By Amy Campbell | October 15, 2007 12:00 am
Over the past two weeks, we’ve looked at various nutrients and how they may impact the health of your eyes. We’ll wrap up this series with a look at some lesser-known nutrients (antioxidants, to be exact) and what their roles are in eye health.
Lutein: Lutein is a type of antioxidant called a carotenoid. Carotenoids are yellowish pigments that lend color to fruits and vegetables. Their role is to protect the organism from ultraviolet light radiation and oxygen. Lutein is found in corn, egg yolks, and green fruits and vegetables. It’s also found in the macula of the retina to help filter out blue light and ultraviolet light.
Several studies have linked a high intake of lutein with a lower incidence of age-related macular degeneration and cataract development. A Harvard study revealed that consuming 6 milligrams of lutein daily (the amount found in ½ cup of cooked spinach) lowered the risk of developing macular degeneration by 43%. Eating lutein-rich foods may also lower the risk of developing cataracts by up to 50%.
Zeaxanthin: Zeaxanthin is another kind of carotenoid that is found, along with lutein, in the retina. The same foods that are rich in lutein (primarily green vegetables and fruits, but also some yellow and orange ones) are also rich in zeaxanthin. These two carotenoids usually go hand-in-hand as far as protecting against macular degeneration and possibly cataracts. The message of the fruit and vegetable campaign “More Matters” is certainly applicable when it comes to eating for eye health.
Other nutrients: Many other nutrients are necessary for proper eye function. Vitamins A, C, E, and the B-complex vitamins, as well as zinc and selenium, all play a role in ensuring that eyes stay healthy.
There’s still more work to be done in the area of nutrition and eye health, and despite all of the dietary supplements that have appeared on the market, there’s not a lot of evidence that shows they can prevent eye problems. Taking a good multivitamin/mineral supplement, along with a fish oil supplement, may prove to be protective. In the meantime, focus on eating a variety of foods, with emphasis on fruits, vegetables, whole grains, lean protein sources, and heart-healthy fats.
A timely study has just been released by Australian researchers from the Centre for Eye Research Australia at the University of Melbourne. Their conclusion, after analyzing 11 studies involving about 150,000 people over the past nine years, is that dietary nutrients don’t prevent age-related macular edema (AMD). However, not all researchers would agree. A seven-year study published by the National Eye Institute in 2001, called the Age-Related Eye Disease Study (AREDS), showed that high doses of vitamins C and E, beta carotene, and zinc reduced the risk of developing advanced AMD by 25%. Furthermore, data from the Third National Health and Nutrition Examination Survey data indicates that higher intakes of lutein and zeaxanthin may reduce the risk of advanced AMD in people ages 40-59. Other studies that have looked at lutein and zeaxanthin report similar results.
So, what should you make of all this? First, if you have or are at high risk for developing any kind of diabetes-related eye conditions, talk to your eye-care professional and the rest of your health-care team about steps you can take to keep your eyes healthy. Aim to get your HbA1c level as close to 7% (or your target goal) as possible. Include plenty of fruits, vegetables, and whole-grain foods in your eating plan. Ask if dietary supplements are right for you. And finally, if you’re a smoker, the health of your eyes is yet another reason to quit. Smoking can contribute to AMD, diabetic retinopathy, cataracts, and glaucoma.
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