Bilberry has been used for centuries, both medicinally and as a food in jams and pies. It is related to the blueberry and is native to Northern Europe. Bilberry fruit contains chemicals known as anthocyanosides, plant pigments that have excellent antioxidant properties. Bilberry also contains vitamin C, which is another antioxidant. Antioxidants have been shown to help prevent a number of long-term illnesses such as heart disease, cancer, and an eye disorder called macular degeneration. Anthocyanosides found in bilberry fruits are also useful for people with vision problems. These compounds also help build strong blood vessels and improve circulation to all areas of the body. Bilberry fruit is also rich in tannins, a substance that acts as an astringent. The tannins have anti-inflammatory properties and may help control diarrhea.