Fish oil supplementation moderately increases circulating adiponectin, according to a review published in the Journal of Clinical Endocrinology & Metabolism.
Jason H.Y. Wu, Ph.D., from Harvard University in Boston, and colleagues conducted a literature review and meta-analysis of randomized placebo-controlled clinical trials (RCTs) in which either fish oil supplementation or isocaloric fish meal feeding was examined to determine the effect of long-chain ω-3 polyunsaturated fatty acid (ω-3 PUFA) consumption on circulating adiponectin.
The researchers found that, of the 14 RCTs included in the analysis, 14 had trial arms evaluating fish oil (fish oil, 682 participants; placebo, 641 participants). Fish oil significantly increased adiponectin by 0.37 µg/mL. Statistical heterogeneity was evident (I² = 72.9 percent) even though effects in 12 of 14 trials were ≥0 and were unexplained by ω-3 PUFA dose or duration, study quality score, study location, or baseline body mass index. Smaller trials with greater effects were identified by asymmetrical funnel plots. There was a theoretical pooled effect of 0.18 µg/mL suggested with the fill-and-trim method (P = 0.28). Fish feeding was evaluated in only two trial arms (136 intervention and 68 control subjects), with the pooled effect on adiponectin not reaching statistical significance.
“These findings provide no evidence for harm and support possible benefits of ω-3 PUFA consumption on insulin sensitivity and adipocyte function,” the authors write.
One author disclosed financial ties to the food and pharmaceutical industries.