Fatty acid composition of the plasma lipids in Greenland Eskimos 1 ’ 2

Gas-liquid chromatography analyses have been carried out to investigate the composition of esterified fatty acids in the plasma lipids in 130 Greenland Eskimos, compared with those of 32 Greenland Eskimos living in Denmark and of 31 Caucasian Danes in Denmark. While the Eskimos living in Denmark did not differ substantially from other persons living in Denmark and, from what is found in other studies in Western communities, the Greenland Eskimos showed a completely different pattern. They demonstrated a much higher proportion of palmitic, palmitoleic, and timnodonic acids, while they had a markedly lower concentration of linoleic acid. The total concentration of polyunsaturated fatty acids was lower in Greenland Eskimos than in the other groups. These findings are discussed in the light of the get erally accepted opinion of the beneficial effect on plasma lipid levels and on the morbidity of coronary atherosclerosis of a high dietary intake of polyunsaturated fatty acids. As plasma lipid and lipoprotein levels in Greeland Eskimos in a previous study were found markedly lower than those found in Western populations, and as coronary atherosclerosis seems to occur far less commonly among Eskimos in Greenland than among peoples in industrialized countries, it was found difficult to combine these observations with the results from the present study. If dietary differences are the main reason for the differences in plasma lipid concentrations, the results from the present study point more toward qualitative than toward quantitative differences in respect of fatty acid composition of the food. Am. J. C/in. Nutr. 28: 958-966, 1975. An intimate relationship between the occurrence of coronary atherosclerosis and the plasma lipid level has been demonstrated for cholesterol as well as for triglycerides. This relationship is especially obvious in certain ethnic groups where there is a combination of a low incidence of coronary atherosclerosis and a low concentration of plasma lipids (1-3). The Greenland Eskimos are no exception from this rule. Coronary atherosclerosis is almost unknown among these people when living in their original cultural environment. In an investigation of their plasma lipids we were able to demonstrate significantly lower plasma concentrations of cholesterol, triglycerides, fi-lipoproteins, and pre-fi-lipoproteins, as compared to a Danish reference population (4, 5). This difference could not be demonstrated if Eskimos living in Denmark were compared to other Danish citizens living in Denmark. The results from these studies are briefly summarized in Table 1. Much interest has been focused on the influence of dietary habits, especially the intake of saturated and unsaturated fats, on the plasma lipids, and secondarily on the morbidity of ischemic heart disease. A high intake of saturated fat relative to a low proportion of polyunsaturated fat has been claimed as one of the main reasons for the growing incidence of coronary atherosclerosis in industrialized communities. Even if the pattern of esterified fatty acids is characteristic for each plasma lipid class, this pattern can be modified by prolonged alterations in the composition of the fatty acids of the diet (6). In this way the fatty acid pattern in the plasma lipids to some degree reflects the dietary intake of these components. The differences in dietary habits between ‘From Dept. of Clinical Chemistry, Aalborg Hospital North, 90#{174}Aalborg, Denmark. 2 The study was supported by grants from the Danish Association for the Prevention of Heart Diseases. “Aalborg Municipality’s Medical Research Fund,” “The Medical Research Fund for the County of North Jutland,” and private sources. ‘Chief chemist. Chief chemist. ‘Pharmacist. by gest on F ebuary 4, 2014 ajcn.trition. org D ow nladed fom