Red grapes contain resveratrol, which is a polyphenol antioxidant. This antioxidant is concentrated in the skins of red grapes. A 1-cup serving of red grapes contains about 160 g of resveratrol, according to the Linus Pauling Institute. Resveratrol seems to have anti-inflammatory, antioxidant and antiestrogenic properties, and may activate the enzymes of the liver that rid the body of unwanted chemicals, according to the American Cancer Society. It is possible that resveratrol may also play a role in preventing cancer and heart disease, as Brandt believed, and could extend a person’s life, but more research needs to be conducted to confirm these theories.