 24-hour period. The study design was completely unrealistic.

The Erythritol Myth

Myth Versus FactsAs described above, this is the first study to suggest an association between erythritol and heart disease, and it was a highly flawed study.

It is also important to know that erythritol is not an artificial sweetener. It is found naturally in healthy foods like grapes, peaches, pears, watermelons, and mushrooms. It is also found in some fermented foods like cheese, soy sauce, beer, sake, and wine.

It is also a byproduct of normal human metabolism, so we always have some of it circulating in our bloodstream. Our body knows how to handle low to moderate intakes of erythritol in small amounts.

However, to help you really understand what this study means, I need to put it into the context of other studies. I will do this in story form (You will find more details about these studies in my book “Slaying The Food Myths”.

First, let’s look at highly processed food consumption:

  • Multiple recent studies have shown that high consumption of highly processed food is associated with increased risk of obesity, diabetes, heart disease, and premature death. We don’t know what it is about highly processed food consumption that is responsible for the increased risk, but it is unlikely to be just one thing.
  • As I pointed out above, the only way to achieve the high blood levels of erythritol associated with increased heart disease risk is to consume large quantities of erythritol-containing highly processed foods.

Next, let’s follow the history of sweeteners in highly processed foods.sugar cubes

  • When I was a young man, sucrose (table sugar) was added to most highly processed foods. Sucrose is found naturally in many fruits and vegetables. Small to moderate intake of sucrose in unprocessed and minimally processed foods posed no problem. However, large intakes of sugar in highly processed foods were found to increase the risk of obesity, diabetes, heart disease, and premature death.
  • At that point, sucrose became a “sugar villain”, and Big Food, Inc substituted fructose and high fructose corn syrup (a mixture of fructose and glucose) for sugar in their highly processed foods. As with sucrose, fructose is found naturally in many foods, and small to moderate intakes of fructose and high fructose corn syrup posed no health risks. However, large intakes of fructose and high fructose corn syrup in highly processed foods were found to increase the risk of obesity, diabetes, heart disease, and premature death.
  • Fructose and high fructose corn syrup then became the sugar villains. And because high fructose corn syrup is chemically and biologically indistinguishable from natural sugars like honey, date sugar, coconut sugar, it is likely that high intakes of these sugars in highly processed foods would cause the same problem.
  • So Big Food, Inc started relying on artificial sweeteners in their highly processed foods. But guess what? Artificial SweetenersRecent studies have suggested that artificial sweeteners in highly processed foods are associated with obesity, diabetes, and heart disease.
  • That has caused Big Food, Inc to rely more on sugar alcohols in their highly processed foods, particularly erythritol because it is the least expensive of the sugar alcohols. Now the current study comes along and suggests that high intake of erythritol in highly processed foods may increase the risk of heart disease.
  • If this hypothesis is confirmed by better designed studies, it is not clear what Big Food, Inc will do next. The metabolomic study described above showed that high blood levels of several other sugar alcohols are associated with an increased risk of heart disease.

Hopefully, you are starting to see a pattern here. It’s time to ask the question, “Is it the sweetener, or is it the food?”

Clearly, it doesn’t matter what sweetener we are talking about. Large intake of any natural sweetener in the context of a diet rich in highly processed foods appears to have an adverse effect on our health. And we don’t know whether these adverse health effects are caused by large amounts of a sweetener that is perfectly healthy in smaller amounts or some other component of the highly processed foods.

If you want to improve your health, the best solution is to decrease your intake of highly processed foods. That will automatically reduce your intake of sweeteners and other unhealthy components of highly processed foods and increase your intake of healthy components from the whole foods you will be eating instead. 

Who Should Be Concerned About Erythritol Intake?

The authors of this study identified two groups who should be most concerned about erythritol consumption – diabetics and adherents of the keto diet.

  • Diabetics are at high risk because they are told to consume non-caloric sweeteners instead of sugars, and they are not told to avoid highly processed foods. Consequently, they consume much higher amounts of non-caloric sweeteners than the average American.
  • I must admit that I didn’t foresee keto adherents as a group who would consume lots of erythritol. However, it appears that keto enthusiasts love their sweets as much as the rest of us, and the sweetener of choice for keto-friendly sweets is The authors said that a single serving of keto ice cream contains 30 grams of erythritol. I can hardly imagine how much erythritol they must be getting in their diet.

And, once again, the best advice for both groups is to simply decrease the amount of highly processed food in their diet.

The Bottom Line 

Erythritol is not an artificial sweetener. It is found naturally in healthy foods like grapes, peaches, pears, watermelons, and mushrooms. It is also found in some fermented foods like cheese, soy sauce, beer, sake, and wine.

It is also a byproduct of normal human metabolism, so we always have some of it circulating in our bloodstream. Our body knows how to handle erythritol in small amounts.

That is why it was a surprise when a recent study claimed that high intake of erythritol is associated with an increased risk of heart attack and stroke. The Dr. Strangeloves of the world are already starting to tell you that erythritol is deadly and you should avoid it at all costs. But reputable scientists are saying, “Not so fast”.

This is the first study to suggest an association between erythritol and heart disease, and it was a highly flawed study.

In fact, the study showed that low to moderate intakes of erythritol had no effect on heart disease risk. It was only the highest intake of erythritol that was associated with increased risk of heart disease. And given the distribution of erythritol in the American diet, the only way someone could take in that much erythritol is to consume large amounts of erythritol-sweetened highly processed foods.

A brief review of the literature on sweeteners reveals that this is a common pattern for every natural sweetener tested. Low to moderate intake of these sweeteners has no adverse health effects. However, high intake of every sweetener tested in the context of a highly processed food diet is associated with an increased risk of obesity, diabetes, heart disease, and premature death.

That raises the question, “Is it the sweetener, or is it the food?”

Clearly, it doesn’t matter what sweetener we are talking about. Large intake of any natural sweetener in the context of a diet rich in highly processed foods is likely to have an adverse effect on our health. And we don’t know whether these adverse health effects are caused by the sweetener or some other component of a highly processed food diet.

If you want to improve your health, the best solution is to decrease your intake of highly processed foods. That will automatically reduce your intake of sweeteners and other unhealthy components of highly processed foods and increase your intake of healthy components from the whole foods you will be eating instead.

For more details on the study and information about which foods are likely to contain erythritol and the population groups who should be most concerned about erythritol 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 text books for medical students.

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

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

Does Creatine Reduce Menopause Symptoms?

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What Does This Study Mean For You? 

Author: Dr. Stephen Chaney

Creatine has been used as a sports supplement for decades. It supports energy metabolism in muscle. And it is known to be both safe and effective for that purpose. For years we thought we knew everything we needed to know about creatine.

So why are there so many new creatine studies popping up in the news? That’s because we have learned that creatine also plays an important role in brain energy metabolism. As a result, scientists are exploring other applications of creatine supplementation. For example, in recent months I have reported on studies showing that creatine supplementation may:

  • Reduce the risk of Alzheimer’s Disease and dementia (link).
  • Improve recovery from traumatic brain injuries (link).
  • Reduce symptoms of sleep deprivation (link).

The effect of creatine supplementation is a new field, so most of these are small, proof of concept, studies that need to be confirmed by larger clinical trials. The study I am reporting on today is no different.

These investigators set out to determine whether creatine monohydrate had any effect on the neurocognitive symptoms associated with perimenopause and menopause (D Korovljev et al, Journal of the American Nutrition Association, 45(3): 199-210, 2026).

The study was also interesting because it utilized low doses of creatine monohydrate (750-1,500 mg/day). The usual sports nutrition dose for women is 3-5 gm/day. And most previous studies have used significantly higher doses for studies involving brain function.

How Was This Study Done?

clinical studyThe study enrolled 36 women experiencing either perimenopause (defined as women who were still menstruating but reported at least one neurocognitive symptom) or menopause (defined as women with no menstrual cycle for at least 12-months). The average age of the women was 50.1 years.

The women received different doses of creatine or a placebo for 8 weeks. (For purposes of simplification, I will simply report the data in terms of creatine supplementation versus placebo).

At the beginning and end of the study, the women used well-established reporting forms to quantify the intensity of common neurocognitive symptoms associated with perimenopause and menopause including:

  • Mood swings.
  • “Brain fog” – measured as reaction time, processing speed, alertness, and executive control.

The investigators also measured creatine levels in the frontal region of the brain.

Does Creatine Reduce Menopause Symptoms?

The results were as follows:

  • Creatine supplementation increased frontal brain creatine levels by 16.4% compared to a 0.9% increase in the placebo group.
  • Creatine supplementation enhanced reaction time by 6.6% compared to a 1.2% increase in the placebo group.
  • Creatine supplementation also increased alertness, processing speed, and executive control compared to the placebo, but the results were not as significant as for reaction time.
  • Creatine supplementation reduced mood swings and concentration difficulties compared to the placebo.
  • Sorry, but there was no significant reduction in hot flashes.
  • The supplementation was well tolerated, with no severe adverse side effects reported.

The authors concluded, “Our findings suggest that this supplementation protocol may be a promising, safe, effective, and practical dietary strategy for improving clinical outcomes and elevating brain creatine levels in perimenopausal and menopausal women.”

What Does This Study Mean For You?

Questioning WomanAs I said above, this is a small, proof of concept, study. In case you were wondering, “proof of concept” simply means the study shows that the hypothesis [in this case creatine reduces perimenopause and menopause symptoms] may work and is worth further studies.

In practical terms it means the investigators have evidence they can use to secure funding for a much larger study to prove or disprove their hypothesis.

What does this mean for you? The answer is that it depends…

  • If the therapy is expensive and has unknown side effects, the best advice is to wait until large-scale studies have been performed establishing that the therapy is safe and effective.
  • In this case, however, the safety of creatine supplementation is well established. So, if you are experiencing severe perimenopause or menopause symptoms, especially mood swings and brain fog, there is little risk to giving creatine supplementation a try. And if you exercise on a regular basis, you might just experience some side benefits.

The dosage used in this study is interesting. Normally, much higher doses have to be used to affect brain function because creatine does not cross the blood-brain barrier easily. However, women have 20-30% lower dietary creatine intakes and lower brain creatine synthesis rates than men.

Plus, the loss of estrogen during perimenopause and menopause is associated with a further decline in brain creatine levels. So, the brains of menopausal women may be primed to take up creatine more efficiently.

In addition, the creatine dosages used in this study are significantly less than the 3-5 grams/day recommended for women who wish to improve exercise efficiency.

The Bottom Line

A recent study suggested that low dose creatine supplementation may be useful for reducing the mood swings and brain fog associated with perimenopause and menopause.

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

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

 _____________________________________________________________________________

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

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

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

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

 _____________________________________________________________________

About The Author 

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

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

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

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

Can DHA Cut Your Risk Of Alzheimer’s In Half?

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How Do You Increase Your DHA Levels?

Author: Dr. Stephen Chaney

Dementia-WomanAs our population ages, the incidence of Alzheimer’s Disease is increasing along with it.

  • Currently an estimated 7.4 million Americans age 65 and older are living with Alzheimer’s.
  • And the number of Americans with Alzheimer’s is expected to double by 2060.

And the cost of Alzheimer’s is high!

  • The health-care cost of Alzheimer’s was estimated to be $355 billion last year and is increasing each year.
  • That doesn’t include lost time and wages by family members involved in taking care of a relative with Alzheimer’s.

But the highest cost is to the Alzheimer’s patients. I can’t imagine how difficult it must be to be surrounded by friends and family and not be able to recognize any of them. We expect our golden years to be golden. But what good is a healthy body, if you have lost your mind?

Worse yet, we have no effective drugs for preventing or treating Alzheimer’s.

We know that lifestyle changes can reduce our risk of Alzheimer’s and other forms of dementia. These include:

  • A primarily plant-based diet like the MIND diet.
  • A good fitness program.
  • Maintaining a healthy weight.
  • Keeping blood pressure and blood sugar under control.

If we do all those things, we can dramatically reduce the risk of Alzheimer’s. The problem is that each of them has only a small effect by themselves. And that’s a lot of changes for the average American to master!

What if there were one thing that dramatically reduced our risk of Alzheimer’s and was simple to implement. A recent study (A Sala-Vila et al, Nutrients, 14, 2408, 2022) has suggested that one thing might be DHA. It’s that study I’m going to be talking about today.

How Was This Study Done?

clinical studyThe investigators used data from the Framingham Offspring Study, which consists of children of participants in the original Framingham Study and their spouses. Data is collected every 4 years from participants in this study with a goal of identifying risk factors for diseases.

Participants in the Framingham Offspring Study were first tested for the DHA content of their red blood cells (the most accurate measure of DHA status) between 2005 and 2008. The study I am reporting on today consisted of 1,490 participants in the Framingham Offspring Study who had RBC DHA measurements, no diagnosed dementia, were 65 or older at the beginning of the study, and whose APOE genotype had been measured (APOE-ɛ4 is a risk factor for Alzheimer’s).

These participants were followed through 2018 (an average of 7.2 years) and were screened regularly for a diagnosis of Alzheimer’s Disease or other forms of dementia using a rigorous set of criteria.

DHA levels were divided into quintiles, and the risk of developing Alzheimer’s or dementia was compared for those in the highest quintile of RBC DHA to those in the lowest quintile of RBC DHA. These data were corrected for non-modifiable risk factors (age, sex, and APOE-ɛ4 status), diabetes status, and cardiovascular disease.

Can DHA Cut Your Risk Of Alzheimer’s In Half?

scissors icon isolated on white

When the investigators compared participants in the highest RBC DHA quintile (DHA >6.1% of RBC fatty acids) to participants in the lowest RBC DHA quintile (DHA < 3.8% of RBC fatty acids),

  • DHA reduced the risk of Alzheimer’s by 49%.
    • This corresponds to a gain of 4.65 Alzheimer’s-free years.
    • The author’s estimated this would lead to an additional 2.7 years of life and would save around $500,000 in health care costs.
  • DHA reduced the risk of all-cause dementia by 44%.
    • This corresponds to a gain of 4.03 dementia-free years.

The effect of DHA on Alzheimer’s and Dementia risk for participants carrying the APOE-ɛ4 gene was even more dramatic.

  • Participants in the highest DHA quintile gained 7.59 Alzheimer’s-free years and &.30 dementia-free years.

The authors concluded, “In a cohort of dementia-free participants from the Framingham Offspring Study aged 65 years and older, we observed that those with a baseline RBC DHA proportion above 6.1% (the top quintile) had nearly half the risk of developing Alzheimer’s Disease (and all-cause dementia), and had an estimated 4.7 extra years of life free from Alzheimer’s Disease compared with below 3.8% (bottom quintile.”

“In addition, we observed a trend for a stronger association between RBC DHA and risk for dementia in APOE-ɛ4 gene carriers, a finding that needs further research.”

“Our results, which concur with a growing foundation of experimental research, suggests that an increased DHA intake may be a safe and cost-effective strategy in preventing Alzheimer’s Disease in specific populations.”

The authors also said, “Our results imply that certain people may benefit from DHA-based interventions than others.” The people who would benefit the most would be:

  • Those with low DHA status.
  • Those carrying the APOE-ɛ4 [Note: This observation requires further research.]

How Do You Increase Your DHA Levels? 

Questioning WomanNow you know that optimal levels of DHA in your cell membranes may significantly reduce your risk of Alzheimer’s and dementia, there are only two questions:

#1: What is your DHA status? My recommendation is to start with an OmegaQuant test. It is not a standard test, but your doctor can order it for you. You are aiming for:

  • An Omega-3 Index of 8% or greater for heart health.
  • DHA levels of 6% or more for brain health.

If your values are low, the test will give you suggestions for optimizing your status.

#2: How do you increase your DHA levels? Here the recommendations are a bit more complex.

  • DHA is an essential fatty acid, so our bodies can’t make.
  • Our bodies can convert EPA to DHA, but the efficiency of that reaction is around 2%.

So, that means diet and supplementation are the only ways to increase DHA levels. But that is not as simple as it seems.

  • Most omega-3-rich foods and omega-3 supplements contain more EPA than DHA. For example:
  • In wild herring, the EPA to DHA ratio ranges from 1.2:1 to 1.7:1
  • In most fish oil supplements, the EPA to DHA ratio ranges from 1.5:1 to 3.2:1.
  • These are great for the heart, but not optimal for the brain.

If you want to focus on brain health, my recommendation is to balance omega-3-rich foods and fish oil supplements with a vegan omega-3 supplement made from algal oil. They usually have DHA:EPA ratios ranging from 3:1 to 4:1 unless the algae have been genetically modified.

Finally, you will want to repeat the OmegaQuant test every 6 to 12 months and modify your DHA and EPA intake until you have reached your target.

And don’t forget to add as many as you can of the modifiable lifestyle changes that decrease the risk of Alzheimer’s and dementia. Things like:

  • A primarily plant-based diet like the MIND diet.
  • A good fitness program.
  • Maintaining a healthy weight.
  • Keeping blood pressure and blood sugar under control.

Supplementation is never the total answer.

The Bottom Line

A recent study showed that optimizing your DHA status may:

  • Decrease your risk of developing Alzheimer’s Disease by 49% and all-cause dementia by 44%
  • The protection may be strongest for people who currently have low DHA status and/or are genetically predisposed to Alzheimer’s.

For more information on this study and how you can raise your DHA status, 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 .

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

Can You Build Muscle in Your Golden Years?

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What Does It Take to Build Muscle in Your 80s?

Author: Dr. Stephen Chaney 

As we age it becomes harder to build muscle, so we start to lose muscle mass and strength, a physiological process called sarcopenia. In previous issues of “Health Tips From the Professor” I have shared studies showing it is possible to slow, and even reverse, age-related loss of muscle mass in our 60’s and 70’s with the correct combination of resistance exercise, protein, and leucine.

But what about those of us in our 80s? Here recent studies have not been as reassuring. The results have been mixed, with some studies suggesting it is impossible to maintain muscle mass in our 80s.

But we know that it is possible for some people to maintain their muscle mass and accomplish incredible physical feats in their 80s. For example, those of you who are my age or older may remember Jack LaLanne, the so-called “Father of the Fitness Movement” who had a popular fitness show on TV from 1953 to 1985. He celebrated his 80th birthday by swimming one and a half miles in the Long Beach harbor towing 80 rowboats with 80 people in them.

Was Jack LaLanne a “freak of nature” or was it his incredible dedication and focus that allowed him to perform incredible physical feats in his 80’s? After all:

  • He ate only whole, unprocessed foods. He did not allow processed foods, fast foods, or convenience foods to cross his lips.
  • He did two hours of high-intensity workouts every day until the day before he died at age 96 in 2011.

More important is the question of what his physical feats mean for us. Does his example hold out hopes for all of us who wish to maintain our strength and vigor until the Lord calls us home? Or did he set a standard too high for mere mortals like us to achieve?

That is essentially the question that today’s study (GN Marzuca-Nassr et al, International Journal of Sports Nutrition and Exercise Metabolism, 34: 11-19, 2024) set out to answer.

The authors postulated that previous studies with subjects in their 80s came up short because they included infirm subjects in their studies and/or the intensity of exercise was too low. This study was designed to overcome those shortcomings.

How Was This Study Done?

clinical studyThe investigators recruited 29 healthy, elderly adults (9 men and 20 women) who were either 65-75 (average age = 68) or over 85 (average age = 87) who were still living in the community rather than being institutionalized for health reasons. The average BMI was 26.4 (moderately overweight) for both groups.

The participants selected for the study had not engaged in any kind of regular resistance training in the previous 6 months. The study excluded individuals with any kind of heart disease, health conditions, or physical limitations that would prevent them from participating in the resistance exercise training program associated with this study.

Participants were asked to fill in a three-day dietary recall at the beginning and end of the study. They were asked not to change their habitual dietary intake or physical activity during the study The diet recall at the end of the study showed compliance with this request. Their dietary intake was calculated based on the average of the two diet recalls.

No significant difference in macronutrient content of the diet was found between groups. For example, the 65-75 group consumed 1.1 g of protein/kg of body weight/day, and the over 85 group consumed 1.2 g of protein/kg of body weight/day.

Both groups were enrolled in a 3-times/week resistance exercise program for 12 weeks. The exercise training program was designed as follows:

  • Warm up consisted of 5-minutes on a cycle ergometer followed by full range of motion upper limb movements and one warm up set on both leg press and leg extension machines.
  • This was followed by 4 sets on the leg press and leg extension machines and 2 sets of upper body exercises (chest press, lat pulldown, and horizontal row).
  • Cool-down consisted of 5 minutes of stretching exercises.

Just prior to the study, the maximum strength on each exercise machine was determined for each participant. The intensity of their workouts was increased from 60% to 80% of that maximum over the 12 weeks of exercise training.

The outcomes of the study were as follows:

  • Quadriceps (the muscles on the front of the thigh) cross-sectional area was measured at the beginning and end of the study.
  • Whole body lean mass and appendicular lean mass (The lean mass in legs and arms) were measured at the beginning and end of the study.
  • The maximum strength for one repetition on each exercise machine was measured at the beginning and end of the study.

The increase in quadriceps cross-sectional area, lean mass, and strength was compared for the 65-75 group and the over 85 group.

Can You Build Muscle In Your Golden Years? 

Frail ElderlyAt the beginning of the study, the over 85 age group scored lower in every category measured in this study. For example:

  • Quadriceps cross-sectional area was 7% less in the over 85 age group than in the 65-75 age group.
  • Leg extension strength was 10% less in the over 85 age group than in the 65-75 age group.

This loss of muscle mass and strength is to be expected. Although the over 85 age group was consuming enough protein, they were not exercising on a regular basis. Consequently, they were experiencing sarcopenia, age-related loss of muscle mass.

The results of this 12-week resistance exercise intervention were impressive.

  • Quadriceps cross-sectional area increased by 10% in the 65-75 age group and by 11% in the over 85 age group.
    • Quadriceps cross sectional area increased for everyone in the study, but the increase varied widely from individual to individual.
    • The increase varied from 1% to 18% in the 65-75 age group and from 6% to 21% in the over 85 age group.
  • Whole body lean muscle mass increased by 2% in both the 65-75 and over 85 age groups.
  • Appendicular lean muscle mass (lean muscle mass in the arms and legs) also increased by 2% in both groups.
  • Leg extension strength increased by 38% in the 65-75 age group and by 46% in the over 85 age group.
    • Once again, the increase in leg extension strength varied considerably from individual to individual. The increase varied from 5% to 76% in the 65-75 age group and from 26% to 70% in the over 85 age group.
  • Similar results were seen for leg press, lat pull down, chest press, horizontal row, and grip strength.

The authors concluded, “Prolonged [12 week] high intensity resistance exercise training increases muscle mass, strength, and physical performance in the aging population, with no differences between 65-75 and 85+ adults. The skeletal muscle adaptive response to resistance exercise training is preserved even in male and female adults older than 85 years.”

What Does It Take To Build Muscle In Your 80s?

Why did this study show the benefit of resistance exercise for building muscle mass in octogenarians when previous studies have come up short? The authors postulated this was due to differences in the subjects included in the study and the intensity, frequency, and duration of resistance exercise.

  • This study included only healthy, community dwelling seniors who could engage in a rigorous training program. Some previous studies included institutionalized seniors who may have been less healthy and frailer.
  • The resistance exercise training used in this study involved multiple sets on exercise machines three times a week at 60-80% of maximum intensity for a total of 12 weeks. Previous studies included 1-2 sets, once or twice a week, at lower intensity, and for a shorter duration.

Much more research needs to be done, but the take-home lessons appear to be:

  • It is possible to increase muscle mass in your 80s with sufficient protein and a sufficiently intense resistance exercise program.
  • Not every 80-year-old adult will be able to increase their muscle mass. At the very least, this and previous studies suggest that frail, institutionalized men and women in their 80s may not be able to increase their muscle mass.
    • Whether this is because their health conditions interfere with their muscle’s ability to build muscle, or they are simply unable to perform the high intensity exercises required to build muscle mass in their 80’s is unclear. More research is needed.
    • While everyone in this study increased muscle mass and strength, the increase varied widely from individual to individual (see above).

My guess is that some of the people in the study did not get enough protein in their diet to support an increase in muscle mass at 85 and older. The over 85 group averaged 1.2 gm of protein/kg body weight/day, but their intake ranged from 0.8gm/kg/day to 1.6 gm/kg/day.

However, the difference in gain of muscle mass and strength could have been due to almost anything. Unfortunately, this study was too small to reliably determine what caused the differences in response to the resistance training.

  • It may require a high intensity resistance exercise program to increase muscle mass in your 80s. Unfortunately, there are very few studies like this for people in their 80s. All we know is that this was a high intensity, high frequency, and long duration resistance exercise program, and it worked. Studies with lower intensity exercise programs have not worked. But nobody has done a study comparing the effectiveness of different intensity exercise programs for people in their 80s.
  • There are too few studies on what it takes for people in their 80s and beyond to stay fit and healthy. The authors of this report argued that this information is vital for guiding government programs designed to support an aging population. It is equally important for all of us who want to remain fit and healthy in our 80s and beyond.

What Does This Study Mean For You?

good news bad newsIn my previous “Health Tips From the Professor” I have discussed multiple studies looking at sarcopenia or age-related muscle loss.

The bad news is that we start losing muscle mass and strength around age 50, and the rate of decline starts to accelerate in our 60s and beyond. This is a normal part of aging. It affects all of us. And if left unchecked, it can have devastating effects on our quality of life in our golden years.

The good news is that we can slow and even reverse the age-related loss of muscle mass by a combination of adequate intake of protein, adequate intake of the essential amino acid leucine, and resistance exercise. Leucine intake is usually adequate when we rely on animal proteins as our main protein source but may be a concern if we rely primarily on plant proteins. So, let’s take a deeper look at protein and exercise requirements.

1) We need more protein to build muscle in our golden years than we did in our 30s. If you want more information on the studies supporting that statement, go to https://chaneyhealth.com/healthtips/ and type sarcopenia in the search box. Most experts in this field of study recommend around 1.2 gm of protein/kg of body weight/day rather than the RDA of 0.8 gm of protein/kg of body weight/day for people 65 or older who wish to maintain or increase muscle mass. This study suggests that 1.2 gm/kg/day is also sufficient for people who are 85 and older. 

Previous studies have shown that the protein is best utilized to preserve muscle mass when it is spread evenly throughout the day. That is a concern because many seniors get most of their protein in the evening meal. An article I shared recently showed that adding 20 grams of supplemental protein to the low-protein meals (typically breakfast and/or lunch) was sufficient to balance protein intake and minimize age-related muscle loss.

[Note: To help you with the calculations, 1.2 gm of protein/kg of body weight/day is equal to 0.54 gm of protein/pound of body weight/day. Some quick calculations show that amounts to 78 grams if you weigh 140, 95 grams if you weigh 170, and 112 grams if you weigh 200. Or to simplify, that amounts to 25-30 grams of protein/meal for most people – more if you weigh above 170 pounds.]

2) We need a higher intensity of resistance exercise to build muscle in our golden years than we did in our 30s. Several previous studies have hinted at that possibility. This study shows that a high intensity resistance exercise program is effective at building muscle mass for people 85 and above. Previous studies suggest that lower intensity exercise programs are not effective in this age group. 

This is an important finding because it is opposite to the usual recommendations for this age group. In the words of the authors, “At an advanced age, people are generally recommended to partake in low-intensive physical activities. We strongly advocate that resistance exercise should be promoted without restriction to support more active, healthy aging.”

Of course, the caveat is that this study excluded frail, institutionalized adults and people with health or physical limitations that would prevent them from participating in a high-intensity resistance exercise program.

So, here are my recommendations:

  • Discuss your desire to implement a high intensity resistance exercise program with your health professional. Ask them about any health issues or physical limitations that would affect the exercises you choose.
  • Ask your health professional to refer you to a physical therapist or personal trainer to design a high-intensity exercise program you can do at home that is appropriate to your health and physical condition. If the referral comes from your health professional, these sessions may be covered by insurance.
  • If you want to utilize the exercise equipment in a gym, start by having a personal trainer knowledgeable about working with people like you design a workout program for you. My personal preference is to continue working with a personal trainer who challenges me to maximize the intensity of my training while taking into account any temporary physical limitations I may be experiencing.

Finally, I recognize that the exercise program described in this study may be too intense for many of my readers. But I also suspect that none of you want to become so frail you can’t enjoy your golden years. So, do what you can. But do something.

The Bottom Line

Most Americans lose lean muscle mass as they age, a physiological process called sarcopenia. This loss of muscle mass leads to reduced mobility, a tendency to fall (which often leads to debilitating bone fractures) and a lower metabolic rate – which leads to obesity and all the illnesses that go along with obesity.

Fortunately, sarcopenia is not an inevitable consequence of aging. There are 3 things we can do to prevent it.

  • Optimize resistance exercise training.
  • Optimize protein intake.
  • Optimize leucine intake.

This week I reviewed an article that compared the effectiveness of a 12-week high intensity resistance exercise program for increasing muscle mass and strength with people in the 65-75 age group with those who were age 85 and above.

The results of this 12-week resistance exercise intervention were impressive.

  • Quadriceps cross-sectional area increased by 10% in the 65-75 age group and by 11% in the over 85 age group.
  • Whole body lean muscle mass increased by 2% in both the 65-75 and over 85 age groups.
  • Leg extension strength increased by 38% in the 65-75 age group and by 46% in the over 85 age group.
  • Similar results were seen for leg press, lat pull down, chest press, horizontal row, and grip strength.

The authors concluded, “Prolonged [12 week] high intensity resistance exercise training increases muscle mass, strength, and physical performance in the aging population, with no differences between 65-75 and 85+ adults. The skeletal muscle adaptive response to resistance exercise training is preserved even in male and female adults older than 65 years.”

“At an advanced age, people are generally recommended to partake in low-intensive physical activities. We strongly advocate that resistance exercise should be promoted without restriction to support more active, healthy aging.”

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

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

_____________________________________________________________________________

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

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

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

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

 _______________________________________________________________________

About The Author 

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

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

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

Can High Protein Diets Reduce Testosterone?

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What Does This Study Mean For You?

Author: Dr. Stephen Chaney

protein foodsProtein is in the news. Recent studies have shown that our need for protein increases as we age. And the latest USDA Dietary Guidelines are telling us that all of us should substantially increase our protein intake.

When you add protein to the diet, you need to remove something. So, many of these diets are lower in carbohydrate. And many people are choosing the high protein versions of low carb diets for “health” reasons. For example:

  • High protein, low carb diets have become popular for weight loss.
  • And in our society, high protein diets are considered a good thing. We associate protein consumption with strength, energy, and virility. So, many athletes also include high protein, low carb diets as part of their training regimen.

Are high protein, low carb diets the best choice? Perhaps not, if the latest study is correct. This study (J Whittaker and M Harris, Nutrition And Health, 1-12, March 2022) claims that high protein, low carb diets decrease testosterone levels.

So, you are probably wondering, “Is this claim accurate?” To answer this question, I will evaluate the study and put it into perspective for you.

How Was This Study Done?

clinical studyThis study was a meta-analysis of 27 studies with a total of 309 participants looking at the effect of low carb diets on cortisol and testosterone levels. The participants were young (average age = 27.3), healthy, non-obese (BMI = 24.8), active males.

The selection criteria for studies included in the meta-analysis were:

  • Measurements of resting and post-exercise cortisol and testosterone levels. For simplicity, I will focus only on the testosterone results for this discussion.
  • Young, healthy male participants to minimize variation in steroid hormone metabolism due to age, sex, or disease.
  • Comparison of a low carb, high protein (average = 18% carb, 49% protein) and high carb, moderate protein diets (average = 58% carbohydrate, 23% protein).
  • Elimination of studies containing confounding variables that might affect steroid hormone metabolism such as:
    • Weight change of more than 6 pounds
    • Use of hormones, phytoestrogens, or medications.

In analyzing the data, they also compared:

  • Duration of <3 weeks or longer because it takes about 3 weeks for the body to fully adapt to ketone body utilization.
  • Moderate protein (average intake = 23.1% of calories) versus high protein (average intake = 48.8% of calories) intake. [Note: For comparison, the average protein intake for adults in this country is ~16%, with some experts recommending 17-21% to prevent weight loss as we age.] 

Can High Protein Diets Reduce Testosterone?

ProfessorThis study looked at the effect of low carb, high protein diets on both resting and post-exercise testosterone levels.

  • Moderate protein (23% of calories), high carb diets had no consistent effect on either resting or post-exercise testosterone levels.
  • However, high protein, low carb diets reduced both resting and post-exercise testosterone levels.
  • The effect on resting testosterone was highly significant. High-protein, low carb diets caused a 37% decrease in resting testosterone levels.
  • The effect on post-exercise testosterone was smaller, but still significant.

In the words of the authors, “High-protein, low carb diets greatly decreased resting and post-exercise total testosterone…Individuals consuming such diets may need to be cautious about adverse endocrine effects.”

Is There A Good Metabolic Rationale For These Results?

Question MarkAs a biochemist, I always like to look at whether there is a metabolic rationale for the results. And there is a good metabolic rationale for the effect of high protein diets on testosterone levels:

  • When protein is metabolized ammonia is released, and excess ammonia is toxic.
  • To combat ammonia toxicity the body has a metabolic pathway called the urea cycle. It removes ammonia from the bloodstream and converts it to urea, which is excreted in the urine.
  • The ability of the urea cycle to remove ammonia from the bloodstream is limited. High protein intakes can overwhelm the ability of the urea cycle to remove ammonia. This typically occurs when protein intake exceeds 35% of calories.
  • In situations like this, the body produces cortisol, and cortisol upregulates the urea cycle so it can handle the excess ammonia.
  • For reasons that aren’t entirely clear, cortisol and testosterone are regulated oppositely. Whenever cortisol goes up, testosterone goes down.

To be clear, I am not saying this is what is happening. I am merely saying this is a plausible mechanism for explaining the fall in testosterone levels on a high protein diet, and many popular low carb diets are also high protein diets.

It could equally well represent a side effect of long-term ketosis. Ketosis was meant as a survival mechanism for short-term starvation. We have no idea what the potential effects of long-term ketosis might be.

What Does This Study Mean For You?

ConfusionIn previous articles in “Health Tips From the Professor” I have expressed skepticism about studies that have excellent experimental design but do not have a plausible metabolic rationale.

This week’s study is the opposite. It has an excellent metabolic rationale, but the study is weak. Specifically, the meta-analysis only included 309 subjects, and several of the individual studies included in the meta-analysis were weak.

The authors considered this as a hypothesis-generating study. The authors went on to say this study shows where we should focus our attention in future studies, namely on the possible health consequences of high protein, low carb diets.

I agree. I am not ready to tell you unequivocally that high protein, low carb diets will lower your testosterone levels.

However, if you are consuming a high protein, low carb diet for either weight loss or because you are a body builder or weightlifter, this study is a potential red flag. It is not a definitive study, but the results are metabolically plausible. They might just be true.

You should also keep in mind that all the “benefits” of high protein, low carb diets are based on short-term studies. There are no long-term studies on the benefits and risks of high protein, low carb diets. There is also no historical precedent for life-long adherence to a high protein, low carb diet.

  • We are omnivores. Our ancestors ate whatever nature provided. There were times when our paleolithic ancestors ate high protein, low carb meals, but it is unlikely any of them had the luxury of eating that way for a lifetime. That is a 21st century luxury.
  • If you plan to consume a high protein, low carb diet for an extended period, you are part of an uncontrolled experiment with an uncertain outcome.

In case you were wondering whether this applies to any high protein (>35% of calories from protein), diet which exceeds the ability of the urea cyclic to remove a toxic byproduct of protein metabolism, the answer is “We don’t know”. However, the typical American diet is around 55% carbohydrate and 20-35% fat. It would be extremely difficult to exceed 35% protein without significantly reducing carbohydrate intake. 

The Bottom Line

A recent study looked at the effect of high protein, low carb diets on testosterone levels. It found:

  • Moderate protein, high carb diets, like the typical American diet, had no consistent effect on either resting or post-exercise testosterone levels.
  • However, high protein, low carb diets reduced both resting and post-exercise testosterone levels.
  • The effect on resting testosterone was highly significant. High-protein, low carb diets caused a 37% decrease in resting testosterone levels.
  • The effect on post-exercise testosterone was smaller, but still significant.

In the words of the authors, “High-protein, low carb diets greatly decreased resting and post-exercise total testosterone…Individuals consuming such diets may need to be cautious about adverse endocrine effects.”

I am not ready to tell you unequivocally that high protein, low carb diets will lower your testosterone levels.

However, if you are consuming a high protein, low carb diet for either weight loss or because you are a body builder or weightlifter, this study is a potential red flag. It is not a definitive study, but the results are metabolically plausible. They might just be true.

You should also keep in mind that all the “benefits” of high protein, low carb diets are based on short-term studies. There are no long-term studies on the benefits and risks of high protein, low carb diets. There is also no historical precedent for life-long adherence to a high protein, low carb diet.

If you plan to consume a high protein, low carb diet for an extended period, you are part of an uncontrolled experiment with an uncertain outcome.

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 Creatine Safety Myth

by

Why Are Placebo Controls Important?

Author: Dr. Stephen Chaney 

The FDA considers creatine monohydrate as GRAS (Generally Recognized as Safe). The International Society For Sports Nutrition, the International Olympic Committee, the NCAA, and professional sports associations all consider creatine to be safe, effective, and legal.

So, why do you keep hearing things on social media like:

  • “Creatine stresses your kidneys. It can damage your kidneys.”
  • “Creatine causes muscle cramping. It can damage your muscles.”
  • “Creatine causes dehydration and heat intolerance. It can cause heat stroke and seizures.”
  • “Creatine causes bloating, nausea, stomachaches, and diarrhea. You will feel terrible.”
  • “Creatine causes you to gain weight. It will make you fat.”

So, the question becomes, are the government and sports authorities lying to us, or are the reports of creatine dangers simply food myths?”

To answer this question a group of sports nutrition experts recently conducted a comprehensive review of all previous placebo-controlled studies of creatine side effects (DE Gonzalez et al, Sports, 14, 137, 2026).

danger symbolIn the words of the authors, “Collectively, the available evidence does not support many of the negative claims commonly attributed to the use of creatine monohydrate; however, these myths and misconceptions continue to persist among the general public and have even influenced policy and legislative discussions…

…Accordingly, the purpose of the present analysis was to directly address these concerns by systematically evaluating whether total creatine monohydrate dose or duration predicts the likelihood of side effects, thereby providing a more granular and clinically relevant assessment of creatine monohydate safety.”

I was particularly interested in this study because, among other things, they looked at the dose dependence of creatine side effects – including doses as high as 38 g/day.

That was of interest to me because I had recently reviewed a study looking at the ability of creatine supplementation to clear up the brain fog associated with sleep deprivation.

That was information that might be useful for anyone who is suffering from sleep deprivation but can’t tolerate caffeine. However, the dose of creatine that was most effective at clearing up the brain fog associated with sleep deprivation was 20-30 grams depending on body weight. That’s much higher than the usual recommended dose of 5 g/day, and I wasn’t certain about the safety of such a high dose.

I was hoping that this study would answer that question for me. And it did.

How Was This Study Done?

clinical studyThe investigators used all available databases to search for creatine studies in humans that included a record of side effects and were placebo controlled. They excluded reviews and meta-analyses to avoid duplication.

They ended up with 684 randomized placebo-controlled clinical trials with 12,800 human subjects.

The dose of creatine monohydrate used in these studies ranged from 2 gm/day to 38 gm/day. And the duration of supplementation ranged from 3 days to 14 years. For both dose and duration, the studies were divided into thirds – a lower third, a middle third, and an upper third.

The investigators assessed the frequency of 35 possible side effects in each dose and duration category. Finally, the data were adjusted for biological sex, age, fitness level, and health status.

Does Creatine Cause Side Effects?

The results were as follows:

  • Reported side effects increased slightly with dose. When they looked at the percentage of side effects reported by participants in the upper third for dosage:
    • 16.4% of participants reported gastrointestinal issues (bloating, stomachache, or diarrhea).
    • 6.2% of participants reported musculoskeletal issues (mainly muscle cramps).
    • 4.9% of participants reported neurological issues (mainly headaches).
    • 4.0% of participants reported sleep, fatigue, or appetite issues.
    • All other side effects were reported by less than 1% of participants. Most notably, renal (kidney) and liver side effects were almost non-existent.
  • Reported side effects also increased slightly with duration. When they looked at the percentage of side effects reported by participants in the upper third for duration of supplementation:
    • 14.9% of participants reported gastrointestinal issues.
    • 5.6% of participants reported musculoskeletal issues.
    • 4.2% of participants reported neurological issues.
    • 2.8% of participants reported sleep, fatigue, or appetite issues.
    • All other side effects were reported by less than 1% of participants.

At first glance, you might look at these data and say, “Aha! There are side effects to creatine supplementation, especially when used at high doses or for a long time.”

But the authors of the study pointed out:

  • The reported side effects in these studies were mild and short-lived.
    • The side effects were reported by a small subset of individuals, and in these cases
    • The gastrointestinal issues can usually be avoided by dividing the creatine dosage into two or three smaller amounts spaced out throughout the day.
    • The musculoskeletal issues can usually be avoided by keeping adequately hydrated.
    • The sleep and fatigue issues can usually be avoided by taking the creatine earlier in the day.

placeboBut there was one other factor that negated any concern about creatine side effects. All these studies were placebo controlled, and side effects in the placebo group were the same or greater than in the creatine group!

The authors concluded, “These findings suggest that creatine supplementation is safe across a range of doses, durations, and populations according to human trials. While higher total doses and longer supplementation periods are associated with more side effects at the study level, the overall incidence remains low, with most effects being mild and nonspecific.

Furthermore, placebo groups often report similar or even higher rates of side effects. These results reinforce the consensus on creatine’s safety and add nuance by considering exposure levels and duration”

Why Are Placebo Controls Important?

Question MarkThis study illustrates the importance of placebo-controlled studies.

  • Some studies report amazing benefits associated with certain foods or supplements. But without placebo controls, they are worthless.
  • Other studies report terrifying side effects associated with certain foods or supplements. But without placebo controls, they are worthless.

You may be wondering why people taking a placebo would experience side effects. In the context of this study, the answer is obvious.

  • Most people experience some sort of gastrointestinal distress on an occasional basis.
  • Everyone who works out has days when they experience muscle cramps.
  • Most people experience nights when they have trouble falling asleep and/or wake up feeling fatigued.

And in clinical studies like the ones included in this review, they will be looking for those symptoms. That’s because medical ethics requires that study participants be informed of the purpose of the study and any side effects they might experience. Before being included in the study they will need to sign an “informed consent” form that lists possible side effects. And during the study, they may be given a form where they can check off any side effects they experience.

And if the informed consent and check off forms happen to miss any side effect, the participants need only to go to the internet to learn all the dreadful things that could happen to them if they were to take a creatine supplement.

The Creatine Safety Myth 

Myth BusterThe FDA and sports authorities were right all along. Creatine is safe and effective.

Yes, some individuals may experience mild side effects, but those can be avoided by dividing up the dose, staying adequately hydrated, and/or changing the timing of creatine supplementation.

In short, the reports of dreadful side effects from creatine are just another food myth.

You might ask, “Where do food myths like this come from?” I have written two books on food myths called “Slaying the Food Myths” and “Slaying the Supplement Myths”, so I am an expert on that topic.

The short answer is that it all starts when a misleading claim is posted online. It usually emphasizes miraculous cures or deadly dangers in a very compelling manner. It is often based on a personal testimony and often references poorly designed studies. For example, the study might report side effects of creatine supplementation without a placebo control to serve as a reference point.

Or the online post might be purposely misleading. As the authors of this study pointed out that, “Much of the misinformation about creatine comes from companies and influencers who are promoting different types of creatine as more effective than creatine monohydrate with fewer side effects.” They are purposely misleading you for financial gain.

The misleading information is repeated online by people who like conspiracy theories and don’t know how to distinguish between reliable and unreliable sources. Once it has been repeated often enough, it becomes generally recognized as true. It becomes a food myth.

And, unfortunately, AI, unless used carefully, answers your queries based on the number of times a statement occurs online rather than on the accuracy of the statement.

In the words of the authors of this study, “Based on the current evidence, creatine is one of the most well-studied and well-tolerated dietary supplements. No consistent or clinically meaningful dose-dependent increases in side-effect reporting were observed across models; even at higher doses and prolonged durations, reporting remained low and largely comparable to placebo at the study level.

This analysis affirms previous findings on the overall safety of creatine supplementation and suggests that high-dose or longer-duration supplementation is well-tolerated by both clinical and athletic users.”

The Bottom Line 

The FDA considers creatine monohydrate as GRAS (Generally Recognized as Safe). The International Society For Sports Nutrition, the International Olympic Committee, the NCAA, and professional sports associations all consider creatine to be safe, effective, and legal.

But online articles abound claiming that creatine supplementation has dangerous side effects. So, the question becomes, are the government and sports authorities lying to us, or are the reports of creatine dangers simply food myths?”

To answer this question a group of sports nutrition experts recently conducted a comprehensive review of all previous placebo-controlled studies of creatine side effects.

This review confirmed previous findings on the overall safety of creatine supplementation and found that even high-dose or longer-duration supplementation is well-tolerated by both clinical and athletic users.”

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

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

 ___________________________________________________________________________

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

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

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

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

______________________________________________________________________

About The Author 

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

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

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

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

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

 

Does Meat Consumption Increase Disease Risk?

by

Is It Meat Or Something Else?

Author: Dr. Stephen Chaney 

ArgumentWe are told we should be consuming more protein. But where should we get our protein?

Meat is an obvious choice. But meat consumption is controversial. The arguments are intense.

There are those who claim that meat consumption, particularly red meat, increases our risk of cancer, heart disease, diabetes, and many other diseases. Others claim that meat has been maligned. It doesn’t increase disease risk. We should eat more of it, not less.

The problem is that both sides are basing their claims on published clinical studies. Studies on meat consumption and disease risk are all over the map.

I have covered this controversy in previous issues of “Health Tips From the Professor”. In attempting to make sense of the conflicting data I made the observation that studies showing meat consumption reduced disease risk tended to come from third world countries while studies showing meat consumption increased disease risk tended to come from high-income western countries.

So, my interest was peaked when I saw a very large study (K Papier et al, BMC Medicine,: 19:53, 2021) on meat consumption and disease risk in the UK.

How Was This Study Done?

clinical studyThe investigators used data from the UK Biobank Study, a study that recruited 503,317 young men and women throughout the UK between 2006 and 2010. Upon entry into the study participants completed questionnaires about physical data (height, weight, etc), biological data (blood sugar, cholesterol levels, etc.), and diet.

This particular study used data from a subset (474,985) participants who completed a 24-hour dietary recall questionnaire.

Participants were then linked to the National Health Service database to assess the first occurrence of the 25 leading non-cancerous causes of hospital admissions for each patient and followed for an average of 8 years.

Cancer admissions were excluded from this study because the International Agency for Research on Cancer (IARC), the cancer agency of the WHO, has already classified red meat as a probable carcinogen and processed meat as a likely carcinogen.

Does Meat Consumption Increase Disease Risk?

SteakThe investigators looked at four distinct categories of meat consumption (total meat, red meat, processed meat, and poultry) and the risk of 25 common diseases (excluding cancer). In each case, they divided meat consumption into quartiles and compared the disease risk for those in the highest quartile to those in the lowest quartile.

For the sake of simplicity, I will only report the most significant disease risks (those with p ≤001).

Total Meat Consumption (Lowest quartile = 1.2 oz/d; Highest quartile = 4.1 oz/d):

Disease Increased

Risk
Heart Disease 29%
Stroke 24%
Diverticular Disease 29%
Colon Polyps 14%
Diabetes 85%

Red Meat Consumption (Lowest quartile = 0.2 oz/d; Highest quartile = 2.0 oz/d):

Disease Increased

Risk
Heart Disease 25%
Stroke NS
Diverticular Disease 26%
Colon Polyps 11%
Diabetes 53%

Processed Meat Consumption (Lowest quartile = 0.15 oz/d; Highest quartile = 1.0 oz/d):

Disease Increased

Risk
Heart Disease 17%
Stroke 23%
Diverticular Disease 18%
Colon Polyps 11%
Diabetes 52%

Poultry Consumption (Lowest quartile = 1.2 oz/d; Highest quartile = 4.1 oz/d):

Disease Increased

Risk
Heart Disease 12%
Stroke NS
Diverticular Disease 18%
Colon Polyps 11%
Diabetes 32%
GERD 16%
Gastritis 10%

My evaluation of the data is:

  • These differences are highly significant (p <001) and the study size was very large (~475,000 participants), so the increased risk is probably true for a high-income Western country like the UK.
    • However, some of these differences are relatively small. It’s easy to understand how they might be missed in smaller studies.
    • Even increased risk in the 25-30% range might disappear in studies that combine data from high-income countries and third world countries.
    • With this perspective it is easy to understand why previous studies have been so confusing.
  • Because the investigators looked at the effect of each kind of meat separately, one can get a better idea of the relative contribution of each meat to various diseases [With, of course, the caveat that people who consume more red meat also tend to consume more processed meat and vice versa.] For example:
    • Red meat appears to contribute more to heart disease risk than processed meat or poultry – possibly due to its high saturated fat and cholesterol content.
    • Processed meat appears to contribute more to stroke risk than red meat or poultry – possibly due to added nitrates and other food additives.
    • All meats appear to contribute to diverticular disease – possibly due to a change in gut bacteria because meats replace plant foods in the diet.
  • The increased risk of GERD and gastritis associated with poultry consumption was surprising, but the increased risk was small.

The authors concluded, “Our findings from this large prospective study of British adults show that meat consumption is associated with higher risks of several common conditions but a lower risk of iron deficiency anemia…Additional research is needed to evaluate whether these differences in risk reflect causal relationships, and if so what proportion [of these outcomes] could be prevented by decreasing meat consumption.”

Is It Meat Or Something Else?

Question MarkOf course, the question, “Is it meat or something else in our diet that is causing the increased risk of disease?” One hint that something else might be contributing to disease risk came when the authors corrected the data for obesity. The results are shown below:

Total Meat Consumption Corrected For Obesity

Disease Increased

Risk

 Corrected

For Obesity
Heart Disease 29% 17%
Stroke 24% 22%
Diverticular Disease 29% 18%
Colon Polyps 14% 10%
Diabetes 85% 33%

Red Meat Consumption Corrected For Obesity

Disease Increased

Risk

 Corrected

For Obesity
Heart Disease 25% 16%
Stroke NS NS
Diverticular Disease 26% 17%
Colon Polyps 11% 8%
Diabetes 53% 21%

Processed Meat Consumption Corrected For Obesity

Disease Increased

Risk

 Corrected

For Obesity
Heart Disease 17% 9%
Stroke 23% 17%
Diverticular Disease 18% 17%
Colon Polyps 11% 8%
Diabetes 52% 24%

Poultry Consumption Corrected For Obesity

Disease Increased

Risk

 Corrected

For Obesity
Heart Disease 12% 8%
Stroke NS NS
Diverticular Disease 14% 10%
Colon Polyps 6% 7%
Diabetes 32% 14%
GERD 16% 17%
Gastritis 10% 12%

When corrected for obesity, the risk of:

  • Heart disease decreased by 33-47%.
  • Diverticular disease decreased by 23-38%.
  • Diabetes decreased by 54-61%.

But how do we interpret that? It would be easy to conclude that the influence of meat consumption on heart disease, diverticular disease, and diabetes is small. However, that’s not the real world. People aren’t meat eaters or overweight. In the real world, people are often meat eaters and overweight.

So, the important question to ask is why so many meat eaters are overweight.

  • It could simply be a question of calories. A serving of steak is around 680 calories, while a serving of beans is around 110 calories.
  • It could be what is eaten with the steak or beans. A medium baked potato with butter and sour cream adds 300-500 calories. A vegetable stir fry adds 170 calories.
  • It could be how we cook it. In our country over 50% of chicken we eat is fried. And to make matters worse, we often add French Fries and other highly processed foods to our fried chicken meal.

What Does This Study Mean For You?

confusionThis study shows that in a high-income western society like ours, meat consumption is likely to increase our risk of several diseases, For example:

  • Red meat is associated with increased risk of heart disease, diabetes, and diverticular disease.
  • Processed meat is associated with increased risk of stroke, diabetes, and diverticular disease.
  • Poultry consumption is associated with increased risk of diabetes and digestive diseases.
  • All three kinds of meat are associated with obesity.

While it is easy to blame meat consumption for all our ills, it may be how we cook it and what we eat along with it.

Perhaps we should eat our meat the way they do in Third World countries. Rather than eating it as a main course, perhaps we should use it as flavoring for a vegetable stir fry or a lentil stew.

The Bottom Line

A recent study looked at the association of meat consumption with disease risk in the UK. It found that:

  • Red meat is associated with increased risk of heart disease, diabetes, and diverticular disease.
  • Processed meat is associated with increased risk of stroke, diabetes, and diverticular disease.
  • Poultry consumption is associated with increased risk of diabetes and digestive diseases.
  • All three kinds of meat are associated with obesity.

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

Is Creatine Better Than Coffee For Sleep Deprivation?

by

The Effect Of Creatine On The Sleep-Deprived Brain 

Author: Dr. Stephen Chaney 

The role of creatine for muscle metabolism is well established. It has been used by athletes for years to optimize their exercise. It is both safe and effective for this purpose.

However, it’s use for optimizing brain function is more controversial. Clinical studies on this topic are conflicting. The problem is 3-fold:

  • Creatine does not cross the blood-brain barrier easily. So, the brain takes up creatine less efficiently than muscle.
  • Some people don’t need extra brain creatine. They make all they need.
  • There appears to be significant individual differences in the uptake of creatine into the brain and/or the effectiveness of creatine at improving brain function.

The authors of the article I am going to review summed up the existing research on creatine and brain function by saying:

  • Most healthy adults do not need extra creatine for brain function. Studies on healthy, non-stressed adults have typically shown no benefit of creatine supplementation.
  • However, there are several conditions that decrease brain creatine levels and/or increase brain energy needs, which creates a need for higher brain creatine levels. These conditions are:
    • Concussions and other forms of traumatic brain injury.
    • Alzheimer’s and other neurodegenerative diseases.
    • Hypoxia (reduced oxygen flow to the brain) caused by atherosclerotic narrowing of the carotid arteries, asthma, and COPD.
    • Depression.
    • Sleep deprivation.
  • Under these conditions, uptake of creatine into the brain appears to be enhanced, and creatine supplementation appears to improve brain function.

The authors of this study focused on sleep deprivation. Sleep deprivation differs from the other conditions listed above in that it is episodic rather than chronic. So, rather than using smaller doses daily, they tested the effect of a single, high dose administered during the sleep deprivation.

In a previous study they had shown that a very high dose of creatine was effective at increasing brain creatine levels by 5% and reducing the symptoms of sleep deprivation by 10-25%.

For this study (A Gordji-Nejad et al, Nutrients, 18: 192, 2026) they repeated their experiments using a lower dosage to determine whether the brain benefits of creatine during sleep deprivation are dose dependent.

What Is Creatine And What Does It Do?

confusionI have discussed this topic at depth in an article from a previous issue of “Health Tips From the Professor”, so I will give the Cliff Notes version here.

Creatine is a storage form of cellular energy.

  • In muscle the best analogy would be a car battery. When we start the car, the battery provides the initial energy to get the engine going. Then, when we are cruising down the highway the kinetic energy generated by the turning of the driveshaft is stored in the battery, so it is fully charged the next time we need to start the car.
  • In our muscles, creatine is the “battery” that provides the initial energy to get our muscles going. And when we are at rest, we recharge our creatine “battery”, so we are ready the next time we need to spring into action.
  • In our brain, our creatine “battery” provides the extra energy our brain needs when it is under stress due to any of the conditions listed above – including sleep deprivation.

In our car, eventually the battery wears out and needs to be replaced. Here the analogy breaks down. Creatine is constantly being converted to creatinine and flushed out of the body, so we need a constant supply of new creatine to keep our cellular creatine “batteries” charged.

  • Our muscles can’t make creatine, so they rely on creatine made by other tissues in the body, diets high in animal protein, and/or creatine supplements. And because it is dependent on exogenous creatine sources, it is very efficient at taking up creatine from the bloodstream. That is why creatine supplements are so effective at improving muscle function.
  • Our brain normally makes all the creatine it needs, so it is inefficient at taking creatine from the bloodstream. However, when the brain is under stress due to traumatic brain injury, neurodegenerative diseases, hypoxia, and sleep deprivation, its need for creatine is increased, and the efficiency of creatine uptake appears to be enhanced. Under these conditions, creatine supplements do appear to improve brain function.

How Was This Study Done?

clinical studyThe authors recruited 29 healthy subjects age 20-40 (average = 29) for the study.

  • 17 were female, 12 were male.
  • None of them reported sleep disorders, psychiatric or neurological conditions, or alcohol or drug abuse.
  • None of them smoked or took medication.

Consumption of caffeine and alcohol were prohibited for 48 hours prior to the study.

They were all well rested prior to the study. They were required to sleep for at least 7 hours every night for the previous two weeks and to record all sleep and awake times. The night before the study they were asked to go to bed by 11 PM and wake up at 7 AM.

The sleep-deprivation occurred over the next 21 hours. During this period the subjects were continuously observed to make sure they didn’t fall asleep. No exercise or cognitively stressful activity was allowed. The subjects were only allowed to drink water and eat non-protein snacks during the deprivation study.

The study was a double-blind, randomized clinical trial with a crossover design. In a crossover study each subject serves as their own control. In the first phase of the study each patient was given 0.09 g of creatine per pound of body weight or a placebo in a double-blind manner (neither the patient nor the investigators knew who got the creatine and who got the placebo). After two weeks at least 7 hours of sleep a night, the deprivation portion of the study was repeated except that what the subjects took was reversed (those who received creatine the first time received the placebo the second time and vice versa).

The subjects were given a battery of tests four times during sleep deprivation. At each occurrence the subjects completed self-assessments for sleepiness and fatigue. They then were given tests to measure the speed and accuracy of seven different measures of mental acuity. The design of the sleep deprivation portion of the study was as follows:

  • Sleep deprivation started at 7 AM.
  • Baseline assessment occurred at 6:30 PM (11.5 hours without sleep).
  • The subjects were given creatine or a placebo at 9 PM (14 hours without sleep).
  • Testing was repeated at 12 PM, 2 AM, and 4 AM (17, 19, and 21 hours without sleep).

The Effect Of Creatine On The Sleep-Deprived Brain

Safe and effective creatine intake is proportional to our body weight. That’s why the authors of this study reported creation dose as grams of creatine per pound of body weight. However, you are not used to seeing it expressed that way, so let me give you a table to help you understand what these numbers mean.

Creatine g/lb to grams per serving
g/lb 120 lb 140 lb 200 lb Comments
0.045g/lb 5 gm 7 gm 9 gm This is the daily intake range you see recommended most often.
0.09 g/lb 10 gm 14 gm 18 gm The amount used in this study. It has been shown to be safe and effective for muscle gain.
0.16 g/lb 19 gm 25 gm 30 gm The amount used in their previous study. Some athletes use this much, but it is not widely studied.

With that in mind, here are the results of the study.

  • Creatine supplementation at this dose was well tolerated. There were no reports of gastrointestinal distress or other adverse physical effects.
  • Creatine supplementation had no significant effect on self-reported sleepiness or fatigue.
  • Creatine improved several measures of cognitive performance during sleep deprivation by 6-12%.
    • The cognitive benefits were most evident for logic, numerical ability, processing speed in language tasks, and psychomotor vigilance.
      • Psychomotor vigilance is how well an individual can maintain attention over time. It is assessed by measuring how long it takes subjects to respond to visual stimuli at random intervals. It is an important cognitive function for activities like driving a car.
  • Women and vegetarians benefitted more than men.

The authors concluded, “Our results show a dose of 0.09g/lb creatine is associated with reduced deterioration in cognitive performance during sleep deprivation. Although the effect is less pronounced than with a high dose of 0.16 g/lb, there is still an improvement of up to 12%…

The decrease in improvement compared to high dose shows that cerebral cellular creatine uptake and the improvement effect during sleep deprivation are dose-dependent.

As the administered dose of 0.09 g/lb is [known to be] safe, future studies could focus on adding additional components or making modifications to increase cellular uptake and enhance the effect. Furthermore, the findings of our study provide a basis for further research to determine the specific dosage for different population groups.”

Is Creatine Better Than Coffee For Sleep Deprivation?

Question MarkLet’s return to the question I posed at the beginning of this article. You didn’t sleep a wink last night. Your brain is fuzzy. Should you reach for a cup of coffee? Or is creatine better than coffee for sleep deprivation?

There are two answers to this question.

The first answer is, “We don’t know”. Coffee has been around forever. Everyone “knows” it helps when we are sleep deprived. But it has never gone through the kind of rigorous testing that creatine was given in this study. And it has never been compared in head-to-head testing with creatine.

The cognitive benefits from creatine were modest, so it is likely that coffee is more effective – but we don’t know for sure.

The second answer is, “It depends”. There are many people who can’t or prefer not to drink coffee.

  • For some people coffee causes jitters, anxiety, and heart palpitations.
  • For others it causes gastrointestinal disturbances.
  • Some people prefer to avoid stimulants of any kind.
  • For many people coffee causes insomnia. And if you have had a sleepless night, the thing you want the most is restful sleep, not more insomnia.

And, if we are sleep deprived, it’s usually not just one cup of coffee. It’s several cups of coffee or one of those “monster drinks” with tons of caffeine. And regular consumption of these high-caffeine drinks is linked to all the issues listed above plus:

  • High blood pressure, cardiac events, severe headaches, and even kidney issues.

If you are someone with any of these concerns, it is useful to know that there is a non-stimulant alternative that can help you think more clearly when you are sleep deprived.

What Does This Study Mean For You?

Simply put, this study suggests that creatine may be an alternative to coffee and other caffeinated beverages when you are sleep deprived.

This study shows that a single dose of 10-20 grams of creatine, depending on your body weight, can give you a modest increase in mental clarity if taken while you are severely sleep deprived. While somewhat higher than the dosages most supplement companies recommend, this is well within the dose range that has been shown to be safe and effective for enhancing muscle function.

The authors of the study said that “Future studies could focus on adding additional components or making modifications to increase cellular uptake and enhance the effectiveness of creatine.

For muscle cells, insulin enhances the uptake of creatine. So, if creatine is taken with a meal that is high in carbohydrate, uptake may be increased by up to 60%. We don’t know whether insulin also increases creatine uptake in the brain, but until further research comes along it is worth a try.

Note: Studies also show that combining creatine with a shake that is high in both carbohydrate and protein after a workout optimizes both creatine uptake and muscle repair. In today’s world of low-carbohydrate protein shakes that is a paradigm shift!

In a previous study, the same authors showed that a single dose of 20-30 grams of creatine, depending on body weight, was even more effective at enhancing mental clarity during severe sleep deprivation. That is a dosage that has not been extensively tested.

Many athletes consume creatine dosages in that range with no apparent ill effects. However, athletes aren’t always the best examples of safe supplement use.

Whichever dose of creatine you choose, there are some cautions you should be aware of.

  • Creatinine, the breakdown product of creatine metabolism, puts some stress on the kidneys.
    • While this is not a problem if your kidneys are healthy, you should consult with your health professional about taking creatine if you have any indications of impaired kidney function.
  • Adequate hydration (preferably with water) is important because creatine pulls water with it as it enters your muscle cells.
    • This plumps up your muscles, which is great if you are a body builder.
    • This dehydrates you, which can cause side effects like muscle cramps, headaches, nausea, stomach cramps, and diarrhea.
    • These side effects are usually transitory and can be avoided or reduced by adequate hydration. If symptoms continue despite adequate hydration, you should lower the dose or discontinue creatine supplementation.

The Bottom Line

A recent study looked at whether a creatine supplement could help prevent the loss of cognitive function associated with severe sleep deprivation. The study showed:

  • Creatine improved several measures of cognitive performance during sleep deprivation.
  • The cognitive benefits were most evident for logic, numerical ability, processing speed in language tasks, and psychomotor vigilance.
  • Women and vegetarians benefitted more than men.
  • The effect was dose dependent.

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

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

_______________________________________________________________________________

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

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

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

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

 _______________________________________________________________________

About The Author 

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

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

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

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

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

Should Women Avoid Soy?

by

Why Is There So Much Confusion About Soy?

Author: Dr. Stephen Chaney

soyMother’s Day was last Sunday. We love the women in our lives and want to keep them happy and healthy. But what should we tell them about soy? Should women avoid soy? Or is it good for them? Is it something they should be including in their diet?

Unfortunately, there is a lot of confusion about soy. The key issue is, “What 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.”

Should Women Avoid Soy?

soy breast cancer mythNow we can get back to the question I posed at the beginning of this article, “Should women avoid soy?”

The evidence from clinical studies says, “No”. But every 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.

With the breast cancer myth out of the way, we can focus on the many benefits of soy.

Soy is one of the very few plant proteins that is complete, meaning that is contains all the essential amino acids we need to build muscle and other important proteins like immunoglobulins. It is also high in fiber and is a good source of healthy polyunsaturated fatty acids and essential nutrients like folate, iron, and magnesium. When you include the phytoestrogens found in minimally processed soy products, soy consumption is associated with:

  • Lower LDL cholesterol and a reduced risk of heart disease.
  • Bone health.
  • A strong immune system.
  • A reduction in menopause symptoms.

The Bottom Line

  • It is time to put the myth that soy increases breast cancer risk to rest and focus on the many health benefits of soy. This myth is based on cell culture and animal studies, and those studies were inconclusive.
  • Multiple clinical studies have shown that soy either has no effect on breast cancer risk, or that it reduces the risk.
  • 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.
  • 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 the benefits of soy 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 54 years Dr. Chaney and his wife Suzanne have been helping people improve their health holistically through a combination of good diet, exercise, weight control and appropriate supplementation.

 

 

Health Tips From The Professor