Dietary antioxidants and primary prevention of age related macular degeneration: systematic review and meta-analysis.
OBJECTIVE
To evaluate the effectiveness of dietary antioxidants in the primary prevention of age related macular degeneration (AMD).


METHODS
Systematic review and meta-analysis.


METHODS
Search of seven databases without limits on year or language of publication, and retrieval of references in pertinent reviews and articles.


METHODS
Two reviewers independently searched the databases and selected the studies, using standardised criteria. Randomised clinical trials and prospective cohort studies were included. Of the 4192 abstracts initially identified, 12 studies (nine prospective cohort studies and three randomised clinical trials) met the selection criteria and were included. Data extraction and study quality evaluation were independently reviewed, using standardised criteria. Results were pooled quantitatively using meta-analytic methods.


RESULTS
The nine prospective cohort studies included 149 203 people, with 1878 incident cases of early AMD. The antioxidants investigated differed across studies, and not all studies contributed to the meta-analysis of each antioxidant. Pooled results from 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 in the primary prevention of early AMD. The three randomised clinical trials did not show that antioxidant supplements prevented early AMD.


CONCLUSIONS
There is insufficient evidence to support the role of dietary antioxidants, including the use of dietary antioxidant supplements, for the primary prevention of early AMD.
Chong
Elaine W-T
EW
Centre for Eye Research Australia, University of Melbourne, Victoria 3002, Australia. twong@unimelb.edu.au
Wong
Tien Y
TY
Kreis
Andreas J
AJ
Simpson
Julie A
JA
Guymer
Robyn H
RH
D000975:Antioxidants / Q000627:therapeutic use*; D015331:Cohort Studies; D006801:Humans; D008268:Macular Degeneration / Q000178:diet therapy / Q000517:prevention & control*; D011446:Prospective Studies; D016032:Randomized Controlled Trials as Topic; D017211:Treatment Failure
D000975:Antioxidants