Some Aspects of Ageing in Africans 113 



are not reversible by any of the therapeutic measures hitherto 

 tried by us over many months and even years. This indicates 

 the persistence of profound metabolic disturbances after re- 

 solution of the acute breakdown — whatever form the latter 

 may take. 



One of the hypotheses underlying our work in Durban is 

 that the frequency of primary liver cancer in the African may 

 perhaps be due, in large measure, to the virtually continuous 

 repair of the chronic hepatic lesions which are almost invari- 

 ably present in these people. Hence our basic interest in 

 wound healing and its relations to neoplasia, experimentally 

 and in man. 



In the light of our findings, both in Johannesburg and in 

 Durban, it seems justifiable to question the opinions today 

 being expressed about the incidence and aetiology of various 

 diseases, especially in Africa. On the basis of ethnological 

 comparisons of the incidence of various types of diseases and 

 their associated biochemical changes, conclusions are often 

 drawn about aetiology or pathogenesis. In particular, I find it 

 difficult to accept the interpretations given to the correlation 

 between alterations in blood lipids and the incidence of coronary 

 disease in Africans, Coloureds and Europeans in the Union — 

 especially when attention is not simultaneously paid to the 

 associated underlying pathological processes common among 

 these peoples. We have shown that the incidence of hepatic 

 cirrhosis in Europeans in South Africa is in the neighbourhood 

 of 3-4 per cent of autopsy cases ; in this racial group coronary 

 disease is quite frequent, and may or may not be correlated 

 with a high intake of fat or associated alterations in the blood 

 lipids. In another racial group — the Africans — the incidence 

 of coronary disease seems to be low and this has been attri- 

 buted to the low fat intake and an associated low blood lipid. 

 However, hepatic cirrhosis, as I have shown, is extremely 

 common in the African. To attempt, in such circumstances, 

 to correlate directly, either the intake of fat or the blood 

 lipid level with the incidence of coronary disease in these two 

 races may be misleading if attention is not simultaneously 



