Risk factors and the absence of coronary heart disease

Coronary heart disease has never been found in Malaysian aborigines. We report the position regarding some of the risk factors usually associated with coronary heart disease in 73 adult aborigine men. They lived a physically active life on a diet largely of unrefined carbohydrate in the jungles of central West Malaysia. None was obese and blood pressures remained low at all ages. While the mean serum cholesterols were low, varying between I4I and I56 mg/Ioo ml at different ages, the mean fasting serum triglyceride levels of I35 to I64 mg/Ioo ml were comparable with thosefound in the West. This may have been due to their high carbohydrate intake. The mean packed cell volume, serum albumin, and erythrocyte transketolase activity were normal, indicating that they were likely to have been adequately nourished. Isolated aborigines living deep in the jungle had significantly lower serum lipids and higher gamma-globulin levels than those living at the fringe in contact with the rest of Malaysian society. Some communities in the world have a very low incidence of coronary heart disease. As people from such communities change their way of life and adopt Western habits coronary heart disease may appear, though it it not known why. A good example of this is that of the African negroes who suffer very,j little from coronary heart disease in their homeland but have acquired in the U.S.A. a frequency similar to that of the white Ameri-can. This may be related to such risk factors as hypertension, diabetes mellitus, and raised serum cholesterol, all of which have been re-ported to increase in populations moving from a rural to an urban society such as the Easter Islanders moving to South America (Cruz