NOV 05, 2007
By Nancy M. Holekamp, MD
Comprehensive Ophthalmology, Retina/Vitreous
Most ophthalmologists know that oral anti-oxidant supplementation can slow the progression of established AMD. But can antioxidants prevent the incidence of early AMD? A study published in the On-line First issue of the British Medical Journal says no.
Elaine W-T Chong and colleagues at the University of Melbourne performed a meta-analysis that included nine prospective cohort studies evaluating antioxidants and three randomized clinical trials evaluating antioxidant supplements.
The nine prospective cohort studies included 149,203 people, with 1,878 incident cases of early AMD. The antioxidants investigated in these studies differed and not all studies contributed to the meta-analysis of each antioxidant, the authors noted.
Pooled results from the nine prospective cohort studies indicated that vitamin A, vitamin C, vitamin E, zinc, lutein, zeaxanthin, alpha-carotene, beta-carotene, beta-cryptoxanthin and lycopene have little or no effect on the primary prevention of early AMD, the authors reported.
In addition, the three randomized clinical trials did not show that antioxidant supplements prevented early AMD.
Although any meta-analysis has limitations, this is an important study. Aggressive marketing of AREDS type vitamins to consumers and doctors has everyone believing they should take oral antioxidants. This simply is not born out in well-done clinical studies. Individuals with no AMD or early AMD (fine hard drusen) likely derive no ocular benefit from anti-oxidant supplementation and should not be encouraged to buy these products.