Influence of dietary n-3 polyunsaturated fatty acids on plasma lipemic effect of vitamin B6 deficiency

Since many connections exist between vitamin B-6 and lipid metabolism, we aim to investigate the lipemic effect of different dietary intakes of polyunsaturated fatty acids in rats fed a vitamin B-6 deficient diet. Diets were either vitamin B-6 deficient (-B-6) or vitamin B-6 sufficient, pair-fed to the deficient group (PF) and ad libitum (N). The diets were combined with normal lipid (LC: soya bean-coconut-palm oils) and fish oil (FO: soya bean - fish oil). The fish oil diet with sufficient vitamin B-6 content caused an increase in n-3 long chain polyunsaturated fatty acids and a decrease in arachidonic acid. In the -B-6 group fed a normal lipid diet, the arachidonic acid percentage decreased and the linoleic acid percentage increased; in the -B-6 group fed fish oil these changes in fatty acid composition, already consequent upon dietary intake of n-3 long chain polyunsaturated fatty acids, did not show further variations. In the dietary condition of vitamin B-6 deficiency, plasma cholesterol content increased in rats fed a lipid control diet, whereas no hypocholesterolemic effect was observed in those fed a fish oil diet. Plasma triglyceride contents were not influenced by dietary lipid quality because, in all conditions, the lower food intake of the PF groups caused a decrease and vitamin B-6 deficiency caused an elevation in triglyceride contents which reached those of the ad libitum groups, The Study highlights the interaction between vitamin B-6 and polyunsaturated fatty acids and the opportunity of dietary intake of fish oil to counterbalance some effects of vitamin B-6 deficiency.