Dietary fish oil decreases C-reactive protein, interleukin-6, and triacylglycerol to HDL-cholesterol ratio in postmenopausal women on HRT

Background: Atherogenesis is a complex process involving both a low-grade inflammation and a disturbed lipid profile. Although dietary fish and fish oil improve the latter of these two risk factors, their impact on the former is less clear. Objective: This study addressed the effect of supplementation with fish oil in doses achievable with diet on serum C-reactive protein (CRP), interleukin-6 (IL-6), and the lipid profile. Methods and results: Thirty healthy subjects taking HRT were randomly divided into three groups and supplemented for five weeks with 14g/day safflower oil (SO), 7g/day of both safflower oil and fish oil (LFO), or 14g/day fish oil (HFO). Measurements included serum high-sensitivity CRP, IL-6 in plasma and in cell culture supernatant collected from 24-hr lipopolysaccharide (LPS)-stimulated whole blood, and lipid profile markers. CRP and IL-6 were adjusted for body mass index (BMI). Fish oil supplementation significantly decreased CRP and IL-6 compared to SO, with a greater effect in the LFO than HFO groups. Plasma triacylglycerol (TG) and the TG/HDL-C ratio were significantly lower in the HFO compared to the SO group. Conclusions: These results suggest that dietary fish oil may decrease the risk for cardiovascular disease through the modulation of both plasma lipids and inflammatory markers in healthy postmenopausal women.