Associations between omega-3 fatty acid-derived lipid mediators and markers of inflammation in older subjects with low-grade chronic inflammation

Cardiovascular disease (CVD), the leading cause of death in the United States and globally, is a chronic inflammatory disease likely caused by an impaired ability to resolve inflammation. Pre-clinical studies have provided strong evidence of the activating role of specialized pro-resolving lipid mediators (SPMs) derived from the omega-3 fatty acids eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA) and docosahexaenoic acid (DHA) on the resolution of inflammation. However, there is a dearth of information on the role of SPMs on inflammation in humans. Therefore, the aim of this study was to assess whether plasma concentrations of omega-3 fatty acids and their derived SPMs are associated with inflammatory markers in subjects with low-grade chronic inflammation (C-reactive protein >2 µg/mL). The plasma phospholipid content of omega-3 fatty acids, a marker of dietary intake, plasma concentrations of SPMs, and serum concentrations of inflammatory markers were measured in 21 older men and postmenopausal women (age 53–73 y) at the end of a four-week placebo phase (3 g/day high oleic acid sunflower oil). The phospholipid DHA content was inversely related to interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), monocyte chemoattractant protein-1 (MCP-1) and IL-10 concentrations. Moreover, MCP-1 was inversely associated with the DHA-derived 14-HDHA and 4-HDHA, and IL-10 was inversely associated with EPA-derived 18-HEPE, 12-HEPE and 5-HEPE, DPA-derived Rv5_DPA, and DHA-derived 4-HDHA. These findings support the anti-inflammatory effect of dietary omega-3 fatty and suggest that lipid mediators derived from EPA, DPA, and DHA participate in the regulation of inflammation in subjects with chronic inflammation.