Pooled trials show no mortality benefit — and beta-carotene and vitamin E may slightly increase death.
What the evidence shows
Because oxidative stress is linked to ageing and disease, it seemed logical that antioxidant supplements (beta-carotene, vitamins A, C, E, selenium) should protect health. Sales grew into a huge industry on that promise.
Bjelakovic et al. (2007), a Cochrane-style meta-analysis of 68 randomized trials with over 230,000 participants, found no reduction in mortality from antioxidant supplements overall. Worse, when limited to the highest-quality trials, beta-carotene, vitamin A, and vitamin E were associated with a small increase in death. Getting antioxidants from a varied diet is fine, but the claim that supplement pills extend life is refuted; for some, they may do slight harm.
Sources
Bjelakovic, G., Nikolova, D., Gluud, L. L., Simonetti, R. G., & Gluud, C. (2007). Mortality in randomized trials of antioxidant supplements for primary and secondary prevention: Systematic review and meta-analysis.
JAMA, 297(8), 842–857
Antioxidant supplements did not reduce mortality; beta-carotene, vitamin A, and vitamin E were linked to slightly higher mortality.
DOI: 10.1001/jama.297.8.842 →