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Lutein: “Ask The Expert” Column
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By Liz Pearson
I've noticed that something called lutein is now being added to vitamin supplements. I've heard that it's good for your eyesight. What is lutein, and should I be taking it?
Ongoing research suggests lutein can help protect your precious eyesight. It's a plant pigment and a member of the carotenoid family, which also includes beta-carotene (found in carrots) and lycopene (found in tomatoes). Lutein and another carotenoid called zeaxanthin are highly concentrated in certain tissues of the eye: the macula (a small area of the retina responsible for your central vision) as well as in the lens. How do these nutrients protect your eyes? First, they absorb or screen blue light, the most damaging of the sun's harmful ultraviolet rays. Second, as antioxidants, they stop nasty free radicals from doing damage to tissues of the eye. Eating a diet rich in lutein now may help you avoid eye disease later in your life.
Protecting your sight
Some, but not all, studies have linked lutein and zeaxanthin intake to a lower risk of age-related macular degeneration, which is the cause of one-third of all adult vision loss in Canada. In the Eye Disease Case Control Study from Boston, which involved over 800 men and women, a diet rich in carotenoids, especially lutein and zeaxanthin, slashed the risk of this disease by 57%. In the Lutein Antioxidant Supplementation Trial from Chicago, patients diagnosed with age-related macular degeneration improved their vision by taking a lutein supplement. This study is especially significant because once you are diagnosed with macular degeneration, very little can be done to treat or reverse it. A number of studies, such as the Harvard Nurses' Health Study and the Health Professional's Follow-Up Study, link lutein and zeaxanthin to a lower risk of cataract surgery (cataracts involve a clouding of the lens of the eye). And that's not all. Preliminary research also suggests lutein can cut your risk of heart disease and certain cancers such as colon, skin and breast cancer.
The eyesight diet
Right now, there is no recommended intake for either lutein or zeaxanthin. Based on the limited research currently available, some researchers suggest an intake of 6 to 15 mg of lutein per day. However, most of us get less than 2 mg a day. Because research on antioxidant supplements is in the early stages and most multivitamins contain amounts as low as .25 mg of lutein, it's best to get your lutein from food. Aim for at least five and ideally closer to ten servings of colourful fruits and vegetables each day. Dark leafy greens, like spinach, collards and kale are by far your best sources of lutein. A large spinach salad, for example, contains about 10 mg of lutein. Broccoli, brussels sprouts, corn, romaine lettuce, peas, kiwi, red grapes, orange juice, zucchini, squash and egg yolks are also good sources. If you already suffer from an eye disease such as macular degeneration, talk to your eye doctor about whether a higher dose supplement makes sense for you.
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