Effect of omega-3 fatty acids on human health

Abstract

Omega-3 fatty acids form part of the polyunsaturated fatty acids, which are prominently represented by the linolenic acids, DHA and EPA. The Omega-3 acids became better known due to their cardioprotective effects, when 50 years ago an extremely low incidence of CHD in Greenland’s Inuit had been observed. This effect was traced back to their high consume of Omega-3 fatty acids. Their cardioprotective effects have been proven by recent studies, as for example the GISSIP and DART. Nevertheless other studies were published, which could not verify these results (e.g.: EURAMIC-Study, Physicians’ Health Study or DART 2). The same applies to studies on other populations with high consume of fish, as Japan and Norway, since their way of living changed and as a consequence the risk of CHD increased. The reduced incidence of cardiac arrhythmias, an anti-inflammatory effect through interference on the AA- cascade, the stabilization of plaques, a positive influence on the endothelial function and the antihypertensive and triglyceride-reducing effects are the most commonly known mechanisms on CHD. The positive effects of Omega-3 fatty acids seem to be limited on determined groups, as for example patients who suffered a MI. Due to recent investigations other areas with correlation to Omega-3 fatty acids could be discovered. The importance of Omega-3 fatty acids for the development of children originates in the observation that both brain and eyes contain high amounts of Omega-3 fatty acids. Furthermore these fatty acids seem to play an essential role in the fetal and cognitive development of children. Additionally the deficiency of DHA was linked with interferences of the visual functions. However, there is no consistent evidence in relation with Omega-3 fatty acids and ARMD and RP. Another branch is cancer research, although no significant evidence on the incidence of cancer and Omega-3 fatty acids has been found. Other possible mechanisms, as for example the repression of COX-2 and the reduction of the NF-kB can hardly be determined, since cancer is extremely complex and genetic mutations over decades influence as well. A new group of therapeutical drugs containing Omega-3 fatty acids have been introduced in the Psychiatry for the treatment of affective disorders, schizophrenia, dementia, insomnia and ADHD. However, the positive effects of the supplementation on reducing the incidence of these disorders and on the treatment of the symptoms have not yet been determined. Metabolites, as prostaglandine and leukotriene, which play an decisive role in degenerative diseases as Asthma, rheumatoid arthritis or inflammatory bowel diseases, can be modified through an interference on the AA-cascade. Nevertheless it has not been determined if the clinical symptoms are reduced. In certain areas it is still necessary to realize large-scale studies to determine the effects of Omega-3 fatty acids.