Epidemiological studies of nutrition and the prevalence of ischemic heart disease risk factors were carried out comparing native Markovskaya populations living in the tundra and coastal areas. There was lower prevalence of IHD risk factors among 30-59 year old males in coastal villages than in a comparable population residing in the tundra. This finding can be partially explained by analysis of the diets of both regions. Although the coastal natives' diet was higher in calories and fats than tundra inhabitants'; it was rich in polyunsaturated fatty acids, the main source of which was sea-animal meat.