Polyphenol

Thu, 02 Apr 2026 00:00:00 +0000

Polyphenols are a large and structurally diverse class of organic compounds produced by plants, characterized by the presence of multiple phenol groups — aromatic rings bearing hydroxyl (-OH) substituents. Over 8,000 polyphenolic compounds have been identified in plants. They are the most abundant antioxidants in the human diet, present in fruits, vegetables, tea, coffee, wine, chocolate, and medicinal herbs.

Plants produce polyphenols primarily as defensive compounds — protecting against ultraviolet radiation, pathogens, and herbivores. This defensive function is why stressed or damaged plants often produce higher concentrations of polyphenols than unstressed plants, and why phytoalexins (stress-induced defensive compounds) are frequently polyphenolic.

Resveratrol

Thu, 02 Apr 2026 00:00:00 +0000

Resveratrol (trans-3,5,4’-trihydroxystilbene) is a polyphenolic stilbenoid produced by plants as a phytoalexin — a defensive compound synthesized in response to injury, ultraviolet radiation, or fungal infection. It is found in grape skins, peanuts, blueberries, and most abundantly in the root and rhizome of Japanese knotweed (Reynoutria japonica), which produces resveratrol at concentrations 50–100 times higher than grape skins and is the primary commercial source for dietary supplements.

The French paradox

Resveratrol entered Western biomedical consciousness through the “French paradox” — the epidemiological observation, reported by Renaud and de Lorgeril in The Lancet in 1992, that French populations had lower rates of coronary heart disease than predicted by their saturated fat intake [@renaud1992]. Red wine consumption was proposed as the protective factor, and resveratrol — present in grape skins and therefore concentrated in red wine — was identified as a candidate molecule responsible for the cardioprotective effect. Whether resveratrol at the concentrations present in wine is sufficient to explain the epidemiological observation remains contested. The paradox may reflect dietary pattern effects (the Mediterranean diet), reporting artifacts, or multiple interacting factors rather than a single compound.

Antioxidant on emsenn.net

Polyphenol

Resveratrol

The French paradox