Anthocyanins are a the largest group of water-soluable plant pigments (flavonoids). They are a group of dark blue pigmented antioxidants found especially in dark fruit such as blueberries and bilberries, aronia berries, dark blue grapes like Norton, Concord and Muscadine. There are also present in acai fruit, cranberries, black raspberry, cherries, and black currants. In vegetables they are found in the peel of eggplant and, in red cabbage, and in black rice. They are a type of flavonoid, ordorless and barely astringent. In flowers they can vary from red to purple or blue depending on the pH of the soil in which the plant grows.
With respect to vision health anthocyanins such as blueberry and bilberry extracts help counter oxidative stress in the retina1, help reduce inflammation in the tissues of the eye2, and also provide anti-allergic, anti-viral and microbial, anti-carcinogenic functions.3 They support blood circulation and the integrity of fine capillaries in the eye.3
1. O.T.Mykkanen, et al, Bilberries potentially alleviate stress-related retinal gene expression induced by a high-fat diet in mice, Molecular Vision, September, 2012
2. S. Miyake, et al, Vision preservation during retinal inflammation by anthocyanin-rich bilberry extract: cellular and molecular mechanism, Laboratory Investigation, January, 2012
3. D. Ghosh, Anthocyanins and anthocyanin-rich extracts: role in diabetes and eye function, Asia Pacific Journal of Clinical Nurition, 2007.
Also see the research discussed on the antioxidant/oxidative stress page and the inflammation page.