These antioxidant compounds are responsible for blue, purple and red pigments. Blueberries are also a good source of vitamin C, soluble fiber, and insoluble fiber, such as pectin. Pectin is a form of soluble fiber that draws water from your digestive tract and forms a gel, helping to slow digestion. Insoluble fiber helps hold food in your digestive system and adds bulk to your stools. Blueberries are also a good source of manganese, vitamin E and riboflavin. The health benefits of blueberries are mainly due to anthocyanidins. Research conducted at Tufts University showed that among sixty fruits and vegetables, blueberries are ranked highest for their antioxidant capacity. Blueberries promote urinary tract and eye health and have anti-cancer benefits. Blueberries are considered acidifying