Part of the The Fiftysomething Diet Special Report
It’s not news that vision changes as eyes grow older — you already know that if you put on glasses to read this article or the small print on a label. Yet new research shows that declining vision is not an inevitable aspect of aging.
Diet and lifestyle strategies may actually protect vision in later years, particularly when it comes to serious eye ailments, like cataracts and macular degeneration, the leading cause of irreversible blindness in older adults.
For many boomers, eye health is still linked to vitamin A — that's why mom made us eat carrots and even liver. But new research shows that vitamin A is only a part of the nutritional picture.
To bring you up to date on the best new diet strategies for healthy eyes, here’s a look at the latest findings followed by a roundup of vision-friendly foods.
(More: The Concessons We Make Before We Age)
Nutrition and AMD
Macular degeneration, also called AMD, is a progressive eye disease that damages the eye’s macula, making it difficult to read fine print. Since the macula is in the center of the retina, central vision becomes cloudy and eventually disappears. About 8 million older Americans have asymptomatic early stage AMD, the kind detectable only with an eye exam. Another 1.75 million have progressed to the point where they have significant vision loss. And as the population ages these numbers will increase to 6.3 million by the year 2030.
Staggering as these numbers appear, a new study from the University of Wisconsin suggests that AMD is on the decline among older adults. After examining the eyes of 7,000 people over 40, scientists noted a one-third drop in the rate of disease, from 9.4 percent to 6.5 percent.
Researchers speculate that the decline is due to lifestyle habits that include quitting smoking and improving diet. (For more information on other factors involved in early and late AMD, check out this fact sheet from the National Eye Institute.)
Diet and Cataracts
With about 2 million surgeries each year, cataract extraction ranks as the most common surgical procedure in the United States. Yet experts at the American Optometric Association report that if the progression of cataracts could be delayed by, say, 10 years, the need for surgery could be cut almost in half.
While not a sure thing, diet and lifestyle strategies could potentially diminish the clouding that leads to cataracts. In one recent study, volunteers eating a diet rich in a variety of vitamins and minerals had a lower risk of developing a nuclear cataract, the most common variety. It forms deep in the center of the lens, fogging vision.
Avoiding obesity and quitting smoking could also substantially lower the need for cataract surgery, say these same researchers. (For more information, check out the National Eye Institute fact sheet.)
Recipe for Healthy Vision
Couple the above findings with a landmark study, the National Eye Institute’s Age-Related Eye Disease Study (AREDS), a clinical trial on over 4700 participants conducted from 1992 through 2001, and reseach continues to build a case that it's not one single nutrient or magical food that protects vision and serious ailments like AMB but an assortment of good-for-you vitamins, minerals and antioxidants. Instead it's an assortment of vitamins, minerals and antioxidants. The beneficial supplement combination researchers tested in AREDS: a mixture of zinc, vitamin C, vitamin E and betacarotne.
"This is an exciting discovery because, for people at high risk for developing advanced ADM, these nutrients are the first effecive treatment to slow progression of the disease," said Paul A. Sieving, M.D., PhD, director of the National Eye Institute, at the time the report was released.
So it’s no surprise that experts feel the first step to protecting vision and delaying or preventing eye disease in later years is to aim for an overall balanced diet: one with healthy types of fat and a colorful array of vegetables rich in all these nutrients and antioxidants.
Need more insurance? Two distinct food categories — Omega-3 fats and a specific pair of carotenoids — keep coming up over and over again in research reports as vital to eye health. Here's the lowdown on these two apparent keys to protecting your vision in the long run.
Key source Fatty fish, like salmon, sardines and mackerel.
Why it helps A Harvard study tracking nearly 40,000 women for more than a decade found that those who ate the most DHA (an Omega-3 fat found in fatty fish) were the least likely to develop AMD. They lowered their risk by 38 percent.
Ideal amount The same Harvard study found that women who ate one or more servings of fatty fish per week decreased their risk of AMD by 42 percent compared with women who ate fish just once a month.
2. Carotenoids: Lutein and Zeaxanthin
Key sources Dark, leafy green vegetables, like kale, collard greens, and spinach. Also peas, broccoli, squash (winter and summer), pumpkin, Brussels sprouts and sweet yellow corn. One non-veggie resource rich in carotenoids: eggs from chickens with a lutein-rich diet.
Why it helps Since lutein and zeaxanthin tend to accumulate in the macula, speculation is that these potent antioxidants could help protect it from oxidative damage.
Ideal amount Lutein and zeaxanthin are actually two different carotenoid compounds, but they typically occur in some of the same foods and are often measured, and talked about, together. Six to seven milligrams a day is the magic range in two studies that found a link between high amounts of the antioxidants and a reduced need for cataract surgery. Eating five servings a day of vegetables, particularly from sources above, will help you reach these numbers. (A vegetable serving is ½ cup cooked or 1 cup raw in the case of greens. Of all the greens, spinach — frozen or fresh, raw or cooked — has the most lutein and zeaxanthin, 29.8 mg per cup. Kale is a close runner-up with 25.6 mg per cup.)