Effect of n-3 fatty acids supplementation during life style modification in women with overweight

The marine n-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) exert numerous beneficial effects on health, but their potency to defend against development of peripheral insulin resistance of healthy person with overweight remains poorly characterized. We aimed to evaluate the effect of a combination intervention using EPA + DHA and the lifestyle modification (LSM) in women with overweight.

In a parallel-group, three-arm, randomized trial (UMIN Clinical Trials Registry - R000031131), 34 women were assigned to a 12-week-intervention using corn oil (1.5 g/day; placebo); LSM and corn oil (1.5 g/day; LSM); or LSM and EPA + DHA concentrate (1.5 g/day, containing ~ 0.6 g EPA + DHA; LSM & n-3). At baseline and after intervention, anthropometric measurements including bioelectrical impedance analysis, spiroergometry, 24-hours dietary recall, and various metabolic markers, adiponectin and cytokines were evaluated in serum using standard procedures. Data from 29 women were used for the final evaluation. Wilcoxon two-sided rank-sum test was used to inspect the differences between LSM and LSM & n-3, and placebo groups, with a p-value of ≤ 0.05. All computations were performed with MATLAB Statistics Toolbox.

In comparison with placebo, LSM and LSM & n-3 decreased body weight, waist circumference, and body fat, and increased VO₂max/kg. LSM & n-3 increased adiponectin levels in comparison to LSM. Fasting insulin, IL8, and cholesterol were decreased by LSM, but were unchanged by LSM & n-3. IL6 was not affected in LSM & n-3, while it was increased in LSM. Other inflammatory markers, as well as leptin, LIF, follistatin, BDNF, and fasting triacylglycerol were not significantly affected by any of the interventions.

Besides preventing a modest negative effect of LSM on IL6 and adiponectin level, the combination of LSM and EPA + DHA supplementation could be probably used to improve the functional capacity of adipose tissue in women with overweight.