By Carrie Dennett, M.P.H., R.D.N., Environmental Nutrition Newsletter
We often take our sight for granted until it starts to fade. More than half of all Americans develop cataracts by age 80, and age-related macular degeneration (AMD) — the top cause of severe vision loss and blindness in adults over age 60 in this country — affects as many as one in three people. Research suggests that people who eat lots of leafy greens, and a variety of other fruits and vegetables, may have less risk of developing cataracts or AMD.
Eat the rainbow
Carotenoids are a family of nutrients that provide the yellow, orange and red colors in many fruits and vegetables, including some that are green. Our bodies use beta-carotene to make vitamin A, which is critical for vision. Two other carotenoids, lutein and zeaxanthin, act as natural antioxidants in the eye, helping to protect it from the damaging rays of ultraviolet light that could increase cataract risk.
Researchers recently examined data from more than 100,000 individuals enrolled in the Nurses’ Health Study and the Health Professionals Follow-Up Study. The group who had the highest blood levels of lutein and zeaxanthin were about 40 percent less likely to develop advanced AMD than the group with the lowest levels. Other carotenoids seemed to provide a 25 to 35 percent risk reduction.
Prep your veggies right
Though you’ve probably heard that minimal processing is best when it comes to prepping your vegetables, in the case of carotenoid-rich veggies, chopping, pureeing and cooking actually help your body absorb those carotenoids better. Cooking vegetables in oil or serving them with fat in the meal also boosts carotenoid absorption. Dietary sources of carotenoids include:
Lutein and zeaxanthin: Dark green leafy vegetables (spinach, kale, turnip greens, collards, dandelion greens, mustard greens), summer squash, peas, pumpkin and winter squash, Brussels sprouts
Alpha-carotene: Pumpkin, carrots, winter squash
Beta-carotene: Pumpkin, sweet potato, dark green leafy vegetables, winter squash, cantaloupe
Beta-cryptoxanthin: Pumpkin, papayas, red peppers
Diet vs. supplements
The Age-Related Eye Disease Study (AREDS), conducted by the National Institutes of Health’s National Eye Institute, examined the effects of a “cocktail” of carotenoids, and other vitamins and minerals linked to eye health, on the risk of cataracts and advanced AMD.
Risk of progressing to advanced AMD dropped by about 30 percent, helping to preserve vision longer, but it didn’t prevent cataracts or the early stages of AMD.
Subjects who benefitted most were those who had the least-healthful diets and who didn’t eat many lutein- and zeaxanthin-rich foods. This was also the only group who saw a reduced need for cataract surgery after taking the supplement cocktail.
For healthy eyes, focus on eating carotenoid-rich foods first, but if you have intermediate or advanced AMD, consider taking an eye health supplement. The high levels of vitamins and minerals used in AREDS are difficult to achieve from diet alone.
(Reprinted with permission from Environmental Nutrition, a monthly publication of Belvoir Media Group, LLC. 800-829-5384. www.EnvironmentalNutrition.com.)