Blueberries are not only tasty, but are low in calories and packed with vitamins, fiber, manganese, iron and antioxidants. The berries and leaves have a number of medicinal properties that have been used for generations to treat and prevent digestive orders, improve circulation, maintain eye health and reduce inflammation. Vitamin C aids the formation of collagen, helps maintain healthy gums and capillaries, promotes iron absorption and a healthy immune system.