Coronary Heart Disease and Cerebral Vascular Disease in the South African Bantu

Abstract

It is widely accepted that the South African Bantu very seldom die from coronary heart disease, but that cerebral vascular disease constitutes an important cause of death. How valid are these beliefs? Since the diseases mentioned primarily affect the middle-aged and elderly, and since the Bantu are a relatively young population in contrast to aging white populations, specific mortalities from 45 to 64 years have been calculated for certain Bantu, and for a few white populations for comparison. Calculations suggest that mortality from coronary heart disease among Johannesburg urban Bantu in the 45–64-year age group, according to death-certificate data (assuming for the moment that such are valid), is, although still much lower than among most white populations, roughly of the same order as that in corresponding French, Italian, and Japanese population groups. Hence, for comparative purposes and when dealing with populations such as the Bantu, the importance of knowing age-specific as well as crude mortality rates for this disease will be obvious. Regarding the accuracy of these rates, whereas the mortality picture among the Johannesburg Bantu hospital population probably is reliable, that among the total urban population is far less certain. Still more uncertain is the position in rural areas, where deaths from this cause are believed to be very infrequent. Apart from the need for more exact knowledge of the mortality picture, it is evident that the large amount of information now available on Bantu unlikely to die from coronary heart disease must now be matched by the far more difficult task of securing antecedents as full as possible on those who do die, to learn whether affected persons were pursuing a traditional, partially, or fully westernized manner of life. Until all the combined information is available the full value of the Bantu for etiologic research will not be realized. Calculations also suggest that for Johannesburg Bantu in the 45–64-year age group, mortality from cerebral catastrophes actually is as high as that in most white populations, and that from cerebral hemorrhage probably is higher. While it is uncertain whether this mortality picture in the Bantu is accurate quantitatively, there is no doubt that cerebral vascular disease among them is a very important cause of death. The reason why these people are so prone to die from this cause is not clear. It is suggested that study of the relevant mortality in Bantu regional groups known to differ significantly in diet, salt intake, and blood pressure may throw some light on the subject.