The Role of Polyphenols in Supporting and Improving Human Health

“Let food be thy medicine, and medicine be thy food.” – Hippocrates

We like to think that we’re far more advanced today than back in the day of Hippocrates (the Father of Medicine). After all, we know that many illnesses come from the spread of germs, not from “ill humors”. We know that the Earth, Mercury, Venus, Mars and all the rest orbit the Sun, and that Earth is not the center of the universe. However, it’s possible that we’re not really as advanced as we’d like to think.

Take our reliance on Western medicine, for instance. When we have aches and pains, a sprain, or we’re suffering from a headache, what do we do? We pop an over-the-counter pain reliever and wait for it to work. As soon as the discomfort lessens, we get back to living our lives.

The assumption here is that because the pain is gone, whatever was causing the pain is also gone. That’s not the case. Acetaminophen, ibuprofen, naproxen, and the like, are just Band-Aids. They mask the problem by alleviating the symptoms without doing anything about the cause. They’re not a cure. They’re not really medicine.

Hippocrates knew a thing or two about real medicine, and modern science is finally beginning to catch up. Take food, for instance. Hippocrates tells us that food should be our medicine, and our medicine should be food. Researchers are finding that polyphenols and other nutraceuticals in our food are actual medicine, and can have profound effects on the cause of our health problems, and not just mask the symptoms so we can pretend that we’re all right.

What Are Nutraceuticals?

Nutraceuticals might sound like a creation of the pharmaceutical industry, but that’s not the case at all. They’re defined as “food or food products that provide medical or health benefits, including the prevention and/or treatment of a disease”. They’re part of alternative medicine, which is used by up to 47% of US adults attempting to combat chronic health problems, ranging from osteoarthritis to obesity.

Nutraceuticals is a category or sector that includes a number of different components, including:

  • Polyphenols
  • Phytoflavonoids
  • Bioflavonoids

Of these polyphenols are one of the more promising, and deserve additional attention.

What Are Polyphenols?

According to a paper by G. Williamson of the University of Leeds, in the UK, “Polyphenols are found in plant-based foods and beverages, notably apples, berries, citrus fruit, plums, broccoli, cocoa, tea and coffee, and many others.”

However, understand that the term “polyphenol” does not apply strictly to chemicals. It can also be applied to things like tannins and acids, as well as products that are synthesized from other polyphenols, or that result from the combining of different elements. A brief look at the classes of polyphenols shows the following:

  • Anthocyanins
  • Chalcones
  • Dihydrochalcones
  • Dihydroflavanols
  • Flavanols
  • Favanones
  • Favones
  • Flavonols
  • Isoflavandoids
  • Lignans
  • Non-phenolic metabolites
  • Alkyphenols
  • Crucuminoids
  • Furanocoumarins
  • Hydroxbenzaldehydes
  • Hydroxybenzoketones
  • Hydroxycinnamaldehydes
  • Hydroxycoumarins
  • Methoxyphenols
  • Naphtoquinones
  • Phenolic terpenes
  • Tyrosols

So, they’re natural compounds found in the fruits and vegetables that we eat (or should eat), on a regular basis. Of course, this poses significant problems immediately. The primary issue here is that the conventional Western diet is very poor in fresh fruits and vegetables, relying instead on highly-processed foods that have been largely robbed of their nutritive value.

So, Westerners are obviously at a disadvantage when it comes to obtaining polyphenols from natural foods in their everyday lives. This has given rise to a multi-billion-dollar supplement industry. The issue here is that supplements are not the same as food – some can have toxic effects over time.

Even if there are no harmful effects, there’s the fact that the body only processes a small portion of a supplement, meaning that you’re only getting a fraction of what’s included per dose. An additional complication is that many polyphenols work in concert with other polyphenols or compounds within the natural fruit or vegetables. Isolating them can reduce or even eliminate their beneficial aspects, rendering the supplement virtually useless.

Finally, the FDA does not regulate the supplement industry, and it’s been proven by several consumer watchdog organizations that even reputable brands often include less than the advertised amount of a particular ingredient in their supplements, and some brands contain next to none of the ingredient.

Why Are Polyphenols Important?

So, now that we’ve identified what polyphenols are, where they come from, and a few of the issues surrounding synthetic supplementation, it’s time to answer the most pressing question of all – why are they important?

Williamson explains, “Common polyphenols in the diet are flavanols, flavanones, hydroxycinnamates, favonols, and anthocyanins. Many intervention studies, mechanistic in vitro data and epidemiological studies support a role for polyphenols against the development of chronic disease. For example, flavanols decrease endothelial dysfunction, reduce blood pressure and cholesterol, and modulate energy metabolism. Hydroxycinnamates reduce the risk of developing type 2 diabetes.”

How do polyphenols do all of this? Actually, science is not exactly sure of the precise mechanism of action here. Extensive research has been conducted, and while it has been proven that polyphenols can have an incredibly profound effect on human health, it has not been determined how that happens.

Where Can You Get Polyphenols Naturally?

As mentioned, polyphenols occur naturally in fruits and vegetables. Therefore, you can obtain them by eating fruits and vegetables – apples, broccoli, asparagus and the like. The more fruits and vegetables you eat, the higher your intake of important, health-boosting polyphenols will be. However, you will also find polyphenols in foods that we don’t always think of as being plant-related, but in actuality are, such as chocolate/cocoa, coffee and tea.


Cocoa, particularly the darker variety, has been shown to have significant levels of polyphenols. In studies conducted over a seven-year period from 2000 to 2007, researchers noted that study participants enjoyed improved endothelial function, as well as reduced “bad” cholesterol. Platelet aggregation was reduced or inhibited, and the levels of F2-isoprostanes in their bodies decreased. In additional studies, researchers found that cocoa intake resulted in reduced blood pressure, as well.


Tea provides a rich source of polyphenols, particularly catechins and gallocatechins, as well as epicatechin. Tea also offers many of the same benefits as cocoa, as well as some not found with cocoa. The health benefits noted during research with tea (black and green, primarily), include reduced blood sugar, reduced risk of developing type 2 diabetes, a reduction in LDL cholesterol. Researchers also find that study participants had a reduced risk of heart disease.


Coffee delivers some of the same health benefits as cocoa and tea, and for the same reason – it’s a good source of polyphenols. Consuming coffee has been shown to reduce the risk of developing type 2 diabetes, up to an 8% reduction per cup consumed per day, which is very strong. However, caffeinated coffee showed unwanted effects on endothelial function (decaf did not show these effects, so the results are likely due to caffeine only). Coffee has also been shown to be effective in protecting against DNA damage from free radicals.


Quercetin is a polyphenol found in a number of different foods, but most notably in onions and apples. It is also found in most types of tea. It has been shown to reduce the chance of developing type 2 diabetes, as well as reducing high blood pressure. It can also reduce overall inflammation within the body.

Using Polyphenols to Combat Oxidative and Degenerative Diseases

In a medical study published by Hindawi Publishing Company in 2016, authors Islam, Alam, Solayman, Khalil, Kamal and Gan state, “Cumulative degenerative disease is one of the most fatal groups of diseases, and it contributes to the mortality and poor quality of life in the world while increasing the economic burden of the suffers. Oxidative stress and inflammation are the major pathogenic causes of degenerative diseases such as rheumatoid arthritis and cardiovascular disease … Phytochemicals (including polyphenols) from natural products such as dietary fruits, vegetables and spices are potential sources of alternative medications to attenuate the oxidative stress and inflammation associated with degenerative diseases.”

In short, polyphenols like those we’ve discussed so far show great promise in not only helping to reduce the symptoms of diseases like osteoarthritis, rheumatoid arthritis and other chronic diseases, but to improve the quality of life of those suffering from them.

Through ongoing research and scientific studies, it has been proven that consuming fresh vegetables and fruits, as well as many different spices, can dramatically reduce the risk of developing cardiovascular disease. They have also been shown to be effective in helping to fight diabetes-related diseases. In patients suffering from rheumatoid arthritis, the regular consumption of fresh fruits and vegetables, anthocyanins reduced oxidative stress, and also addressed inflammation. Resveratrol from grapes was also able to reduce the pain, discomfort and inflammation associated with RA.

In Conclusion

Ultimately, eating a diet rich in fresh fruits and vegetables is not just good for you. It’s an important way of ensuring your get optimum intake of vital polyphenols to support overall health and wellness. From coffee and tea to peaches and plums, broccoli, cabbage and the thousands of options in between, fresh fruits and vegetables deliver compounds essential for beating disease and living a healthy, happy life.


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