Polyunsaturated Fatty Acids and Disease-associated and Cytokine-induced Neurological Manifestations

Fish oil supplementation is suggested as possible mean to improve neurological manifestations of chronic diseases and cytokine immunotherapies. Preclinical and clinical studies show that fish oil supplementation seems able to reduce disease-associated anorexia and body weight loss. This improvement could be due to shifts in metabolism and changes in proinflammatory cytokine production and action. ω-3 Polyunsaturated fatty acids (PUFAs), especially eicosapentaenoic acid, are used as substrates for eicosanoid synthesis, competing for enzymes with arachidonic acid, which is a substrate for the synthesis of proinflammatory immunomodulators, such as prostaglandin E2. Fish oil supplementation is generally found to lower production of cytokines including interleukin-1 and tumor necrosis factor-α, thereby reducing various immune responses, including inflammation. However, conflicting results regarding the effects of fish oil interventions have been reported. The main factor that emerges from the contradictory reports is the variety of models, assays and methodologies that have been used. This brief review presents an overall perspective on the potential use of ω-3 PUFAs as a nutritional intervention to ameliorate disease-associated and cytokine-induced neurological manifestations. We conclude that substantial further research is required to understand the exact nature of n-3 PUFA-induced immunomodulation in health and disease.