Omega 3 fatty acids: biological activity and effects on human health.

Polyunsaturated fatty acids (PUFAs) have an important role in human diet, both for the prevention and the therapy of different pathologies. In this review, a critical evaluation of PUFAs dietary sources and biological functions in human organism has been done. In particular, the efficacy of ω-3 fatty acids in the improvement of the lipidic pattern and in the excitability of myocardium has been analyzed, and therefore their usefulness in the prevention of cardiovascular diseases and post-infarction arrhythmias. As PUFAs are precursors of prostaglandins and leucotriens, which are involved in phlogosis and immune response, a diet rich in fish oil reduces the production of PGE2 involved in many phlogosis events. Moreover, an increase in the eicosapentaenoic acid (EPA) intake leads to a reduction in the production of inflammatory cytokines (interleukin 1, 2, 6 and Tumor Necrosis Factor); so, it is important to use ω-3 in cronic inflammatory diseases, as the rheumathoid arthritis. It seems that ω-3 could prevent the onset of hormon-dependent tumours (i.e. breast and prostatic cancer); in vitro observations, in fact, have shown that the PG of the series 2, derived from ω-6, have a carcinogenic action; instead, the anticancer effect of ω-3 could derive from their effect in antagonizing the formation of such PG; it can be useful, therefore, to increase the dietary ω-3/ ω-6 ratio. Moreover, the effects of ω-3 on the anatomic and functional central nervous system development and of their possible therapeutical use in some psychiatric pathologies were evaluated.