Antioxidants and Aging

Written by Dr. Steve Chaney on . Posted in current health articles, Healthy Lifestyle, Healthy Living, Supplements and Health

Author: Dr. Stephen Chaney

 

antioxidant agingModern medicine has helped mankind greatly extend our lifespan, but what about our “healthspan”? Aging is often associated with major degenerative diseases and loss of physical and mental functioning. As the saying goes: “Aging isn’t for sissies”. But, what if you could live healthy into your 80s and 90s? What if you had the health to truly enjoy the wisdom that comes with your years of experience?  In this article we will explore antioxidants and aging.

While healthy aging is a very personal issue for all of us in our golden years, it is a very important societal issue as well. The United Nations estimates that by 2050 more than 1/3 of the population of developed countries will be over 60. Unless we can find a way to preserve the health of these older adults, health care costs will bankrupt even the richest of countries.

That’s why the recently published study on the effect of antioxidant supplements on healthy aging in French adults (Assmann et al, American Journal of Epidemiology, 182: 694-704, 2015) is so interesting.

How Was The Study Designed?

studyThis study was a follow-up to the “Supplementation With Antioxidant Vitamins and Minerals” study that was conducted in France during 1994-2002. That was a double blind, placebo controlled study in which participants were given either a placebo or a supplement containing 120 mg of vitamin C, 6 mg of beta-carotene, 30 mg of vitamin E, 100 ug of selenium, and 20 mg of zinc every day for an eight-year period. These nutrient levels were designed to be equivalent to the quantities provided by a balanced diet rich in fruits and vegetables.

The follow-up study was conducted approximately 5 years later with 3,996 of the original participants. The investigators specifically selected participants who were disease free when they entered the original study. These study participants were equally divided between men and women and had an average age of 65.3 years.

The participants were put through a battery of screens and assigned a “healthy aging score” based on:

  • Absence of cancer, heart disease and diabetes
  • Good physical and cognitive function
  • No limitations in activities associated with daily living
  • No depressive symptoms
  • No health-related limitations in social life
  • Good overall perceived health
  • No function-limiting pain

In short those participants with a high healthy aging score had good health and good quality of life.

Are Antioxidants the Secret to Healthy Aging?

antioxidant nutrientsWhen the investigators looked at the group as a whole, the results were pretty discouraging:

  • Antioxidant supplementation provided no significant benefit to the population as a whole.
  • Antioxidant supplementation also provided no significant benefit to the women in the group.

However, when they looked at subgroups, the results were much more encouraging:

  • Antioxidant supplementation increased the probability of healthy aging by 18% for the men in the study.
  • For those participants with low serum vitamin C levels at the beginning of the study antioxidant supplementation increased the probability of healthy aging by 28%
  • For those participants with low serum zinc levels at the beginning of the study antioxidant supplementation increased the probability of healthy aging by 26%
  • For those participants consuming very few fruits and vegetables at the beginning of the study, antioxidant supplementation increased the probability of healthy aging by 17%

The conflicting results for men and women were puzzling, but the investigators pointed out that very few women had low serum vitamin C status at the beginning of the study, while 25% of the men had low serum vitamin C levels at the beginning of the study. The investigators speculated that supplementation may have been less effective in women simply because they had better diets than the men in the study. That certainly wouldn’t surprise me.

What Are The Strengths And Weaknesses Of This Study?

Let’s start with the strengths. This is the very first double-blind, placebo-controlled study to look at the role of antioxidant nutrients in healthy aging. A number of previous studies looking at the effect of antioxidant nutrients on individual components of aging have given conflicting results. The investigators pointed out that this study may have shown more beneficial effects of antioxidants than previous studies because:

  • Most previous studies have been relatively short in duration. This was an 8-year study with a 5-year follow-up period (total study length = 13 years).
  • Most previous studies did not measure baseline intake of the nutrients. This study shows that individuals with low baseline intake or low serum levels at the beginning of the study are significantly more likely to benefit from supplementation.
  • Most previous studies have measured the effects of single antioxidant nutrients, or at most combinations of 2 or 3 antioxidant nutrients. This study used a combination of 5 different antioxidant nutrients. The synergy between these nutrients may have increased the magnitude of the observed benefits.

The weaknesses of the study are also pretty apparent.

  • Since it is the first study of its kind, it does need to be validated by additional studies.
  • There is no universally accepted index for healthy aging (This is a problem for aging research as a whole, not just this study).
  • The participants in the study were not evaluated for healthy aging criteria at the beginning of the study so we have no idea how their healthy aging score changed over time.
  • The beneficial effect of antioxidant nutrients, while significant, were relatively small. You are obviously not going to live healthy to 100 by consuming antioxidant supplements alone.

Antioxidants and Aging:  Will Antioxidant Nutrients Help You?

aging gracefullyThis study does suggest that antioxidant supplements may help you achieve healthy aging. This study also makes three other very important points:

  • A holistic approach to supplementation – one involving multiple antioxidant nutrients – is much more likely to be beneficial than individual antioxidant supplements.
  • Supplementation is most likely to be beneficial for those individuals who are consuming a poor diet.
  • Supplementation is also most likely to be beneficial for those individuals who have low serum level of essential nutrients. This can be due to poor diet, but low serum levels of individual nutrients can also be caused by individual differences in metabolism or genetic make-up.

However, as noted above:

  • The study has some weaknesses and needs to be repeated.
  • The beneficial effects of antioxidant nutrients were relatively small.

That means that holistic approaches to healthy aging are more likely to be beneficial than individual supplements. Based on what we currently know a holistic approach to healthy aging includes:

  • Consuming a combination of a balanced diet and supplementation that provides sufficient levels of all the essential nutrients, not just the antioxidant nutrients. This would include things like omega-3 fatty acids and polyphenols.
  • Avoiding saturated and trans fats, excess sugar, red and processed meats, which may have bad effects on your health.
  • Controlling your weight.
  • Staying mentally and physically active.
  • Maintaining strong social networks.
  • Maintaining a positive outlook on life.

 

The Bottom Line

  • A recent study suggests that antioxidant supplements may help you achieve healthy aging. This study also makes two other very important points:
  • A holistic approach to supplementation – one involving multiple antioxidant nutrients – is much more likely to be beneficial than individual antioxidant supplements.
  • Supplementation is most likely to be beneficial for those individuals who are consuming a poor diet and/or have low serum levels of essential nutrients.
  • Since the beneficial effect of antioxidant nutrients on healthy aging was relatively small, this suggests the antioxidant nutrients are just one part of a holistic approach to healthy aging that includes.
  • Consuming a combination of a balanced diet and supplementation that provides sufficient levels of all the essential nutrients, not just the antioxidant nutrients. This would include things like omega-3 fatty acids and polyphenols.
  • Avoiding saturated and trans fats, excess sugar, red and processed meats, which may have bad effects on your health.
  • Controlling your weight.
  • Staying mentally and physically active.
  • Maintaining strong social networks.
  • Maintaining a positive outlook on life.

 

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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Is Our Microbiome Affected By Exercise?

Posted November 6, 2018 by Dr. Steve Chaney

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.

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