What are polyphenols?
Polyphenols are a huge family of plant compounds, giving many fruits, vegetables, tea, coffee and olive oil their color and bitterness, that plants use to protect themselves.
Think of polyphenols as a plant's sunscreen and pest spray. When we eat the plant, we take in those protective compounds, and some of them send helpful signals in our own bodies.
Why it matters for aging
There are thousands of polyphenols, including flavonoids in berries, cocoa and tea, ellagitannins in pomegranates and walnuts, and resveratrol in grapes. Diets rich in polyphenol-containing foods are linked to better health in many observational studies.
Isolated polyphenol supplements have a weaker track record than whole foods, partly because of poor absorption. Eating a variety of colorful plants, plus tea, coffee and extra-virgin olive oil, is the best-supported way to get them.
A common myth
Polyphenols work mainly as antioxidants mopping up free radicals in your blood.
Most polyphenols are poorly absorbed. Many of their benefits seem to come from how gut bacteria transform them into other compounds, such as urolithin A from pomegranates and walnuts, and from mild stress signals that switch on cell defenses.
Go deeper
Deep dives
- Does coffee break a fast? It depends what you're fasting for
- Does urolithin A work? What the human trials actually show
- Resveratrol: what happened to the red wine miracle?
Related terms
Updated Nov 9, 2026 · All terms