According to one study, high vitamin C intakes may decrease the risk of cataracts. Cataracts, a clouding of the eye’s lens that can occur during aging, are the leading cause of blindness around the world. The study was published in Ophthalmology and included data from 2,054 female twins, ages 50 to 83, who participated in the TwinsUK cohort study. Participants completed food frequency questionnaires regarding their vitamin C intake (from foods and supplements) and their intake of other nutrients. Researchers used digital imaging to examine the participants’ eyes for cataracts at the beginning of the study. Then, around ten years later, researchers followed up with 324 of the twins to examine for cataracts again. Researchers also tested the participants for a genetic predisposition to cataracts to understand which factors contributed to the development of cataracts. At the end of the study, researchers found that:
At around age 60, participants who had high dietary vitamin C intakes had a 19% reduced risk of cataracts, and ten years later, they had a 33% reduced risk, compared with those who had low dietary vitamin C intakes.
Over the ten-year follow-up period, genetic factors accounted for 35% of cataract formation, while environmental factors (such as diet) accounted for the remaining 65%.
While more clinical research is needed to confirm these findings, this was the first study to show environmental factors may play a larger role in cataract formation than hereditary factors. The evidence also suggests that eating a diet rich in vitamin C may help keep your eyes healthy. If you want to boost your vitamin C intake, citrus fruits are a great place to start. But if you’re in the mood for something else, broccoli, yellow peppers, Brussels sprouts, parsley, and kale are also vitamin C superstars.