Roles of Trans and ω Fatty Acids in Health; Special References to Their Differences Between Japanese and American Old Men

Omega and trans-fatty acids play important roles in atherogenesis of vascular system. In this review, we discuss such roles in health; there are much differences in coronary heart disease (CHD) rates between the US and Japan. Fatty acids profiles in the plasma are related to risks of CHD. There have been few studies that compared plasma levels of fatty acids, including trans-fatty acids, in people in Japan and the US. Plasma levels of long-chain omega-3 fatty acids (docosahexae-noic acid [DHA] and eicosapentaenoic acid [EPA]) were higher in Japanese men, and omega-6 fatty acids (e.g., arachidonic acid [AA]) were lower compared with American men. American people had higher plasma levels of the major industrially produced trans-fatty acids (IP-TFAs; elaidic and inoelaidic acids), and levels of the potentially cardioprotective, primarily ruminant-derived trans-fatty acid, palmitoelaidic acid (POA) were higher in Japanese men. Plasma levels of saturated or monounsaturated fatty acids were also higher in American men. Only intakes of preference drinks have significant correlation with plasma levels of palmitoelaidic acid and linoelaidic acid. The higher levels of DHA and EPA, along with the lower levels of the IP-TFAs, are consistent with the markedly lower risk for coronary heart disease in Japan vs. the US.