Please use this identifier to cite or link to this item: https://open.ni.ac.rs/handle/123456789/848
Title: Mortality in randomized trials of antioxidant supplements for primary and secondary prevention: Systematic review and meta-analysis
Authors: Bjelaković, Goran 
Nikolova D.
Gluud L.
Simonetti R.
Gluud C.
Issue Date: 28-Feb-2007
Journal: Journal of the American Medical Association
Abstract: Context: Antioxidant supplements are used for prevention of several diseases. Objective: To assess the effect of antioxidant supplements on mortality in randomized primary and secondary prevention trials. Data Sources and Trial Selection: We searched electronic databases and bibliographies published by October 2005. All randomized trials involving adults comparing beta carotene, vitamin A, vitamin C (ascorbic acid), vitamin E, and selenium either singly or combined vs placebo or vs no intervention were included in our analysis. Randomization, blinding, and follow-up were considered markers of bias in the included trials. The effect of antioxidant supplements on all-cause mortality was analyzed with random-effects meta-analyses and reported as relative risk (RR) with 95% confidence intervals (CIs). Meta-regression was used to assess the effect of covariates across the trials. Data Extraction: We included 68 randomized trials with 232 606 participants (385 publications). Data Synthesis: When all low- and high-bias risk trials of antioxidant supplements were pooled together there was no significant effect on mortality (RR, 1.02; 95% CI, 0.98-1.06). Multivariate meta-regression analyses showed that low-bias risk trials (RR, 1.16; 95% CI, 1.05-1.29) and selenium (RR, 0.998; 95% CI, 0.997-0.9995) were significantly associated with mortality. In 47 low-bias trials with 180 938 participants, the antioxidant supplements significantly increased mortality (RR, 1.05; 95% CI, 1.02-1.08). In low-bias risk trials, after exclusion of selenium trials, beta carotene (RR, 1.07; 95% CI, 1.02-1.11), vitamin A (RR, 1.16; 95% CI, 1.10-1.24), and vitamin E (RR, 1.04; 95% CI, 1.01-1.07), singly or combined, significantly increased mortality. Vitamin C and selenium had no significant effect on mortality. Conclusions: Treatment with beta carotene, vitamin A, and vitamin E may increase mortality. The potential roles of vitamin C and selenium on mortality need further study. ©2007 American Medical Association. All rights reserved.
URI: https://open.ni.ac.rs/handle/123456789/848
ISSN: 00987484
DOI: 10.1001/jama.297.8.842
Appears in Collections:Naučne i umetničke publikacije

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