The Age-Related Eye Disease Study (AREDS), a research project conducted by the National Eye Institute, has given us some clues about how nutrition might help prevent macular degeneration, or at least delay the progression to blindness. AREDS results showed that certain antioxidant vitamins and zinc helped to slow the progression of advanced macular degeneration by about 25 percent over a six-year period.
The antioxidants — vitamins C and E and beta-carotene — are thought to prevent damage caused by free radicals, and the mineral zinc is important for the health of all body tissues but is found in unusually high concentrations in tissues of the retina.
The results of AREDS were so impressive that in the wake of the study's publication, several supplement manufacturers created special macular-degeneration-fighting formulas. They’re a great treatment option for some, but not everyone is a candidate for these supplements. The supplements don’t appear to be as effective at slowing the progression of macular degeneration from the early to intermediate stage, so most doctors don’t recommend them for people that fall into this group. On top of that, high supplemental doses of antioxidants, especially vitamin E, may pose health risks. Only your eye doctor can determine whether your condition has progressed to a point at which supplements are beneficial. If your condition is still in its early phases, or if you have a family history of macular degeneration but no signs of disease, your best bet is to load up on food sources of vision-friendly nutrients by following my plan.
ANTIOXIDANTS: VITAMIN C, VITAMIN E, BETA-CAROTENE
A study led by researchers from Erasmus Medical Center in Rotterdam, the Netherlands, followed a group of more than 4,000 people to see how diet affected the risk of developing macular degeneration. After eight years, the scientists compared the diets of people who developed the condition with the diets of those who did not. The results were encouraging: People who ate a diet rich in vitamins C and E, beta-carotene, and zinc had a 35 percent reduced risk of developing macular degeneration compared with people who ate an average diet. And those who ate worse-than-normal diets, with low levels of those nutrients, actually had a 20 percent increased risk of disease. A 2009 study by Tufts University researchers confirmed the links between diets rich in C, E, and zinc (plus lutein and zeaxanthin) and decreased risk of macular degeneration. The Tufts study, however, failed to show any benefit from beta-carotene (that said, I figure it’s best to include extra beta-carotene-rich foods in your diet until we know more). I highly recommend that those with a family history of macular degeneration follow the food plan for high-antioxidant, high-zinc foods to reduce their risk. For an easy way to get a large dose of all the nutrients, try one of my Smooth-SEE recipes.
BEST FOODS FOR VITAMIN C: Guava, bell peppers (all colors), oranges and orange juice, grapefruit and grapefruit juice, strawberries, pineapple, kohlrabi, papaya, lemons and lemon juice, broccoli, kale, brussels sprouts, kidney beans, kiwi, cantaloupe, cauliflower, cabbage (all varieties), mangoes, white potatoes, mustard greens, tomatoes, sugar snap peas, snow peas, clementines, rutabagas, turnip greens, raspberries, blackberries, watermelon, tangerines, okra, lychees, summer squash, persimmons
BEST FOODS FOR VITAMIN E: Almonds and almond butter, sunflower seeds and sunflower butter, wheat germ, hazelnuts, spinach, dandelion greens, Swiss chard, pine nuts, peanuts and peanut butter, turnip greens, beet greens, broccoli, canola oil, flaxseed oil, red bell pepper, collard greens, avocados, olive oil, mango
BEST FOODS FOR BETA-CAROTENE: Sweet potatoes, carrots, kale, butternut squash, turnip greens, pumpkin, mustard greens, cantaloupe, red bell pepper, apricots, Chinese cabbage, spinach, lettuce (especially darker lettuces), collard greens, Swiss chard, watercress, grapefruit (pink and red), watermelon, cherries, mangoes, tomatoes, guava, asparagus, red cabbage
AREDS and the Rotterdam study confirmed zinc's role in eye health. Zinc is found in the retina, and helps the functioning of enzymes responsible for eye health. In people with macular degeneration, levels of zinc in the retina can be very low, so eating zinc-rich foods is a logical first step for preventing and treating macular degeneration.
BEST FOODS FOR ZINC: Oysters, lobster, lean beef, crab, ostrich, wheat germ, skinless turkey (especially dark meat), skinless chicken (especially dark meat), lean lamb, clams, mussels, pumpkin seeds, yogurt (fat-free, low-fat), pork tenderloin, starchy beans (such as black, navy, pinto, garbanzo, and kidney), lentils, black-eyed peas, soybeans (edamame), lima beans, pine nuts, cashews, peanuts and peanut butter, sunflower seeds and sunflower butter, pecans
ANTIOXIDANTS: LUTEIN AND ZEAXANTHIN
Lutein and zeaxanthin are a matched pair of antioxidants: Almost without exception, foods that contain one also contain the other. They are found in high concentrations in the tissue of the macula. Because they absorb 40 to 90 percent of blue light intensity, these nutrients act like sunscreen for your eyes. Our bodies can’t make these nutrients on their own, so we have to get them from food. Studies have shown that eating foods rich in lutein and zeaxanthin can increase the pigment density in the macula — and greater pigment density means better retina protection, and possibly a lower risk of macular degeneration. A second AREDS trial, now underway, is testing whether supplemental lutein and zeaxanthin are more effective than beta-carotene at slowing the progression of macular degeneration and should provide more clarity on the benefits of this nutrient duo.
BEST FOODS FOR LUTEIN AND ZEAXANTHIN: Kale, spinach, Swiss chard, collard greens, turnip greens, dandelion greens, mustard greens, beet greens, radicchio, summer squash (all varieties), watercress, green peas, persimmons, winter squash (acorn, butternut, etc.), pumpkin, broccoli, brussels sprouts, lettuce (especially dark lettuces), asparagus, corn, green beans, okra, artichokes, green bell peppers
OMEGA-3 FATTY ACIDS
Retinal pigment cells contain a type of omega-3 called docosahexaenoic acid (DHA), which helps protect light receptor cells in the eye from damage by sunlight and free radicals. Researchers are excited by recent findings that omega-3 fats may help stave off macular degeneration. One study found that eating just one weekly serving of fish, some of which are good sources of omega-3 fats, cut the risk of macular degeneration by over 30 percent. The good news doesn’t stop there— omega-3 fats may be just as effective for those already at high-risk. In a 2009 study of people who already showed early signs of disease in their retina, eating a diet rich in omega-3s reduced the risk of developing advanced macular degeneration by about 30 percent. If you want to take advantage of this promising research, I recommend eating fatty fish at least two times each week, and strive to incorporate the other omega-rich foods into your daily diet, too.
BEST FOODS FOR OMEGA-3 FATTY ACIDS: Wild salmon (fresh, canned), herring, mackerel (not king), sardines, anchovies, rainbow trout, Pacific oysters, chia seeds, ground flaxseed, walnuts, butternuts (white walnuts), seaweed, walnut oil, canola oil, flaxseed oil, soybeans (edamame)
ANTIOXIDANTS: B VITAMINS
It seems the whole alphabet of vitamins promote healthy vision! B vitamins are the latest to show potential for protection from macular degeneration. In a recent study, Harvard researchers tested whether a combination B-vitamin supplement containing B6, B12, and folic acid reduced the risk of cardiovascular disease in a group of over 5,000 women. The B vitamins didn’t provide any heart protection, but (surprise!) they did dramatically reduce the risk of macular degeneration. Scientists speculate that B vitamins may help by lowering blood levels of homocysteine, an amino acid that may damage the eye in some way. This is the first trial to look at the benefits of B vitamins for macular degeneration, and though the results are encouraging, it’s definitely too soon to recommend supplements. While we wait for the science to catch up, I recommend loading up on healthy foods naturally rich in B6, B12, and folate (and consider taking a standard multi with 100% of the Daily Value for each).
BEST FOODS FOR VITAMIN B6: Wild salmon (fresh, canned), trout (rainbow, wild), skinless chicken, pork tenderloin, skinless turkey, starchy beans (especially chickpeas and pinto beans), bananas, pistachio nuts, tuna (canned light), fish (especially haddock, halibut, cod), potatoes (white and sweet), spinach, winter squash (especially acorn), lentils, avocados, bell peppers
BEST FOODS FOR VITAMIN B12: Shellfish (clams, oysters, crab), wild salmon (fresh, canned), soy milk, trout (rainbow, wild), tuna (canned light), lean beef, veggie burgers, cottage cheese (fat-free, 1% low-fat), yogurt (fat-free, low-fat), milk (fat-free, 1% low-fat), eggs, cheese (fat-free, reduced-fat)
BEST FOODS FOR FOLATE: Lentils, black-eyed peas, soybeans (edamame), oats, turnip greens, spinach, mustard greens, green peas, artichokes, okra, beets, parsnips, broccoli, broccoli rabe, sunflower seeds, wheat germ, oranges and orange juice, brussels sprouts, papaya, seaweed, berries (boysenberries, blackberries, strawberries), starchy beans (such as black, navy, pinto, garbanzo, and kidney), cauliflower, Chinese cabbage, corn, whole-grain bread, whole-grain pasta
Sugary foods and refined starches (the white stuff like white bread, rice, and pasta) may be double trouble for your eyes. High amounts of low-quality (high-glycemic) carbs may increase your chance of cataracts, and new findings also implicate them in the progression of macular degeneration. Researchers at Tufts University discovered that people who ate a diet with a high-glycemic-index score faced a greater risk of developing macular degeneration. High-glycemic foods cause a dramatic rise in blood sugar, which also increases the sugar concentration in the eye. Long-term exposure to high sugar loads may damage the retina and tiny capillaries in the eye by promoting oxidative stress and inflammation. Avoiding sugary foods and refined carbs is a smart strategy for overall health, so this is just one more good reason to sweep these foods out of your kitchen.
LOW-QUALITY CARBS TO LIMIT INCLUDE: Sugar, honey, and other sweeteners, soda and other sugary drinks, candy, baked goods, sugary cereals, anything made with white flour (including white bread and regular pasta), and white rice