Polyphenols
The largest class of plant protective compounds — antioxidants, anti-inflammatories, and prebiotic substrates all in one molecule family.
— Definition
Polyphenols are a structurally diverse class of over 8,000 plant compounds characterised by multiple phenol rings. They include flavonoids (anthocyanins, flavonols, isoflavones), phenolic acids (gallic, ferulic, chlorogenic), stilbenes (resveratrol), and lignans.
— In Detail
Polyphenols serve as the plant's own defence system against UV radiation, pathogens, and oxidative stress. In humans, their mechanisms include: direct antioxidant activity (though less potent than once thought), modulation of inflammatory signalling (NF-κB inhibition), prebiotic activity (polyphenols reaching the colon intact are fermented by gut bacteria), and epigenetic effects (histone modification). Key point: most polyphenols are not absorbed intact in the small intestine — they reach the colon where they are transformed by the microbiome into smaller bioactive metabolites (urolithins from ellagitannins, equol from daidzein). This means gut microbiome composition determines how much benefit a person gets from polyphenol-rich foods — a finding that explains why clinical trials of polyphenol extracts show inconsistent results while whole food studies do not.
— Why It Matters
Traditional Indian spices, heirloom grains, and forest honey are among the most polyphenol-dense foods on earth. Turmeric, black pepper, kokum, and Chak-Hao black rice contain polyphenol concentrations that rival any superfood in the world — at a fraction of the price. Polishing rice and milling wheat removes the bran fraction where 90%+ of grain polyphenols reside.
— Related Terms
— See in Field Guide
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