The Benefits of Resveratrol

Written by Dr. Steve Chaney on . Posted in current health articles, Drugs and Health, Exercise, Food and Health, Muscle Therapy and Health

Author: Dr. Stephen Chaney

 

exerciseSome athletes, particularly Olympic athletes, are starting to use resveratrol to improve their workouts and their performance in events. Is their belief in the benefits of resveratrol justified, or is resveratrol just another of those “mythical” sports nutrition supplements? There have only been a few small studies on the subject, and those studies have been conflicting.

The study I am featuring this week (Polley et al, Appl. Physiol. Nutr. Metab. 41: 26-32, 2016) asked a more fundamental question. It asked whether resveratrol enhanced the effect of exercise on muscle mitochondrial capacity. For those of you who aren’t scientists that statement may require some interpretation.

What Are Mitochondria and Why Are They Important?

You can think of mitochondria as the power packs of the cell. They are tiny organelles that are found in most cells in our body. The foods that we eat contain a lot of energy (calories), but that energy is not in a form that our cells can use. Our cells metabolize those foods into small molecules that donate electrons to our mitochondria, and the mitochondria use those electrons to create energy in a form that our cells can utilize.

As you might imagine, mitochondria are particularly important for cells with high energy requirements, like our muscle cells. Those muscle cells responsible for endurance and high intensity (think gymnastics or weight lifting) exercise have the highest density of mitochondria and are the most dependent on those mitochondria for optimal performance.

Why Resveratrol Might Increase Muscle Mitochondrial Capacity?

mitochondriaMitochondria have a finite lifetime in our cells. As our cells age their mitochondria become less efficient and start doing bad things like releasing damaging free radicals into the cell. Exercise stress causes the mitochondria in our muscles to age more rapidly than the mitochondria in other cells. Fortunately, regular exercise also stimulates a pathway that causes production of new mitochondria and enhances their efficiency. Thus, the net effect of any exercise program is to increase both the number and efficiency of mitochondria, something referred to as mitochondrial capacity.

It turns out that resveratrol and a small group of related polyphenols also stimulate the same pathway. Animal and cell culture studies show that resveratrol can increase muscle mitochondrial capacity. However, since resveratrol and exercise increase mitochondrial capacity by the same mechanism, the question is whether resveratrol has any added benefit over exercise alone. That is the question this study was designed to answer.

The Benefits of Resveratrol on Muscle Mitochondrial Capacity?

Previous studies had suggested that one of the benefits of resveratrol might be increasing muscle mitochondrial capacity for people who have engaged in relatively little physical activity in the past. For examples, studies have shown that resveratrol activates the pathway leading to increased mitochondrial capacity in obese and diabetic populations, both groups that may not have been involved in regular exercise. In contrast, other studies found no enhancement of those same pathways compared to exercise alone in more highly trained populations involved in high intensity training.

benefits of resveratrolBased on those results, the present study (Polley et al, Appl. Physiol. Nutr. Metab. 41: 26-32, 2016) was specifically designed to assess the effect of resveratrol supplementation along with low-intensity exercise in an untrained muscle group. The authors recruited healthy young adults with approximately equal numbers of men and women. To assure that the muscle group was relatively untrained, they asked the subjects to perform wrist flexor exercises in their non-dominant arm. They excluded from the study anyone whose exercise regimen involved regular use of the non-dominant forearm such as rowing, rock climbing or CrossFit.

This was a double-blind, placebo-controlled study. Half of the group received 500 mg of resveratrol and the other half received the placebo. The placebo group served as a control for the effect of exercise alone. The dominant arm was not exercised, so it served as a control for the effect of resveratrol alone. The participants took resveratrol or placebo upon wakening each morning. The wrist flexor exercises were performed 3 times per week for 4 weeks. Mitochondrial capacity measurements were made using near infrared spectroscopy on a weekly basis.

The results were pretty straight-forward.

  • Low-intensity training alone (placebo group) for 4 weeks resulted in a 10% increase in mitochondrial capacity.
  • Low-intensity training plus resveratrol for 4 weeks resulted in a 40% increase in mitochondrial capacity. This represented a highly significant difference between the resveratrol and placebo groups.
  • Neither the resveratrol group or the placebo group exhibited changes in the untrained arm, which suggests that resveratrol without exercise has little or no effect on mitochondrial capacity in young, healthy subjects.

The authors concluded: “Taken together, these findings indicate that [the] combination of exercise and resveratrol is needed for eliciting maximal muscle mitochondrial adaptations to low-intensity training programs.”

What Are the Strengths and Weaknesses of This Study?

Strengths:Because previous studies had suggested that the effects of resveratrol might be masked in highly trained individuals or by high intensity exercise, this study was specifically designed to look at the effects of resveratrol on mitochondrial capacity when administered along with low-intensity exercise in untrained muscles. In that sense this study breaks new ground and suggests that, under the right conditions, resveratrol can enhance exercise training.

Weaknesses:The weaknesses of this study were many:

  • It was a very small study. That is not unusual in this area of research, but clearly much more research is needed.
  • It used a higher dose of resveratrol than previous studies. However, plasma levels of resveratrol were not determined and the effect of lower doses was also not determined, so we have no idea how much resveratrol is actually needed to elicit this response.
  • While increased mitochondrial capacity is a probable predictor of improved exercise efficiency, no performance outcomes were actually measured. Most people probably don’t care how well their mitochondria work. They care about how well their muscles perform.

What Does This Mean For You?

We are in the very early stages of research into the benefits of resveratrol on exercise. Many more studies are needed before we will be in a position to fully understand the effects of resveratrol on exercise efficiency and performance outcomes. This and previous studies suggest that resveratrol is likely to be most effective at enhancing exercise efficiency with low intensity exercise in relatively untrained muscles.

If true, that would mean resveratrol might be helpful for the millions of Americans who are “weekend warriors” or exercise sporadically. It may even be beneficial for those of us who exercise regularly at a low to moderate intensity level.

However, because resveratrol and exercise improve mitochondrial capacity by the same mechanism, previous studies suggest that resveratrol might be a less effective addition for highly trained athletes engaged in high-intensity exercise.If true, this would put resveratrol in the same category as several other popular exercise supplements such as arginine and citrulline that also appear to be more effective for untrained individuals than they are for highly trained athletes.

However, I am aware of many Olympic athletes who use and swear by a resveratrol polyphenol blend. It could be placebo, but it could also suggest that resveratrol does enhance performance for highly trained athletes engaged in high-intensity exercise. As I said at the beginning of this section, there is much more research to do. That’s what makes science so much fun. There are always new things to learn.

 

The Bottom Line 

We are in the very early stages of research into the benefits of resveratrol on exercise. Many studies will be needed before we will be in a position to fully understand the effects of resveratrol on exercise efficiency and performance outcomes. However, a recent study is of interest because it introduces a new perspective to our understanding of the possible effects of resveratrol on exercise efficiency.

  • Thisstudy reports that resveratrol significantly enhances the increase in mitochondrial capacity caused by low-intensity exercise in untrained muscles
  • If true, that would mean resveratrol might increase exercise efficiency for the millions of Americans who are “weekend warriors” or exercise sporadically. It may even be beneficial for those of us who exercise regularly at a low to moderate intensity level.
  • However, because resveratrol and exercise improve mitochondrial capacity by the same mechanism, previous studies suggest that resveratrol might be a less effective addition for highly trained athletes engaged in high-intensity exercise.
  • If true, this would put resveratrol in the same category as several other popular exercise supplements such as arginine and citrulline that also appear to be more effective for untrained individuals than they are for highly trained athletes.
  • However, I am aware of many Olympic athletes who use and swear by a resveratrol polyphenol blend. It could be placebo, but it could also suggest that resveratrol does enhance performance for highly trained athletes engaged in high-intensity exercise.

As I said before, there is much more research to do. That’s what makes science so much fun. There are always new things to learn.

 

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

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Latest Article

Can Plant-based Diets Be Unhealthy?

Posted September 10, 2019 by Dr. Steve Chaney

Do Plant-Based Diets Reduce Heart Disease Deaths?

Author: Dr. Stephen Chaney

 

plant-based diets vegetablesPlant-based diets have become the “Golden Boys” of the diet world. They are the diets most often recommended by knowledgeable health and nutrition professionals. I’m not talking about all the “Dr. Strangeloves” who pitch weird diets in books and the internet. I am talking legitimate experts who have spent their life studying the impact of nutrition on our health.

Certainly, there is an overwhelming body of evidence supporting the claim that plant-based diets are healthy. Going on a plant-based diet can help you lower blood pressure, inflammation, cholesterol and triglycerides. People who consume a plant-based diet for a lifetime weigh less and have decreased risk of heart disease, diabetes, and cancer.

But, can a plant-based diet be unhealthy? Some people consider a plant-based diet to simply be the absence of meat and other animal foods. Is just replacing animal foods with plant-based foods enough to make a diet healthy?

Maybe not. After all, sugar and white flour are plant-based food ingredients. Fake meats of all kinds abound in our grocery stores. Some are very wholesome, but others are little more than vegetarian junk food. If you replace animal foods with plant-based sweets, desserts, and junk food, is your diet really healthier?

While the answer to that question seems obvious, very few studies have asked that question. Most studies on the benefits of plant-based diets have compared population groups that eat a strictly plant-based diet (Seventh-Day Adventists, vegans, or vegetarians) with the general public. They have not looked at variations in plant food consumption within the general public. Nor have they compared people who consume healthy and unhealthy plant foods.

This study (H Kim et al, Journal of the American Heart Association, 8:e012865, 2019) was designed to fill that void.

 

How Was The Study Done?

plant-based diets studyThis study used data collected from 12,168 middle aged adults in the ARIC (Atherosclerosis Risk in Communities) study between 1987 and 2016.

The participant’s usual intake of foods and beverages was assessed by trained interviewers using a food frequency questionnaire at the time of entry into the study and again 6 years later.

Participants were asked to indicate the frequency with which they consumed 66 foods and beverages of a defined serving size in the previous year. Visual guides were provided to help participants estimate portion sizes.

The participant’s adherence to a plant-based diet was assessed using four different well-established plant-based diet scores. For the sake of simplicity, I will include 3 of them in this review.

  • The PDI (Plant-Based Diet Index) categorizes foods as either plant foods or animal foods. A high PDI score means that the participant’s diet contains more plant foods than animal foods. A low PDI score means the participant’s diet contains more animal foods than plant foods.
  • The hPDI (healthy plant-based diet index) is based on the PDI but emphasizes “healthy” plant foods. A high hPDI score means that the participant’s diet is high in healthy plant foods (whole grains, fruits, vegetables, nuts, legumes, coffee and tea) and low in animal foods.
  • The uPDI (unhealthy plant-based diet index) is based on the PDI but emphasizes “unhealthy” plant foods. A high uPDI score means that the participant’s diet is high in unhealthy plant foods (refined grains, fruit juices, French fries and chips, sugar sweetened and artificially sweetened beverages, sweets and desserts) and low in animal foods.

For statistical analysis the scores from the various plant-based diet indices were divided into 5 equal groups. In each case, the group with the highest score consumed the most plant foods and least animal foods. The group with the lowest score consumed the least plant foods and the most animal foods.

The health outcomes measured in this study were heart disease events, heart disease deaths, and all-cause deaths. Again, for the sake of simplicity, I will only include 2 of these outcomes (heart disease deaths and all-cause deaths) in this review. The data on deaths were obtained from state death records and the National Death Index. (Yes, your personal information is available on the web even after you die.)

 

Do Plant-Based Diets Reduce Heart Disease Deaths?

plant-based diets reduce heart deathsThe participants in this study were followed for an average of 25 years.

The investigators looked at heart disease deaths over the 25 years and compared people with the highest intake of plant foods to people with the highest intake of red meat and other animal foods. The results were:

  • People with the highest intake of plant foods and the highest intake of healthy plant foods (whole grains, fruits, vegetables, nuts, legumes, coffee and tea) had a 19-32% lower risk of dying from heart disease than people with the highest intake of red meat and other animal foods.
  • People with the highest intake of unhealthy plant foods (refined grains, fruit juices, French fries and chips, sugar sweetened and artificially sweetened beverages, sweets and desserts) had the same risk of dying from heart disease as people with the highest intake of red meat and other animal foods.

When the investigators looked at all-cause deaths over the 25 years:

  • People with the highest intake of plant foods and the highest intake of healthy plant foods had an 11-25% lower risk of dying from any cause than people with the highest intake of red meat and other animal foods.
  • People with the highest intake of unhealthy plant foods had the same risk of dying from heart disease as people with the highest intake of red meat and other animal foods.

What Else Did The Study Show?

The investigators made a couple of other interesting observations:

  • The association of the overall diet with heart disease and all-cause deaths was stronger than the association of individual food components. This underscores the importance of looking at the effect of the whole diet on health outcomes rather than the “magic” foods you hear about on Dr. Strangelove’s Health Blog.
  • Diets with the highest amount of healthy plant foods were associated with higher intake of carbohydrates, plant protein, fiber, and micronutrients, including potassium, magnesium, iron, vitamin A, vitamin C, folate, and lower intake of saturated fat and cholesterol.
  • Diets with the highest amount of unhealthy plant foods were associated with higher intake of calories and carbohydrates and lower intake of fiber and micronutrients.

The last two observations may help explain some of the health benefits of plant-based diets.

 

Can Plant-Based Diets Be Unhealthy?

plant-based diets unhealthy cookiesNow, let’s return to the question I asked at the beginning of this article: “Can plant-based diets be unhealthy?” Although some previous studies have suggested that unhealthy plant-based diets might increase the risk of heart disease, this study did not show that.

What this study did show was that an unhealthy plant-based diet was no better for you than a diet containing lots of red meat and other animal foods.

If this were the only conclusion from this study, it might be considered a neutral result. However, this result clearly contrasts with the data from this study and many others showing that both plant-based diets in general and healthy plant-based diets reduce the risk of heart disease deaths and all-cause deaths compared to animal-based diets.

The main message from this study is clear.

  • Replacing red meat and other animal foods with plant foods can be a healthier choice, but only if they are whole, minimally processed plant foods like whole grains, fruits, vegetables, nuts, legumes, coffee and tea.
  • If the plant foods are refined grains, fruit juices, French fries and chips, sugar sweetened and artificially sweetened beverages, sweets and desserts, all bets are off. You may be just as unhealthy as if you kept eating a diet high in red meat and other animal foods.

There is one other subtle message from this study. This study did not compare vegans with the general public. Everyone in the study was the general public. Nobody in the study was consuming a 100% plant-based diet.

For example:

  • The group with the highest intake of plant foods consumed 9 servings per day of plant foods and 3.6 servings per day of animal foods.
  • The group with the lowest intake of plant foods consumed 5.4 servings per day of plant foods and 5.6 servings per day of animal foods.

In other words, you don’t need to be a vegan purist to experience health benefits from adding more whole, minimally processed plant foods to your diet.

 

The Bottom Line

A recent study analyzed the effect of consuming plant foods on heart disease deaths and all-cause deaths over a 25-year period.

When the investigators looked at heart disease deaths over the 25 years:

  • People with the highest intake of plant foods and the highest intake of healthy plant foods had a 19-32% lower risk of dying from heart disease than people with the highest intake of red meat and other animal foods.
  • People with the highest intake of unhealthy plant foods had the same risk of dying from heart disease as people with the highest intake of red meat and other animal foods.

When the investigators looked at all-cause deaths over the 25 years:

  • People with the highest intake of plant foods and the highest intake of healthy plant foods had an 11-25% lower risk of dying from any cause than people with the highest intake of red meat and other animal foods.
  • People with the highest intake of unhealthy plant foods had the same risk of dying from heart disease as people with the highest intake of red meat and other animal foods.

The main message from this study is clear.

  • Replacing red meat and other animal foods with plant foods can be a healthier choice, but only if they are whole, minimally processed plant foods like whole grains, fruits, vegetables, nuts, legumes, coffee and tea.
  • If the plant foods are refined grains, fruit juices, French fries and chips, sugar sweetened and artificially sweetened beverages, sweets and desserts, all bets are off. You may be just as unhealthy as if you kept eating a diet high in red meat and other animal foods.

A more subtle message from the study is that you don’t need to be a vegan purist to experience health benefits from adding more whole, minimally processed plant foods to your diet. The people in this study were not following some special diet. The only difference was that some of the people in this study ate more plant foods and others more animal foods.

For more details on the study, read the article above.

 

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

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