Effect of Plant- and Fish-Oil Derived n-3 Polyunsaturated Fatty Acids on Counteraction of n-3 Fatty Acid Shortage in Adult Rats Fed a Lard Diet

Abstract

These studies aimed to compare the effects of alpha-linolenic acid (ALA)+eicosapentaenoic acid (EPA)+docosahexaenoic acid (DHA) on plasma-lipid concentrations and preferential fat intake of rats fed a lard diet (LD). Each of 2 groups of 4-wk-old male rats was used in studies 1 and 2. In studies 1 and 2, two groups of rats received the LD (LD group) and the fish-oil diet (FD; FD group), and the LD and the perilla-oil diet (PD; PD group), respectively (dietary treatment period). After 6 wk, 6 rats per group were sacrificed. The remaining rats in studies 1 and 2 were placed on a self-selection regimen of the LD and the FD, and the LD and the PD, respectively, for 3 wk (self-selection period). After the dietary treatment period, plasma lipid concentrations in the FD group were lower than those in the LD group. However, no significant difference in the concentrations was observed between the LD group and the PD group. At the beginning of the self-selection period, the ratio of the FD intake of the LD group was higher than that of the FD group. As the the ratio of the LD group decreased and that of the FD group increased no significant difference in the ratio was observed after the 9th day during the self-selection period. No significant difference in the ratio of the PD intake was observed between the LD group and the PD group during the self-selection period. Thus, although the FD decreased plasma lipid concentration and increased the preferential FD intake of the LD group at the beginning of the self-selection period, the PD did not. Our studies clearly show that dietary EPA+DHA and ALA have different physiologic effects.