World Resources 
I should also like to draw your attention to the incidence of 
certain forms of carcinoma in groups matched in sex, age and 
size, from the United States on the one hand and Africa on the 
other. This really does come down to something fairly funda- 
mental. The coloured folk of the United States came largely 
from West Africa and are predominantly Bantu, although pos- 
sibly they have some genetic variation from those in South 
Africa. An excellent carcinoma survey was carried out in 
Johannesburg, from which the ratio of liver cancer in Africans 
was found to be about five times as frequent as in American 
negroes, but curiously enough the gastrointestinal tract showed 
less cancer in Africa. I suggest that this is best explained in 
terms of the end results of a certain diet rather than climatic and 
genetic variation. 
Is there any difference in the internal chemistry of the tissues 
of Africans as compared with Europeans? So far as I know 
no difference has been demonstrated at birth. Consider the 
figures for two groups of adult men (African and European) 
matched in age. All had been resident in Johannesburg and 
were examined by the same method at the same laboratory. 
European men had a higher serum albumin and a lower 
globulin than Africans; this was due to chronic disease of the 
liver in the latter group. Africans had far lower blood choles- 
terol and broke up clotted blood more quickly than Europeans; 
this ties up with less coronary heart disease in Africans. Simi- 
larly there were other differences in some of the hormones such 
as 17-ketogenic steroids and oestradiol. Other workers have 
reported changes with respect to magnesium, iron, copper, 
and protein-bound iodine. The suggestion is that diet alters 
the internal chemistry of the body, which is not as constant as 
physiologists have assumed. One pattern of internal chemistry 
predisposes to one set of diseases but protects against another. 
Which is the better dietary regime, the African or the 
European? Perhaps we cannot answer that question while we 
disregard environment. We have come to understand the 
complexity of value for survival of certain aspects of genetic 
inheritance but we have not taken the corresponding step in 
65 
