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Multicenter Study
. 2008 Dec 23:337:a2931.
doi: 10.1136/bmj.a2931.

Effect of fish oil on arrhythmias and mortality: systematic review

Hernando León  1 , Marcelo C Shibata, Soori Sivakumaran, Marlene Dorgan, Trish Chatterley, Ross T Tsuyuki
Affiliations
Multicenter Study

Effect of fish oil on arrhythmias and mortality: systematic review

Hernando León et al. BMJ. .

Abstract

Objective: To synthesise the literature on the effects of fish oil-docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA)-on mortality and arrhythmias and to explore dose response and formulation effects.

Design: Systematic review and meta-analysis.

Data sources: Medline, Embase, the Cochrane Library, PubMed, CINAHL, IPA, Web of Science, Scopus, Pascal, Allied and Complementary Medicine, Academic OneFile, ProQuest Dissertations and Theses, Evidence-Based Complementary Medicine, and LILACS. Studies reviewed Randomised controlled trials of fish oil as dietary supplements in humans.

Data extraction: The primary outcomes of interest were the arrhythmic end points of appropriate implantable cardiac defibrillator intervention and sudden cardiac death. The secondary outcomes were all cause mortality and death from cardiac causes. Subgroup analyses included the effect of formulations of EPA and DHA on death from cardiac causes and effects of fish oil in patients with coronary artery disease or myocardial infarction.

Data synthesis: 12 studies totalling 32 779 patients met the inclusion criteria. A neutral effect was reported in three studies (n=1148) for appropriate implantable cardiac defibrillator intervention (odds ratio 0.90, 95% confidence interval 0.55 to 1.46) and in six studies (n=31 111) for sudden cardiac death (0.81, 0.52 to 1.25). 11 studies (n=32 439 and n=32 519) provided data on the effects of fish oil on all cause mortality (0.92, 0.82 to 1.03) and a reduction in deaths from cardiac causes (0.80, 0.69 to 0.92). The dose-response relation for DHA and EPA on reduction in deaths from cardiac causes was not significant.

Conclusions: Fish oil supplementation was associated with a significant reduction in deaths from cardiac causes but had no effect on arrhythmias or all cause mortality. Evidence to recommend an optimal formulation of EPA or DHA to reduce these outcomes is insufficient. Fish oils are a heterogeneous product, and the optimal formulations for DHA and EPA remain unclear.

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Conflict of interest statement

Competing interests: None declared.

Figures

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Fig 1 Flow of papers through review
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Fig 2 Effect of fish oil on appropriate implantable cardiac defibrillator intervention and sudden cardiac death
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Fig 3 Effect of fish oil on death from cardiac causes
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Fig 4 Funnel plot for assessment of publication bias for death from cardiac causes in 11 included studies reporting data on this outcome
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Fig 5 Effect of fish oil on all cause mortality
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Fig 6 Effect of fish oil on sudden cardiac death and death from cardiac causes in patients with coronary artery disease
See this image and copyright information in PMC

Comment in

References

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