Antioxidant vitamin and mineral supplements for preventing age-related macular degeneration.
BACKGROUND
Some observational studies have suggested that people who eat a diet rich in antioxidant vitamins (carotenoids, vitamins C and E) or minerals (selenium and zinc) may be less likely to develop age-related macular degeneration (AMD).


OBJECTIVE
The aim of this review was to examine the evidence as to whether or not taking vitamin or mineral supplements prevents the development of AMD.


METHODS
We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Group Trials Register) in The Cochrane Library (2007, Issue 3), MEDLINE (1966 to August 2007), SIGLE (1980 to 2005/03), EMBASE (1980 to August 2007), National Research Register (2007, Issue 3), AMED (1985 to January 2006) and PubMed (on 24 January 2006 covering last 60 days), reference lists of identified reports and the Science Citation Index. We contacted investigators and experts in the field for details of unpublished studies.


METHODS
We included all randomised trials comparing an antioxidant vitamin and/or mineral supplement (alone or in combination) to control. We included only studies where supplementation had been given for at least one year.


METHODS
Both review authors independently extracted data and assessed trial quality. Data were pooled using a fixed-effect model.


RESULTS
Three randomised controlled trials were included in this review (23,099 people randomised). These trials investigated alpha-tocopherol and beta-carotene supplements. There was no evidence that antioxidant vitamin supplementation prevented or delayed the onset of AMD. The pooled risk ratio for any age-related maculopathy (ARM) was 1.04 (95% CI 0.92 to 1.18), for AMD (late ARM) was 1.03 (95% CI 0.74 to 1.43). Similar results were seen when the analyses were restricted to beta-carotene and alpha-tocopherol.


CONCLUSIONS
There is no evidence to date that the general population should take antioxidant vitamin and mineral supplements to prevent or delay the onset of AMD. There are several large ongoing trials. People with AMD should see the related Cochrane review "Antioxidant vitamin and mineral supplements for slowing the progression of age-related macular degeneration" written by the same author.
Evans
J R
JR
London School of Hygiene & Tropical Medicine, International Centre for Eye Health, Keppel Street, London, UK WC1E 7HT. jennifer.evans@lshtm.ac.uk
Henshaw
K
K
D000975:Antioxidants / Q000008:administration & dosage*; D019587:Dietary Supplements; D006801:Humans; D008268:Macular Degeneration / Q000517:prevention & control*; D008903:Minerals / Q000008:administration & dosage*; D016032:Randomized Controlled Trials as Topic; D014815:Vitamins / Q000008:administration & dosage*; D024502:alpha-Tocopherol / Q000008:administration & dosage; D019207:beta Carotene / Q000008:administration & dosage
D000975:Antioxidants; D008903:Minerals; D014815:Vitamins; D019207:beta Carotene; D024502:alpha-Tocopherol