exercise

600th Issue Celebration

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Nutrition Advances Over The Last Two Years

Author: Dr. Stephen Chaney 

celebrationIn the nearly twelve years that I have been publishing “Health Tips From The Professor”, I have tried to go behind the headlines to provide you with accurate, unbiased health information that you can trust and apply to your everyday life.

The 600th issue of any publication is a major cause for celebration and reflection – and “Health Tips From The Professor” is no different.

I am dedicating this issue to reviewing some of the major stories I have covered in the past 100 issues. There are lots of topics I could have covered, but I have chosen to focus on three types of articles:

  • Articles that have debunked long-standing myths about nutrition and health.
  • Articles that have corrected some of the misinformation that seems to show up on the internet on an almost daily basis.
  • Articles about the issues that most directly affect your health.

Here are my picks from the last two years:

Weight Loss Diets

weight lossSince it is almost January, let’s start with a couple of articles about diet and weight loss (or weight gain). I have covered the effectiveness of the Paleo, Keto, Mediterranean, DASH, vegetarian, and Vegan diets for both short and long-term weight loss in my book “Slaying The Food Myths”, so I won’t repeat that information here. Instead, I will share a few updates from the past 100 issues.

Is Time-Restricted Eating Better Than Other Diets? Time-restricted eating is one of the latest fads. But is it really better than other diets for weight loss and improved health? In this article I reviewed two studies that compare time-restricted eating with diets that do not restrict time of eating but cut calories to the same extent. You may be surprised at the results.

Can You Lose Weight Without Dieting? In this article I share 8 tips for losing weight without going on a diet. The article is based on research by Dr. Brian Wansink, a behavioral psychologist who specializes in studying how external clues influence our eating patterns. As you might suspect his 8 tips for losing weight have nothing to do with counting calories or going on restrictive diets.

Healthy Diets

dairy foodsIs Whole Fat Dairy Healthy? For years dietary guidelines have been telling us to select low fat dairy foods. But some health gurus are telling you that isn’t true. They claim whole fat dairy is healthy. So, you are probably wondering, “What is the scoop (as in ice cream) on whole fat dairy?” In this article I look at the study behind the headlines and answer that question. But the answer is not a simple “Yes” or “No”. The answer is more nuanced. It turns out that whole fat dairy is healthier in some diets than in others. 

Are Low Carb Diets Healthy? Are low carb diets good for you or bad for you? It depends on which study you quote. Two major studies in recent years have come to opposite conclusions. In this article I help you sort through the conflicting studies and rephrase the question. Instead of, “Are low carb diets healthy”, the question should be, “Which low carb diets are healthy?”

Are All Plant-Based Diets Healthy? Plant-based diets have acquired a “health halo” in recent years. Your mama told you to eat your fruits and vegetables. And many health gurus have been telling you not to neglect your grains, legumes, nuts, and seeds as well. But some of these foods require a lot of food preparation.

Never fear! The food industry has come to your rescue with a wide variety of processed plant-based foods. No need for food prep. But are they as good for you as the unprocessed plant foods they replace? In this article I review a study that answers that question.

You probably know what that answer is, but the article is worth a read anyway. That is because the study also asks whether vegan and vegetarian diets are healthier than other primarily plant-based diets. And you may not know the answer to that question.

Diet And Heart Disease

egg confusionAre Eggs Bad For You? For years we were told that eggs are bad for us because they contain cholesterol. Then we were told that eggs in moderation may not increase our risk of heart disease. And recently studies have appeared claiming eggs may be good for our hearts. What is the truth about eggs and heart disease? In this article I review a recent study claiming eggs are bad for our heart and put that study into the context of other recent studies to clear up the “eggfusion”.

Which Diets Are Heart Healthy? Every popular diet claims to help you lose weight, reduce your risk of diabetes, and reduce your risk of heart disease. All these claims can’t be true. Which diets deliver on their promises, and which are just pretenders? In this article I review a recent study that answered that question for heart disease.

This study was a very large metanalysis of over 40 studies with 35,548 participants that looked at the effect of different diets on heart disease outcomes. The study identified two diets that significantly reduced the risk of heart disease. There are other diets that might reduce the risk of heart disease, but their benefits have not been proven by high quality clinical studies. They are merely pretenders.

The Dangers Of Processed Foods 

In previous issues of “Health Tips From the Professor” I have shared articles showing that diets high in processed foods are associated with an increased risk of obesity, diabetes, and heart disease. But the story keeps getting worse. Here are two articles on recent studies about processed foods that appeared in “Health Tips From The Professor” in the last two years.

Why Does Processed Food Make You Fat? We already know that eating a lot of highly processed food is likely to make us fat. But what is it about processed food that makes us fat? In this article I review a recent study that answers that question.

This study is interesting for two reasons.

  • It identifies the characteristics of processed foods that make us want to eat more.
  • It identifies some minimally processed foods that have the same characteristics and suggests we should choose minimally processed foods wisely. Simply put, knowledge is power. We may want to avoid minimally processed foods that have the same obesity-inducing characteristics as processed foods.

Do Processed Foods Cause Cancer? Previous studies have shown that processed food consumption is associated with a higher risk of obesity, diabetes, and heart disease. Can it get any worse? In this article I review a recent study that shows processed food consumption is associated with an increased risk of several kinds of cancer.

Maintaining Muscle Mass As We Age

As we age, we begin to lose muscle mass, a process called sarcopenia. Unless we actively resist loss of muscle mass it will eventually impact our quality of life and our health.

We can prevent this loss of muscle mass with resistance exercise, adequate protein intake, and adequate intake of the amino acid leucine. Previous studies have shown people over 50 need more of each of these to maintain muscle mass, but the amount they need has been uncertain until now. Three recent studies have given seniors better guidelines for maintaining muscle mass.

Can You Build Muscle In Your 80s? In this article I review a recent study that enrolled a group of octogenarians in a high-intensity exercise program to see if they could gain muscle mass. They were able to increase their muscle mass, but the intensity of the exercise required may surprise you.

Optimizing Protein Intake For Seniors. In this article I review two recent studies that looked at the amount, timing, and kind of protein needed for seniors in their 60s and 70s to maximize gain in muscle mass.

How Much Leucine Do Seniors Need? In this article I review a recent study that determined the amount of leucine seniors in their 70s need to optimize gains in muscle mass and strength.

The Benefits And Risks Of Supplementation

Omega-3s And Heart DiseaseIf you listen to Big Pharma or the medical profession, you hear a lot about the “risks” of supplementation and very little about the benefits. In “Health Tips From the Professor” I try to present a more balanced view of supplementation by sharing high-quality studies showing benefit from supplementation and studies that put the supposed risks into perspective.

The Good News About Omega-3s and Stroke. Multiple studies have shown that omega-3 supplementation reduces the risk of ischemic strokes (strokes caused by a blood clot). But it has been widely assumed they might increase the risk of hemorrhagic strokes (strokes caused by bleeding). In this article I review a meta-analysis of 29 clinical studies with 183,000 participants that tested that assumption.

How Much Omega-3s Are Best For Blood Pressure? Multiple studies have shown that omega-3 supplementation can reduce high blood pressure. But the doses used vary widely from one study to the next. In this article I review a meta-analysis of 71 double-blind, placebo-controlled clinical studies that determined the optimal dose of omega-3s for controlling blood pressure.

Omega-3 Supplements Are Safe. As I said above, it has been widely assumed that omega-3 supplementation increases the risk of bleeding and hemorrhagic stroke. In this article I review the definitive study on this topic. More importantly, it reveals which omega-3 supplements might increase bleeding risk and which do not.

Are Calcium Supplements Safe? Big Pharma and the medical profession have been warning us that calcium supplements may increase heart disease risk. In this article I review the definitive study on this topic.

Prenatal Supplements

prenatal dha supplementIf you are pregnant or thinking of becoming pregnant, your health professional has likely recommended a prenatal supplement. You probably assume that prenatal supplements provide everything you need for a healthy pregnancy. Unfortunately, recent research has shown that assumption is not correct.

Is Your Prenatal Supplement Adequate? In this article I review a study that should serve as a wakeup call for every expectant mother. It showed that most prenatal supplements were woefully inadequate for a healthy pregnancy.

What Nutrients Are Missing In Prenatal Supplements? In this article I review a study that identified additional nutrients that are missing in most prenatal supplements.

Prenatal Supplements Strike Out Again. In this article I review a study that looked at the diet of pregnant women to determine their needs and compared that to the nutrients found in prenatal supplements. Once again, most prenatal supplements were woefully inadequate. Is it, “Three strikes and you are out”?

Exercise

Walking FastWalking Your Way To Health. We have been told that walking is good for our health. But how many steps should you take, how fast should you walk, and does it matter whether these steps are part of your daily routine or on long hikes? In this article I review a study that answers all these questions.

Which Exercise Is Best For Reducing Blood Pressure? If you have high blood pressure, you have probably been told to exercise more. But which exercise is best? In this article I review a study that answers that question. And the answer may surprise you.

Did You Know? 

Question MarkIf you have been reading “Health Tips From the Professor” for a while, you probably know that I enjoy poking holes in popular myths. Here are two new ones I deflated in past two years.

Is Low Alcohol Consumption Healthy? You have probably heard that low alcohol intake (that proverbial glass of red wine) is good for you. But is that true? In this article I review a recent study that shows that myth was based on faulty interpretation of the data and provides a more nuanced interpretation of the data.

Is HDL Good For Your Heart? You have been told that increasing your HDL levels reduces your risk of heart disease so many times it must be true. But is it? In this article I review HDL metabolism and a recent study to provide a more nuanced interpretation of the relationship between HDL and heart disease risk.

How To Talk With Your Doctor About Cancer 

Because of my years in cancer research, I am often asked whether someone should follow their oncologist’s advice and go on a recommended chemotherapy or radiation regimen. Of course, it would be unethical for me to provide that kind of advice.

In this article I tell you the questions to ask your oncologist about the prescribed treatment regimen, so you can make an informed decision. However, I also recommend you only ask these questions if you can handle the answers.

The Bottom Line

I have just touched on a few of my most popular articles above. You may want to scroll through these articles to find ones of interest to you that you might have missed over the last two years. If you don’t see topics that you are looking for, just go to https://chaneyhealth.com/healthtips/ and type the appropriate term in the search box.

In the coming years, you can look for more articles debunking myths, exposing lies and providing balance to the debate about the health topics that affect you directly. As always, I pledge to provide you with scientifically accurate, balanced information that you can trust. I will continue to do my best to present this information in a clear and concise manner so that you can understand it and apply it to your life.

Final Comment: You may wish to share the valuable resources in this article with others. If you do, then copy the link at the top and bottom of this page into your email. If you just forward this email and the recipient unsubscribes, it will unsubscribe you as well.

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

_______________________________________________________________________________

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

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

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

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

 _______________________________________________________________________

About The Author 

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

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

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.

Which Exercise Is Best For Reducing Blood Pressure?

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How Can You Keep Your Blood Pressure Under Control? 

Author: Dr. Stephen Chaney 

high blood pressureHypertension (high blood pressure) is called a silent killer. That’s because you often don’t notice any symptoms until you die from a stroke or heart attack.

Nearly half of all American adults (120 million or 48%) have high blood pressure. Of Americans with high blood pressure:

  • About half (46%) of them don’t know it.

And of those who know they have high blood pressure:

  • Only half of them have it under control.
    • In case you weren’t doing the math, that means that only 1 in 4 Americans with high blood pressure has it under control.

That is scary because every 20 mm Hg increase in systolic blood pressure:

  • Doubles your risk of death from a stroke or heart attack.

And if the personal costs of high blood pressure were not enough, the cost of high blood pressure to our health care system is enormous.

  • The CDC estimates that the cost of high blood pressure in the United States is around $131 to $198 billion per year. And this may be an underestimate because it does not include productivity losses from non-fatal illnesses caused by high blood pressure.

Medications are effective at reducing blood pressure, but they have significant side effects. And those side effects have two unintended consequences.

  • Around half of patients stop taking their blood pressure medication within the first year because of side effects or cost.
  • For patients who continue taking blood pressure medication, they are usually prescribed other medications to reduce the side effects from their blood pressure medication.

This is often the start of a downward spiral in which they need more medications to reduce the side effects of the medicines they were just prescribed. And they end up on multiple medications, and a poor quality of life because of it.

Because of this, many patients and health care practitioners are looking for natural ways to keep blood pressure under control. One of the most recommended approaches is to increase exercise, and the type of exercise most frequently recommended is aerobic exercise.

But is that the best advice? That advice is based on clinical studies performed 20 to 30 years ago. And those studies were an excellent example of “the tail wagging the dog”.

Let me explain. In the early days most experts believed that aerobic exercise would be the most effective exercise for reducing blood pressure. So, most of the original studies on the effect of exercise at reducing blood pressure were done using aerobic exercise.

From those studies we knew that aerobic exercise was effective at reducing blood pressure, but we didn’t really know whether it was the most effective exercise for reducing blood pressure. And more recent studies have suggested a more nuanced view of exercise and blood pressure control.

For that reason, the authors of the current article (JJ Edwards et al, British Journal of Sports Medicine, 57: 1317-1326, 2023) decided to conduct a comprehensive review of all randomized controlled studies between 1990 and February 2023 on the effect of exercise on reducing blood pressure.

How Was The Study Done? 

clinical studyThe investigators performed a comprehensive, systematic review of all randomized controlled studies (meaning patients were randomly assigned to an exercise or non-exercise group) looking at reductions in blood pressure following an exercise intervention of ≥ 2 weeks.

They excluded studies that:

  • Included dietary counseling or exercise recommendations in the control group.
  • Included dietary counseling, supplementation, or medication in the exercise group.

However, there were no exclusions based on the health or disease state in the patient population.

Their analysis included 270 randomized controlled trials with a total of 15,827 participants. All the studies reported systolic and/or diastolic blood pressure before and after the exercise intervention.

Exercise interventions were divided into five classifications:

  • Aerobic exercises.
  • Resistance exercises.
  • Combined exercises (a combination of aerobic and resistance exercises).
  • High-intensity interval exercises (high-intensity, short-duration exercises).
  • Isometric exercises.

Several of these exercise classifications were further subdivided into individual exercises (see below)

Which Exercise Is Best For Reducing Blood Pressure? 

When the reduction in systolic blood pressure was considered, the rank order of exercise effectiveness was:

  • High-intensity interval exercise (4.08 mm Hg reduction).
  • Aerobic exercise (4.48 mm Hg reduction).
  • Resistance exercise (4.53 mm Hg reduction).
  • Combined aerobic and resistance exercise (6.04 mm Hg reduction).
  • Isometric exercise (8.24 mm Hg reduction).

When the reduction in diastolic blood pressure was considered, the amount of reduction was less but the rank order of exercise effectiveness was the same:

  • High-intensity interval exercise (2.50 mm Hg reduction).
  • Aerobic exercise (2.53 mm Hg reduction).
  • Resistance exercise (3.04 mm Hg reduction).
  • Combined aerobic and resistance exercise (3.54 mm Hg reduction).
  • Isometric exercise (4.00 mm Hg reduction).

When the exercise classifications were subdivided into individual exercises.

  • Running and cycling were significantly more effective than walking for aerobic exercise, with running being the most effective form of aerobic exercise.
  • Cycling was the most effective form of high-intensity interval exercise.
  • No effect of exercise type was seen for the effectiveness of resistance training.
  • Isometric wall squats and leg extensions were much more effective than isometric handgrip exercises.

There was not enough data from diastolic blood pressure studies to subdivide into individual exercises.

There were two other results of interest.

  • Aerobic exercise interventions were slightly more effective with lower exercise frequency, suggesting that 3 times a week may be more effective than 5 or more times a week.
  • All exercise interventions were much more effective for people with significantly elevated blood pressure than for people with slightly elevated blood pressure or normal blood pressure.

Of course, the important question for people with normal blood pressure is the effectiveness of exercise in preventing future increases in blood pressure, and this study is not designed to answer that question.

The authors concluded, “Various exercise training modes improve resting blood pressure, particularly isometric exercise. The results of this analysis should inform future exercise guideline recommendations for the prevention and treatment of arterial hypertension.”

What Does This Study Mean For You? 

Question MarkThe takeaways from this study are clear.

If you wish to reduce your blood pressure:

  • Any kind of exercise is helpful, but current recommendations that prioritize aerobic exercise may be misleading.
  • If you want to get the most “bang for your buck”:
    • Isometric exercise is the most effective and high intensity interval exercise is the least effective.
    • Aerobic and resistance exercise are equally effective.
    • A combination of aerobic and resistance exercise is more effective than either alone.
  • And if you want to know the most effective individual exercises:
    • Wall squats and leg extensions are the most effective isometric exercises.
    • Running and cycling are the most effective aerobic exercises.
    • Any kind of resistance exercise is equally effective.

Here are my thoughts about this study:

  • If you haven’t been keeping up with clinical studies on exercise and blood pressure (like me), the conclusions of this comprehensive review are probably a surprise. I would not have expected isometric exercises to be more effective than aerobic exercises for lowering blood pressure.
  • The authors of this review postulated that isometric exercise decreases blood flow to the muscles involved. When those muscles relax, blood flow increases which sends metabolic signals that cause blood vessels to relax.
  • This study is good news for people with health conditions that limit their ability to do aerobic exercises or traditional resistance exercises.
  • We also need to remember that lowering blood pressure is not the only value of exercise.
    • Aerobic exercise improves cardiovascular function.
    • Resistance exercise increases muscle mass, which is particularly important for seniors who are trying to maintain muscle mass and function. Regular resistance exercise also helps minimize bone loss as we age.

Isometric exercise can be considered a form of resistance exercise, but it may need to be supplemented with resistance exercises that target other muscle groups.

  • As I said above, this study shows that all forms of exercise reduce blood pressure. The most effective exercise for you is the one you enjoy and will do on a regular basis.
  • Finally, while this study looked at the effectiveness of different exercises at reducing high blood pressure, these findings are probably also applicable to the types of exercise that can reduce risk of developing high blood pressure as we age.

How Can You Keep Your Blood Pressure Under Control?

dash dietExercise alone is not a “magic bullet” for controlling blood pressure. And therein lies a story.

One reason so many people choose medications to control their blood pressure is that there is no “magic bullet” natural approach for controlling blood pressure. Exercise is just one part of a holistic approach for controlling blood pressure that also includes:

  • The DASH (Dietary Approaches To Stop Hypertension) was designed to prevent high blood pressure. I refer to it as an Americanized version of the Mediterranean diet.

Both diets are rich in fruits, vegetables, and whole grains and limit high fat meats and dairy products. And both diets have been shown to reduce the risk of high blood pressure.

  • Weight control. Overweight and obesity are both associated with increased risk of high blood pressure. One estimate is that every two pounds of weight gain increases blood pressure by 1 mm Hg.
  • Supplementation. The most effective supplements appear to be:
    • Omega-3 fatty acids.
    • Supplements containing grape seed extract and/or nitrates from beetroots and leafy greens.
    • Calcium and magnesium if dietary intakes are not optimal.

Diet, weight control, supplementation, and exercise are the top 4 lifestyle factors for keeping blood pressure under control, but a comprehensive holistic approach to controlling blood pressure includes:

  • Low sodium/potassium ratio. I mention it here for completeness, but it is an integral part of the DASH diet.
  • Stress management. Chronic stress can increase blood pressure.
  • Adequate sleep.

We may be outliers, but my wife and I have followed this approach for years and in our 80s have the blood pressure of teenagers.

The Bottom Line 

Most experts recommend aerobic exercise for reducing blood pressure, but these recommendations are based on outdated studies. A recent study examined the effectiveness of various exercises at reducing blood pressure based on all randomized controlled clinical trials between 1990 and 2023.

This study shows:

If you wish to reduce your blood pressure:

  • Any kind of exercise is helpful, but current recommendations that prioritize aerobic exercise may be misleading.
  • If you want to get the most “bang for your buck”:
    • Isometric exercise is the most effective and high intensity interval exercise is the least effective.
    • Aerobic and resistance exercise are equally effective.
    • A combination of aerobic and resistance exercise is more effective than either alone.

For more information on this study, what it means for you, and recommendations for a holistic approach for controlling blood pressure naturally, read the article above.

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

______________________________________________________________________________

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

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

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

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

_____________________________________________________________________

About The Author 

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

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

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

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

Do Optimists Live Longer?

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What Does This Study Mean For You? 

Author: Dr. Stephen Chaney 

You have probably heard the statement that optimists live longer before. In fact, you have probably heard so many times you assume it must be true. But is it a myth or is it the truth?

This question is important because it can affect how people feel about themselves. If you are a natural optimist, statements like this support your feeling of self-worth. But if you are naturally pessimistic, statements like this provide one more reason to feel bad about yourself.

For example, a recent article on the topic in WebMD starts with the statement, “Want to live longer? You might want to try improving your outlook on life.” I am mostly optimistic, so I find this statement to be positive and encouraging.

But I am not sure I would feel about this statement if I were pessimistic or depressed and had tried for years to be more optimistic.

Because of this it is important to ask, “How good is the evidence supporting this claim?”

There are several published studies supporting this claim (For example). However,

  • Most of these studies have been performed with white, high-income participants. It is not clear whether these same results would apply to other racial and ethnic groups.
  • There is also the “chicken versus egg” conundrum. The studies claiming that optimists live longer are all association studies. Simply put, that means optimism is associated with longevity, but does not prove cause and effect. That is important because:
    • Some studies show that both a healthy diet and exercise improve mood.
    • Other studies show that optimists tend to take better care of themselves, and that includes both diet and exercise.
    • So, it’s hard to know which comes first – a healthy lifestyle, which creates optimism, or optimism, which creates a healthy lifestyle.
  • Because of this “chicken versus egg” conundrum, it is not clear whether it is a healthy lifestyle or optimism that is the primary cause of greater longevity.

The study (HK Koga et al, Journal of the American Geriatrics Society, 70: 2793-2804, 2022)) I will review today was designed to answer both questions. Specifically, this study was designed to ask:

  • Is higher optimism associated with a longer lifespan and exceptional longevity across diverse racial and ethnic groups?
  • To what extent do lifestyle factors influence this association?

How Was The Study Done?

clinical studyThe data for this study was obtained from the Women’s Health Initiative which enrolled 161,808 postmenopausal women of diverse racial and ethnic groups from 40 medical centers within the United States between 1993 and 1998. The women were aged 50-79 (average = 63.5) at enrollment and were followed for an average of 26 years.

Optimism was assessed at enrollment into the program using the 6-item Life Orientation Test Revised. For each item on the questionnaire, participants were asked to report the degree they agreed with each statement on a scale of 1 = “strongly agree” to 5 = “strongly disagree”. Their responses were summed to create scores ranging from 6 to 30, with 30 being the highest optimism rating.

Lifestyle was assessed on a questionnaire measuring diet quality, physical activity, BMI (a measure of obesity), smoking status, and alcohol consumption. If participants met predefined “healthy standards in each of these categories, they were given a score of 1. Otherwise, their score was 0. Scores from each category were summed to create a composite lifestyle score ranging from 0 (least healthy) to 5 (most healthy).

Longevity was based on survival compared to national averages using the National Death Index (Yes, “Big Brother” is watching you even when you die) to identify and confirm deaths. Deaths of participants were monitored through March 1, 2019. Exceptional longevity was defined as survival to age 90 or older. Overall, 64,301 women (40.3%) died over the 26 years of follow-up.

Finally, women who died within the first 2 years of follow-up were excluded from the data analysis “to mitigate concerns that health status might affect the reporting or experience of optimism levels.” In plain English, people who are within 2 years of dying are often very sick and feel lousy. Even the most optimistic individuals find it hard to maintain an optimistic outlook in those circumstances. This left 159,255 women in the database.

Do Optimists Live Longer?

When comparing women in the highest to women in the lowest quartile of optimism:

  • Longevity was increased by 5.4%, which corresponds to an additional 4.4 years. When this was broken down by race and ethnicity, longevity was increased by:
    • 1% for Non-Hispanic White women.
    • 6% for Black women.
    • 4% for Hispanic women.
    • 5% for Asian women. However, this may have been an underestimate because of the small sample size of this population in the Women’s Health Initiative database.
  • Exceptional longevity (survival ≥ 90 years) was increased 10%.

When the authors used a complex statistical method to assess the contribution of lifestyle to the increase in longevity, they found:

  • Lifestyle contributed to 24% of the increased longevity. When this was broken down by race and ethnicity, lifestyle contributed:
    • 25% for Non-Hispanic White women.
    • 10% for Black women.
    • 24% for Hispanic women.
    • 43% for Asian women.

The authors concluded, “We found that higher levels of optimism were associated with longer lifespan and greater likelihood of achieving exceptional longevity across racial and ethnic groups, suggesting the health benefits of optimism may hold across these groups.”

“The contribution of lifestyle to these associations was evident but modest.”

“As prior work has demonstrated that optimism is modifiable, it may be a novel target for interventions that aim to extend lifespan across diverse racial and ethnic groups.”

What Are The Strengths And Weaknesses Of This Study?

strengths and weaknessesThis is not the first study to suggest that optimists live longer. But it is the best study to date because:

  • It was larger (159,255 participants) than most previous studies.
  • It followed the participants far longer (26 years) than previous studies.
  • It included a more racially and ethnically diverse group of participants than previous studies.
  • It addressed the “elephant in the room” for studies of this type, namely that optimists tend to actively seek a healthier lifestyle, so the “benefits” of optimism could be due to a healthy lifestyle rather than a state of mind. The study employed statistics to estimate that a healthy lifestyle contributed around 25% to the longevity experienced by optimists.

However, the study did have some weaknesses. In my opinion, the most important weaknesses were:

  • Optimism and lifestyle were only assessed at the beginning of the study. No effort was made to determine whether either of these important variables changed during the 26-year study.
  • The relative influence of lifestyle and optimism on longevity was based on a complex statistical analysis. As Mark Twain said, “There are lies, damn lies, and statistics.” Simply put, statistics can sometimes give misleading answers. I would like to see this very important part of the study confirmed using a different method of analysis.

What Does This Study Mean For You?

Questioning WomanAs I shared above, I have some misgivings about this and other studies claiming that optimists live longer. But let’s assume this claim is true. What does that mean for you?

A 5.4% increase in lifespan might not sound like much, but it added 4.4 years to the lives of the women in the study. What would you do with an extra 4.4 years?

And, as the authors of the study pointed out, that’s equivalent to the gain in lifespan for adults engaged in a regular exercise program. Are those benefits addible? We don’t know, but it is possible that an optimist who exercised regularly and had a healthy diet might experience more than a 4-year gain in lifespan.

The authors said, “Although optimism is partly heritable (23-32%), experimental research has demonstrated that optimism is modifiable…”

Let me share a few things that have helped me maintain a more optimistic outlook:

  • Affirmations and visualizations of a positive future.
  • I start my daily prayers by listing the things I am grateful for. For others, a gratitude journal works equally well.
  • Accept positive input. You can accept compliments with humility by simply thanking the person for the compliment. But in your mind, use the compliment to overcome your inner doubts of self-worth.
  • Question negative input. Ask if each critic is the kind of person you want to become. If so, ask if what they said is really true.
  • Create a support network. These are family and friends who will support you when you need it and will give you a gentle kick in the …. when you need that.
  • Trust in a higher power. I know from experience that it is only God who can give me the “peace that passes all understanding” in my most difficult circumstances. And while I am Christian, I think this is a cornerstone of most religions.

Finally, I know that many people are predisposed to depression and pessimism, so I don’t want to be like the author of the WebMD article and tell you, “Want to live longer? You might want to try improving your outlook on life.”

We know that a healthy lifestyle is associated with longevity. And you don’t have to be an optimist to choose a healthy diet, exercise regularly, avoid smoking and excess alcohol intake, and get regular health check-ups.

We also know these things are associated with a longer healthspan which, simply put, is the number of years you live in good health.

So, whether you are a pessimist or an optimist you can live healthier longer.

The Bottom Line

You have probably heard that optimists live longer, but is it true? In the article above I describe the latest study on this topic. It is better than most previous studies on this topic because:

  • It was larger (159,255 participants) than most previous studies.
  • It followed the participants far longer (26 years) than previous studies.
  • It included a more racially and ethnically diverse group of participants than previous studies.
  • It addressed the “elephant in the room” for studies of this type, namely that optimists tend to actively seek a healthier lifestyle, so the “benefits” of optimism could be due to a healthy lifestyle rather than a state of mind. The study employed statistics to estimate that a healthy lifestyle contributed around 25% to the longevity experienced by optimists.

When the study compared women in the highest to women in the lowest quartile of optimism:

  • Longevity was increased by 5.4%, which corresponds to an additional 4.4 years.
  • Exceptional longevity (survival ≥ 90 years) was increased by 10%.
  • Lifestyle contributed to 24% of the increased longevity.

The authors concluded, “We found that higher levels of optimism were associated with longer lifespan and greater likelihood of achieving exceptional longevity across racial and ethnic groups, suggesting the health benefits of optimism may hold across these groups.”

“As prior work has demonstrated that optimism is modifiable, it may be a novel target for interventions that aim to extend lifespan across diverse racial and ethnic groups.”

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

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

______________________________________________________________________________

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

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

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

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

______________________________________________________________________

About The Author 

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

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

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

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

For the past 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.

How Much Leucine Do Seniors Need?

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Where Can Seniors Find The Protein And Leucine They Need?

Author: Dr. Stephen Chaney 

Frail ElderlyMost Americans lose lean muscle mass as they age, a physiological process called sarcopenia. There are three factors that influence the rate at which we lose muscle mass as we age:

  • Our physiology changes. Our bodies break down our protein stores more rapidly and we have a harder time utilizing the protein in our diet to replenish those protein stores.
  • We become less active. In some cases, this reflects physical disabilities, but all too often it is because we are not giving weight-bearing exercises the proper priority in our busy lives.
  • Our diets have become inadequate. A major driver of this phenomenon is loss of appetite which results in decreased caloric intake. However, physical disability, isolation, and insufficient income also contribute.

Some of you may be saying “So what? I wasn’t planning on being a champion weightlifter in my golden years.” The “So what” is that 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 things that we can do to prevent it. The most important thing that we can do to prevent muscle loss as we age is to exercise – and I’m talking about resistance (weight) training, not just aerobic exercise.

But we also need to optimize our protein intake and our leucine intake. Protein is important because our muscle fibers are made of protein.

Leucine is an essential amino acid. It is important because it stimulates the muscle’s ability to make new protein. Leucine and insulin act synergistically to stimulate muscle protein synthesis after exercise.

In a previous issue of “Health Tips From the Professor” I shared studies showing that the amount of protein and leucine we need to prevent muscle loss increases as we get older. The study (ME Lixandrao et al, Nutrients, Volume 13, Issue 10, 10.3390/nu13103536) I am reviewing today is an update on the leucine needs for seniors.

How Was This Study Done?

clinical studyThe investigators recruited 67 healthy, elderly, overweight adults (34 men and 33 women; average age = 69.7; average BMI = 26.4) in Basel, Switzerland for the study. The participants selected for the study were not engaged in any kind of regular resistance or aerobic training in the previous 6 months.

Participants were asked to fill in three 24-hour dietary recalls (2 on non-consecutive weekdays and one on a weekend day). A trained nutritionist gave instructions on how to perform the dietary recalls. After the dietary recalls were completed, the nutritionists used pictures of foods included in each participant’s diet recall to confirm the accuracy of their portion size estimates. This diet information was used to calculate habitual daily protein and leucine intake.

The investigators used magnetic resonance imaging (MRI) to measure quadriceps cross-sectional area – a measure of muscle mass. They also used performance on a leg extension machine to measure unilateral maximum dynamic muscle strength – a measure of muscle strength.

The study correlated leucine intake with both muscle mass and muscle strength. The data were corrected for sex, age, and total protein intake normalized to body weight.

How Much Leucine Do Seniors Need? 

leucineThere was a biphasic correlation between leucine intake and both muscle mass and muscle strength in this population.

  • There was a positive association between leucine intake and muscle mass up to 7.6 gm/day. After that a plateau was reached. Additional leucine had no effect on muscle mass.
  • There was a positive association between leucine intake and muscle strength up to 8.0 gm/day. After that a plateau was reached. Additional leucine had no effect on muscle strength.
  • These associations held true even after correcting for total protein intake. This is an important control because none of these participants were taking a leucine supplement, so those consuming more leucine were also consuming more protein.

The authors concluded, “We demonstrated that total daily leucine intake is associated with muscle mass and strength in healthy older individuals, and this association remains after correcting for multiple factors, including overall protein intake. Furthermore, our…analysis revealed…a potential threshold for habitual leucine intake, which may guide future research on the effect of chronic leucine intake in age-related muscle loss [sarcopenia].

Randomized control trials should test the utility of additional leucine to counteract frailty in the elderly.”

What Does This Study Mean For You?

ConfusionLet me start by saying that leucine is not a “magic bullet” that will prevent sarcopenia (age-related loss of muscle mass) by itself. Three things are essential for preventing sarcopenia:

  • Resistance (weight bearing) exercise. You should aim for at least 3 days/week of moderate intensity weight bearing exercise a week.

If you have physical limitations, consult with your health professional before beginning an exercise program. And if you have not done weight bearing exercise before, it is best to start with instruction from a personal trainer to be sure you are using appropriate weights and appropriate form.

[Note: The participants in this study had not done weight bearing exercise for 6 months prior to the study and did not exercise during the study.]

  • Adequate protein. I have discussed this in a previous issue of “Health Tips From the Professor”. If you are in your 30’s, 15-20 grams of protein per meal will do. But if you are in your 60’s and above, it’s better to aim for 25-30 grams of protein per meal.

[Note: On average the men in this study were consuming 87 grams of protein per day. That’s 29 grams per meal. The women in this study averaged 67 grams of protein per day or 22 grams per meal. So, most of the participants in this study were consuming adequate protein.]

  • Adequate leucine. This study showed that the benefits of leucine plateaued at around 7.6-8.0 grams per day or 2.5 to 2.7 grams per meal for non-exercising adults in their 60’s and 70’s.

This is in close agreement with studies showing that 25-30 grams of protein and 2.7 grams of leucine were optimal for seniors in this age range following weight bearing exercise.

[Note: This study only determined the optimal intake of leucine. Remember for maximal effectiveness at reducing age-related muscle mass (sarcopenia) you need optimal protein, optimal leucine, and an optimal resistance (weight bearing) exercise program.]

Where Can Seniors Find The Protein And Leucine They Need?

For most Americans this is not too difficult as the table above shows. If you look at single foods, chicken and soybeans are the best sources of both protein and leucine. Other meats and other beans & legumes are also good choices.

I included things like eggs, dairy foods, broccoli, and spinach as a reminder that you don’t need to get all your protein and leucine from a single food source. Other whole foods included in your meal can contribute to your protein and leucine totals.

This table also shows that you don’t need to be a carnivore to get the protein and leucine you need. However, if you avoid most meats or are a pure vegan, you will need to plan your diet a bit more carefully.

Finally, if you are looking to optimize your workouts with an after-workout plant-based protein shake, soy protein would be your best choice. If you chose plant protein, you should look for high-quality protein shakes with added leucine to make sure you meet both your protein and leucine goals.

The Bottom Line

Most Americans lose lean muscle mass as we 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.

  • Exercise – and I’m talking about resistance (weight) training, not just aerobic exercise. This is the most important thing that we can do to prevent muscle loss as we age.
  • Optimize our protein intake.
  • Optimize our leucine intake.

Previous studies have determined the optimal protein intake for preventing sarcopenia. The study I describe above determined the optimal leucine intake.

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

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

______________________________________________________________________________

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

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

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

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

 ______________________________________________________________________

About The Author 

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

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

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

Is HDL Good For Your Heart?

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Is Everything You Knew About HDL Wrong?

Author: Dr. Stephen Chaney 

HDL CHolesterolIn last week’s “Health Tips From the Professor” I talked about one of the greatest strengths of the scientific method – namely that investigators constantly challenge, and occasionally disprove, existing paradigms. That allows us to discard old models of how things work and replace them with better ones.

Last week I shared a study that disproved the paradigm that low to moderate alcohol consumption is healthier than total abstinence. This week I share several studies that challenge the belief that HDL cholesterol is good for your heart.

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

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

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

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

But what if the underlying HDL/heart health paradigm weren’t true? These hypotheses would be like the parable of a house built on a foundation of sand. The paradigm will be washed away as soon as it is critically tested.

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

Do Drugs That Increase HDL Levels Work?

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

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

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

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

That was 16 years ago, and no HDL-increasing drug has made it to market. Have they just not found the right drug, or does this mean the HDL/heart health paradigm is incorrect?

Does Saturated Fat Decrease Heart Disease Risk?

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

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

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

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

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

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

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

Is HDL Good For Your Heart?

strong heartOnce the studies were published showing that…

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

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

But before I describe the study, I need to review the term “confounding variables”. I described the term and how it affects clinical studies in last week’s article. Here is a brief synopsis:

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

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

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

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

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

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

  • 7.1% reduction in heart disease events (both heart disease deaths and non-fatal heart attacks).
  • 7.2% reduction in heart disease deaths.
  • 4.4% reduction in total deaths.

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

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

In other words, this study:

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

Is Everything You Knew About HDL Wrong?

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

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

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

And if you want to go the drug route:

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

On the other hand:

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

The Bottom Line 

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

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

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

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

In other words, this study:

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

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

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

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

____________________________________________________________________________

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

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

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

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

Best Way To Reduce Risk Of Breast Cancer

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What Does The American Cancer Society Say About Reducing Breast Cancer Risk? 

Author: Dr. Stephen Chaney

breast cancerBreast cancer is a scary disease. The American Cancer Society tells us:

  • 281,000 women will be diagnosed with invasive breast cancer in 2021.
  • 43,000 women will die from breast cancer in 2021.
  • The good news is that both prevention and treatment of breast cancer have gotten much better:
    • The 5-year survival rate is 90%.
    • The 10-year survival rate is 84%.
    • For women over 50 the death rate has decreased by 1%/year between 2013 and 2018 (mainly due to recognition that hormone replacement therapy is a risk factor for breast cancer).
  • The bad news is:
    • The cost of breast cancer treatment can range from $50,000 to over $180,000.
    • The side effects of breast cancer treatment can be brutal.
      • For example, there is an effective treatment to prevent breast cancer recurrence for some forms of breast cancer, but many women discontinue the treatment after a few years because of the side effects.

So, wouldn’t it be wonderful if there were some simple changes you could make that would dramatically reduce your risk of developing breast cancer in the first place? There are lots of options for reducing your risk of developing breast cancer, but which one(s) should you choose?

  • Dr. Strangelove and his friends are only too happy to recommend their favorite potion, food, or diet.
  • There are long lists of foods you should avoid if you want to reduce your risk of breast cancer.
  • There are also lists of harmful chemicals in cleaners and other household products that you should avoid.

It can become confusing. It can become overwhelming. It would be easy to just throw up your hands and say, “I give up. I don’t know what to do.”

You may be thinking, “Why doesn’t someone simplify things by identifying the top few lifestyle changes that are most effective for reducing my risk of developing breast cancer?”

It turns out someone has. Today I will share two recent studies that have identified the top 6 strategies for reducing your risk of breast cancer, and I have ranked them from 1 to 6 in order of effectiveness.

What Is The Best Way To Reduce Risk Of Breast Cancer?

AwardThe first study (RM Tamimi et al, American Journal of Epidemiology, 184: 884-893, 2016 was designed to identify the major modifiable risk factors for invasive, postmenopausal breast cancer (The term “modifiable risk factors” refers to those risk factors that are under your control.

The study utilized data collected from the Nurses’ Health Study between 1980 and 2010. During that time 8,421 cases of invasive breast cancer were diagnosed in 121,700 postmenopausal women in the study. The study looked at the effect of nonmodifiable and modifiable risk factors on the development of invasive breast cancer in these women.

  • Nonmodifiable risk factors included current age, age at which menstruation began, height, age of first birth, number of births, weight at age 18, family history of breast cancer, and prior benign breast disease.
  • Modifiable risk factors included weight change since age 18, alcohol consumption, physical activity level, breastfeeding, and postmenopausal hormone therapy use.

Here were the results from the study:

  • All the risk factors included in this study accounted for 70% of the risk of developing invasive breast cancer in postmenopausal women.
  • Modifiable risk factors accounted for 34.6% of the risk of developing invasive breast cancer in postmenopausal women.

When they analyzed the effect of modifiable risk factors on the risk of developing invasive breast cancer separately:

  • 44 pounds of weight gain since age 18 increased the risk by 50%.
  • Postmenopausal hormone replacement use increased the risk by 35%.
  • More than one alcoholic beverage/day increased the risk by 32%.
  • Low physical activity increased the risk by 7%.
  • Lack of breastfeeding increased the risk by 5%.

What About The Effect Of Diet On Breast Cancer Risk?

You may be wondering, “What about the effect of a healthy diet on my risk developing invasive breast cancer?” Unfortunately, the study I described above completely disregarded the effect of diet on breast cancer risk.

However, the second study (MS Farvid et al, International Journal of Cancer, 144: 1496-1510, 2019) I will discuss today partially addresses this issue. It uses the same database as the first study and looks at the effect of fruit and vegetable consumption on the risk of developing invasive breast cancer.

When this study compared high versus low intake of fresh fruits and vegetable on the risk of developing invasive breast cancer:

  • Women eating >5.5 servings/day of fruits and vegetables had a 11% lower risk than women consuming ≤2.5 servings/day.
  • Women consuming >2.5 servings/day of fruit had a 9% lower risk than women consuming ≤0.5 servings/day.
  • Women consuming >4.5 servings/day of vegetables had a 9% lower risk than women consuming ≤0.5 servings/day.

While all fresh fruits and vegetables contributed to this effect:

  • The most protective fruits were berries and cantaloupe & melons.
  • The most protective vegetables were yams & sweet potatoes, green leafy vegetables (such as kale, mustard greens, and chard), and cruciferous vegetables (such as Brussels sprouts).

The authors concluded, “Our findings support that higher intake of fruits and vegetables, and specifically cruciferous and yellow/orange vegetables, may reduce the risk of breast cancer, especially those that are more likely to be aggressive tumors.”

Now we are ready to answer your question, “Which lifestyle changes are most effective for reducing your risk of developing breast cancer?” If we combine the two studies and rank order the modifiable risk factors, it would look like this.

#1: Minimize weight gain during your adult years.

#2: Don’t use postmenopausal hormone replacement therapy unless absolutely necessary.

#3: Drink little or no alcohol.

#4: Eat a healthy diet with lots of fresh fruits and vegetables.

#5: Be physically active.

#6: Breastfeed when possible.

What Does The American Cancer Society Say About Reducing The Risk Of Breast Cancer?

American Cancer SocietyThe advice of the American Cancer Society is remarkably similar. Here are their recommendations:

  1. Get to and stay at a healthy weight.

After menopause, most of your estrogen comes from fat tissue. Having more fat tissue increases the amount of estrogen your body makes, raising your risk of breast cancer. Also, women who are overweight tend to have higher levels of insulin. Higher insulin levels have also been linked to breast cancer.

If you are already at a healthy weight, stay there. If you are carrying extra pounds, try to lose some. Losing even a small amount of weight can also have other health benefits and is a good place to start.

3) Be physically active and avoid time spent sitting.

Current recommendations are to get at least 150-300 minutes of moderate intensity or 75-150 minutes of vigorous intensity activity each week. Getting to or exceeding 300 minutes is ideal.

In addition, you should limit sedentary behavior such as sitting, lying down, watching TV, and other forms of screen-based entertainment. This is especially important if you spend most of your working day sitting.

3) Follow a healthy eating plan.

A healthy eating pattern includes a variety of vegetables, fiber-rich legumes (beans and peas), fruits in a variety of colors, and whole grains. It is best to avoid or limit red and processed meats, sugar-sweetened beverages, highly processed foods, and refined grain products. This will provide you with key nutrients in amounts that help you get to and stay at a healthy weight.

4) It is best not to drink alcohol.

Research has shown that drinking any alcohol increases the risk of breast cancer. If you choose to drink alcohol, the American Cancer Society recommends that women have no more than 1 alcoholic drink on any given day. A drink is 12 ounces of regular beer, 5 ounces of wine, or 1.5 ounces of hard liquor.

5) Think carefully about using hormone replacement therapy.

Studies show that HRT using a combination of estrogen and progestin increases the risk of breast cancer. This combination can also lead to increased breast density making it harder to find breast cancer on mammogram.

Talk with your doctor about all the options to control your menopause symptoms, including the risks and benefits of each. If you decide to try HRT, it is best to use it at the lowest dose that works for you and for as short a time as possible.

The Bottom Line

Breast cancer is a scary disease. The good news is that detection and treatment of breast cancer has improved over the past decade. The bad news is that treatment is expensive, and the side effects can be brutal.

There are lots of options for reducing your risk of developing breast cancer, but which one(s) should you choose?

  • Strangelove and his friends are only too happy to recommend their favorite potion, food, or diet.
  • There are long lists of foods you should avoid if you want to reduce your risk of breast cancer.
  • There are also lists of harmful chemicals in cleaners and other household products that you should avoid.

It can become confusing. It can become overwhelming. It would be easy to just throw up your hands and say, “I give up. I don’t know what to do.”

You may be thinking, “Why doesn’t someone simplify things by identifying the top few lifestyle changes that are most effective for reducing my risk of developing breast cancer?”

It turns out someone has. Today I will share two recent studies that have identified the top 6 strategies for reducing your risk of breast cancer, and I have ranked them from 1 to 6 in order of effectiveness in the article above.

For more details about these studies, my ranking of the top 6 strategies for reducing your risk of breast cancer, and the American Cancer Society recommendations, 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.

Do Collagen Supplements Build Muscle?

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Could Collagen Supplements Make You Leaner? 

Author: Dr. Stephen Chaney

Sports SupplementsCollagen supplements have been considered “vanity products”. Their largest market is people who want to have younger, more beautiful skin. And for many people, collagen delivers on this promise.

However, collagen plays many other roles in the body. It also helps rebuild tendons and ligaments. Many people take collagen supplements to reduce joint pain.

But could collagen supplements coupled with resistance training also build muscle and reduce fat? If so, that would be huge.

A recent study (D Zdzieblik et at, British Journal of Nutrition, 114: 1237-1245, 2015) suggested collagen supplements may do just that. This study showed that a collagen supplement plus resistance training increased lean muscle mass and decreased fat mass in elderly men (average age = 72).

If this finding is duplicated in future studies, it has significant health implications. Both men and women in their 70s lose muscle mass at a rapid rate (a process called sarcopenia). Anything that slows or reverses this process has the potential to extend high quality life and prolong their golden years.

But what about younger adults? Could a collagen supplement plus resistance training also help them build muscle and lose fat? This study (D Zdzieblik et at, International Journal of Environmental Research and Public Health, 18: 4837-4855, 2021) was designed to answer that question.

It was a randomized, placebo-controlled study comparing 15 g of collagen peptides with 15 g of whey protein, and a placebo (silicon dioxide).

How Was This Study Done?

couch potatoThe study recruited 120 middle-aged (average age = 50), overweight (average BMI = 30) men who were untrained (<60 minutes of exercise per week over the previous year). [In other words, the study recruited middle-aged couch-potatoes.]

The participants were asked to fill out a three-day diet analysis at the beginning and end of the 12-week study with the assistance of a nutritionist.

  • Average caloric intake was 2,600 calories/day.
  • Average protein intake was 104 grams/day. That is 30% higher than the recommended protein intake for men of that age and weight.
  • The macronutrient content of the diet was 16% protein, 37% fat, and 43% carbohydrate.
  • These values were not significantly different between groups and did not change during the study.

All participants participated in a one-hour training program three times per week. The training began with a 10-minute cardio exercise to warm up. That was followed by a three-set program consisting of horizontal leg presses (both legs), reverse crunches, lat-pull exercise, sit-ups, and chest presses with 1 to 2 min rest periods between sets. The intensity of exercise was gradually increased over the 12-week study.

The participants were randomly divided into three groups. After each workout they were given sachets containing 15 g of collagen peptides, 15 g of whey isolate, or 15 g of silicon dioxide (placebo). They were instructed to dissolve the powder in 8 ounces of water and drink it within one hour of the workout. They were also given the same sachets and instructed to take them at the same time of day for the days they were not working out.

Finally, the participants were instructed not to change their diet or physical activity apart from the intake of the powder in the sachets they were given and the one-hour training sessions.

Do Collagen Supplements Build Muscle?

Collagen Supplement & Muscle MassAll three groups had statistically significant:

  • Increases in percent lean muscle mass.
  • Decreases in percent fat mass.
  • Increases in leg muscle strength.

No surprises here. If you take a group of middle-aged couch-potatoes and put them in a strength training program, you will see increases in lean muscle mass, decreases in fat mass, and increases in muscle strength.

The real question was what was the effect of the collagen and whey protein supplements? This is where the results got really interesting.

  • The collagen peptide supplement gave a significantly greater increase in lean muscle mass and decrease in fat mass than the placebo. The increase in leg muscle strength was also greater than the placebo, but this difference was not statistically significant.
  • The whey protein supplement also increased lean muscle mass and decreased fat mass compared to the placebo, but these differences were not statistically different.

In other words, at the doses used in this study (see next section for discussion), the collagen supplement worked better than the whey protein supplement. Here is the actual data from the study:

  • Increase in percent lean muscle mass: collagen supplement = 7.4%, whey protein supplement = 5.8%. placebo = 5.0%.
  • Decrease in percent fat mass: collagen supplement = 15%, whey protein supplement = 11.5%, placebo = 10%.

In the words of the authors, “In conclusion, collagen peptide supplementation combined with resistance training was associated with a significantly greater increase in fat free mass and a decrease in fat mass compared with placebo. Resistance training combined with whey protein also had a positive impact on body composition, but the respective effects were more pronounced following the collagen peptide administration.”

Could Collagen Supplements Make You Leaner?

strengths-weaknessesThis study leaves lots of questions. Let me handle the main ones here.

What Are The Strengths and Weaknesses Of The Study?

The strengths are obvious. This was a well-design, randomized, placebo-controlled clinical trial, which is the gold standard for determining the efficacy of a treatment.

The weaknesses are also obvious. This was a very small clinical study. There is one previous study that showed the same benefit of collagen in an older age group. However, both studies were published by the same group of scientists. And these scientists were funded by the manufacturer of the collagen product used in the study. More and larger studies performed by other laboratories are needed to confirm this finding.

How Do Resistance Exercise, Whey Protein, And Collagen Stimulate Muscle Growth?

Muscle growth is stimulated by a regulatory pathway called mTOR that (among other things) regulates protein Weight Trainingsynthesis in muscle cells. For the purposes of this article, I will discuss 3 mechanisms for activating mTOR and increasing muscle protein synthesis.

#1: Resistance exercise (weight training) activates mTOR. That should come as no surprise. The main reason people do weight training is to increase strength and muscle mass. mTOR is the pathway that makes this possible.

#2: Whey protein is rich in the essential amino acid leucine, and leucine also stimulates the mTOR pathway.

  • Leucine is one of three branched chain amino acids. While all three branched chain amino acids have been traditionally credited with stimulating muscle protein synthesis, recent research has shown that only leucine is needed. The other two branched chain amino acids just play a supportive role. You only need enough of the them to make a complete protein.
  • While whey protein gets all the attention in the sports world, any complete protein with high levels of leucine has the same effect.
  • The effect of leucine and resistance training on the mTOR pathway are additive. That is why whey and other leucine-rich proteins enhance the effect of resistance exercise on both muscle mass and strength.

#3: Collagen does not contain enough leucine to activate the mTOR pathway. However, the authors have proposed another mechanism to account for collagen activation of the mTOR pathway.

  • Most proteins we eat are digested to their individual amino acids before they are absorbed. However, collagen is rich in an unusual amino acid called hydroxyproline that makes collagen resistant to our digestive enzymes.
  • Thus, collagen is not digested to individual amino acids, but to small peptides that are absorbed from our intestine.
  • One of these breakdown products, a dipeptide composed of glycine and hydroxyproline, has been shown to stimulate the mTOR pathway.

While this mechanism has not been proven, collagen does appear to enhance the effect of resistance exercise on both muscle mass and strength.

Collagen Only Has 8 Essential Amino Acids. How Could It Stimulate The Synthesis Of Muscle Protein, Which Requires 9 Essential Amino Acids?

Question MarkThe answer is simple. The people in this study were consuming 30% more than the recommended amount of protein in their diet in addition to the collagen supplement. They already had all the essential amino acids needed to synthesize muscle protein. The collagen supplement simply stimulated the rate of muscle protein synthesis by activating the mTOR pathway.

However, there are situations in which the 9th essential amino acid could become important for muscle protein synthesis. Here are two examples

  • Vegans and strict vegetarians might not be getting enough protein in their diet. As I pointed out in a previous article vegan “experts” know how to get enough protein from their diet, but many vegan “novices” do not.
  • Older Americans are also at risk. They need extra protein in their diet to prevent sarcopenia (muscle loss) as they age. And some of them are on restrictive diets, either because of the latest fad or because of loss of income and/or mobility.

Why Did The Collagen Supplement Work Better Than Whey Protein In This Experiment? 

Again, the answer is simple. Both collagen and leucine-rich proteins like whey enhance muscle protein synthesis by activating the mTOR pathway (see above). This study used the same amount of protein (15 g/day) for both collagen supplement and the whey protein supplement.

While 15 g/day appears to be optimal for the collagen supplement, the authors pointed out that previous studies suggest that the optimal dose for whey protein is closer to 20 g/day for middle-aged men.

So, I would ignore the apparent difference in effectiveness of the collagen and whey protein supplements.

The important conclusion is that both collagen and leucine-rich proteins like whey enhance the effect of resistance exercise on lean muscle mass to a similar extent. But they appear to do so by slightly different mechanisms.

What Does This Mean For You?

This study is intriguing. It suggests that collagen may have some tricks up its sleeve we didn’t know about.

  • It may do more than give you a healthy, youthful looking skin.
  • It may do more than help with achy joints.
  • Coupled with resistance exercise it may also help you increase muscle mass and reduce fat mass. It may make you leaner.

The Bottom Line

Collagen supplements have been considered “vanity products”. Their largest market is people who want to have younger, more beautiful skin. And for many people, collagen delivers on this promise.

However, collagen plays many other roles in the body. It also helps rebuild tendons and ligaments. Many people take collagen supplements to reduce joint pain.

But collagen may have other tricks up its sleeve. A recent study suggests that collagen supplements may enhance the effect of resistance exercise on increased muscle mass and reduced fat mass. It may make you leaner.

The study also concluded that both collagen and whey protein enhance the effect of resistance exercise on lean muscle mass to a similar extent. But they appear to do so by slightly different mechanisms.

Let me be clear. I am not recommending you take a collagen supplement to help you build muscle mass. I consider these results as preliminary, and we have good evidence that leucine-rich proteins plus resistance exercise helps build muscle mass. 

However, if you are taking a collagen supplement for another reason and are working out, this could be an unexpected benefit.

For more details about this study and how collagen supplements may increase muscle mass, 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.

Are Carnitine Supplements Good For You Or Bad For You?

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What Is The Truth About Carnitine And TMAO?

BodybuilderIf you are a weightlifter or bodybuilder, chances are you are taking an L-carnitine supplement or a protein shake fortified with L-carnitine. That is because L-carnitine has been promoted for increasing muscle mass and physical performance for so long that most people have come to believe it must be true. Is it true, or is it just another food myth?

If you visit Dr. Strangelove’s website, you may also be told that carnitine supplementation is beneficial for weight loss, migraines, baldness, ADHD and autism, chronic fatigue syndrome, and/or low energy, muscle loss, and cognitive decline in older adults. Are these claims fact or fiction?

On the flip side, recent studies have suggested that the carnitine in red meat might be bad for your heart. Could the same be true for carnitine supplements? Could they also be bad for your heart?

A recent systematic review (AG Sawicka et al, Journal of the International Society of Sports Nutrition, 17: 49, 2020) of L-carnitine supplementation answers these important questions. The authors called their study “The bright and dark sides of L-carnitine supplementation” because they set out to systematically investigate the benefits and potential risks of L-carnitine supplementation.

But before I share the results of this study, I need to give you a little background on L-carnitine. It is time for another Biochemistry 101 segment.

Biochemistry 101: What You Need To Know About Carnitine

professor owlCarnitine plays an essential role in human metabolism. It is required for transport of fatty acids into our mitochondria so they can be used to generate energy. Without carnitine we would be unable to utilize most of the fats in our diet as an energy source.

As you might expect, carnitine is essential for any tissues that have mitochondria, but it is particularly important for high energy tissues like skeletal and heart muscle.

For most of us, our liver and kidneys make all the carnitine we need. So, we don’t really need carnitine from food or supplements.

However, we do get significant amounts of carnitine from red meat, much smaller amounts of carnitine from other animal foods, and almost no carnitine from plant foods. Adults consuming diets with red meat and other animal foods get about 60-180 mg of carnitine a day from their diet, whereas vegans only get around 10-12 mg/day.

Uptake of carnitine from the blood into muscle tissues requires insulin. Thus, carnitine uptake into muscle is significantly less on a low-carbohydrate or keto diet than it is on a mixed diet containing carbohydrates.

Finally, our kidneys do an excellent job of regulating blood carnitine levels, with excess carnitine being excreted into the urine. Thus, total body carnitine levels are virtually the same with high-carnitine and low-carnitine diets.

Question MarkThis raises the question: “Are L-carnitine supplements good for you?”

Now, let’s talk about the dark side of carnitine. I have discussed this in a previous issue of “Health Tips From the Professor”. Here is a brief summary:

  • People who eat a lot of red meat harbor a species of bacteria in their intestine that converts carnitine to trimethylamine (TMA). We don’t know whether this species of gut bacteria is favored by the presence of red meat in the diet or the absence of certain fruits, whole grains, and legumes from the diet of meat eaters.
  • The TMA is reabsorbed into the bloodstream, and the liver converts TMA to TMAO (trimethylamine N-oxide).
  • TMAO is associated with an increased risk of heart attack, stroke, and heart failure.

When you think about it, this is a perfect example of double jeopardy. Red meat is high in carnitine, and red meat eaters have gut bacteria that result in carnitine being converted to a compound that may increase the risk of heart disease.

This raises the question: “Are L-carnitine supplements bad for you?”

Let’s look at these two questions. First, I will discuss the recent review. Then I will put the conclusions of that review into perspective by looking at what other health experts say.

Are Carnitine Supplements Good For You Or Bad For You?

good news bad newsMost previous studies of carnitine supplementation have lasted only two or three weeks, which may not be long enough to measure an effect of carnitine supplementation on performance. So, the authors of this review paper selected studies that lasted 11 weeks or more for their review.

The review included 11 studies. They lasted either 12 or 24 weeks. Participants received doses ranging from 1 gm to 4.5 gm of L-carnitine per day. Here are the conclusions of the review:

  • Participants receiving L-carnitine alone had no increase in muscle carnitine content.
  • Participants receiving L-carnitine + 80 grams of carbohydrate had around a 10% increase in muscle carnitine content. [To put that into perspective, 80 grams of carbohydrate is roughly equivalent to 2 cups of white rice or two medium potatoes.]
  • One study compared male vegetarians with male omnivores. The omnivores had no increase in muscle carnitine content, but the vegetarians did. [The study did not analyze the diets of the omnivores and vegetarians, but it is probably safe to assume that the carbohydrate content was higher on the vegetarian diet.]
  • There was no significant effect of L-carnitine on muscle mass or physical performance. [This is logical, given the minimal effect of L-carnitine supplementation on muscle carnitine levels.

Thus, this review found little evidence that L-carnitine supplementation was good for you. It resulted in little or no increase in muscle carnitine levels or in physical performance.

  • Two of the 11 studies measured plasma TMAO levels. These studies found that L-carnitine supplementation resulted in a significant increase in plasma TMAO levels.

Thus, this review found some evidence that L-carnitine supplementation might be bad for you.

What Is The Truth About Carnitine And TMAO?

the truth signIs carnitine good for you? With respect to this question, the conclusions of this review are similar to the conclusions of other health experts. For example, in their Fact Sheet On Carnitine For Health Professionals the NIH states “Some athletes take carnitine to improve performance. However, twenty years of research finds no consistent evidence that carnitine supplements can improve exercise or physical performance in healthy subjects—at doses ranging from 2–6 grams/day administered for 1 to 28 days. For example, carnitine supplements do not appear to increase the body’s use of oxygen or improve metabolic status when exercising, nor do they necessarily increase the amount of carnitine in muscle.”

The NIH fact sheet goes on to list some diseases causing muscle loss or muscle weakness, for which L-carnitine supplementation is appropriate. However, in these cases, the carnitine supplementation should be recommended by health professionals.

Is carnitine bad for you? The TMAO story is a bit more complicated. As I mentioned above, there is an association between red meat consumption and blood TMAO levels and an association between blood TMAO levels and heart disease.

Is it TMAO that increases the risk of heart disease or is it some other component (saturated fat, for example) of red meat that increases the risk of heart disease? Nobody knows. More research is needed.

There is also a “red herring” that complicates the TMAO story. It turns out that TMAO helps fish survive the high pressures they encounter in the deep ocean. Thus, many fish are high in TMAO, and fish consumption also increases blood TMAO levels.

Are the bad effects of TMAO in fish outweighed by the heart healthy components in fish (omega-3s, for example)? Nobody knows. More research is needed.

To summarize:

  • There is no reason to take L-carnitine supplements unless directed by your health professional. There is little evidence they will help your physical performance. There is also no good evidence to support the other benefits of L-carnitine you find listed on Dr. Strangelove’s blog or the website of your favorite supplement company.
  • L-carnitine supplements may be bad for your heart, but much more research will be needed to be sure. [Note: Based on what we know about the role of gut bacteria in TMAO production, vegans could probably take l-carnitine supplements without causing an increase in TMAO levels. However, that is probably a moot point. There is no evidence that L-carnitine is more effective for vegans than it is for omnivores.]

The Bottom Line 

If you are a weightlifter or bodybuilder, chances are you are taking an L-carnitine supplement or a protein shake fortified with L-carnitine. That is because L-carnitine has been promoted for increasing muscle mass and physical performance for so long that most people have come to believe it must be true. Is it true, or is it just another food myth?

On the flip side, recent studies have suggested that the carnitine in red meat might be bad for your heart. Could the same be true for L-carnitine supplements? Could they also be bad for your heart?

A recent review looked at these questions. Here are the conclusions of the review:

  • Participants receiving L-carnitine alone had no increase in muscle carnitine content.
  • Participants receiving L-carnitine + 80 grams of carbohydrate had around a 10% increase in muscle carnitine content. [To put that into perspective, 80 grams of carbohydrate is roughly equivalent to 2 cups of white rice or two medium potatoes.]
  • There was no significant effect of L-carnitine on muscle mass or physical performance. [This is logical, given the minimal effect of L-carnitine supplementation on muscle carnitine levels.

Thus, this review found little evidence that L-carnitine supplementation was beneficial. It resulted in little or no increase in muscle carnitine levels or in physical performance.

  • This review also found that L-carnitine supplementation resulted in a significant increase in plasma TMAO, a compound that has been associated with an increased risk of heart disease.

Thus, this review found some evidence that L-carnitine supplementation might be bad for you.

The NIH has also issued a fact sheet for health professionals summarizing research on L-carnitine over the past 20 years. The conclusions from their fact sheet can be best summarized as:

  • There is no reason to take L-carnitine supplements unless directed by your health professional. There is little evidence they will help your physical performance. There is also no good evidence to support the other benefits of L-carnitine you find listed on Dr. Strangelove’s blog or the website of your favorite supplement company.
  • L-carnitine supplements may be bad for your heart, but much more research will be needed to be sure.

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.

Is The Keto Diet Best For Endurance Exercise?

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Where Do Food Myths Come From?

ketogenic dietI don’t need to tell you that the keto diet is popular right now. It is touted for weight loss, mental sharpness, and improved health. I discuss the accuracy of those claims in my book, “Slaying the Food Myths”.

Perhaps more surprising has been the adoption of the keto diet by so many endurance athletes. As I point out in my book, there is a kernel of truth for that idea. Fats and ketone bodies are a very efficient energy source for low to moderate intensity exercise, and we have a virtually unlimited source of stored fat that can be converted to ketone bodies.

However, I always add this caveat, “The keto diet is perfect for endurance exercise – as long as you don’t care how fast you get there”. That is because high intensity exercise requires muscle glycogen stores, which come from the carbohydrates we eat. When you cut carbs from the diet, you deplete your glycogen stores.

And, if you are running a marathon and you want to sprint to the finish line, you will need those muscle glycogen stores. Or, if you are in a cycling event and you want to power up a mountain, you will need those glycogen stores.

Of course, you are probably asking, “Why do so many endurance athletes swear by the keto diet?” There is a dirty little secret behind athlete endorsements. I’m not talking about the money that top athletes get paid for endorsements, although that is also a problem.

I’m talking about the testimonials you hear from your friend who runs marathons or your personal trainer. Unfortunately, testimonials from athletes are notoriously unreliable. The problem is that the placebo effect approaches 70% for athletes.

Competitive athletes are strong willed. If they think a diet or sports nutrition product will help them, they will themselves to a higher level of performance. And this happens subconsciously. They aren’t even aware that their mind is influencing their performance.

So, just because your favorite athlete endorses the keto diet doesn’t mean it is the perfect diet for you. Testimonials can be very misleading.

The important question to ask is, “Do clinical studies support the keto diet as the best diet for endurance exercise?” But, before I answer that question, let me frame the question by asking. “Where do food myths come from?” because the belief that keto diets are best for endurance exercise is a classic food myth.

Where Do Food Myths Come From?

I discussed this question at length in my book, “Slaying The Food Myths”. Let me summarize it briefly here.

Secrets Only Scientists Know: First you need to know the secrets only scientists know. Here are the top 2:

#1: Scientists design their studies to disprove previous studies. There is no glory for being the 10th person to confirm the existing paradigm. The glory comes from being the first to show the existing paradigm might be wrong. While this may seem to be a contrary approach, it is actually the strength of the scientific method.

However, it means that there will be published clinical studies on both sides of every issue.

#2: Every study has its flaws. There is no perfect study.

This is why the scientific community doesn’t base their recommendations on 2 or 3 published studies. We wait until there are 10 to 20 good quality studies and base our recommendations on what 90% of them show.

Now, let me contrast the scientific approach with how food myths are born.

Where Do Food Myths Come From? Food myths usually originate on blogs or websites. Often the articles are written by people with no scientific credentials. But some of them are written by doctors (I will call them Dr. Strangelove to “protect the guilty”). The articles they write have these things in common:

cherry picking studies

  • The articles are based on the biases of the author. No effort is made to look at the other side of the story.
  • The authors “cherry pick” studies that support their bias and ignore studies that contradict them.
  • They use scientific-sounding mumbo jumbo to make their hypothesis sound credible.
  • Their articles are usually spectacular. For example, they say things like, “A particular diet, food, or supplement will either cure you or kill you”, and/or “The medical community is hiding the truth from you.”
  • They never let the facts get in the way of a good story.

Since the idea sounds credible it is picked up by other blogs and websites without any fact checking (social media at its worst). Once it has been repeated often enough, it becomes generally accepted as true. It becomes a food myth. From that point on, studies that disprove the myth are often ignored.

How do you know whether a common belief is true, or just another myth? The only way to be sure is to take a balanced look at all the clinical studies, not just the studies that support the belief.

That is what the authors of a recent review paper (CP Bailey and E Hennessy, Journal of the international Society of Sports Nutrition, 17, Article number: 33, 2020) did for the belief that the keto diet is the best diet for endurance exercise.

Is The Keto Diet Best For Endurance Exercise?

CyclistsBefore I discuss the findings of the review article, there are two things you should know:

#1: There is little scientific research on the effectiveness of the keto diet on endurance exercise. After an exhaustive search of the literature, the authors were only able to find 7 published studies on the topic.

#2:Most sports nutrition studies are of poor quality. In general, they are very small studies, are of short duration, and do not use common test procedures to measure a successful outcome. These studies on keto diets were no different. For example:

    • The number of subjects in these studies ranged from 5 to 29 (average = 14).
    • The duration of time on the diet in these studies ranged from 3 weeks to 12 weeks (average = 5 weeks).
    • Tests used to measure the effectiveness of specific diets on endurance exercise were VO2max (the maximum amount of oxygen you can utilize during exercise), Time to exhaustion (how long you can exercise before you are exhausted), Rating of perceived exertion (feeling of fatigue at the end of the exercise), Race time (time required to complete an event), and Peak power output during the event.
    • Four studies used a treadmill to simulate endurance exercise. The other three used a stationary bike.
    • Five of the studies compared the keto diet to a high carbohydrate diet. Two studies used the keto diet only.

The results were all over the place:

Question Mark

  • Two studies reported an increase in VO2max for both the keto diet and the high carbohydrate diet. One study reported a decrease in VO2max for both diets. The other studies reported no change in VO2max. In short, there was no difference between the diets for VO2max.
  • One study reported a decrease in race time for the high carbohydrate diet and a non-significant increase in race time for the keto diet. Two other studies reported no effect of either diet on race time. In short, one study suggested the high carbohydrate diet was more effective at shortening race time. The other two studies found no effect of either diet.
  • Two studies showed an increase in time to exhaustion for both diets. One study showed a decrease in time to exhaustion for the keto diet (participants got tired more quickly). That study did not include the high carbohydrate diet for comparison. In short, there was no clear difference between the two diets for time to exhaustion.
  • One study showed that the group on the keto diet reported a higher rating of perceived exertion (were more tired) at the end of the endurance event than the group on the high carbohydrate diet. Another study found no difference between the two diets. In short, one study suggested the high carbohydrate diet was better with respect to perceived exertion (tiredness) at the end of the endurance event. Another study found no difference between the two diets.
  • One study reported that peak power was significantly greater for the group on the keto diet than the group on the high carbohydrate diet. One of the studies with the keto group reported that peak power decreased for 4 out of 5 subjects on the keto diet. In short, one study suggested that the keto diet was more effective at increasing peak power than the high carbohydrate diet. Another study suggested the keto diet decreased peak power.

The authors concluded: “When compared to a high carbohydrate diet, there are mixed findings for the effect of the keto diet on endurance performance…The limited number of published studies point to a need for more research in this field.” I would add that we need larger, better designed studies, with common measures of exercise performance.

What Does This Mean For You?

confusionYou may be wondering why I even bothered to talk about such poor-quality studies and a review that could not provide a definitive answer. In fact, that is exactly my point.

This is characteristic of the kind of “evidence” that Dr. Strangelove and his buddies present to support whatever food myth they are featuring on their website. They don’t know how to distinguish good studies from bad studies, and they “cherry pick” only the studies that support their food myth.

So, if you believe that the keto diet is best for endurance exercise, you can “cherry pick” the one published clinical study that supports your belief. You just need to ignore the other 6 published studies.

And, if you believe that a high carbohydrate diet is better for endurance exercise than the keto diet, you can “cherry pick” two clinical studies that support your belief. You just need to ignore the other 5 published clinical studies.

None of the studies are high-quality studies, and the effect of either diet on endurance exercise in these studies is miniscule.

In short, there is no convincing evidence that the keto diet is best for endurance exercise. Or, put another way, we do not have enough evidence to elevate that belief from a food myth to a recommendation we can confidently make for an endurance athlete.

The Bottom Line

A recent publication conducted an impartial review of the evidence for and against the popular belief that a keto diet is the best diet for endurance exercise. The review found only 7 poor-quality studies on this topic in the scientific literature, and the results of those studies were all over the map.

  • One study reported the keto diet was better than a high carbohydrate diet for endurance exercise.
  • Two studies reported that the high carbohydrate diet was better.
  • The other 4 studies were inconclusive.
  • None of the studies found a significant effect on endurance performance by either diet.

So, if you believe that the keto diet is best for endurance exercise, you can “cherry pick” the one published clinical study that supports your belief. You just need to ignore the other 6 published studies.

And, if you believe that a high carbohydrate diet is better for endurance exercise than the keto diet, you can “cherry pick” two clinical studies that support your belief. You just need to ignore the other 5 published clinical studies.

In short, there is no convincing evidence that the keto diet is best for endurance exercise. Or, put another way, we do not have enough evidence to elevate that belief from a food myth to a recommendation we can confidently make for an endurance athlete.

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.

Does Vitamin D Affect Muscle Strength?

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Why Is Vitamin D Research So Controversial?

vitamin dMost people lose muscle strength as they age, something called sarcopenia. This is not a trivial matter. Loss of muscle mass:

  • Leads to loss of mobility. It can also make it difficult to do simple things like lifting your grandchild or carrying a bag of groceries.
  • Increases your risk of falling. This often leads to serious fracture which increases your of dying prematurely. In fact, bone fractures increase your risk of dying by 3-fold or more. Even in those who recover their mobility and quality of life may never be the same.
  • Lowers your metabolic rate. This increases your risk of obesity and all the diseases that are associated with obesity.

Loss of muscle strength as we age is preventable. There are several things we can do to preserve muscle strength as we age, but in today’s article I will focus on the effect of vitamin D on muscle strength.

What if something as simple as preventing vitamin D deficiency could improve muscle strength as we age? That idea has been around for a decade or more. But, for reasons I will detail below, it has proven controversial. Let me start by sharing the latest study on vitamin D and muscle strength (N Aspell et al, Clinical Investigations in Ageing, volume 2019:14, pages 1751-1761).

How Was The Study Done?

Clinical StudyThe data for this study came from 4157 adults who were enrolled in the English Longitudinal Study On Aging. Participants in this study were all over the age of 60 and were still living in their own homes. The general characteristics of the study population were:

  • Their average age was 69.8 with 45% male and 55% female.
  • While 76% of the participants rated their health as “good” or above
    • 73% were overweight or obese.
    • 54% had a longstanding disease that limited mobility.
    • 29% were taking multiple medications.

Serum 25-hydroxy vitamin D levels were determined as a measure of vitamin D status.

  • 22% of the participants were vitamin D deficient (<30 nmol/L 25-hydroxy vitamin D).
  • 34% of the participants were vitamin D insufficient (between 30 and 50 nmol/L 25-hydroxy vitamin D).
  • 46% of the participants had adequate vitamin D status (>50 nmol/L 25-hydroxy vitamin D).

Muscle strength was assessed by a handgrip strength test with the dominant hand. Muscle performance was assessed with something called the short physical performance battery (SPPB), consisting of a walking speed test, a repeated chair raise test, and a balance test.

Does Vitamin D Affect Muscle Strength?

When the data on handgrip strength were analyzed:

  • Only 22% of the participants who had adequate vitamin D status had low handgrip strength.
  • 40% of participants who were vitamin D deficient had low handgrip strength. That’s almost a 2-fold difference.
  • Handgrip strength increased linearly with vitamin D status.
    • The relationship between vitamin D status and handgrip strength was highly significant (p<001).
    • The beneficial effect of vitamin D status on handgrip strength plateaued at around 55-69 nmol/L 25-hydroxy vitamin D. In other words, you need adequate vitamin D status to support muscle strength, but higher levels provide no additional benefit.

When the data on muscle performance (the SPPB test) were analyzed:

  • Only 8% of the participants who had adequate vitamin D status scored low on this test.
  • 25% of participants who were vitamin D deficient scored low on this test. That’s a 3-fold difference.
  • Muscle performance also increased linearly with vitamin D status.
    • The relationship between vitamin D status and muscle performance was also highly significant (p<001).
    • The beneficial effect of vitamin D status on muscle performance also plateaued at around 55-69 nmol/L 25-hydroxy vitamin D.

The authors concluded: “Vitamin D deficiency was associated with impaired muscle strength and performance in a large study of community-dwelling older people. It is generally accepted that vitamin D deficiency should be reversed to prevent bone disease. This strategy may also protect skeletal muscle function in aging.”

Why Is Vitamin D Research So Controversial?

ArgumentYou can be forgiven if you are saying to yourself: “I’ve heard this sort of thing before. I see a blog or headline claiming that vitamin D has a certain benefit, but it’s usually followed by later headlines saying those claims are false. Why can’t the experts agree? Is all vitamin D research bogus?”

The relationship between vitamin D status and muscle strength is no different.

  • Most, but not all, studies looking at the association between vitamin D status and muscle strength find that vitamin D status affects muscle strength.
  • However, many randomized, placebo-controlled clinical trials looking at the effect of vitamin D supplementation on muscle strength have come up empty.

A meta-analysis (L Rejnmark, Therapeutic Advances in Chronic Disease, 2: 25-37, 2011) of randomized, placebo-controlled clinical trials of vitamin D supplementation and muscle strength provides insight as to why so many of them come up empty.

The meta-analysis combined data from 16 clinical trials. The conclusions were similar to what other meta-analyses have found:

  • Seven of the studies showed a benefit of vitamin D supplementation on muscle strength. Nine did not.
  • When the data from all 16 studies were combined, there was only a slight beneficial effect of vitamin D supplementation on muscle strength.

However, it was in the discussion that the reason for these discrepancies became apparent. There were three major deficiencies in study design that were responsible for the discrepancies.

1) There was a huge difference in study design.

    • The subjects were of different ages, genders, and ethnicities.
    • The dose of vitamin D supplementation varied.
    • Different measures of muscle strength and performance were used.

Until the scientific and medical community agree on a standardized study design it will be difficult to obtain consistent results.

While this deficiency explains the variation in outcomes from study to study, there are two other deficiencies in Garbage In Garbage Outstudy design that explain why many of the studies failed to find an effect of vitamin D on muscle strength. I call this “Garbage In, Garbage Out”. Simply put, if the study has design flaws, it may be incapable of detecting a positive effect of vitamin D on muscle strength.

2) Many of the studies did not measure vitamin D status of the participants at the beginning of the study.

    • The results of the study described above show that additional vitamin D will be of little benefit for anyone who starts the study with an adequate vitamin D status.
    • In the study above 46% of the participants had adequate vitamin D status. This is typical for the elderly community. When almost 50% of the participants in a study have adequate vitamin D status at the beginning of a study it becomes almost impossible to demonstrate a beneficial effect of vitamin D supplementation on any outcome.

It is essential that future studies of vitamin D supplementation start with participants who have low vitamin D status. Otherwise, you are almost guaranteeing a negative outcome.

3) Most of the studies ignored the fact that vitamin D status is only one of three factors that are essential for muscle strength.

    • In the case of muscle strength, especially in the elderly, the three essentials are vitamin D, protein, and exercise. All three are needed to maintain or increase muscle strength. Simply put, if one is missing, the other two will have little or no effect on muscle strength. Unfortunately, you cannot assume that exercise and protein intake are adequate in older Americans:
      • Many older adults don’t get enough exercise because of physical limitations.

Unfortunately, many clinical studies on the effect of vitamin D supplementation and muscle strength fail to include exercise and adequate protein intake in the study. Such clinical trials are doomed to failure.

Now you know why vitamin D research is so controversial. Until the scientific and medical community get their act together and perform better designed experiments, vitamin D research will continue to be controversial and confusing.

What Does This Mean For You?

Old Man Lifting WeightsLoss of muscle mass as we age is not a trivial matter. As described above, it:

  • Leads to loss of mobility.
  • Increases your risk of falling. This often leads to serious fracture which increase your risk of disability and death.
  • Lowers your metabolic rate, which increases your risk of obesity and obesity-related diseases.

So, what can you do prevent loss of muscle mass as you age? The answer is simple:

1) Aim for 25-30 grams of high-quality protein in each meal.

    • That protein can come from meat, fish, eggs, or legumes.
    • That doesn’t mean you need to consume an 8-ounce steak or a half chicken. 3-4 ounces is plenty.
    • However, it does mean you can’t subsist on green salads and leafy greens alone. They are healthy, but you need to include a good protein source if you are going to meet your protein needs.

2) Aim for 150 minutes of moderate intensity exercise per week.

    • At least half of that exercise should be resistance exercise (lifting weights, for example).
    • If you have physical limitations, consult your doctor and a physical therapist or personal trainer to design resistance exercises you can do.
    • Aim for a variety of resistance exercises. You will only strengthen the muscles you exercise.

3) Aim for an adequate vitamin D status.

    • Start with a multivitamin containing at least 800 IU of vitamin D3.
    • Because there is large variation in the efficiency with which we convert vitamin D to 25-hydroxy vitamin D, you should get your serum 25-hydroxyvitamin D tested on a yearly basis. Your health professional can tell you if you need to take larger amounts of vitamin D3.
    • This study suggests that a serum 25-hydroxy vitamin D level of 55-69 nmol/L is optimal, and higher levels provide no additional benefit. That means there is no need to take mega-doses of vitamin D3 unless directed by your health professional.

The Bottom Line

A recent study looked at the effect of vitamin D status on muscle strength and performance in a healthy population with an average age of 69.

When they looked at handgrip strength:

  • Only 22% of the participants with an adequate vitamin D status had low handgrip strength.
  • 40% of participants who were vitamin D deficient had low handgrip strength. That’s almost a 2-fold difference.
  • Handgrip strength increased linearly with vitamin D status.

When they looked at muscle performance:

  • Only 8% of the participants with an adequate vitamin D status scored low on this test.
  • 25% of participants who were vitamin D deficient scored low on this test. That’s a 3-fold difference.
  • Muscle performance also increased linearly with vitamin D status.

The authors concluded: “Vitamin D deficiency was associated with impaired muscle strength and performance in a large study of community-dwelling older people. It is generally accepted that vitamin D deficiency should be reversed to prevent bone disease. This strategy may also protect skeletal muscle function in aging.”

If we look at the research more broadly, there are three factors that are essential for maintaining muscle mass as we age: exercise, protein, and vitamin D. Therefore, my recommendations are to:

1)  Aim for 25-30 grams of high-quality protein in each meal.

2) Aim for 150 minutes of moderate intensity exercise per week. At least half of that exercise should be resistance exercise.

3) Aim for an adequate vitamin D status (>50 nmol/L of serum 25-hydroxy vitamin D). A good place to start is with a multivitamin providing at least 800 IU of vitamin D3.

For more details on my recommendations and a discussion of why studies on vitamin D supplementation are often confusing, read the article above.

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

 

Health Tips From The Professor