AREDS II in the Works

In June of this year, I talked about vitamin supplements that retard the progression of AMD. This new and important information was discovered by the Age-Related Eye Disease Study (AREDS I). The last blog, which stated that cataract surgery doesn’t appear to increase the progression of AMD, was also information gained from AREDS I.

Now the National Eye Institute is recruiting clinical sites to begin AREDS II. Findings from epidemiologic studies as well as AREDS I showed that patients with reduced dietary intakes of lutein and zeaxanthin and omega-3 fatty acids had an increased risk of AMD (see also the August 4th blog, www.medrounds.org/amd/2005/08/lutein-zeaxanthin-and-omega-3-poly.html). AREDS II will test whether supplementation with a combination of 10mg of lutein and 2mg of zeaxanthin a day and/or one gram of omega-3 long-chain polyunsaturated fatty acids will decrease the risk of progression of AMD.

In AREDS I, a large dose of zinc (80mg/day) was used. High doses of zinc can cause prostate enlargement. There is also laboratory evidence that zinc can increase the risk of Alzheimer’s disease, however no such connection was found in AREDS I. AREDS II will compare the results of patients given 80mg/day of zinc to patients given 40mg of zinc per day.

Two large studies showed that supplementation with beta-carotene increased the risk of lung cancer in smokers. Therefore AREDS II will also test whether removing the beta-carotene reduces the efficacy of the combination of vitamins and minerals used in AREDS I.

Once AREDS II is up and running, I would encourage patients with AMD to join the study. You will be advancing our knowledge of AMD and also be “in the know,” so to speak, of any new developments.

Many of you may think, “Why don’t I just take this supplements and not bother to join the study?” If you do this, we may never know whether these supplements work. Taking unproven supplements is also potentially dangerous. The information about lutein, zeaxanthin, and omega-3 fatty acids came from dietary questionnaires. No one knows if oral supplements will have the same protective effect. In addition, AREDS II could show no benefit or even a harmful effect of these new supplements. If you were a smoker and just decided to take beta-carotene on your own, you would have exposed yourself to a higher risk of lung cancer. That’s why we need patients to join AREDS II and answer these questions as quickly as we call. It’s the right thing for you to do.

See also: The Age-Related Eye Disease Study II (AREDS II) will begin soon after the initial AREDS concludes in January 2006.