Low- and High-Dose Plant and Marine (n-3) Fatty Acids Do Not Affect Plasma Inflammatory Markers in Adults with Metabolic Syndrome

Chronic inflammation is considered to play a role in the development of cardiovascular disease. Various (n-3) fatty acids (FA) have been reported to have antiinflammatory effects, but there is a lack of consensus in this area, particularly in regard to optimal source(s) and dose(s). This study aimed to determine the effects of high and low doses of (n-3) FA from plant and marine sources on plasma inflammatory marker concentrations. One-hundred adults with metabolic syndrome were randomly assigned to a low or high dose of plant-(2.2 or 6.6 g/d alpha-linolenic acid) or marine- (1.2 or 3.6 g/d EPA and DHA) derived (n-3) FA or placebo for 8 wk, using a parallel arm design (n = 20/arm). Fasting blood samples collected at 0, 4, and 8 wk were analyzed for concentrations of monocyte chemotactic protein-1 (MCP-1), IL-6, and soluble intercellular adhesion molecule-1 (sICAM-1) and for cardiovascular risk factors. Baseline concentrations across all 5 groups combined were (mean +/- SD) 103 +/- 32 ng/L for MCP-1, 1.06 +/- 0.56 ng/L for IL-6, and 0.197 +/- 0.041 ng/L for sICAM-1. There were no significant differences in 8-wk changes in plasma inflammatory marker concentrations among the 5 groups. Plasma TG and blood pressure decreased significantly more and the [LDL cholesterol concentration increased more in the high-dose fish oil group compared to the 8-wk changes in some of the other 4 groups (P <= 0.041. In conclusion, no beneficial effects were detected for any of the 3 inflammatory markers investigated in response to (n-3) FA in adults with metabolic syndrome regardless of dose or source. J. Nutr. 141: 2166-2171, 2011.