Dietary n-3 Fatty Acids Didn’t Significantly Affect Insulin Sensitivity

(HealthDay News) — Dietary n-3 polyunsaturated fatty acids (PUFAs), including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), do not appear to have clinically meaningful effects on peripheral or hepatic insulin sensitivity in insulin-resistant adults without diabetes, according to research published in Diabetes Care.

Antigoni Z. Lalia, MD, of the Mayo Clinic College of Medicine in Rochester, Minnesota, and colleagues conducted a randomized, double blind study in which 31 insulin-resistant adults, without diabetes, received either 3.9 grams per day EPA plus DHA or placebo for 6 months. 

A hyperinsulinemic-euglycemic clamp with somatostatin was used to assess hepatic and peripheral insulin sensitivity. Insulin secretion and muscle mitochondrial function were also evaluated.

The researchers found that, compared with placebo, EPA plus DHA did not affect peripheral insulin sensitivity, postprandial glucose disposal or insulin secretion. 

A small, but significant, improvement in hepatic insulin sensitivity, determined from the suppression of endogenous glucose production by insulin, was observed for EPA plus DHA compared with placebo. 

Neither EPA plus DHA nor placebo influenced muscle mitochondrial function.

“This study demonstrates that dietary EPA plus DHA does not improve peripheral glucose disposal, insulin secretion, or skeletal muscle mitochondrial function in insulin-resistant nondiabetic humans,” the researchers wrote. “There was a modest improvement in hepatic insulin sensitivity with EPA plus DHA, but this was not associated with any improvements in clinically meaningful outcomes.”

One author is a member of the Scientific Advisory Board of Sancilio and Company, which supplied materials for the study.


  1. Lalia AZ et al. Diabetes Care. 2015;doi:10.2337/dc14-3101.