The effect of dietary n-3 polyunsaturated fatty acids on HDL cholesterol in Chukot residents vs muscovites.

Native Chukot Peninsula residents, in contrast to Muscovites, consume a diet rich in n-3 polyunsaturated fatty acids. This dietary peculiarity is reflected in differences in plasma lipid and apolipoprotein contents. The Chukot residents have lower contents of total cholesterol, triglyceride, LDL (low density lipoprotein) cholesterol and apolipoprotein B, but higher HDL (high density lipoprotein) cholesterol levels than do Muscovites. The apolipoprotein A-I levels were identical in both groups. A higher HDL cholesterol to apolipoprotein A-I ratio was determined in the coastline Chukot residents (0.52 +/- 0.01) than in Muscovites (0.43 +/- 0.01; p less than 0.01). In contrast to Muscovites, the coastline Chukot residents also had higher n-3 and lower n-6 polyunsaturated fatty acid percentages in plasma and erythrocyte lipids, and lower phosphatidylcholine and higher sphingomyelin or phosphatidylethanolamine levels in HDL2b and HDL3. The higher HDL cholesterol levels in the plasma of the coastline Chukot residents appears to reflect the higher cholesterol-scavenging capacity of their HDL. We conclude from this study that the regular consumption of dietary n-3 polyunsaturated fatty acids by the coastline Chukot residents decreased LDL cholesterol transfer from plasma to peripheral cells, and enhanced cholesterol efflux from cellular membranes toward HDL.