title: Omega-3 polyunsaturated fatty acids and inflammatory processes: nutrition or pharmacology?
abstract: Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are n-3 fatty acids found in oily fish and fish oil supplements. These fatty acids are able to inhibit partly a number of aspects of inflammation including leucocyte chemotaxis, adhesion molecule expression and leucocyte-endothelial adhesive interactions, production of eicosanoids like prostaglandins and leukotrienes from the n-6 fatty acid arachidonic acid, production of inflammatory cytokines and T cell reactivity. In parallel, EPA gives rise to eicosanoids that often have lower biological potency than those produced from arachidonioc acid and EPA and DHA give rise to anti-inflammatory and inflammation resolving resolvins and protectins. Mechanisms underlying the anti-inflammatory actions of n-3 fatty acids include altered cell membrane phospholipid fatty acid composition, disruption of lipid rafts, inhibition of activation of the pro-inflammatory transcription factor nuclear factor kappa B so reducing expression of inflammatory genes, activation of the anti-inflammatory transcription factor NR1C3 (i.e. peroxisome proliferator activated receptor γ) and binding to the G protein coupled receptor GPR120. These mechanisms are interlinked. In adult humans, an EPA plus DHA intake greater than 2 g day⁻¹ seems to be required to elicit anti-inflammatory actions, but few dose finding studies have been performed. Animal models demonstrate benefit from n-3 fatty acids in rheumatoid arthritis (RA), inflammatory bowel disease (IBD) and asthma. Clinical trials of fish oil in patients with RA demonstrate benefit supported by meta-analyses of the data. Clinical trails of fish oil in patients with IBD and asthma are inconsistent with no overall clear evidence of efficacy.
authors: Human Development and Health Academic Unit, Faculty of Medicine, University of Southampton, MP887 Southampton General Hospital, Southampton, United Kingdom. pcc@soton.ac.uk
authors: Philip C
authors: PC
authors: Calder
mesh_terms: D000328:Adult; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D018925:Chemokines / Q000494:pharmacology*; D002986:Clinical Trials as Topic; D019587:Dietary Supplements; D015525:Fatty Acids, Omega-3 / Q000494:pharmacology*; D005395:Fish Oils / Q000494:pharmacology; D055951:Functional Food; D006801:Humans; D007249:Inflammation / Q000188:drug therapy*; D023421:Models, Animal
chemical_list: D000893:Anti-Inflammatory Agents; D018925:Chemokines; D015525:Fatty Acids, Omega-3; D005395:Fish Oils