What Are Polyphenols?

Fresh berries are loaded with nutrients and polyphenols.
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Polyphenols are plant chemicals that may have health benefits for people. There are different types of polyphenols, and they're located in all different plants that you eat. Let me explain -- first it's time for a little food chemistry -- plant-based food chemistry, in particular.


Much has been made in the media about phytochemicals, a word that refers to plant chemicals. Phytochemicals are naturally occurring compounds that give plants their colors or help to protect them from various things they might face in nature.

These compounds are often extracted from the plants and examined for their potential health benefits.

In general, the phytochemicals are thought to work as antioxidants to protect the cells in your body from free radical damage. Sometimes they have impressive results in the lab and sometimes they don't. For the most part, it seems to be better for you to get them from foods rather than pills.

There are three major groups: carotenoids, which are related to vitamin A; allyl sulfides in garlic and onions; and the largest group, the polyphenols, which are found in many different foods.


Polyphenols all have similar ring-shaped chemical structures, but they differ in the number of rings and molecules that are attached to those rings. Thus, polyphenols are grouped into four different categories based on those differences. The categories are phenolic acids, flavonoids, stilbenes, and lignans.

Phenolic acids include hydroxybenzoic acids, such as gallic acid found in tea, and hydroxycinnamic acids found in coffee, blueberries, kiwis, plums, apples, and cherries.

Flavonoids work as both antioxidants and anti-inflammatory agents. There are several different types of flavonoids: flavones, flavonols, flavanones, isoflavones, anthocyanidins, chalcones, and catechins.

They're found in a wide variety of plant-based foods, including fruits, vegetables, legumes, red wine, and green tea (including decaffeinated forms of green tea).

Stilbenes are a small group - resveratrol is the most common. It's found in small quantities in red wine and peanuts.

Lignans are found in legumes, cereals, grains, fruits, algae, and some vegetables.

Eating a balanced diet with fruits, vegetables, whole grains and legumes should provide you with a broad range of polyphenols. Some polyphenols, such as epigallocatechin gallate (EGCG) and resveratrol, are available as dietary supplements. Always speak with your healthcare provider before taking large doses of dietary supplements, including any polyphenols. 


American Cancer Society. "Phytochemicals." 

Manach C, Scalbert A, Morand C, Rémésy C, Jiménez L. "Polyphenols: food sources and bioavailability." Am J Clin Nutr. 2004 May;79(5):727-47. 

Tresserra-Rimbau A, Rimm EB, Medina-Remón A, Martínez-González MA, de la Torre R, Corella D, Salas-Salvadó J, Gómez-Gracia E, Lapetra J, Arós F, Fiol M, Ros E, Serra-Majem L, Pintó X, Saez GT, Basora J, Sorlí JV, Martínez JA, Vinyoles E, Ruiz-Gutiérrez V, Estruch R, Lamuela-Raventós RM; PREDIMED Study Investigators. "Inverse association between habitual polyphenol intake and incidence of cardiovascular events in the PREDIMED study." Nutr Metab Cardiovasc Dis. 2014 Jun;24(6):639-47.

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