Suplemen Antioksidan Meningkatkan Mortalitas

Suplemen antioksidan yang mengandung salah satu atau kombinasi dari
selenium, betakaroten, vitamin A, vitamin E dan vitamin C, banyak digunakan
untuk pencegahan berbagai penyakit.

Para ahli ingin mengetahui efek suplementasi antioksidan terhadap mortalitas
(kematian) penggunanya dengan melakukan meta-analisis.

Hasil penelitian ternyata penggunaan betakaroten, vitamin A dan vitamin E
dapat meningkatkan mortalitas. Sedangkan untuk vitamin C dan Selenium perlu
penelitian lebih lanjut.

Dengan demikian dapat disimpulkan bahwa pemberian suplementasi vitamin
sekalipun perlu hati-hati karena dapat membawa efek yang tidak diinginkan.

Mortality in Randomized Trials of Antioxidant Supplements for Primary and
Secondary Prevention

JAMA. 2007;297:842-857.
Goran Bjelakovic, MD, DrMedSci; Dimitrinka Nikolova, MA; Lise Lotte Gluud,
MD, DrMedSci; Rosa G. Simonetti, MD; Christian Gluud, MD, DrMedSci

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.

Author Affiliations: The Cochrane Hepato-Biliary Group, Copenhagen Trial
Unit, Center for Clinical Intervention Research, Copenhagen University
Hospital, Rigshospitalet, Copenhagen, Denmark (Drs Bjelakovic, L. L. Gluud,
Simonetti, and C. Gluud and Ms Nikolova); Department of Internal Medicine,
Gastroenterology and Hepatology, University of Nis, Nis, Serbia (Dr
Bjelakovic); and Divisione di Medicina, Ospedale V. Cervello, Palermo, Italy
(Dr Simonetti).