Overview of antioxidants: emphasis on raisins.

Antioxidants are components of foods and found in some supplements. They function to detoxify excessive free radical build-up, which results from normal metabolism and environmental stresses like air pollution. Most studies of dietary antioxidants showed beneficial effects in reducing the risk of chronic diseases like cardiovascular disease. In contrast, intervention studies using antioxidants from dietary supplements did not typically show these positive results; sometimes dietary supplement use increased disease risk. Herein is reviewed the definition of antioxidants, physiological actions, and selected studies of foods and supplements containing them. In addition, summarized are new studies on the antioxidative effects of raisins and cardiovascular disease risk reduction.