On Nutrition

We often take our sight for granted until it starts to fade. Age-related macular degeneration (AMD) is the top cause of severe vision loss and blindness in adults over age 50 in this country, affecting as many as one in three people as they age. AMD destroys the macula, the part of the eye that provides central vision, the type of vision you need to see what’s in front of you in sharp detail. This is important for activities like driving — which many of us aren’t doing as much of right now — but also reading, cooking and gardening, which you may be doing more of. It’s also important for seeing faces, and that’s true whether those faces are in the room with you or on Zoom.

Research suggests that people who eat lots of leafy greens, and a variety of other fruits and vegetables, may have less risk of developing AMD or cataracts. Carotenoids are a family of nutrients that provide the yellow, orange and red colors in many fruits and vegetables. Our bodies use beta-carotene to make vitamin A, which is critical for vision. Two other carotenoids, lutein and zeaxanthin, act as natural antioxidants, protecting eyes from the damaging ultraviolet light that could increase cataract risk.

Your body absorbs carotenoids best from vegetables that have been chopped, pureed or cooked. Cooking vegetables in oil or serving them with fat in the meal also boosts absorption. Dietary sources of carotenoids include:

  • Lutein and zeaxanthin: Cooked dark green leafy vegetables (spinach, kale, turnip greens, collards, dandelion greens, mustard greens), cooked summer squash, cooked peas, baked pumpkin and winter squash, Brussels sprouts
  • Alpha-carotene: Canned pumpkin, cooked carrots, raw carrots, winter squash
  • Beta-carotene: Canned pumpkin, baked sweet potato, cooked dark green leafy vegetables, winter squash, cantaloupe
  • Beta-cryptoxanthin: Cooked pumpkin, papayas, red peppers

For a 2015 study, researchers examined data from more than 100,000 adults 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% less likely to develop advanced AMD than the group with the lowest levels. Other carotenoids seemed to reduce risk by about 25 to 35%.

While getting nutrients from food is ideal whenever possible, 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 vitamin and mineral supplements. Researchers found that the risk of developing advanced AMD dropped by about 30%, helping to preserve vision longer, but it didn’t prevent cataracts or early-stage AMD. Participants who benefited most were those who had the least healthful diets and who didn’t eat many foods rich in lutein and zeaxanthin.

The high levels of vitamins and minerals used in AREDS are difficult to achieve from diet alone. If you have intermediate AMD in one or both eyes, or advanced AMD in one eye, you might consider taking a widely available AREDS supplement, which should contain 500 mg vitamin C, 400 IU vitamin E, 10 mg lutein, 2 mg zeaxanthin, 25 mg zinc (as zinc oxide), and 2 mg copper (as cupric oxide). If you smoke, or used to smoke, it’s important to avoid older formulations that include beta-carotene, as beta-carotene in supplement form could increase your risk of lung cancer. While there is no treatment that can prevent AMD from developing, the AREDS formula can delay the progression to advanced AMD and help you keep your vision longer. Of course, consult your primary care doctor or eye care specialist.