Effect of fish oil supplementation on fasting vascular endothelial function in humans: a meta-analysis of randomized controlled trials

PLoS One. 2012;7(9):e46028. doi: 10.1371/journal.pone.0046028. Epub 2012 Sep 21.

Abstract

Background: Effect of fish oil supplementation on flow-mediated dilation, an index of endothelial function in humans, remains controversial. We performed a meta-analysis to determine whether fish oil supplementation could improve endothelial function.

Methods: Human intervention studies were identified by systematic searches of Medline, Embase, Cochrane's library and references of related reviews and studies. A random-effect model was applied to estimate the pooled results. Meta-regression and subgroup analyses were performed to evaluate the impact of study characteristics on the effect of fish oil supplementation on flow-mediated dilation.

Results: A total of sixteen records with 1,385 subjects were reviewed. The results of the pooled analysis showed that fish oil supplementation significantly improved flow-mediated dilation (weighed mean difference: 1.49%, 95% confidence interval 0.48% to 2.50%, p = 0.004). Meta-regression and subgroup analysis suggested that the quality of included studies were inversely related to the overall effect (regression coefficient = -1.60, p = 0.04), and the significance of the effect was mainly driven by the studies with relatively poor quality. Sensitivity analysis including only double-blind, placebo-controlled studies indicated fish oil supplementation has no significant effect on endothelial function (weighed mean difference: 0.54%, 95% confidence interval -0.25% to 1.33%, p = 0.18). Besides, normoglycemic subjects or participants with lower diastolic blood pressure seemed to be associated with remarkable improvement of endothelial function after fish oil supplementation.

Conclusions: Although current evidence suggested a possible role of fish oil in improving endothelial function, large-scale and high-quality clinical trials are needed to evaluate these effects before we can come to a definite conclusion.

Publication types

  • Meta-Analysis

MeSH terms

  • Adolescent
  • Adult
  • Brachial Artery / drug effects*
  • Brachial Artery / physiology
  • Dietary Supplements / analysis
  • Double-Blind Method
  • Endothelium, Vascular / drug effects*
  • Endothelium, Vascular / physiology
  • Female
  • Fish Oils / therapeutic use*
  • Humans
  • Male
  • Middle Aged
  • Placebo Effect
  • Randomized Controlled Trials as Topic
  • Vasodilation / drug effects*
  • Young Adult

Substances

  • Fish Oils

Grant support

No current external funding sources for this study.