The resveratrol in red wine comes from the skin of grapes used to make wine. Because red wine is fermented with grape skins longer than is white wine, red wine contains more resveratrol. Simply eating grapes, or drinking grape juice, has been suggested as one way to get resveratrol without drinking alcohol. Red and purple grape juices may have some of the same heart-healthy benefits of red wine.
Resveratrol is a chemical found in the skin of grapes and in red wine that has long been conjectured to be a partial explanation for the French paradox, the puzzling fact that people in France enjoy a high-fat diet yet suffer less heart disease than Americans. More recently, scientists have been exploring whether resveratrol could extend lifespan as well.