Here’s fuel to add to the fire in the debate over the influence of nutrition on cataract and other eye diseases.

Harvard University recently released data from two landmark research surveys, The Physicians’ Health Study and The Nurses Health Study. Using a questionnaire, researchers assessed dietary intake of carotenoids and other nutrients in 36,644 male health professionals ages 45 to 75, and 77,466 female registered nurses ages 45 to 71.

After controlling for other risk factors such as age and smoking, the physicians’ study found that a high intake of lutein and zeaxanthin correlated with a 19% lower risk of cataracts severe enough to require extraction. The nurses’ study found that the highest intake of carotenoids was associated with a 22% risk of these cataracts.