Donald A. Smith, MD, MPH, FACP, FNLA
Do omega-3 polyunsaturated fatty acids (PUFAs) reduce risk for major cardiovascular (CV) events in adults?
Included studies compared omega-3 PUFAs, in diet or supplement form, with another diet or placebo in adults in primary or secondary settings of CV disease prevention; and had treatment duration ≥ 1 year. Outcomes were all-cause and cardiac mortality, sudden death, myocardial infarction (MI), and stroke.
MEDLINE, EMBASE/Excerpta Medica, and Cochrane Central Register of Controlled Trials to August 2012, and reference lists of relevant systematic reviews were searched for randomized controlled trials (RCTs). 20 RCTs (n = 68 680, median age 68 y, median treatment duration 2 y) met inclusion criteria: 2 used omega-3–targeted dietary counseling, and 18 compared omega-3 supplements (mean omega-3 dose 1.51 g/d) with placebo (16 RCTs), standard care (1 RCT), or no treatment (1 RCT). 13 RCTs were done in secondary prevention settings, 4 in mixed primary/secondary prevention settings, and 3 in patients with implantable cardioverter defibrillators. 14 studies reported allocation concealment, 16 were double-blind, and 16 used intention-to-treat analysis.
Meta-analyses showed that omega-3 PUFA supplements did not reduce all-cause or cardiac mortality, sudden death, MI, or stroke more than control treatment (Table). In 2 RCTs comparing omega-3–targeted dietary counseling with non–fish oil diets, results were inconsistent for both all-cause mortality (n = 3114, relative risk [RR] 1.15, 95% CI 0.98 to 1.34 in one trial; n = 2033, RR 0.73, CI 0.56 to 0.93 in the other) and cardiac mortality (n = 3114, RR 1.27, CI 1.03 to 1.57 in one trial; n = 2033, RR 0.67, CI 0.51 to 0.89 in the other).
Omega-3 polyunsaturated fatty acid supplements do not reduce major cardiovascular events more than control treatment in adults.
Omega-3 polyunsaturated fatty acid supplements vs placebo, standard care, or no treatment (control) in adults*
*Abbreviations defined in Glossary. Weighted event rates, RRR, RRI, and CI calculated from relative risks and control event rates in article using a random-effects model.
†Not statistically significant after adjustment for multiple comparisons.
Donald A. Smith. Review: Omega-3 polyunsaturated fatty acid supplements do not reduce major cardiovascular events in adults. Ann Intern Med. 2012;157:JC6–5. doi: 10.7326/0003-4819-157-12-201212180-02005
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Published: Ann Intern Med. 2012;157(12):JC6-5.
Cardiology, Coronary Risk Factors, Dyslipidemia, Prevention/Screening.
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Print ISSN: 0003-4819 | Online ISSN: 1539-3704
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