Maximizing Polyphenols Benefits

Written by Dr. Steve Chaney on . Posted in Gut Bacteria, Polyphenols Benefits

The Symbiotic Relationship Between Gut Bacteria And Polyphenols

Author: Dr. Stephen Chaney

 

How to maximize polyphenols benefits?

grape polyphenolsPolyphenols are ubiquitous in the plant world. There are many kinds of polyphenols, and they are found in a wide variety of fruits, vegetables, whole grains, and legumes. You probably already know that polyphenols are also found in tea, coffee, chocolate, and many herbs and spices.

Polyphenols are thought to have a wide array of health benefits. For example, the polyphenols in grapes are thought to:

  • Reduce inflammation.
  • Reduce the risk of heart disease, cancer, and diabetes.
  • Prevent or delay the onset of neurodegenerative diseases like Alzheimer’s.

The amazing thing is that polyphenols are effective at all. They are poorly absorbed and rapidly eliminated from the circulation. For example, resveratrol, a polyphenol found in red grapes, only stays in the circulation for a few hours.

In the case of resveratrol, we know that, during its brief time in our bodies, it turns on “anti-aging” genes that control things like inflammation, protection against free radical damage, cholesterol metabolism, blood sugar control, and blood pressure. We are less certain how other polyphenols exert their beneficial effects during the short time they are in our bodies.

When we scientists are facing a problem like this, it stimulates our creative thinking. We start asking questions like:

  • Can we improve the absorption of beneficial polyphenols into the bloodstream?
  • Would that improve their effectiveness and health benefits?

A recent review (D Zhao et al, Critical Reviews In Food Science and Nutrition: Jan 7, 1-29, 2019) looked at the first question. It summarized the most promising strategies for improving the absorption of grape polyphenols. We don’t yet know the answer to the second question.

Before I discuss the most promising strategies, the professor in me wants to cover Polyphenols 101, something I call “The Symbiotic Relationship Between Gut Bacteria and Polyphenols”.

 

The Symbiotic Relationship Between Gut Bacteria and Polyphenols

 

polyphenols gut bacteriaThe world of polyphenols is complex. For example:

  • Resveratrol is the best-known and best-studied polyphenol in grapes, but there are dozens of other beneficial polyphenols in grapes.
  • Each of these polyphenols have unique metabolic pathways and unique health benefits.
  • Each variety of grapes has a unique blend of polyphenols.
  • Each polyphenol is metabolized differently by our gut bacteria and by enzymes in our body.
  • You start with dozens of polyphenols in the grape and end up with hundreds of metabolites in the body.
  • Some of these metabolites are better absorbed. Some are not absorbed at all. Some of these metabolites are highly active. Others are inactive. The possibilities are endless.

As if that weren’t enough, there are two more complexities to factor into the equation.

  • There is a symbiotic relationship between gut bacteria and polyphenols.
  • Our gut bacteria influence the metabolism and absorption of the polyphenols in our diet.
  • The polyphenols we consume influence the population of bacteria in our gut.
  • The kinds of fiber we consume influence which bacteria populate our gut, and that, in turn, influences how we metabolize the polyphenols we consume.

Faced with this level of complexity, there have been two types of approaches to improving the absorption of polyphenols.

  • The pharmaceutical approach, which tries to bypass the complexities of polyphenol absorption.
  • The natural approach, which tries to optimize the complexities of polyphenol absorption.

The review (D Zhao et al, Critical Reviews In Food Science and Nutrition: Jan 7, 1-29, 2019) gives examples of each type of approach, which I will discuss below.

 

Maximizing Polyphenols Benefits

 

polyphenols effectivenessPharmaceutical Approaches: These are approaches designed to bypass the complexities of polyphenol absorption. The authors considered the following two strategies to have the most probability of success:

  • Chemical alteration of polyphenol structure. This is a classical pharmaceutical strategy. You start with naturally occurring compound that has medicinal benefit. Then you chemically modify it in multiple ways until you find a chemical modification that is efficiently absorbed and is stable in the circulation. There are two drawbacks to this approach:
  • You have created a new compound with its own properties. You have created a drug that needs to be tested for safety and efficacy. Resveratrol, for example, offers a cautionary tale. A drug company modified it. The modified form was efficiently absorbed and was stable in the bloodstream. They thought they had created the perfect drug. Unfortunately, when they tested it, they found out it was toxic.
  • Even if you did optimize safety and efficacy of the polyphenol, you have only optimized one polyphenol out of the dozens found in the real food.
  • Incorporate the polyphenol into nanoparticles that are absorbed so efficiently by the intestine that they effectively bypass metabolism by gut bacteria. This is a strategy currently being explored by drug companies to improve the efficacy of poorly absorbed drugs. Even if successful, this approach has the same type of drawbacks.
  • This is a relatively new technology. There are some concerns it may not be safe.
  • Foods have dozens of polyphenols. A nanoparticle strategy may improve the absorption of one or two polyphenols, but it is unlikely to replace the real food.

maximize polyphenols benefitsNatural Approaches: These approaches are designed to optimize the complexities of polyphenol absorption.

  • Develop a probiotic supplement containing bacteria that improve polyphenol uptake. There is some promising research in this area.
  • However, when we talk about gut bacteria, the phrase “It takes a village” takes on a whole new meaning. There may be dozens of bacteria involved in improving polyphenol uptake, not just one or two. The probiotic supplement may need to be a horse pill
  • Add fiber to the diet to support the growth of the gut bacteria that enhance the absorption of polyphenols. This may be the most promising strategy.
  • Studies have already shown that pectin and similar non-digestible polysaccharides improve the absorption of polyphenols found in grapes and many other foods.
  • While grapes are low in pectin, other fruits (most notably apples, peaches, citrus fruit, apricots, and plums) are high in pectin. Legumes and some vegetables are also high in pectin. The only reason you don’t find them on most lists of high pectin foods is these lists are for foods that have enough pectin to make good jams without any added pectin. Legumes and vegetables are also high in insoluble fibers, which interfere with the gelling required for a good jam. Besides, kale or pea jam are probably not high on anyone’s list of favorite jams.
  • The best thing about this approach is that it is completely natural. It involves eating a plant-based diet with fruits, vegetables whole grains, and legumes, something humans have been doing for thousands of years. This a diet chock full of beneficial polyphenols and the fiber needed to support the gut bacteria that help us utilize those polyphenols. There are no side effects. There is no danger associated with this approach. 

Once again, Mother Nature knows best.

Addendum

While writing this article I happened to read “The People’s Pharmacy” column by Joe & Terry Graedon in our local paper (Yes, I still read a physical newspaper). They were talking about combining pectin with grape juice to relieve arthritis pain. Some of the polyphenols in grape juice have anti-inflammatory effects. But, grape juice alone is not very effective at relieving arthritis pain. However, it turns out that pectin plus grape juice, something called “purple pectin remedy,” is a home remedy for arthritis pain relief that has been around since the 1940s. They did not discuss a mechanism, but now we know how it works.

Note: I suppose if you are getting your grape polyphenols from grape juice, wine, or some other liquid source, you could stir in some pectin to improve their absorption. However, my recommendation would be to consume a primarily plant-based diet with a variety of fruits, vegetables, whole grains, and legumes along with your liquid polyphenol source.

 

The Bottom Line

 

Resveratrol and other polyphenols found in grapes have many health benefits. However, these polyphenols are poorly absorbed. A recent review described ongoing research into approaches for improving the absorption of grape polyphenols

I discuss the various approaches that are being studied in my article above. Some are pharmaceutical approaches that involve structural alterations to the polyphenol or nanoparticle delivery systems to improve absorption. Others involve probiotics that contain bacterial strains that enhance polyphenol absorption. Each of these approaches have limitations, or dangers, or both.

The most promising approach was to simply add fiber to the diet to support the growth of the gut bacteria that enhance the absorption of polyphenols.

  • Studies have already shown that pectin and similar non-digestible polysaccharides improve the absorption of polyphenols found in grapes and many other foods.
  • While grapes are low in pectin, other fruits (most notably Apples, peaches, citrus fruit (especially the skin), apricots, and plums) are high in pectin. Legumes and some vegetables are also high in pectin. The only reason you don’t find them on most lists of high pectin foods is these lists are for foods that have enough pectin to make good jams without any added pectin. Legumes and vegetables are also high in insoluble fibers, which interfere with the gelling required for a good jam. Besides, kale or pea jam are probably not high on anyone’s list of favorite jams.
  • The best thing about this approach is that it is completely natural. It involves eating a plant-based diet with fruits, vegetables whole grains, and legumes, something humans have been doing for thousands of years. This a diet chock full of beneficial polyphenols and the fiber needed to support the gut bacteria that help us utilize those polyphenols. There are no side effects. There is no danger associated with this approach.

Once again, Mother Nature knows best.

Note: If you are getting your grape polyphenols from grape juice, wine, or some other liquid source, you could stir in some pectin to improve their absorption. However, my recommendation would be to consume a primarily plant-based diet with a variety of fruits, vegetables, whole grains, and legumes along with your liquid polyphenol source.

For more details read the article above. You will also find an interesting story about the “purple pectin remedy”.

 

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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