A Recent Update on the Effects of Omega-3 Fatty Acids in Alzheimer’s Disease

摘要

Dietary long chain polyunsaturated fatty acids belong to omega (ω)-3, -6 or -9 series.Both experimental and clinical studies demonstrated the beneficial effect of ω -3 fatty acids of fishoil, Eicosapentaenoic Acid (EPA) and Docosahexaenoic Acid (DHA) against human ailments includingcardiovascular diseases and rheumatoid arthritis. They are metabolized in cyclooxygenase andlipooxygenase pathways and also by cytochrome P450 isozymes. Biological importance of DHA inthe development of brain and retina are well established. Recent studies highlighted the beneficialeffect of ω-3 fatty acids in Alzheimer’s Disease (AD) which may be attributed to their antioxidant,anti-inflammatory, antiapoptotic and neurotrophic properties. The effect was obtained by the consumptionof either individual or combination of ω -3 fatty acids. The anti-inflammatory effect canbe ascribed to the decreased cytokines and monocytic chemotactic protein-1 level by suppressingthe nuclear factor-kappa B. Further, they inhibit cyclooxygenase-2 and nitric oxide synthase-2 activities.The antiapoptotic activity is due to the lowered Bax/Bcl ratio or caspase 3 levels. They caninduce the transcription factor, nuclear erythroid factor-2 mediated expression of superoxide dismutase-2 in order to facilitate the antioxidant effect. Both DHA and EPA can enhance the nervegrowth factor level. Overall, they are beneficial to improve the cognitive function in very mild ADand major depressive disorder. Despite the beneficial effects, ω-3 fatty acids are easily prone toperoxidation. This review article discusses the recent update on the roles of ω -3 fatty acids in AD.