Zeaxanthin

Zeaxanthin is an antioxidant carotenoid that may help prevent a leading cause of blindness among older people: macular degeneration.

The macula is a tiny dimple on the retina that is responsible for fine vision. Damage to the macula can cause blurry vision, or a dark spot in the field of vision. It can eventually lead to a loss of central vision, which can make it impossible to read, drive, or operate a computer. There is no cure for macular degeneration, but in some cases surgery may help to slow its progress. Free radical damage from ultraviolet radiation is believed to be a contributing factor, if not the cause, of macular degeneration. In fact, studies have shown lower than normal blood levels of protective antioxidants in people who develop macular degeneration.

The good news is that some carotenoids appear to protect against this disease. According to a 1994 study, people who ate foods with the highest amounts of two carotenoids-zeaxanthin and lutein-had the lowest risk of developing macular degeneration. Zeaxanthin may help protect the macula by blocking the activity of peroxide free radicals, guarding cell membranes against free radical damage. Zeaxanthin is found in high concentration in watercress, Swiss chard, chicory leaf, beet greens and okra. If you don't regularly eat these foods, you should consider taking a carotenoid supplement with zeaxanthin, or one of the new combination formulas designed to enhance vision that includes zeaxanthin.

Because of its antioxidant properties, zeaxanthin may also protect against various forms of cancer that can be initiated by free radical activity. In fact, preliminary studies show that zeaxanthin can decrease the rate of growth of tumor cells.