Thursday, October 30, 2008

Decreased antioxidant levels increase risk of age-related macular degeneration with exposure to sunlight

The journal Archives of Ophthalmology recently reported that having reduced plasma antioxidant levels and increased exposure to sunlight increases the risk of neovascular, or advanced age-related macular degeneration (AMD).

In a recent study (titled the European Eye Study), over 4,400 participants over age 65 were analyzed for the presence of macular degeneration. Their blood plasma was evaluated for vitamins C and E, the carotenoids lutein and zeaxanthin, and the mineral zinc. Each individual also completed a questionnaire regarding their typical exposure to sunlight. This was used to estimate blue light exposure from visible light, which is known to contribute to the development of macular degeneration.

Early stage macular degeneration was detected in 2,182 participants, and 101 had the advanced form of the disease. The research found no association between blue light exposure and early macular degeneration. However, among participants in the lowest quartile (25 percent) of serum vitamin C, zeaxanthin, vitamin E and zinc, exposure to blue light significantly increased the risk of advanced macular degeneration.

Source: Sunlight exposure, antioxidants, and age-related macular degeneration; Fletcher et al; Arch Ophthalmol 2008 Oct;126(10):1396-403