Diet or Vitamins for AMD?

Patients with AMD often ask me if it is better to get the AREDS vitamins through diet or by taking vitamins. Most epidemiological studies have shown that diets high in vitamin C and E, beta-carotene, and zinc protect against the development and progression of AMD. An excellent study from the Netherlands reported recently that people who ingested higher than the median (the top 50%) amounts of vitamins C and E, beta-carotene, and zinc had a 35% reduced risk of AMD compared to those who had ingested lower than the median (the bottom 50%) amounts of these micronutrients. This 35% risk reduction compares favorably with the 25% risk reduction of the progression of AMD found in the Age-Related Eye Disease Study.

The daily dose of the supplements in the AREDS was: vitamin C 500mg; vitamin E 400 IU; beta-carotene 15mg; zinc 80mg; and copper 2mg. These are high amounts that may be difficult to obtain through diet alone. The study from the Netherlands calculated that the mean amount of vitamin E ingested daily by the highest quarter of people in their study was only 30 IU. This may mean that the high doses used in the AREDS aren’t necessary to reduce the risk of progression of AMD. It is also difficult to obtain the high doses used in the AREDS (especially the vitamin E and zinc) through diet alone.

So what should you do? I would eat a diet rich in these antioxidants and zinc (blog August 23, 2005). I would also take supplements that contain the AREDS doses. There is some concern that high doses of vitamin E may increase mortality and that the zinc doses used in AREDS were higher than necessary. Therefore if you take the AREDS supplements, you could take half of the usual vitamin and zinc dose one day each week while taking the full dose the other six days. This would work out about right. I would not though, eat a poor diet, and expect the AREDS supplements to take care of any deficiency. Your mother was right – eat your vegetables.

Reference:

1. van Leeuwen R., Boekhoorn S, Vingerling JR, Witteman JCM, Klaver CCW, Hofman A, de Jong PTVM. Dietary Intake of Antioxidants and Risk of Age-Related Macular Degeneration. JAMA 2005; 294(24):3101-3107.