Dr. Steve Chaney, Author at Health Tips From The Professor

Do NAD Levels Decrease With Age?

August 4, 2026 by Dr. Steve Chaney

Why Do We Care About NAD Levels?

Author: Dr. Stephen Chaney

We have heard for years that NAD decreases as we age and supplements like NMN that increase NAD levels may be beneficial because they:

Increase cellular energy production which can reduce fatigue and improve stamina.

Activate sirtuins (your anti-aging genes) which, among other things, enhance DNA repair and reduce cellular stress.

Enhance energy metabolism in the brain. Studies are currently ongoing to evaluate its effectiveness in combating neurodegenerative conditions like Alzheimer’s and Parkinson’s diseases.

Enhance energy production in muscle which could improve physical performance and exercise capacity in older adults.

Regulate your circadian rhythms which could improve sleep quality and reduce systemic inflammation.

But what if none of this were true? A recent study has reported that blood levels of NAD don’t decline with age (MM Tretowicz et al, Nature Metabolism, 8: 1282-1290, 2026).

The headlines from social media influencers and bloggers, and even the New York Times, are saying things like:

“The idea that NAD levels decrease as we age is a myth”

“Supplements that raise NAD levels are a waste of money”

You are probably confused by the headlines. You are wondering, “What is true and what is a myth?” To answer that question, I need to evaluate the study behind the headlines.

But first it’s time for the professor’s favorite topic, Metabolism 101. It’s time to ask, “Why do we care about NAD levels?”

Why Do We Care About NAD Levels”

Let’s start by looking at the structures of NMN and NAD, so you can envision their relationship.

In the upper left corner, you see the structure of NMN, the abbreviation for nicotinamide mononucleotide. It contains nicotinamide (a form of vitamin B3), the 5-carbon sugar ribose, and a phosphate.

In the lower left corner, you see the structure of adenine mononucleotide, consisting of adenine, ribose, and phosphate. However, the better-known name for that structure is adenosine monophosphate, or AMP. If you add two phosphates to that molecule, you have ADP. If you add three phosphates to that molecule, you have ATP, which is the energy currency of the cell.

If you join nicotinamide mononucleotide and adenine mononucleotide together, you get nicotinamide adenine dinucleotide or NAD, which is the structure on the right.

With that behind us, let’s get back to the original question, “Why do we care about NAD levels?” Below I have put together a simplistic, conceptual diagram to explain the importance of NAD.

Simply put, the foods we eat are primarily composed of carbon, hydrogen, and oxygen, with an occasional nitrogen or sulfur thrown in for good measure. As the foods we eat are broken down in our cells…

The carbons and oxygens are converted to CO₂, which we exhale.

The hydrogens are transferred to NAD to produce NADH.

In an oxygen environment hydrogen, or more properly the electrons it possesses, are “high energy”.

When NADH enters our mitochondria, it encounters a biochemical pathway called the electron transport chain.

NADH transfers its hydrogen to the oxygen we breathe in to produce H₂O, or water.

It transfers its electrons to the electron transport chain where they provide the energy to convert ADP to ATP, which is the energy currency of the cell.

NAD does have a sister molecule called FAD which plays a similar role. As you can see from the simplistic diagram above, they are essential for energy (ATP) production in our cells. By feeding electrons into the electron transport chain, they are responsible for 90% of the energy our bodies need to survive and thrive. With that in mind, you can begin to appreciate why a decrease in the levels of either one of these molecules is concerning.

On a personal note, my thesis advisor at UCLA, Dr. Paul Boyer, received the Nobel Prize for deciphering the complex mechanism by which the electron transport chain uses electrons to generate ATP.

Do NAD Levels Decrease With Age?

So, now it is time to peak behind the curtain. It’s time to look at the study behind the headlines.

The researchers obtained blood samples from seven small clinical studies that looked at the variation in blood NAD levels with age. They used a very high precision method for measuring blood levels of NAD and applied it to the blood samples obtained from each study.

[Note: This is important because some of the variability in blood NAD levels between studies could have been due to variations in the way blood NAD levels were measured.]

They reported that:

Whole-blood NAD levels remained remarkably stable with age. This is different from the generally accepted paradigm.

Whole-blood NAD levels were not influenced by lifestyle.

- Elite athletes had blood NAD levels comparable to sedentary controls.

- Exercise had little effect on blood NAD levels.

- Diet had little effect on blood NAD levels.

Whole-blood NAD levels increased with NMN supplementation. This confirms previous studies.

They concluded:

“Our results challenge the utility of blood NAD levels as a biomarker of ageing or lifestyle factors.”

That conclusion is significantly different from the headlines you may have seen. The headlines suggest that the whole NAD hypothesis is a myth. This study is just saying that measuring blood NAD levels is easy, but it may not be the best way to gauge the effect of age or lifestyle on NAD stores.

But before I discuss that further, I should point out that this study has some glaring flaws. Let me share what the critics of this study are saying about it.

What Are The Critics Saying?

Here are the top four criticisms that other experts have raised about this study:

“Lack of Red Blood Cell Normalization: The study did not adjust NAD measurements for red blood cell (RBC) count, hematocrit, or hemoglobin—values that normally decrease with age and tend to be lower in women than in men.”

Why Is This Important? The authors of this study measured whole blood NAD levels. Red blood cells typically make up 40-45% of total blood volume. Red blood cells lack mitochondria, so they don’t need as much NAD as energy-intensive tissues. However, white blood cells do have mitochondria and do need higher levels of NAD.

As the percentage of red blood cells decrease with age, the percentage of white blood cells increases. This leaves open the possibility that a decrease in NAD levels in white cells might be offset by an increase in the number of white cells in the same volume of blood.

What do other studies show? Studies that normalize whole blood measurements for the red blood cell count generally show a decrease in blood levels of NAD with age.

One Step Forward, Two Steps Back. The scientists who designed the study should be commended for using the same, high-precision method to measure NAD levels in blood samples from different studies. However, neglecting to normalize for red blood cell count is a fatal flaw that may invalidate their study.

“Insufficient Sample Size: The study pooled several smaller observational studies and clinical trials rather than drawing from a single large cohort—an approach that introduces heterogeneity and limits the ability to detect modest but real biological effects.”

My Perspective: This is what I call the Garbage-in, Garbage-out principle that invalidates many well-intentioned meta-analysis studies.

“Pre-Analytical Variability Across Cohorts: The study combined blood samples from seven studies collected under different conditions, introducing potential variability from factors such as collection tubes, processing delays, storage temperature, and freeze-thaw handling—all of which can substantially influence NAD measurements. The variation between studies in this meta-analysis was approximately 10-15 nmol/mL—while the age-related decrease they were looking for was only around 1.5 nmol/mL. When technical variation is nearly ten times the size of the biological signal, it is very difficult to draw confident conclusions.”

My Perspective: Another example of Garbage-in, Garbage-out.

“Measurements Were Done In The Wrong Tissue: The critical distinction that is easily lost in most coverage is that the study measured NAD in whole blood—not in the organs and tissues where age-related NAD biology may be most relevant. Whole blood is a complex matrix dominated by red blood cells and circulating immune cells. It may tell us relatively little about NAD status in energy-intensive tissues like the brain, skeletal muscle, skin, liver, or kidney—the compartments where the scientific case for age-related NAD decline is mostly built.”

“Concluding from stable whole blood NAD levels that NAD does not decline with aging anywhere in the body is the scientific equivalent of measuring the temperature outside your front door and concluding it must be the same temperature in every room of your house.”

What Do Other Studies Show? Previous studies have shown an age-related NAD decline in skin, brain, skeletal muscle, and liver.

My Perspective: Even if this study, despite many flaws, is correct in concluding that blood NAD levels do not decline with age, that finding is irrelevant. In essence, that is what the authors were saying when they concluded, “Our results challenge the utility of blood NAD levels as a biomarker of ageing or lifestyle factors.”

So, ignore what you may be hearing from social media, your favorite health blogger, or other sources. Anything beyond saying that a recent study showed that blood may not be the best place to measure the effect of aging on NAD levels is pure fiction.

And don’t forget that the study also confirmed that NMN supplementation was effective at increasing NAD levels.

The Bottom Line

You may have seen headlines saying things like:

“The idea that NAD levels decrease as we age is a myth”

“Supplements that raise NAD levels are a waste of money”

When we peak behind the curtain and look at the study behind the headlines, we discover the study came to two conclusions:

It confirmed that NMN supplements were effective at increasing NAD levels in our blood.

It concluded that blood NAD levels may not be useful biomarkers of aging or lifestyle factors.

Neither of these conclusions look anything like the headlines you may have seen.

Experts who have reviewed that study have concluded that:

It is highly flawed.

Even if blood levels of NAD do not decrease with age, that is irrelevant because NAD levels have been shown to decrease with age in energy-intensive tissues like brain, muscle, skin, liver, and kidney.

As one of the experts put it, “Concluding from stable whole blood NAD levels that NAD does not decline with aging anywhere in the body is the scientific equivalent of measuring the temperature outside your front door and concluding it must be the same temperature in every room of your house.”

For more details on the study and what critics are saying about it, 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 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.

Are All Food Additives Bad-Part2?

July 28, 2026 by Dr. Steve Chaney

The Bad and The Ugly

Author: Dr. Stephen Chaney

Are All Food Additives Bad-Part2?

I get a lot of questions about food ingredient labels. That’s because in today’s social media world everyone is an “expert” wanting to be heard. Couple that with the fact that old news is boring, and we have a problem. To keep their followers engaged these “experts” must keep coming up with new information that is novel and scary. It doesn’t need to be true – just novel and scary.

Last week I talked about “good” food additives, which I defined as food additives that are on the social media “naughty lists” but are actually OK for most people most of the time. I would be the ﬁrst to admit the using the word “good” as a descriptor for food additives is a bit of a misnomer.

Of course, the word “good” should really be reserved for organic fresh fruits and vegetables along with other whole, unprocessed foods. The problem is that most of us don’t eat enough of those foods, so we need to know which ingredients in the processed foods and food supplements we eat are OK.

This week I will cover food additives that are “bad” for some of us, and food additives that are bad for most of us – These are the ones I call “ugly”.

Food Additives – The Bad

The term “bad” for the food additives is also a bit of a misnomer. In some cases, these are food ingredients that some people should avoid but are perfectly OK for others. In other cases, the type of food determines whether the additive is OK or should be avoided. However, these are nuances that seem to escape the average internet social media influencer.

Sodium Nitrate and Nitrite: This is a perfect example of a food ingredient that can be “bad” in certain foods and “good” in others. Brieﬂy:

When sodium nitrate and/or sodium nitrite are added to processed meats, they can combine with the amino acids from the meat in the intestine to form cancer-causing nitrosamines. As you might suspect, this is not a good

On the other hand, when sodium nitrate or sodium nitrite are found in fruits and vegetables or combined with natural antioxidants such as vitamin C in food supplements, they are converted to nitric oxide, which improves arterial health and can lower blood pressure.

Sugar & High Fructose Corn Syrup: As I have described in earlier issues of “Health Tips From The Professor”, there are no sugar villains and there are no sugar heroes. The problems associated with sugars of all types in the American diet are related to the amount of sugar in our diet (too much) and the kinds of foods they are found in. In summary:

When sugars are consumed as a part of foods that are rich in ﬁber and/or protein they have much less of an eﬀect on blood sugar levels (a lower glycemic index) than when they are consumed in sodas, juices and highly processed That’s important because the bad health consequences of sugars are primarily caused by foods that lead to high blood sugar levels.

Consequently, we should focus on the glycemic index (the eﬀect on blood sugar levels) of the foods we eat rather than obsessing about the amount or kinds of sugar on the label.

MSG: MSG, or monosodium glutamate, is a particularly interesting case. MSG is the sodium salt of the amino acid glutamate. Glutamate is found in every protein in our body and in every protein we eat. However, glutamate is also a neurotransmitter. That poses a problem for some people:

When MSG is used as a ﬂavor enhancer in foods with a low protein content, the glutamate is very rapidly taken up by the brain and can overstimulate some neurons.

- For most people this is no problem, but a small number of people experience what used to be called “Chinese Restaurant Syndrome” due to the large amounts of MSG used in some Chinese foods.

- The common symptoms associated with “Chinese Restaurant Syndrome” are headache, sweating, skin ﬂushing, nausea & fatigue. Allergic reactions to MSG can even be life threatening in some individuals.

Because of that, MSG is no longer widely used as a ﬂavor enhancer, and most restaurants either no longer use it or provide warning labels so sensitive individuals can avoid foods containing MSG.

However, now the internet bloggers are warning you to avoid foods containing hydrolyzed or enzymatically digested vegetable protein and sodium caseinate because they contain MSG. That is utter nonsense.

Glutamate is one of the 20 amino acids found in every protein we eat. As that protein is digested in our intestine, monosodium glutamate (MSG) is released. Hydrolyzed vegetable protein and sodium caseinate are simply pre-digested They contain no more MSG than we would have produced if we digested them ourselves.

Monosodium glutamate (MSG) formed during the digestion of a complete protein is no more dangerous than any of the other amino acids released during digestion of that protein. That is because when all the amino acids are in the blood at the same time, they compete with glutamate for uptake into the brain. This slows the entry of glutamate into the brain and prevents overstimulation of neurons.

The bottom line is that MSG as a ﬂavor enhancer is harmless for most people, but problematic for some. MSG as a component of hydrolyzed vegetable protein or sodium caseinate is harmless for everyone because it is in balance with the other naturally occurring amino acids.

Salt (Sodium): I could, and probably should, write a whole article on sodium intake. Suﬃce it to say that:

1) most of us consume too much sodium,

2) most of that sodium is hidden in the foods we eat rather than added at the table.

3) some people are more sensitive to the bad eﬀects of sodium than others.

As a rule, most of us should consume only limited amounts of high sodium foods and be careful with our saltshaker (Try using herbs for flavoring rather than sodium). However, we need to be aware that some of us are more sensitive to sodium than others.

Food Additives – The Ugly

Finally, there are some food ingredients that most experts (except for those in the food industry) agree should be avoided. The Environmental Working Group ie respected for their careful evaluation of foods and food ingredients that are good for us and those that should be avoided. So I have listed their “Dirty Dozen” – The food additives most likely to cause major health harms, increased risk of cancer, and/or developmental harm and hormone disruption.

1) Potassium Bromate. Potassium bromate is a possible human carcinogen added to flour used in packaged baked goods

2) Propyl Paraben. Propyl paraben is a preservative used in pastries and some tortillas. It causes developmental and reproductive harm.

3) BHA. Butylated hydroxyanisole, better known as BHA, is a preservative used in cured meats and other foods. Multiple sources have identified it as a possible human carcinogen.

4) BHT. Butylated hydroxytoluene, also called BHT, is a preservative found in cereals and other foods. It’s a chemical cousin of BHA and is a possible human carcinogen.

5) Titanium Dioxide. Titanium dioxide is a color additive used mostly in candy. It may damage DNA.

6) Artiﬁcial Colors. Synthetic food dye can be found in many types of food and beverages. It can affect development and cause behavioral difficulties in children. There are seven dyes that are especially concerning: Red 3, Red 40, Yellow 5, Yellow 6, Blue 1, Blue 2 and Green 3.

7) Aspartame. Aspartame is an artificial sweetener that can affect the hormones that regulate metabolism and have a negative effect on weight control. It has also been linked to heart disease and increased risk of cancer.

8) ADA. Azodicarbonamide, or ADA, is used as a dough conditioner and strengthener, as well as a bleaching agent in breads and pastries. ADA has been linked to an increased risk of cancer. It may also cause liver and kidney injury and affect the blood and the nervous and respiratory systems.

9) Propyl Gallate. Propyl gallate is a preservative used in vegetable oil, meat products and chewing gum, among other products. It may cause hormone disruption and has been linked to an increased risk of asthma, hyperactivity and even cancer.

10) TBHQ. TBHQ is a preservative that prevents oxidation. Also known as tertiary butylhydroquinone, it is typically added to packaged foods like crackers, potato chips and baked goods containing oil. Many animal studies have associated TBHQ with immune dysfunction, including potential impairment of the body’s ability to regulate inflammation and fight infections and cancer.

11) Sucralose. Sucralose is an artificial sweetener that is about 600 times sweeter than sugar. Non-sugar sweeteners like sucralose may increase risk of Type 2 diabetes, cardiovascular disease and mortality in adults, as well as preterm birth.

12) Sodium Nitrate. Sodium nitrite is an additive used to preserve meat. When added to processed foods, nitrites are associated with an increased risk of cancer. [As I noted above sodium nitrate is actually good for us when found naturally in plant foods or paired with antioxidants in food supplements.]

The Bottom Line

Last week I listed some “good” food additives, which I define as food additives that are on the social media “naughty lists” but are actually OK for most people most of the time.

This week I have discussed the bad and the ugly food additives.

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

___________________________________________________________________________

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

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

_____________________________________________________________________

About The Author

Dr. Chaney 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.

Are All Food Additives Bad-Part1?

July 21, 2026 by Dr. Steve Chaney

Are Any Food Additives “Good” For You?

Author: Dr. Stephen Chaney

Are All Food Additives Bad-Part1?

In the last two issues of “Health Tips From The Professor” I have debunked myths about the dangers of erythritol and sorbitol – alcohol sugars that are widely used in supplements and processed foods. Perhaps it’s time to take a broader look at food additives and separate myths from facts.

The warnings about which food additives to avoid are a perfect example. A few years ago, it was simple to know which ingredients to avoid. If you avoided foods with sugar, reﬁned ﬂour, trans fats and all the artiﬁcial stuﬀ, you were OK. However, in recent years the list of ingredients to avoid keeps getting longer and longer.

It has reached the point where it is getting hard to ﬁnd a food product or food supplement that doesn’t have any of the additives on the “naughty list”. You may even be wondering if there is anything besides organic fresh fruits and vegetables that you can eat. How did we get to this point?

The answer is obvious. All the social media “experts” needed something new to warn us about, so they took molehills and turned them into mountains. They took food additives that might cause a few problems for a limited number of people and characterized them as ingredients that were dangerous for everyone. Their posts were picked up and repeated by other “experts” and soon everyone thought they had to be true. The warnings about food ingredients became “nutrition myths”.

It is time for a myth buster to come along and help you sort through all the ingredient warnings so that you know which ones are true and which are myths. Let me be your guide.

I began my “research” by Googling “Food Ingredients to Avoid” to see what was on the internet. After a bit of “research” I came up with 25 of the most frequently mentioned “dangerous” food ingredients and have divided them into 3 categories. I call them “The Good, The Bad and the Ugly”.

Are Any Food Additives “Good” For You?

Let me start by identifying the “good ones” – those are food additives that are on the social media “naughty lists” but are actually OK for most people most of the time. I would be the ﬁrst to admit the using the word “good” as a descriptor for food additives is a bit of a misnomer.

The word “good” should really be reserved for organic fresh fruits and vegetables along with other whole, unprocessed foods. Of course, the problem is that most of us don’t eat enough of those foods, so we need to know which ingredients in the processed foods and food supplements we eat are OK.

The list of food additives that are perfectly OK for most of us would be a long one, so let me just mention a few that have inadvertently slipped onto the social media “naughty lists” that you may have seen.

I have discussed GMO foods and ingredients derived from GMO crops, soy foods and soy-derived food additives, and canola oil in previous editions of “health Tips From the Professor”. So, I won’t discuss them here. If you want more information on those topics, just go to https://chaneyhealth.com/healthtips/ and put the appropriate term in the search box

Carrageenan

Carrageenan comes from seaweed and red algae. It has been used in food for thousands of years because of its gelling properties. In the supplement world, it is used to improve consistency and the disintegration of tablets.

There is a lot to like about carrageenan. It is natural, organic and non-GMO. Why then has it become an internet villain in the food ingredient world? The problem is that most of the internet “experts” who are vilifying carrageenan are not distinguishing between carrageenan and its breakdown product poligeenan. Here are the facts:

In some animal studies poligeenan at very high doses has been shown to cause diarrhea, hemorrhaging & ulcerations of the colon and even colon Not all animal studies agree, but this does raise the possibility that high doses of poligeenan might cause the same eﬀects in humans.

Food grade carrageenan contains <5% poligeenan and does not raise the same concerns.

Food grade carrageenan does not cause gastrointestinal problems in most animal studies. Nor has it been shown to cause cancer in any animal study.

The FDA, USDA and WHO have reviewed all available studies and have concluded that food grade carrageenan is safe.

The International Agency for Research on Cancer (IARC) has concluded that carrageenan does not cause cancer.

Caramel coloring is another example. I won’t go into detail here, but the situation is like that for carrageenan. It is a minor impurity of caramel coloring that is the concern. However, caramel coloring itself should not be a concern for products made by any reputable manufacturer that employs rigorous quality control tests on their ingredients.

Maltodextrin

Food sources of complex carbohydrates, isolated on white.

Maltodextrin is a natural food ingredient made from enzymatically digesting starchy foods. It is used as a stabilizer and thickener in foods. It is also combined with glucose and fructose in sports drinks to provide sustained energy.

Myth #1: Social media is ﬁlled with claims that maltodextrin causes gastrointestinal problems or that it is unsafe. There is very little evidence to back that up, and we need to consider those claims in light of the fact that we produce lots of maltodextrin in our intestines every day as we digest the starches in our diet.

Myth #2: “Maltodextrin is just another sugar. It is just another way for food manufacturers to hide the total amount of sugar in their products.” Maltodextrin is actually less sweet than most sugars. As described above, it is primarily added to foods for reasons other than to impart sweetness.

Myth #3: “Maltodextrin is GMO.” It’s true that most maltodextrin in the US comes from GMO corn. However, as I pointed out in my article on GMO foods, the genetic modifications are found only in the DNA and protein. Maltodextrin is a highly puriﬁed food ingredient that contains neither DNA nor protein. That means there are no health concerns associated with maltodextrin, only possible environmental concerns about the pesticides and herbicides used with GMO corn.

Carmine (Also Known As Cochineal)

I ﬁnd this one truly amusing. Social media posts breathlessly proclaim: “Did you know that the red dye used in your favorite food comes from ground up insects?”

Of course, the statement is factually correct. Carmine is a red food dye extracted and puriﬁed from a tropical beetle. However, the implication the statement suggests is completely misleading.

This is a highly puriﬁed ingredient. It contains no insect parts. In fact, you are far more likely to ﬁnd insect parts in your breakfast cereal or piece of toast. The FDA allows up to 350 insect fragments, 5 rodent hairs, and 2 rodent poop pellets in every cup of ﬂour. Enjoy your breakfast cereal and toast!

Carmine dye is natural, organic, and non-GMO. It is much safer than the Red #2 or Red #40 it replaces. What’s not to like?

Are the alarmists worried that the beetles will become an endangered species or are they concerned about the suﬀering of the beetles who give up their lives to produce carmine dye?

The Bottom Line

A few years ago, it was simple to know which ingredients to avoid. If you avoided foods with sugar, reﬁned ﬂour, trans fats and all the artiﬁcial stuﬀ, you were OK. However, in recent years the list of ingredients to avoid keeps getting longer and longer.

It has reached the point where it is getting hard to ﬁnd a food product or food supplement that doesn’t have any of the additives on the “naughty list”. How did we get to this point?

The answer is obvious. Social media “experts” always need something new to warn us about, so they can engage their followers. Their posts were picked up and repeated by other “experts” and soon everyone thought they had to be true. Their warnings about food ingredients became “food myths”.

It is time for a myth buster to come along and help you sort through all the ingredient warnings so that you know which ones are true and which are myths.

This week I started with the “good” additives, which I define as food additives that are on the social media “naughty lists” but are actually OK for most people most of the time.

The list of food additives that are perfectly OK for most of us would be a long one, so I have just mentioned a few that have inadvertently slipped onto the social media “naughty lists” that you may have seen.

Next week I will discuss the bad and the ugly food additives. Stay tuned.

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.

___________________________________________________________________________

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

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

______________________________________________________________________

About The Author

Is Sorbitol Dangerous?

July 14, 2026 by Dr. Steve Chaney

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?

This 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?

The 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.

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.

___________________________________________________________________________

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

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

______________________________________________________________________

About The Author

For the past 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

July 7, 2026 by Dr. Steve Chaney

Who Should Be Concerned About Erythritol Intake?

Author: Dr. Stephen Chaney

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.

#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 heart 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:

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:

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

As 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.

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? Recent 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.

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.

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.

________________________________________________________________________

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

Does Creatine Reduce Menopause Symptoms?

June 30, 2026 by Dr. Steve Chaney

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?

The 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?

As 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.

_____________________________________________________________________________

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

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

_____________________________________________________________________

About The Author

For the past 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?

June 23, 2026 by Dr. Steve Chaney

How Do You Increase Your DHA Levels?

Author: Dr. Stephen Chaney

As 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?

The 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?

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?

Now 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.

_____________________________________________________________________________

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

Can You Build Muscle in Your Golden Years?

June 16, 2026 by Dr. Steve Chaney

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 80^th 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?

The 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?

At 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?

In 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.

“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.

_____________________________________________________________________________

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

Can High Protein Diets Reduce Testosterone?

June 9, 2026 by Dr. Steve Chaney

What Does This Study Mean For You?

Author: Dr. Stephen Chaney

Protein 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?

This 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?

This 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?

As 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?

In 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 21^st 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.

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

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.

_____________________________________________________________________________

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

The Creatine Safety Myth

June 1, 2026 by Dr. Steve Chaney

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).

In 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?

The 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.

But 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?

This 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

The 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

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.

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

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

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About The Author

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