En español | You've may have heard the adage “You are what you eat.” But what you eat also may affect how well you see the world, both now and in the future. Certain nutrients — including those that come from carrots — really are important for eye health. It seems that Bugs Bunny was onto something with his frequent carrot munching.
The good news is, you don't need to reinvent your diet if you've been heeding the advice of your primary care physician or cardiologist. “Most people know about eating the right way to keep their heart healthy. The same diet — one that's low in fat and rich in fruits, vegetables and whole grains — keeps your eyes healthy,” says Marguerite McDonald, M.D., clinical professor of ophthalmology at the New York University School of Medicine and Tulane University Health Sciences Center.
Consuming a balanced, largely plant-based diet will help your eyes, but here's a closer look at six nutrients that can have a particularly powerful effect on protecting your eye health and vision.
Simply put, “the retina needs vitamin A to function,” says Milam A. Brantley, M.D., an associate professor of ophthalmology and visual sciences at Vanderbilt University Medical Center in Nashville. The retina, which is the layer of cells that lines the back wall inside the eye, senses light and sends signals to the brain that allow you to see. Consuming sufficient amounts of vitamin A also helps with night vision and dry eye, both of which become bigger challenges as people get older. Your body converts beta-carotene in orange and yellow fruits and vegetables — such as carrots, sweet potato, cantaloupe, pumpkin and winter squash — into vitamin A.
A strong antioxidant, “vitamin C protects the eyes on a cellular level from damage caused by sunlight, cigarette smoke and air pollution,” Brantley says. In addition, research has found that a higher vitamin C intake is associated with a lower risk of age-related cataracts and age-related macular degeneration (AMD), damage to the central part of the retina (macula). AMD is the leading cause of vision loss as people get older. Foods that are rich in vitamin C include oranges and other citrus fruits, bell peppers, kiwi, berries, broccoli, cauliflower and tomatoes.
Another powerful antioxidant, vitamin E supports a healthy immune system and helps clear out pollutants from the eye, Brantley says. In a similar vein, it helps protect the eyes against damage from unstable molecules called free radicals. What's more, an adequate intake of vitamin E — from nuts, seeds, vegetable oils, nut butters, wheat germ and avocado — may slow the progression of AMD and cataracts.
Omega-3 fatty acids
“People who consume diets rich in omega-3 fatty acids, from cold-water fish, are less likely to develop age-related macular degeneration,” McDonald says. This may be partially because these essential fatty acids — which are present in salmon, tuna, halibut, sardines and herring — have anti-inflammatory effects, but also because these fatty acids help maintain the structural and functional properties of the retina. But that's not all: Omega-3 fatty acids also help with dry eye issues, notes Andrew Iwach, M.D., an associate clinical professor of ophthalmology at the University of California, San Francisco, and a clinical spokesperson for the American Academy of Ophthalmology.
Lutein and zeaxanthin
These carotenoids naturally accumulate in the retina of the eye, and they “can protect the retina and the lens from sunlight, smoke and pollution,” Brantley says. A high dietary intake of these nutrients is associated with a reduced risk of developing AMD and cataracts, McDonald notes. Fortunately, lutein and zeaxanthin are found together in many foods, particularly green, leafy vegetables such as kale, spinach, collard and turnip greens, as well as broccoli and peas. An added perk: Consuming lots of green, leafy vegetables, which contain nitrates, may reduce the risk of glaucoma by increasing blood flow to the eye tissue, Iwach says.
An essential trace mineral, “zinc protects the eyes against the ultraviolet effects of sunlight,” McDonald says. Zinc also plays a vital role in maintaining the health of the retina and the structure and function of cell membranes in the eyes. Research has found that a high zinc intake can even reduce the risk of AMD progression in those who have it. Good dietary sources of zinc include beans, legumes, oysters, poultry, lean red meat, almonds, milk and yogurt.
"We want a healthy person to strive to get all of these nutrients from food, rather than supplements,” Brantley says. But some people who are diagnosed with AMD may be candidates for higher doses of vitamins C and E, lutein, zeaxanthin and copper through an AREDS-2 supplemental formula because “these can slow the progression and help protect against advanced AMD,” Brantley says. “Consult an eye doctor to see if you could potentially benefit from these supplements.” (AREDS is short for the Age-Related Eye Disease Study, sponsored by the National Eye Institute.)
Meanwhile, keep an eye on the big picture when it comes to your food choices. “Be mindful of the fat content of your diet,” McDonald advises. “Having fried chicken once a year isn't a problem,” but having it every day is; the same thing goes for processed foods. After all, foods that can clog the arteries in your heart or increase your risk of developing systemic conditions such as high blood pressure or diabetes can cause trickle-down damage on your eyes.