Efficacy of antioxidant supplementation in reducing primary cancer incidence and mortality: systematic review and meta-analysis.

摘要: OBJECTIVE To estimate the association between antioxidant use and primary cancer incidence mortality to evaluate these effects across specific compounds, target organs, participant subgroups. METHODS Multiple electronic databases (MEDLINE, Cochrane Controlled Clinical Trials Register, EMBASE, Science Citation Index) were searched from their dates of inception until August 2005 identify eligible randomized clinical trials. Random meta-analyses estimated pooled relative risks (RRs) 95% confidence intervals (CIs) that described effect antioxidants vs placebo on mortality. RESULTS Twelve trials, 9 high methodological quality, identified (total subject population, 104,196). Antioxidant supplementation did not significantly reduce total (RR, 0.99; CI, 0.94-1.04) or 1.03; 0.92-1.15) any site-specific incidence. Beta carotene was associated with an increase in among smokers 1.10; 1.03-1.10) a trend toward increased 1.16; 0.98-1.37). Selenium reduced men 0.77; 0.64-0.92) but women 1.00; 0.89-1.13, value for interaction, P CONCLUSION appeared smokers, whereas vitamin E had no effect. might have anticarcinogenic thus requires further research. effect; selenium effects.