J. F. BROCK 
HEALTH 
Against a necessary background of health as an all-embracing 
“‘wholeness”’ which is relevant to every section of this symposium 
it is my task to concentrate particularly on “‘physical or bodily 
health’. This can be either promoted by favourable environ- 
ment or impaired by unfavourable environment (Fig. 1). 
For each individual there is a fixed genotype which is the raw 
material upon which environment operates and which deter- 
mines in considerable part the pattern of both health and 
disease. ‘This genotype is determined by the pattern of chromo- 
some and gene inheritance from father and mother. 
The state of health or disease on any one day is favourably 
or unfavourably determined in part by recent environment, 
such as a good holiday or exposure to infection. It is determined, 
however, also by the long-term product of environment and 
genotype. Thus, the reaction of the body to recent exposure 
to the tubercle bacillus may be determined, in part, by the 
favourable effect of rest, good food, physical exercise and 
recreation during a recent holiday. But it will be determined 
also by the long-term product of genotype and healthy or 
unhealthy upbringing, including the mixture of immunity and 
sensitivity induced by previous exposure to the tubercle 
bacillus. This long-term product I prefer to call, in the case 
of physical health and disease, “‘physical constitution”’. 
I am well aware that another use of the term “‘constitution”’ 
has been advocated by Bauer! in the sense of “the sum total of 
an individual’s characteristics as they are potentially deter- 
mined at the moment of fertilization’’, but I reject this usage. 
That, to me, is the genotype. The physical constitution as 
preferably defined? is of great importance in determining man’s 
Fig. 1. Diagram illustrating relationships between genotype and environment, 
both favourable and unfavourable, in determining the development of constitution 
and life expectation, and of experience of health and disease. The long-term 
progressive development of a healthy and of an unhealthy constitution are shown 
in the vertical straight lines; the short-term experiences of health and disease 
are shown in the sinuous deflections about the straight lines. 
(From Brock, J. F. (1961), Recent Advances in Human Nutrition. London: 
Churchill.) 
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