Benefits of Lutein in Eye Diseases
Written by Gloria Tsang, RD
Published in January 2005
(HealthCastle.com) Age-related macular degeneration (MD) is a disease that blurs the sharp, central vision you need for "straight-ahead" activities such as reading, sewing, and driving. MD affects the macula, the part of the eye that allows you to see fine detail In some cases, MD advances so slowly that people notice little change in their vision.
A cataract, on the other hand, is a clouding of the lens in the eye that affects vision. Cataracts are very common in older people. By age 80, more than half of all Americans either have a cataract or have had cataract surgery.
What is Lutein?
Lutein is an antioxidant, belonging to the carotenoid family. Lutein can be found in dark green leafy vegetables such as spinach, collards, kale and broccoli, various fruits and corn. Egg yolks are also sources of lutein.
Lutein and Macular Degeneration
Lutein is highly concentrated in the macula, a small area of the retina responsible for central vision, and high visual acuity. It is also thought that lutein filters blue wavelengths of light from the visible-light spectrum. Blue light, in both indoor lighting and sunlight, is believed to induce oxidative stress and possible free-radical damage in human organs exposed to light such as the eyes. A current trial by the US National Eye Institute NEI is working on the recommended dosage, but Frederick Ferris, the director of clinical research at the NEI suggested that it would probably be between 6 and 15 mg per day.
Lutein and Cataract
The exact mechanism of how lutein prevents cataracts is still unknown. A few large studies revealed that people consumed a high quantity of lutein have a 20 - 50% lower risk of getting a cataract than people who consumed the least lutein. Another study also showed that men who ate broccoli or raw spinach more than 2 times a week were 25% less likely to have cataract surgery than men who ate them less than once a month. Researchers found that people who consumed ~ 6 mg of lutein or more a day.
Other Helpful Supplements: As the role of lutein plays an important role in prevention or slowing of eye disease progression, other scientists also studied the role of general nutrition in eye disease prevention. In 2001, the NEI published the results of a seven-year study which showed that a high-dose combination of vitamin C, vitamin E, beta-carotene, and zinc significantly reduces the risk of developing advanced stages of MD by about 25 percent. These high levels of antioxidants and zinc are the first effective treatment to slow the progression of MD.
Lutein Bottom Line: Incorporate a variety of dark green leafy vegetables in your diet and enjoy the possible benefits of eye disease prevention.