Can This Supplement Preserve Your Eyesight?
For: Caring for Your Eyes, May 2003
If you read newspapers or watch TV, you may have been led to think that age-related macular degeneration (AMD) can now be prevented. AMD is a major cause of severe vision problems and blindness among older people, particularly those over 75. It starts as a distortion in the visual field, progressing to a "hole" in the macula, a spot at the center of the retina. Nobody knows what causes it, and there is no cure or even any effective treatment so far.
Many supplements claim to benefit eyesight, but recently one called Ocuvite PreserVision has emerged as a possible treatment for AMD. It contains zinc and copper (the latter to offset the copper deficiencies caused by zinc supplementation), vitamin C and E, and beta carotene. Some formulations, marketed as Ocuvite Lutein, contain additional carotenoids.
Manufactured by Bausch & Lomb, which has
a good reputation in the eye-care field, Ocuvite PreserVision was used
last year in a major study called the Age-Related Eye Disease Study (AREDS),
funded by the National Eye Institute and published in the Archives
of Ophthalmology. This study found that in those already diagnosed
with AMD, the supplement reduces the risk of AMD progressing to blindness.
Food and eyesight
It is well known that several nutrients help protect vision. The old story that carrots are good for your eyes has turned out to be true. Beta carotene, plentiful in carrots and many other fruits and vegetables, is essential to good eyesight. Recently, researchers have found that the retina actually contains beta carotene as well as two other carotenoids, lutein and zeaxanthin—pigments that protect the retina from ultraviolet rays. Lutein and zeaxanthin are found in many foods, including corn, dark leafy greens, sweet peppers, squash, pumpkin, and red grapes. Vitamins C and E, also found in plant foods, may be protective, too. Zinc also occurs in high concentrations in healthy retinal tissue. Zinc deprivation can result in blindness in animals and humans. For all these reasons you need a varied diet rich in fruits and vegetables, and including fish and small amounts of meat (for zinc). A daily multivitamin/mineral pill is also a good idea, particularly for vegetarians. Supplements specifically designed for the eyes are another story.
Ocuvite and eyesight
The AREDS study was sound, and its findings encouraging. Over 3,600 people aged 55 to 80 were enrolled and followed for six years. All were at high risk for AMD-related blindness: all had at least some symptoms; some had advanced disease in one or both eyes. One group took a formulation specially prepared for the study (later marketed as Ocuvite PreserVision) with zinc and antioxidants (C, E, and beta carotene); another group took zinc alone; another the antioxidants alone; and still another a placebo. Those who took zinc alone reduced their risk of AMD progression by 21%, those taking only antioxidants had a 17% reduction in risk, and those taking the combination reduced their risk by 25%.
However, the researchers did not recommend that everybody take this supplement. High doses of zinc can interfere with immune function, impair the formation of red blood cells, and lower beneficial HDL cholesterol. In addition, nobody knows what the long-term effects of various carotenoid supplements may be. It is known that beta carotene pills may increase the risk of lung cancer in smokers. The people in the study already had symptoms of AMD. There's no evidence that Ocuvite or any other supplements can prevent the disorder.
Bottom line: If you are over 55, get regular dilated eye exams and ask about your risk of developing AMD. If your optometrist or ophthalmologist diagnoses you as having AMD symptoms, by all means consider taking a supplement of zinc and antioxidants such as Ocuvite PreserVision. But tell your doctor all the supplements you are taking. Some of them may contain vitamin C or E or zinc, and you could end up getting too much if you start taking an eye supplement. The daily 4-pill dose of Ocuvite PreserVision contains 70 milligrams of zinc—which is already a lot, since the safe upper limit is 40 milligrams a day, according to the Institute of Medicine. It also supplies 450 milligrams of vitamin C, 400 IU of vitamin E, 28,600 IU of beta carotene, and almost 2 milligrams of copper. A month's supply costs about $16.
Bottom bottom line: If
your eyes are healthy, don't take this supplement on your own, "for
good measure." It is not known to prevent AMD, only to slow its
progression. And its high levels of zinc may be dangerous.
UC Berkeley Wellness Letter, August 2002