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Meta-Analysis
. 2017 Jan 17;8(1):27-39.
doi: 10.3945/an.116.013516. Print 2017 Jan.

Dietary Supplements and Risk of Cause-Specific Death, Cardiovascular Disease, and Cancer: A Systematic Review and Meta-Analysis of Primary Prevention Trials

Lukas Schwingshackl  1 , Heiner Boeing  2 , Marta Stelmach-Mardas  2   3 , Marion Gottschald  2 , Stefan Dietrich  2 , Georg Hoffmann  4 , Anna Chaimani  5
Affiliations
Meta-Analysis

Dietary Supplements and Risk of Cause-Specific Death, Cardiovascular Disease, and Cancer: A Systematic Review and Meta-Analysis of Primary Prevention Trials

Lukas Schwingshackl et al. Adv Nutr. .

Abstract

Our aim was to assess the efficacy of dietary supplements in the primary prevention of cause-specific death, cardiovascular disease (CVD), and cancer by using meta-analytical approaches. Electronic and hand searches were performed until August 2016. Inclusion criteria were as follows: 1) minimum intervention period of 12 mo; 2) primary prevention trials; 3) mean age ≥18 y; 4) interventions included vitamins, fatty acids, minerals, supplements containing combinations of vitamins and minerals, protein, fiber, prebiotics, and probiotics; and 5) primary outcome of all-cause mortality and secondary outcomes of mortality or incidence from CVD or cancer. Pooled effects across studies were estimated by using random-effects meta-analysis. Overall, 49 trials (69 reports) including 287,304 participants met the inclusion criteria. Thirty-two trials were judged as low risk-, 15 trials as moderate risk-, and 2 trials as high risk-of-bias studies. Supplements containing vitamin E (RR: 0.88; 95% CI: 0.80, 0.96) significantly reduced cardiovascular mortality risk, whereas supplements with folic acid reduced the risk of CVD (RR: 0.81; 95% CI: 0.70, 0.94). Vitamins D, C, and K; selenium; zinc; magnesium; and eicosapentaenoic acid showed no significant risk reduction for any of the outcomes. On the contrary, vitamin A was linked to an increased cancer risk (RR: 1.16; 95% CI: 1.00, 1.35). Supplements with β-carotene showed no significant effect; however, in the subgroup with β-carotene given singly, an increased risk of all-cause mortality by 6% (RR: 1.06; 95% CI: 1.02, 1.10) was observed. Taken together, we found insufficient evidence to support the use of dietary supplements in the primary prevention of cause-specific death, incidence of CVD, and incidence of cancer. The application of some supplements generated small beneficial effects; however, the heterogeneous types and doses of supplements limit the generalizability to the overall population.

Keywords: cancer; cardiovascular disease; dietary supplements; meta-analysis; mortality; systematic review.

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Conflict of interest statement

2 Author disclosures: L Schwingshackl, H Boeing, M Stelmach-Mardas, M Gottschald, S Dietrich, G Hoffmann, and A Chaimani, no conflicts of interest.

Figures

FIGURE 1
FIGURE 1
Flow diagram.
See this image and copyright information in PMC

References

    1. Bailey RL, Gahche JJ, Lentino CV, Dwyer JT, Engel JS, Thomas PR, Betz JM, Sempos CT, Picciano MF. Dietary supplement use in the United States, 2003–2006. J Nutr 2011;141:261–6. - PMC - PubMed
    1. Nutrition Business Journal. NBJ’s Supplement Business Report: an analysis of markets, trends, competition and strategy in the U.S. dietary supplement industry. New York: Penton Media; 2016.
    1. Skeie G, Braaten T, Hjartaker A, Lentjes M, Amiano P, Jakszyn P, Pala V, Palanca A, Niekerk EM, Verhagen H, et al. Use of dietary supplements in the European Prospective Investigation into Cancer and Nutrition calibration study. Eur J Clin Nutr 2009;63(Suppl 4):S226–38. - PubMed
    1. Radimer K, Bindewald B, Hughes J, Ervin B, Swanson C, Picciano MF. Dietary supplement use by US adults: data from the National Health and Nutrition Examination Survey, 1999–2000. Am J Epidemiol 2004;160:339–49. - PubMed
    1. Li K, Kaaks R, Linseisen J, Rohrmann S. Consistency of vitamin and/or mineral supplement use and demographic, lifestyle and health-status predictors: findings from the European Prospective Investigation into Cancer and Nutrition (EPIC)-Heidelberg cohort. Br J Nutr 2010;104:1058–64. - PubMed