Vitamin C Keeps Cataracts Away

Study finds taking supplement every day may lower risk of this vision-robbing condition

MONDAY, Feb. 25, 2002 (HealthDayNews) -- An apple a day keeps the doctor away, but if you toss in some vitamin C pills, you might not have to visit the ophthalmologist for a long time.

That's the suggestion of a new study, which found women who take vitamin C regularly can reduce their risk of developing a certain kind of cataract. Researchers also found that taking folate, a type of vitamin B, and carotenoids such as beta carotene can lower the risk of another type of cataract in women who have never smoked.

Part of the aging process, cataracts are a vision-robbing condition that clouds over the lens of your eye.

The research, conducted at Tufts University and published in the current American Journal of Clinical Nutrition, also found the longer you take vitamin supplements on a daily basis, the lower your risk of cataracts. In some cases, it was 60 percent lower for women who took vitamin C for more than 10 years.

For New York cataract specialist Dr. Calvin Roberts, the news is good.

"I think anything that can help reduce the risk of a cataract, without increasing any other health risks, is certainly worth paying attention to," says Roberts, an ophthalmologist at New York Weill Cornell Medical Center who was not involved in the study.

As Roberts explains, there are three types of cataracts, largely determined by where in the lens the clouding begins -- the outside rim, the middle or the back.

While this study looked at all three types of cataracts, researchers found vitamins affected only two of the three types. Cortical cataracts (outside rim) were impacted by vitamin C, while folate and carotenoids affected posterior subcapsular cataracts (back of the lens).

"Often, older people can have multiple types of cataracts occurring at the same time, so a good deal of the lens can be clouded, and vision significantly reduced," Roberts notes.

While no one is certain how or why cataracts develop, there is some evidence that growth is exacerbated by exposure to X-rays or by spending lots of time in strong sunlight. Certain medications, such as steroids, can also increase risk, as do diseases such as diabetes and high blood pressure.

For many years, doctors have believed little could be done to prevent cataracts, particularly since nearly everyone over the age of 60 seems to have them to some degree. Cataract removal -- the operation that takes out the clouded lens and replaces it with a synthetic one -- is the most common surgical procedure in older adults.

However, the Tufts researchers have now shown there may be a way to stop cataracts before they start -- and the answer could be as simple as a daily vitamin pill.

The research involved 492 women between the ages of 53 and 73. They were culled from the Nurses Health Study, a large group of women from the Boston area whose diet and health information has been followed biennially since 1976.

Researchers extrapolated data from questionnaires filled out by the women between 1980 and 1995. Questions dealt with long-term vitamin supplement use, smoking, long-term exposure to sunlight, and alcohol use -- all factors thought to be related to cataract formation.

Each of the women also had eye exams, with specific emphasis on cataracts. The doctors found 34 percent of the eyes had cortical opacities -- a common type of cataract located on the periphery of the lens. An additional 39 percent of the eyes had other forms of cataracts, with one-third showing clouding in more than one spot.

"This would indicate more than one type of cataract was present," Roberts says.

However, most of the women had such early cataracts they were not even aware of the slight clouding of vision that had already begun.

When all the data was analyzed, doctors found two distinct correlations between vitamin supplement intake and cataracts -- with the most distinct connection made between vitamin C and a woman's age.

In short: Those under 60 who consumed 362 milligrams of vitamin C a day had a 57 percent lower risk of developing cortical cataracts when compared to those who took 140 milligrams or less of vitamin C a day. Moreover, if the women used the supplements for at least 10 years, their risk was reduced by 60 percent, when compared to women who took no supplements.

For those women who never smoked and regularly consumed folate and carotenoids for 10 years or more, there was up to an 81 percent reduction in the development of posterior subcapsular cataracts.

"If my patients asked if they should use vitamins based on this data, I would definitely say they can give it a try. They have nothing to lose and everything to gain," Roberts says.

What To Do

To learn more about cataracts, visit The Vision Channel.

To learn more about the effects of all nutrients on cataract formation, check out the Encyclopedia of Health Concerns and Individual Nutrients.

SOURCES: Interview with Calvin Roberts, M.D., ophthalmologist, New York Weill Cornell Medical Center, New York City; Feb. 22, 2002, American Journal of Clinical Nutrition
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