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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
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
Date last modified 3/26/2000