Omega-3 polyunsaturated fatty acid and insulin sensitivity: a meta-analysis of randomized controlled trials

BACKGROUND &AIM: n-3 PUFA has been shown to decrease the risk of several components of the metabolic syndrome; however, the role of n-3 PUFA on glucose metabolism is not clear. Our aim was to systematically review the effect of n-3 PUFA on IS by conducting a meta-analysis of available RCTs.

We followed the guidelines of Cochrane's review of systematic interventions. We searched MEDLINE, EMBASE, CENTRAL and clinicaltrials.gov from the beginning of each database until October 2010. Meta-analysis was performed using a random effects model to estimate a pooled SMD and the corresponding 95% CI.

From 303 screened citations, 11 RCTs (n = 618) were eligible for inclusion in the analysis. In a pooled estimate, n-3 PUFA intervention had no effects on IS compared to placebo (SMD 0.08, 95% CI -0.11-0.28). Similarly, n-3 PUFA had no effects on IS in sub-group analyses (Type 2 diabetes vs. other population; QUICKI and other test subgroups). In the HOMA subgroup, n-3 PUFA was associated with a statistically significant increase in IS (SMD 0.30, CI 0.03-0.58) when compared to placebo.

This meta-analysis is consistent with a lack of n-3 PUFA effects on IS.