Association of serum n-3 polyunsaturated fatty acids with C-reactive protein in men

Background/Objectives: N-3 polyunsaturated fatty acids (PUFAs) have been associated with reduced inflammation. We tested the hypothesis that high serum concentrations of the n-3 PUFAs are associated with lower serum C-reactive protein (CRP) concentrations in healthy middle-aged Finnish men. We also examined whether exposure to mercury, an environmental contaminant in fish, which is also a major source of long-chain n-3 PUFA, was associated with CRP. Subjects/Methods: Data from the prospective, population-based Kuopio Ischaemic Heart Disease Risk Factor Study were analyzed cross-sectionally to determine the associations between serum n-3 PUFAs, hair mercury and serum CRP in 1395 healthy men, aged 42-60 years. Linear regression analyses were performed to analyze the associations. Results: In the multivariate models, the mean serum CRP in quartiles of serum total n-3 PUFA concentration was 1.23, 1.27, 1.18 and 1.08 mg/l, P for trend 0.01. Statistically significant inverse associations were also observed with the total serum long-chain n-3 PUFA concentration and with the individual long-chain n-3 PUFAs docosapentaenoic acid and docosahexaenoic acid, but not with eicosapentaenoic acid or with the intermediate-chain n-3 PUFA alpha-linolenic acid. Hair methylmercury content was not associated with serum CRP levels and it did not modify the associations between serum n-3 PUFAs and CRP either. Conclusions: Serum n-3 PUFAs and especially the long-chain n-3 PUFA concentration, a marker of fish or fish oil consumption, were inversely associated with serum CRP in men. Exposure to mercury was not associated with serum CRP. European Journal of Clinical Nutrition (2012) 66, 736-741; doi: 10.1038/ejcn.2011.195; published online 23 November 2011