Fresh blueberries contain antioxidants called anthocyanins, the pigments responsible for the blue color of blueberries. Antioxidants are important because they appear to be at least partially responsible for lowering the risk of cancer and heart disease. Antioxidants do this by protecting the body's blood vessel walls, making them more resistant to damage caused by oxidation.
Antioxidants also seem to have a role in delaying the aging process. Fresh blueberries contain 15 different anthocyanins, as well as other antioxidants like vitamin C. Research indicates that adding half cup of fresh blueberries to an average daily variety of fruits and vegetables consumed by an individual would essentially double the body's antioxidant level.
Fresh blueberries are rich in vitamin C and naturally low in fat, cholesterol and sodium. Fresh blueberries contain iron, potassium and other important minerals, and are a good source of dietary fiber.