Resveratrol is a natural compound found in red grape skin, Japanese knotweed (polygonum cuspidatum), peanuts, blueberries and some other berries. It is a powerful antioxidant produced by some plants to protect them against environmental stresses. Antioxidants neutralize free radicals, which are believed to be the cause of aging.  Resveratrol has been hypothesized to be responsible for low rates of heart disease in the French population compared to other populations, in spite of the fact that they have many risk factors including a high fat diet, smoking and consumption of high amounts of coffee. All of these are known contributors of high cholesterol, high blood pressure, stroke and heart attacks. In theory, this benefit in the French population is due to the consumption of moderate amounts of red wine, which is a source resveratrol. Other ingredients in wine or other factors may contribute to longevity seen in the French.