Exercise

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.

Can You Slow The Aging Process?

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A Holistic Approach To Living Healthy Longer

Author: Dr. Stephen Chaney 

Fountain Of YouthEver since Ponce de Leon’s famed 1513 expedition, people have been searching for the proverbial “Fountain of Youth”.

There have been hucksters selling pills and potions to reverse the aging process. Most of them didn’t work. They were no better than snake oil.

There have been legitimate scientists investigating the effect of supplements, diets, and lifestyle on the aging process. Most of these studies have come up empty.

In this study (M Gagesch et al, Journal of Frailty And Aging, 12: 71-77, 2023) the authors hypothesized that a holistic approach might be better than individual interventions. They asked whether a combination of vitamin D3 supplementation, omega-3 supplementation, and exercise might be more effective at slowing the aging process than any one of them alone.

There was good reason for choosing each of these interventions:

  • Low 25-hydroxyvitamin D levels have been associated with frailty in several studies. But association studies do not prove cause and effect, and no randomized, placebo control studies have measured the effect of vitamin D supplementation on frailty.
  • Omega-3 fatty acids have been linked to skeletal muscle health, and some studies have suggested omega-3 supplementation may improve muscle function in older adults.
  • A recent study has reported that a supervised exercise program reduced frailty in older adults. The authors wanted to see if the same was true for unsupervised, at-home exercise program.

How Was This Study Done?

clinical studyThe data from this study were collected as part of the DO-HEALTH study, a 3-year, double-blind, randomized, placebo-controlled clinical trial designed to identify interventions that support healthy aging in European adults aged 70 and older.

Initially, 2,157 healthy, community-dwelling adults were enrolled from five countries (Switzerland, Germany, Austria, France, and Portugal). They were examined in clinical centers at the beginning of the study and years 1, 2, and 3, with phone follow-up at 3-month intervals.

Aging was measured by something called the frailty index. At each clinic visit the participants were evaluated in five areas:

  1. Weakness was measured as grip strength. Weakness was defined as being in the lowest quintile of grip strength for someone their age and gender.

2) Fatigue was defined as a positive answer to the question, “In the last month have you had too little energy to do the things you wanted to do?”

3) Involuntary weight loss was defined as >5% weight loss within a year.

4) Low gait speed was defined as <2 ft/sec walking speed.

5) Low activity level was defined as a response of, “Less than once a week” to the question, “How often do you engage in activities that require a low or moderate level of energy such as gardening, cleaning the car, or going on a walk?”

    • Participants with 0 positive items were classified as robust.
    • Those with 1 or 2 positive items were classified as pre-frail.
    • Those with 3 or more positive items were classified as frail.

Only those participants from the DO-HEALTH study classified as robust at the first clinical visit (1,137 participants) were included in this study. The study measured how many of them became pre-frail or frail during the average follow-up of 2.9 years.

The interventions were:

  • Capsules containing a total of 2,000 IU/day of vitamin D3 with sunflower oil capsules as a placebo.
  • Capsules containing a total of 1,000 mg of EPA and DHA in a 1:2 ratio with a sunflower oil capsule as a placebo.
  • Exercise consisting of an unsupervised strength-training routine for 30 minutes, 3 times per week.
  • In this case the control was an unsupervised joint-flexibility routine for 30 minutes, 3 times per week.

The interventions were done individually, two together (vitamin D + omega-3, vitamin D + exercise, omega-3 + exercise), and all three together (vitamin D + omega-3 + exercise).

The results were corrected for age, sex, and low-trauma falls in the preceding 12 months.

Finally, the study measured blood 25-hydroxyvitamin D levels and omega-3 levels at each office visit. They found:

  • 28% of the participants were deficient in vitamin D at the beginning of the study.
  • The interventions gave the expected increase in vitamin D and omega-3 status.

Can You Slow The Aging Process?

Older Couple Running Along BeachAt the end of 3 years:

  • 61.2% of the participants had declined from robust health to the pre-frail category.
  • 2.6% of the participants had declined from robust health to the frail category.

[Note: The terms “pre-frail” and “frail” are measures of aging which I have described above.]

The number of participants in the frail category were too small to obtain a statistically significant measure of the effects of vitamin D, omega-3s, and exercise on frailty, so I will only discuss the results measuring their effect on pre-frailty in this review. These results are:

  • None of these interventions had a statistically significant effect on aging by themselves, as measured by the transition from robust health to pre-frailty.
  • None of these interventions had a statistically significant effect on aging when combined in pairs, although the vitamin D3-omega-3 pair came close to significance (31% reduction in pre-frailty with a probability of 94% (probabilities of 95% and above are considered significant.))
  • However, the combination of vitamin D3, omega-3s, and exercise reduced the risk of aging by 39%, which was statistically significant (96% probability).

The authors concluded, “Robust, generally healthy and active older adults without major comorbidities [diseases], may benefit from a combination of high-dose, supplemental vitamin D3, marine omega-3s, and SHEP [unsupervised strength training] with regard to the risk of becoming pre-frail over 3 years.”

A Holistic Approach To Living Healthy Longer

holistic approachThis study was a double-blind, placebo-controlled study, which is the gold standard for clinical studies. It was also unusually large (1,137 participants) and long (3 years) for this kind of study.

It was also much better than most double-blind, placebo-controlled studies in that it included three interventions (vitamin D3 supplementation, omega-3 supplementation, and exercise) and looked at their effect on aging individually, in pairs, and all three together.

One take-home lesson from this study was that a holistic approach that included all 3 interventions was superior to any one of these interventions alone or in pairs.

But the most important take-home lesson is this:

If you asked your doctor what you should do to slow the aging process, he or she would probably tell you, “Exercise may help, but forget supplementing with extra vitamin D or omega-3s. They have no proven benefits.”

They would be correct based on studies of each of these interventions individually. And the studies they might quote would be double-blind, placebo-controlled studies, the gold standard of clinical studies.

But would that be the best advice. Clearly not. The best advice would be to follow a holistic approach and use all 3 interventions together.

Unfortunately, this is true for most studies of supplementation. Supplements are tested individually, as if they were “magic bullets”. And most of these studies come up short. They fail to find a significant benefit of supplementation.

Supplements are almost never tested holistically in combination with each other and other interventions, but that’s where the “magic” really happens.

If you are a regular reader of “Health Tips From The Professor”, this should come as no surprise to you. I have often shared the Venn diagram on the upper left and said that the sweet spot is when two or more of these interventions overlap.

Of course, this is the first study of its kind. More studies are needed. More importantly, we need studies to fill in the other parts of the Venn diagram. We need to ask about the effect of diet and obesity on aging. For example:

  • If we add a healthy diet to vitamin D, omega-3s, and exercise, can we reduce aging even more dramatically?
  • Is the effort it takes to lose excess weight worth it? Does adding it to diet, supplementation, and exercise reduce the aging process even more?

Of course, I think the answer to those questions is an unequivocal, “Yes”. Multiple studies have shown that both a healthy weight and a healthy diet help you live healthier longer.

But I am a scientist. Neither diet nor weight loss have been tested in combination with supplementation and exercise. I would like to see studies combining all these modalities in a single double-blind, placebo-controlled experiment.

So, what does this mean for you? If you want to slow the aging process, if you are in search of your personal “Fountain of Youth…

  • This study suggests that vitamin D3 supplementation (2,000 IU/day), omega-3 supplementation (1,000 mg of EPA + DHA), and an exercise program that emphasizes strength training can help you slow the aging process.

But that is only the beginning. I also recommend…

  • Including a healthy diet and a healthy weight in your anti-aging regimen.
  • Making sure your diet has enough protein and leucine, since older adults need more of both to maximize the benefits of strength training.
  • Including other supplements as evidence for their benefit in slowing the aging process becomes available.

The Bottom Line 

A recent double-blind, placebo-controlled study looked at the effect of vitamin D3 supplementation (2,000 IU/day), omega-3 supplementation (1,000 mg/day EPA + DHA in a 1:2 ratio), and an unsupervised strength training program on the aging process.

It differed from most other double-blind, placebo-controlled studies in that:

  • It was larger (1,137 participants) and longer (3 years) than most.
  • More importantly, each intervention was tested individually, in pairs, and all 3 together.

The study found that:

  • None of these interventions had a statistically significant effect on aging by themselves.
  • None of these interventions had a statistically significant effect on aging when combined in pairs, although the vitamin D3-omega-3 pair came close to significance.
  • However, the combination of vitamin D3, omega-3s, and exercise reduced the risk of aging by a statistically significant 39%.

One take-home lesson from this study was that a holistic approach that included all 3 interventions was superior to any one of these interventions alone or in pairs.

But the most important take-home lesson is this:

If you asked your doctor what you should do to slow the aging process, he or she would probably tell you, “Exercise may help, but forget supplementing with extra vitamin D or omega-3s. They have no proven benefits.”

They would be correct based on studies of each of these interventions individually. And the studies they might quote would be double-blind, placebo-controlled studies, the gold standard of clinical studies.

But would that be the best advice? Clearly not. The best advice would be to follow a holistic approach and use all 3 interventions together.

Unfortunately, this is true for most studies of supplementation. Supplements are tested individually, as if they were “magic bullets”. And most of these studies come up short. They fail to find a significant benefit of supplementation.

Supplements are almost never tested holistically in combination with each other and other interventions, but that’s where the “magic” really happens.

For more information on this study and my recommendations on how to slow the aging process 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.

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.

Preparing For The New Normal

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Can Supplements Strengthen My Immune System?

COVID-19The United States and the rest of the world are facing the biggest challenge of our lifetimes. COVID-19 has killed hundreds of thousands of people and decimated economies around the world.

As of the publication date of this article we have no vaccine and only one treatment option that appears to be about 30% effective in a preliminary clinical trial. People are scared.

The question I get asked most often is: “Can supplements protect me from COVID-19”. That’s not a question I can answer with confidence. The few studies we have are small and preliminary. Plus, there is too much we still do not know about COVID-19.

However, there are studies about how diet and supplements affect the immune system. I can answer the question, “Can Supplements Strengthen My Immune System”, with confidence. That will be the focus of this article.

However, before covering that, let me take an objective look at what our “New Normal” will be like and how we can prepare for it.

Preparing For The New Normal

ProfessorAs a scientist I am appalled by the divisive and hyper-partisan arguments about how we should be handling the COVID-19 pandemic. This is a time when our country should be united against a common enemy. Instead I see myths and lies propagated on both sides of this important issue.

The press only magnifies the problem by repeating the myths without fact checking. Whether they are on the left or the right, the media only repeats myths that fit their narrative. As a result, people like you are confused and scared.

Let me try to give you a more objective and scientific view of what the “New Normal” will look like, and how we can prepare for it.

Let’s start with one of the biggest arguments over the past few weeks – when should we reopen our country. This argument is based on the myth that if we wait long enough, the virus will be gone, and life can return to normal.

Nothing could be further from the truth. In reality viruses don’t work that way. They continue to circulate through the population at low levels. Whenever we emerge from our homes and resume our daily lives, the virus will be lurking. There will be flare-ups. There will be hot spots. There will be deaths. And the press will report every one.

So, the question should not be when we emerge. It should be how we emerge. We should emerge cautiously. We should continue to take appropriate precautions. These precautions will become our “New Normal” until we have an effective vaccine. By now, you probably have the CDC precautions memorized, but let me repeat them here:

  • If you are sick, stay home until you recover. If your symptoms worsen, contact your doctor right away.
  • If you are exposed, get tested right away and self-quarantine for 14 days if you test positive.
  • When you go out, wear a face mask and practice social distancing. When you get home, wash your hands in soap and water for 20”.
  • For now, we will need to avoid the customary handshake (and if you are from the South like me, the customary hug).
  • If you are very old or very sick, you should stay home as much as possible. If you have a loved one in this category, you should do everything in your power to protect them from exposure.
  • The guideline that is hardest to project into the future is the one on crowd size. It is hard to predict what the CDC will recommend about crowd size as part of our “New Normal” a few months from now. However, because this virus is extremely contagious, it may be risky to attend any gatherings where there are large, tightly packed crowds for the foreseeable future. This could include some of our favorite things – like movies, live theater, night clubs, and sporting events.Myth Versus Facts

Finally, there is another big myth, namely that the virus will simply disappear once we have a vaccine. Vaccines reduce your risk of exposure because fewer people are carriers of the virus. However, coronaviruses never disappear. They continue to circulate in the population for decades.

Even after we have a vaccine, people will still get sick from COVID-19. People will still die from COVID-19. The difference is that we will no longer hear about COVID-19 cases and deaths on the nightly news. Those cases and deaths will just become part of the statistics that the CDC collects on flu-like illnesses each year – and everyone ignores.

Now that I have discussed what the “New Normal” will look like and summarized the CDC guidelines for reducing your exposure to COVID-19 as the lockdown eases, let me add another guideline of my own:

  • Keep your immune system as strong as possible.

Why Is Keeping Your Immune System Strong Important?

strong immune systemIt is no secret that the media likes to focus on bad news. It is the bad news that draws people in and keeps them coming back for more.

Pandemics are no different. It doesn’t matter whether we are talking about the Spanish flu, SARS, MERS, or COVID-19. We focus on cases and deaths – the bad news. We ignore the good news – there are millions of people who were infected and had no symptoms.

However, if you have been listening closely to what the experts have been saying rather than relying on the media for your information, the good news is obvious.

  • 80-85% of people who have tested positive for COVID-19 have mild or moderate symptoms. Their symptoms are no worse than they experience with the seasonal flu.
  • Preliminary antibody tests suggest that the number of people infected with COVID-19 who experience no symptoms may be 10 to 40 times higher than reported cases.
  • The experts say that the difference is a strong immune system. They tell us that it is people with weakened immune systems that suffer and die from COVID-19.

So, how do you keep your immune system strong? Let’s start by looking at the role of supplementation.

Can Supplements Strengthen My Immune System?

MultivitaminsThose of you who follow me know that I consider supplementation as just one aspect of a holistic approach to health. However, I am starting with supplements because the question I am often asked these days is: “Can supplements protect me from COVID-19”.

As I said at the beginning of this article, that is not a question I can answer with confidence. Instead, the question you should be asking is, “Can Supplements Strengthen My Immune System?”

As I mentioned above, the experts are telling us that it is people with weakened immune systems who suffer and die from COVID-19. That means it is important to keep our immune system as strong as possible.

How do we do that? Here is what an international group of experts said in a recent review (PC Calder et al, Nutrients, 12, 1181-1200, 2020).

1) “A wealth of mechanistic and clinical data show that vitamins A, B6, B12, C, D, E, and folate; trace elements zinc, iron, selenium, magnesium, and copper; and omega-3 fatty acids EPA and DHA play important and complementary roles in supporting the immune system.”

2) “Inadequate intake and status of these nutrients are widespread, leading to a decrease in resistance to infections, and an increase in disease burden.”

They then made the following recommendations:

1) Supplementation with the above micronutrients and omega-3 fatty acids is a safe, effective, and low-cost strategy to help support optimal immune function.

    • They recommended 100% of the RDA for vitamins A, B6, B12, C, D, E, and folate and minerals zinc, iron, selenium, magnesium, and copper in addition to the consumption of a well-balanced diet.
    • They recommended 250 mg/day of EPA + DHA.

2) Supplementation above the RDA for vitamins C and D is warranted.

    • They recommend 200 mg/day of vitamin C for healthy individuals and 1-2 g/day for individuals who are sick.
    • They recommend 2000 IU/day (50 ug/day) for vitamin D.

3) Public health officials are encouraged to include nutritional strategies in their recommendations to improve public health.

Their recommendations could be met by a multivitamin that provides all the micronutrients they recommend, an omega-3 supplement, and extra vitamins C and D.

What Else Should I Do To Strengthen My Immune System?

healthy foodsAs I said above, supplementation is only one part of a holistic approach to a strong immune system. Here are the other components of a holistic approach:

1) It starts with a healthy diet.

    • Eat foods from all 5 food groups.
    • Eat plenty of fruits and vegetables. They provide antioxidants and phytonutrients that are important for our immune system.
    • Eat plenty of high fiber foods. Include whole grains and beans in addition to fruits and vegetables. That’s because the friendly gut bacteria that strengthen our immune system need a variety of fibers from different food sources to feed on.
    • Eat oily fish on a regular basis.
    • Avoid sodas, sugary foods, and highly processed foods.
    • Avoid high fat diets

2) Get adequate sleep. For most of us, that means 7-8 hours of sleep a night.

3) Maintain a healthy weight.

4) Get adequate exercise. Aim for a minimum of 150 minutes of moderate intensity exercise each week.

5) Manage stress and anxiety in healthy ways. Yes, that means if you let the news about COVID-19 cause anxiety, you are weakening your immune system. You may want to turn off the news and try prayer, meditation, yoga, or whatever relieves stress for you.

The Bottom Line

In this article, I summarized the “New Normal” we face as we emerge from lockdown and how to navigate the new normal as safely as possible. If I were to summarize this article in a few short sentences, this is what I would say:

Until we have an effective vaccine the “New Normal” is a world in which a dangerous virus is lurking in the community, waiting to strike the unprepared.

Forget all the angry rhetoric about when we should emerge from lockdown. The important question is not when we emerge. It is how we emerge.

We don’t need to stay huddled in our homes, fearful to leave, unless we are very old or very sick.

We do need to take appropriate precautions when we leave home based on the recommendations of the CDC. None of us are invincible as far as this virus is concerned. More importantly, if we bring the virus home, we may kill the very people we love the most. We need to follow the guidelines.

We should also make sure that our immune system is as strong as possible through a holistic combination of diet, supplementation, adequate sleep, exercise, weight management, and stress reduction.

For more information on CDC COVID-19 Guidelines, click here.

For more details about preparing for the new normal and diet & supplementation 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.

Preventing And Reversing Osteoporosis

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A Bone Health Lifestyle

Author: Julie Donnelly, LMT – The Pain Relief Expert

Editor: Dr. Steve Chaney

Woman Enjoying Autumn LeavesFall is glorious in my book.  I was up in New York a few weeks ago, and the trees were just changing – I was about a week too early for the best colors, but it was still beautiful. Then I flew out to Lake Tahoe, and it was really beautiful there.  The air was crisp and clean, and I loved all the fall decorations.

In Florida we are entering our most wonderful time of year. It’s starting to get cooler, the humidity is going down, and hurricane season is over. Hooray!  It’s great to be outdoors again!

Please remember all the people who are still going through very difficult times in the Bahamas.  Many people have lost their homes, their workplaces and the income that supports them, and some have lost loved ones. A devastating loss.

We here in the USA were blessed that Dorian didn’t come any further west and do the same thing to Florida, Georgia, and the Carolinas. I wanted to share what I have with the people who now have nothing. That made me search for places I trust that will send all the money I donate. In case you want to help, and you don’t have a favorite charity, I want to share those places with you:

https://disaster.salvationarmyusa.org

http://secure.americares.org/help/now‎

https://www.mercycorps.org/articles/hurricane-dorian-bahamas#mercy-corps-helping

Preventing And Reversing Osteoporosis

Exercise And NutritionWeight-bearing exercise builds strong bones. That statement is so common that just about everyone knows they need to exercise for strong muscles and bones, and for all the good it does for just about every system in the body.  And, we are what we eat, so nutrition is vital.

Do you like to exercise? Some people are almost addicted to exercise, but I’m not one of them.  I go to the gym and I have a fitness trainer to help me stay on track, but it fits right in with my eagerness of going to the dentist.  I must say, I’d like that to change, and maybe if I can find a workout partner, it will.

Meanwhile I need to do something because I’ve been told I have osteoporosis. Yikes! One thing for sure, I’m not taking any type of medication. I truly believe there is another solution.

While I’m not an exercise nut, I do love nutrition and I know that the body is so adaptable that if it’s given the proper nutrition, it can do miracles. I believe nutrition and exercise can reverse this osteoporosis diagnosis.

A Bone Healthy Lifestyle

A Bone Healthy Lifestyle
A Bone Healthy Lifestyle

The first thing I did was contact my friend, Steve Chaney, PhD, author of the weekly blog “Health Tips From The Professor.  He pointed me to an article he had written on a “Bone Healthy Lifestyle”. Here is a brief summary:

  • Exercise, calcium, and vitamin D are all essential for bone formation. If any of them are missing, you can’t form healthy bone. The reason so many clinical studies on calcium supplementation and bone density have come up empty is that exercise, or vitamin D, or both were not included in the study.
  • Get plenty of weight bearing exercise. This is an essential part of a bone healthy lifestyle. Your local Y can probably give you guidance if you can’t afford a personal trainer. Of course, if you have physical limitations or have a disease, you should consult with your health professional before beginning any exercise program.
  • Get your blood 25-hydroxy vitamin D level tested. If it is low, take enough supplemental vitamin D to get your 25-hydroxy vitamin D level into the adequate range – optimal is even better. Adequate blood levels of 25-hydroxy vitamin D are also essential for you to be able to utilize calcium efficiently.
  • Consume a “bone healthy” diet that emphasizes fresh fruits and vegetables, minimizes meats, and eliminates sodas and other acidic beverages. For more details on whether your favorite foods are acid-forming or alkaline-forming, you can find plenty of charts on the internet.
  • Minimize the use of medications that adversely affect bone density. You’ll need to work with your doctor on this one.
  • Consider a calcium supplement. Even when you are doing everything else correctly, you still need adequate calcium in your diet to form strong bones. Dr. Chaney wasn’t advocating a “one-size fits all” 1,000 to 1,200 mg/day for everyone. Supplementation is always most effective when you actually need it. For example:

o   If you are not including dairy products in your diet (either because they are acid-forming or for other health reasons), it will be difficult for you to get adequate amounts of calcium in your diet. You can get calcium from other food sources such as green leafy vegetables. However, unless you plan your diet very carefully you will probably not get enough.

o   If you are taking medications that decrease bone density, that may increase your need for supplemental calcium. Ask your pharmacist about the effect of any medications you are taking on your calcium requirements.

  • If you do use a calcium supplement, make sure it is complete. Don’t just settle for calcium and vitamin D. At the very least you will want your supplement to contain magnesium and vitamin K. Dr. Chaney recommends that it also contain zinc, copper, and manganese.

Between increasing my exercise and ramping up all the nutrients that build bone, I just know that by this time next year I’m going to be surprising the doctor with my great health

Is Our Microbiome Affected By Exercise?

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Microbiome Mysteries

Author: Dr. Stephen Chaney

is our microbiome affected by exerciseIn a recent post,  What is Your Microbiome and Why is it Important,  of “Health Tips From The Professor” I outlined how our microbiome, especially the bacteria that reside in our intestine, influences our health. That influence can be either good or bad depending on which species of bacteria populate our gut. I also discussed how the species of bacteria that populate our gut are influenced by what we eat and, in turn, influence how the foods we eat are metabolized.

I shared that there is an association between obesity and the species of bacteria that inhabit our gut. At present, this is a “chicken and egg” conundrum. We don’t know whether obesity influences the species of bacteria that inhabit our gut, or whether certain species of gut bacteria cause us to become obese.

Previous studies have shown that there is also an association between exercise and the species of bacteria that inhabit our gut. In particular, exercise is associated with an increase in bacteria that metabolize fiber in our diets to short chain fatty acids such as butyrate. That is potentially important because butyrate is a primary food source for intestinal mucosal cells (the cells that line the intestine). Butyrate helps those cells maintain the integrity of the gut barrier (which helps prevent things like leaky gut syndrome). It also has an anti-inflammatory effect on the immune cells that reside in the gut.

However, associations don’t prove cause and effect. We don’t know whether the differences in gut bacteria were caused by differences in diet or leanness in populations who exercised regularly and those who did not. This is what the present study (JM Allen et al, Medicine & Science In Sports & Exercise, 50: 747-757, 2018 ) was designed to clarify.  Is our microbiome affected by exercise?

 

How Was The Study Designed?

is our microbiome affected by exercise studyThis study was performed at the University of Illinois. Thirty-two previously sedentary subjects (average age = 28) were recruited for the study. Twenty of them were women and 12 were men. Prior to starting the study, the participants filled out a 7-day dietary record. They were asked to follow the same diet throughout the 12-week study. In addition, a dietitian designed a 3-day food menu based on their 7-day recall for the participants to follow prior to each fecal collection to determine species of gut bacteria.

The study included a two-week baseline when their baseline gut bacteria population was measured, and participants were tested for fitness. This was followed by a 6-week exercise intervention consisting of three supervised 30 to 60-minute moderate to vigorous exercise sessions per week. The exercise was adapted to the participant’s initial fitness level, and both the intensity and duration of exercise increased over the 6-week exercise intervention. Following the exercise intervention, all participants were instructed to maintain their diet and refrain from exercise for another 6 weeks. This was referred to as the “washout period.”

VO2max (a measure of fitness) was determined at baseline and at the end of the exercise intervention. Stool samples for determination of gut bacteria and concentrations of short-chain fatty acids were taken at baseline, at the end of the exercise intervention, and again after the washout period.

In short, this study divided participants into lean and obese categories and held diet constant. The only variable was the exercise component.

 

Is Our Microbiome Affected By Exercise?

is our microbiome affected by exercise fitnessThe results of the study were as follows:

  • Fitness, as assessed by VO2max, increased for all the participants, and the increase in fitness was comparable for both lean and obese subjects.
  • Exercise induced a change in the population of gut bacteria, and the change was comparable in lean and obese subjects.
  • Exercise increased fecal concentrations of butyrate and other short-chain fatty acids in the lean subjects, but not in obese subjects.
  • The exercise-induced changes in gut bacteria and short-chain fatty acid production were largely reversed once exercise training ceased.

The authors concluded: “These findings suggest that exercise training induces compositional and functional changes in the human gut microbiota that are dependent on obesity status, independent of diet, and contingent on the sustainment of exercise.” [Note: To be clear, the exercise-induced changes in both gut bacteria and short-chain fatty acid production were independent of diet and contingent on the sustainment of exercise. However, only the production of short-chain fatty acids was dependent on obesity status.]

 

What Does This Study Mean For You?

is our microbiome affected by exercise gut bacteriaThere are two important take home lessons from this study.

  • With respect to our gut bacteria, I have consistently told you that microbiome research is an emerging science. This is a small study, so you should regard it as the beginning of our understanding of the effect of exercise on our microbiome rather than conclusive by itself. It is consistent with previous studies showing an association between exercise and a potentially beneficial shift in the population of gut bacteria.

The strength of the study is that it shows that exercise-induced changes in beneficial gut bacteria are probably independent of diet. However, it is the first study to look at the interaction between obesity, exercise and gut bacteria, so I would interpret those results with caution until they have been replicated in subsequent studies.

  • With respect to exercise, this may be yet another reason to add regular physical activity to your healthy lifestyle program. We already know that exercise is important for cardiovascular health. We also know that exercise increases lean muscle mass which increases metabolic rate and helps prevent obesity. There is also excellent evidence that exercise improves mood and helps prevent cognitive decline as we age.

Exercise is also associated with decreased risk of colon cancer and irritable bowel disease. This effect of exercise has not received much attention because the mechanism of this effect is unclear. This study shows that exercise increases the fecal concentrations of butyrate and other short-chain fatty acids. Perhaps, this provides the mechanism for the interaction between exercise and intestinal health.

 

The Bottom Line

A recent study has reported that:

  • Exercise induces a change in the population of gut bacteria, and the change was comparable in lean and obese subjects.
  • Exercise causes an increase in the number of gut bacteria that produce butyrate and other short-chain fatty acids that are beneficial for gut health.
  • These effects are independent of diet, but do not appear to be independent of obesity because they were seen in lean subjects but not in obese subjects.
  • The exercise-induced changes in gut bacteria and short-chain fatty acid production are largely reversed once exercise training ceases.

The authors concluded: “These findings suggest that exercise training induces compositional and functional changes in the human gut microbiota that are dependent on obesity status, independent on diet, and contingent on the sustainment of exercise.”

For more details and my interpretation of the data, 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.

Can You Eat Spinach For Muscle Growth

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Was Popeye Right?

Author: Dr. Stephen Chaney

can eat spinach for muscle growthYou may have seen the recent headlines proclaiming that eating spinach will make you stronger. The more “mature” adults among my readers may remember the Popeye cartoons of our youth. Every time Popeye was on the brink of disaster he would down a can of spinach and become superhuman. Was Popeye right? Can spinach actually improve strength and endurance?  Can you eat spinach for muscle growth?  To answer those questions, I analyzed the study behind the headlines.

The short answer is that there may be some truth to the headlines, but you would never be able to prove it from the study they quoted.

Even worse, this study and the headlines it generated are typical of the sports nutrition marketplace. There are far too many headlines and sports nutrition products based on weak and inconclusive studies.

Spinach for Muscle Growth?

spinachLet’s start at the beginning. In the first place the study behind the headlines (De Smet et al., Frontiers In Physiology, 7: 233-244, 2016) did not actually use spinach. In fact, participants were advised to avoid nitrate-rich foods like spinach and beets during the study.

The study enrolled moderately-trained male students from the University of Leuven in Belgium. All the participants completed 5 weeks of sprint interval training (SIT) consisting of 30 second sprints followed by 4.5-minute recovery intervals on an exercise cycle. This was repeated 4-6 times per session 3 times per week.

One group took a sodium nitrate supplement containing 400 mg of nitrate 30 minutes before each workout. The other group received a placebo. There were only 9 students in each group. [I have simplified the study design for the purposes of this discussion. There were other aspects of the study, but they are not relevant to our discussion.]

The investigators measured maximum oxygen consumption (a measure of exercise efficiency and endurance), maximum power output during a 30-second sprint, and composition of quadriceps muscle fibers both before the 5-week training started and again when it was completed.

The results were disappointing:

  • thumbs downNitrate supplementation caused a modest increase in fast twitch (type IIa) muscle fibers compared to placebo. That is a physiological response that may (or may not, depending on who you believe) allow high intensity exercise to be sustained for longer without fatigue.
  • Nitrate supplementation failed to show any significant benefit for any other measure of exercise capacity. In particular, no effect of nitrate supplementation was observed on:
    • Maximum oxygen consumption
    • Maximum power output
    • Peak heart rate
    • Time to exhaustion.
    • Various metabolic markers of exercise efficiency

In spite of these largely negative results, the authors concluded: “The current experiment demonstrated that oral nitrate supplementation during short-term sprint-interval training increased the proportion of type IIa muscle fibers, which may contribute to enhanced performance in short maximal exercise events…”

“May” is the operative word here. Their data did not provide any evidence that nitrate supplementation actually improved performance.

Online headlines (the kind of nutrition information most people read) took it a step further. For example, one headline claimed “Spinach Can Boost Your Physical Fitness and Muscle Strength.” That headline came out of thin air.

Sports Nutrition Myths

mythsUnfortunately, this study is typical of many of the sports nutrition studies I have reviewed over the years. Most of them are very small studies. In many of them only one or two measure exercise performance change, while other measures show no effect of supplementation.

That doesn’t stop bloggers from hyping the studies and creating sports nutrition myths. It also doesn’t stop companies from offering sports products with those ingredients and making outrageous claims about how their product will make you bigger, faster, and stronger.  For example, a claim that you can eat spinach for muscle growth.

It is only when dozens of studies have been published, and a meta-analysis combines the data from all the studies that we are in a position to see whether any particular nutrient has a statistically significant effect on performance.

Must You Eat Spinach for Muscle Growth or Could Nitrates Provide Exercise Benefits?

nitrates and exerciseDespite the weakness of this particular study, there is reason to believe that nitrates might improve exercise performance.

  • There is a plausible mechanism. In the body nitrates are converted to nitric oxide, which improves arterial health, lowers blood pressure, and enhances blood flow. Increased blood flow to the muscles could enhance exercise efficiency.
  • Other studies have come to a similar conclusion. There are several other exercise studies Health Benefits of Beetroot Juice involving supplements containing either nitrates or beetroot juice (which is rich in nitrates) that have suggested that supplementation improves exercise efficiency. Each of the studies are small and inconclusive by themselves, but in the aggregate they suggest that nitrate may have some benefits.
  • Arginine, which also enhances nitric oxide production, is well established in the sports nutrition world. There are dozens of published exercise studies involving arginine and meta-analyses of these studies suggest that arginine provides modest benefits. However, there is an important caveat, which I shall explain below.

In short, the idea that nitrate supplementation might improve exercise performance is plausible. However, plausible is a long way from proven.

The Ultimate Irony

When you analyze the meta-analyses of arginine supplementation and exercise performance studies, the ultimate irony is that arginine supplementation is most effective for untrained individuals who are just beginning an exercise program. It provides little benefit for trained athletes (R. Bescos et al, Sports Medicine, 42: 99‐117,2012).

There is a logical explanation for this observation. Intense exercise also enhances nitric oxide production and blood flow to the muscle. Most highly trained athletes have already maxed their nitric oxide levels and have excellent blood flow to their muscles. Arginine (or nitrate) supplementation provides little additional benefit for them.

Why do I call this the ultimate irony? Think about it for a minute.

The people most likely to use sports supplements with arginine or nitrate are gym rats and highly trained athletes – the people who get the least benefit from those supplements.

The people least likely to use special sports supplements with arginine or nitrate are the weekend warriors and the busy professionals who are just trying to stay fit – the people who are most likely to benefit from those supplements.

 

The Bottom Line

 

  • Recent headlines have suggested that you can eat spinach for muscle growth and exercise performance.
  • When you look at the study behind the headlines, the study was done with nitrate, not with spinach. Spinach is a nitrate-rich food (as are beet roots), but the headlines were clearly misleading.
  • The study was also inconclusive. It was a small study, and most parameters of exercise performance were not affected by nitrate supplementation.
  • Unfortunately, this kind of small, inconclusive study is all too common in the sports nutrition literature. That doesn’t stop bloggers from hyping the studies and creating sports nutrition myths. It also doesn’t stop companies from offering sports nutrition products with those ingredients and making outrageous claims about how their product will make you bigger, faster, and stronger.
  • However, other studies suggest the idea that nitrate in food or supplements could improve exercise performance is plausible.
  • In our bodies, nitrate is converted to nitric oxide, which enhances blood flow to the muscles.
  • Other studies with nitrate and with beetroot juice (an excellent source of nitrate) have shown some exercise benefits.
  • Arginine, which is also converted to nitric oxide, is a fairly well established sports supplement.

Of course, plausible is a long way from proven.

  • The ultimate irony is that the people most likely to use sports supplements with arginine or nitrates are gym rats and highly trained athletes. They already have excellent blood flow to their muscles. They are the people who get the least benefit from those supplements.
  • In contrast, the people least likely to use special sports supplements with arginine or nitrates are the weekend warriors and the busy professionals who are just trying to stay fit. Those are the people who are most likely to benefit from those supplements.

 

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