Dietary supplement use in the prevention of age-related macular degeneration progression
26 May 2011
Age-related macular degeneration (AMD) is the leading cause of visual impairment and blindness in the developed world among people aged 65 years or older. The Age-Related Eye Disease Study Group (AREDS) has found that high-dose vitamin supplementation may have a role in preventing the progression of Category 3 and 4 age-related maculopathy.
Oxidative damage has been implicated in the pathogenesis of AMD, secondary to the retina’s high consumption of oxygen, its high proportion of polyunsaturated fatty acids, and its exposure to visible light. Over the last decade, nnumerous cross-sectional and cohort studies have investigated the role of antioxidant supplementation in preventing age-related maculopathy. The largest randomised controlled trial, undertaken by the Age-Related Eye Disease Study (AREDS) Group, compared antioxidant and zinc supplementation to placebo. The AREDS Group demonstrated a statistically significant odds reduction for the risk of progression to advanced AMD and reduction in the rate of at least moderated visual acuity loss with the use of tablets containing antioxidants plus zinc.
A recent study published in the New Zealand Medical Journal compared dietary antioxidant, zinc, and copper intakes of Australia, New Zealand, United Kingdom, and the United States to determine the difference between the actual and suggested AREDS intakes for these nutrients. The total median intake of vitamins A, C, and E; zinc; and copper is analysed from the most recent nutrition data published by the four countries. Forty multivitamin brands and 32 individual nutrient brands were analysed.
Results from this study revealed that the median intakes of antioxidants, zinc, and copper were comparable across the four countries, but substantially lower than the AREDS-recommended intakes to reduce the risk of progression to advanced AMD. Sixteen of the 40 multivitamin preparations contained all recommended nutrients. The study authors suggested that dietary supplementation is required to achieve the AREDS nutrient intake recommendations. This may be achieved by using any combination of multivitamin and individual supplement preparations available.
Source:
Aparna Raniga & Mark J Elder, Journal of the New Zealand Medical Association, 24-July-2009, Vol 122 No 1299
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