Q: Is it true that you need to eat red grapes to get resveratrol, the compound found in red wine?
A: No, but it’s a common misunderstanding because of the many news stories about resveratrol and red wine. Resveratrol is a phytochemical found in grape skins of all colors and is produced by plants to fight off fungus. The amount of resveratrol in grapes depends much more on growing conditions than on the color or type of grape. Much of the resveratrol is in the grape’s skin. Red wine contains much more resveratrol than white because red wine is made by fermenting grapes with skins; for white wine, the grape skins are removed before fermenting. Alcohol – including red wine – increases risk for several common cancers, so it’s best to avoid or limit alcohol to no more than 1 standard drink (5 ounces of wine) per day for women, two for men.
In laboratory studies resveratrol can inhibit cancer development. However, most of this evidence comes from cell studies using concentrations of resveratrol much higher than a person is likely to reach. We don’t have nearly enough good research to make resveratrol content a sound basis for choosing specific types of fruit.
Grapes also contain a variety of other phytochemicals and we need more human studies to understand their potential cancer-protective effects. Red grapes’ color comes from anthocyanins, compounds being studied for potential antioxidant and cancer-protective effects, too. But the potential for health protection from grapes and other plant foods, including beans and whole grains, comes from more than any one function or compound.
For more information on grapes, visit Foods that Fight Cancer, Grapes and Grape Juice.