Fat Intake, Serum Cholesterol Concentration, and Atherosclerosis in the South African Bantu. Part I. Low Fat Intake and the Age Trend of Serum Cholesterol Concentration in the South African Bantu1

During the past few decades, interest in the ef- fects of overnutrition and undernutrition on blood cholesterol values, and their bearing on the pathogenesis of atherosclerosis, has led to the carrying out of numerous experimental studies on both ani- mals and man (1, 2).Several studies have shown that diets characterized by reduced fat intake, are associated with, or give rise to reductions in serum cholesterol levels (3,4).Dealing specifically with changes in fat intake, Keys, Mickelsen, Miller, and Chapman (5), using iso-caloric diets, found that when fat intake is substantially altered, well- marked changes appear in serum cholesterol con- centration, which, moreover, are independent of cholesterol intake.Confirmation of the correlation between fat in- take and cholesterol values is afforded by two types of evidence.Firstly, populations subjected to dietary restrictions, which invariably include reduced fat intake, have been shown to have lower cholesterol levels than when the relevant conditions returned to normal.Thus, in the last war, very low cholesterol values were observed among the inmates of various European concentration camps (6-8).Conversely, a significant rise in mean blood cholesterol level occurred in groups of Ger- man subjects from 1947 to 1949, this change being attributed to dietary improvements, including in- creased fat intake (9).The second type of evidence is provided by pop- ulations habituated to a high fat intake, e.g., the inhabitants of the United States (10) and Den- mark (11), who have higher mean serum choles- terol values than peoples accustomed to a lower fat intake, e.g., population groups in Italy (12), Spain (13), China (14), India (15), Belgian Congo