AGE-RELATED EYE DISEASE STUDY (AREDS)
Findings from a nationwide clinical trial regarding antioxidant vitamins and zinc
The October 2001 issue of the Archives of Ophthalmology reported on findings from a nationwide clinical trial regarding antioxidant vitamins and zinc. The clinical trial – called the Age-Related Eye Disease Study (AREDS) – was sponsored by the National Eye Institute. Scientists found that people at high risk of developing advanced stages of age-related macular degeneration (AMD) lowered their risk by about 25% when treated with a high-dose combination of vitamin C, vitamin E, beta-carotene and zinc. In the same high-risk group – which included people with intermediate AMD, or advanced AMD in one eye but not the other eye – the nutrients reduced the risk of vision loss caused by AMD by about 19%. For those study participants who had either no AMD or early AMD, the nutrients did not provide an apparent benefit.
The nutrients evaluated by the AREDS researchers contained 500 milligrams of vitamin C; 400 international units of vitamin E; 15 milligrams of beta-carotene; 80 milligrams of zinc (as zinc oxide); and 2 milligrams of copper (as cupric oxide). Copper was added to the AREDS formulations containing zinc to prevent copper deficiency, which may be associated with high levels of zinc supplementation. The AREDS clinical trial involved 4,757 participants, aged 55 to 80, in eleven clinical centers nationwide.
For more information:
- Clinical Advisory: Antioxidant Vitamins and Zinc Reduce Risk of Vision Loss from Age-Related Macular Degeneration Same Nutrients Have No Effect on the Development of Cataract
- The AREDS Formulation and Age-Related Macular Degeneration
- AREDS II Study
Examples of Over-the-Counter AREDS Formula Supplements*
*As with all vitamins and nutritional supplements, speak with your physician before taking the AREDS Formula. If you are or have been a smoker, look for a formula without beta carotene. The AMDF does not endorse the use of any specific nutritional supplements.
October 12, 2001
Supplements Work to Treat Vision Loss in Elderly
By KENNETH CHANG
High doses of certain dietary supplements provide the first effective treatment for the leading cause of vision loss among the elderly, a new nationwide clinical study has concluded.
The disease, macular degeneration, destroys the central portion of the retina, the light-gathering cells at the back of the eye. Among people who already have significant yellowish deposits accumulating at the back of their eyes – the hallmark of the disease – the supplements cut their risk of vision loss by one-fifth.
“This is keeping them with good vision,” said Dr. Frederick Ferris, director of clinical research at the National Eye Institute, which sponsored the study. “We were surprised at how effective it is, given it is just supplements.”
The supplements – a combination of zinc and the antioxidants vitamin C, vitamin E and beta-carotene – did not appear to slow the early stages of the disease, when the yellowish deposits develop, but that is a normal part of aging and is not necessarily of concern, Dr. Ferris said. “Almost everyone over age 70 has at least one or two of them,” he said.
The supplements also did not protect against the formation of cataracts, despite hopeful signs from earlier studies. “We were surprised by that,” Dr. Ferris said.
About 1.7 million Americans, mostly over 60, have lost part of their vision from macular degeneration. As the disease progresses, the center of the field of view begins to blur, making it difficult to read, drive and recognize faces. Victims must rely on their peripheral vision, looking out of the corners of their eyes and missing much of the color and detail.
Glaucoma and cataracts strike more people than macular degeneration, but effective treatments exist for those diseases. “This is the one disease for which we had nothing prior to this,” Dr. Ferris said. At best, laser surgery can slow down the growth of abnormal blood vessels in the most severe cases of macular degeneration.
Earlier studies had indicated that people who eat large amounts of fruits and vegetables, which contain vitamins and beta-carotene, are at lower risk of developing macular degeneration. An earlier, smaller clinical study had suggested zinc might be helpful.
The 4,757 participants in the study ranged in age from 55 to 80.
Among those whose disease had progressed to the intermediate stage, the zinc supplements reduced by 11 percent the risk of the disease progressing to the advanced stage, and the antioxidants reduced the risk by 10 percent. When the two were combined, the risk dropped by 19 percent. The study followed the participants for 6.5 years on average.
Researchers do not know whether the supplements merely delay vision loss or whether they can postpone it indefinitely. “At this point, I don’t have any reason to believe this 25 percent reduction wouldn’t continue out to seven, eight, nine years,” Dr. Ferris said.
The findings are published in the October issue of the journal Archives of Ophthalmology. The researchers are also presenting the results at a news conference today at the National Institutes of Health in Bethesda, Md.
The daily dosages of the antioxidants used in the study were 500 milligrams of vitamin C, 400 milligrams of vitamin E and 15 milligrams of beta-carotene, a molecule that provides the color of carrots and sweet potatoes. The body converts the beta-carotene into vitamin A. The daily dosage of zinc was 80 milligrams with 2 milligrams of copper. High levels of zinc can cause a deficiency of copper in the body, which can lead to anemia.
Those amounts are well above the usual levels recommended by the Food and Drug Administration: three times as much vitamin A, eight times as much vitamin C, 13 times as much vitamin E and five times as much zinc.
Although all the supplements are readily available without prescription, “People ought to discuss this with their doctor,” Dr. Ferris said. Beta-carotene raises the risk of lung cancer among smokers. “For that group, we probably recommend they take a formulation without the beta- carotene,” Dr. Ferris said.
People who took zinc supplements in the study suffered a slightly higher rate of problems like urinary tract infections and kidney stones.