Coffee is the number one source of antioxidants in the U.S. diet, according to research from the University of Scranton (Pa.).
"Americans get more of their antioxidants from coffee than any other dietary source," study leader Joe Vinson, Ph.D., said at the time. "Nothing else comes close."
Antioxidants are chemicals that fight free radicals, and may protect cells from damage. Studies have indicated that the antioxidants in coffee may have a protective effect against some cancers, as well as chronic diseases including Alzheimer’s and Parkinson’s. They may also potentially fight obesity and aid in losing weight. Past researchers discovered that these compounds may actually help in protecting retinas and eyes.
Coffee is a major source of chlorogenic acids (CGA). As an antioxidant, CGA is thought to be especially beneficial in modulating sugar metabolism, controlling blood pressure, and possibly defending against heart disease and cancer. Coffee drinkers' daily CGA intake typically ranges from 0.5-1.0 g, while abstainers typically ingest less than 100 mg per day. A single cup of coffee may contain 70 – 350 mg of chlorogenic acids. [Source]