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New Study Indicates Nutrition May Play Greater Role in Preventing Cataracts

SAN FRANCISCO, March 10 /PRNewswire/ -- A study published in the March issue of Ophthalmology, the medical journal of the American Academy of Ophthalmology, suggests nutrition may play a greater role in preventing the development of cataracts than was previously thought. Twenty-nine hundred people participated in the population-based cross-sectional study as part of the Blue Mountains Eye Study in Australia.

Earlier studies have shown that antioxidants, (vitamins A, C and E), may protect against the development of nuclear cataracts. This study, however, indicates other nutrients may also play a role in reducing the risk of cataract. Consuming polyunsaturated fat -- which is also associated with reducing the risk of heart disease -- and higher intakes of protein, may also be factors in protecting against cataracts.

Cataract is the leading cause of blindness in the world, especially among older people. A cataract is a cloudy or opaque area in the normally transparent lens of the eye. As the opacity thickens, it prevents light rays from passing through the lens and focusing on the retina, the light sensitive tissue lining the back of the eye. As the cataract develops, it can lead to blurred vision, sensitivity to light and glare, increased nearsightedness and distorted images.

There are three types of cataracts. Each is described by its location on the lens. The most common type, which is usually associated with aging, is called a nuclear cataract and occurs in the center of the lens. The cortical cataract, often found in people with diabetes, begins as wedge-shaped spokes in the cortex of the lens, then progresses as spokes extending from the outside of the lens to the center. A subcapsular cataract, also found in people with diabetes, as well as those with high myopia, retinitis pigmentosa or steroid intake, develops slowly and starts as a small opacity under the capsule, usually at the back of the lens.

``As with other studies, we established vitamin A may protect against nuclear cataract and that spinach -- a good source of lutein, which is part of the vitamin A group -- may play a role,'' said one of the study's authors, Australian physician Robert G. Cumming, MB BS, PhD, from the University of Sydney. The study also found the intake of polyunsaturated fats may reduce the prevalence of cortical cataracts, while eating foods high in protein and some of the B group of vitamins such as thiamin (B1) riboflavin (B2) and niacin significantly reduced the risk of developing nuclear cataracts.``

``It has already been theorized that antioxidants lower the risk for developing nuclear cataracts, and our study supports this,'' Dr. Cumming said. ``However, our study indicates that the B vitamins may also play a role in protecting against nuclear cataracts.'' The study's authors concluded that further research on nutrition and the development of cataracts should extend beyond the antioxidants.

The Academy is the world's largest association of eye physicians and surgeons (Eye M.D.s) with more than 26,000 members. For more information about the Academy or cataracts, visit the Academy's Web site at www.eyenet.org.

SOURCE: American Academy of Ophthalmology

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