Blueberries are the most exciting, in-demand berry in today's market. Not only is their unique flavor highly prized, research shows that blueberries are rich in antioxidants, natural substances which guard against cancer and heart disease. The dark blueberry color contains anthocyanins which have been found to improve eyesight. Blueberries are also high in fiber, iron and vitamin C and contain no fat, sodium or cholesterol.