Eating highly colored vegetables, particularly dark green ones, may help prevent macular degeneration, a common eye disease in aging Americans.

In the latest study, researchers from several universities evaluated nearly 1,800 postmenopausal women who consumed either high or low amounts of lutein and zeaxanthin, antioxidant pigments in such foods as leafy greens, broccoli, corn, peas, and squash. Among women younger than 75, macular degeneration was about 40 percent less common in those with diets rich rather than poor in the pigments. (In those over 75, the relationship was not seen, for unknown reasons.)

The researchers theorize that the pigments in vegetables may protect the eyes by absorbing blue sunlight, which damages the retina; by soaking up harmful free radicals; or by strengthening retinal-cell membranes. Women who ate the most vegetables in general had roughly half the macular degeneration risk of those who ate the least. The researchers expect their findings to apply to men as well.

While vegetables are the best source of lutein and zeaxanthin, fruits also contain those pigments, as well as other antioxidants. The findings add yet another reason to eat 5 to 13 servings of fruits and vegetables a day, especially if you have a family history of macular degeneration. Other foods containing possibly eye-protective nutrients include whole grains, lean meat, low-fat dairy, fish, nuts, seeds, and egg yolks. Exercise may help, too: One study found that physically active people were 30 percent less likely than inactive people to develop the more severe form of this disorder.