Aging eyes have absorbed a lifetime of damaging effects from light and pollution, but a group of Boston scientists say that how we eat may help to minimize some of that damage. Reporting in the journal Archives of Ophthalmology, they say that vitamins C and E and the plant pigment lutein appear to provide some protection against the development of cataracts in women.

A closer look at diet

Tufts University researchers recruited 478 participants of the long-running Nurses' Health Study to take part in a smaller study of the effect of nutrient intake on the risk of developing cataracts. Food intake records submitted periodically over a 13-year period were used to assess the women's intakes of specific nutrients. Each woman then received an eye examination to detect the presence of cataracts.

The researchers found that diet seemed to make a difference. As vitamin C intake increased, the risk of developing cataracts declined; the women who routinely consumed 240 to 360 milligrams (mg) of vitamin C a day from food and supplements were more than 60% less likely to develop cataracts than those who consumed less than 140 mg per day.

More is better, up to a point

At intakes up to 140 mg per day, some of the women in the lower-intake group were still consuming almost twice the U.S. recommended intake level for vitamin C. (This is the amount of vitamin C in about 10 ounces of orange juice.) However, the beneficial effects of vitamin C appeared to level off at just above 300 mg per day; those who consumed appreciably more than that did not have substantially healthier eyes as a result.

The link between vitamin E intake and cataract risk was not as strong in these women, but those who consumed the most vitamin E - primarily from supplements - were still less likely than others to develop cataracts over the course of the study. A steady diet of foods high in lutein and zeaxanthin (the pigments that give deep green and yellow vegetables their characteristic color) was also linked to a reduced risk of cataracts.

Key nutrients

The authors note that it's not always possible to attribute a specific health outcome to one particular nutrient, since people who routinely take dietary supplements or who eat a produce-rich diet also consume healthy combinations of many nutrients. But the nutrients profiled here stand out because all are considered antioxidants, able to protect the body from oxygen-related cell damage that results from everyday living. In fact, scientists know that both vitamin C and lutein are normally found in the eye.

Cataracts can result from more than one cause, and even the most healthful diet can't guarantee continued good eye health. But this study adds to the argument that antioxidant-rich fruits and vegetables (along with no cigarettes and a good pair of sunglasses) can help protect against age-related eye problems.