SELECTED ARTICLES

                                    DIET AND DISEASE

                                                    BY

                                PROF. STUART J. COWELL,

   Professor of Dietetics, St. Thomas's Hospital Medical School, London.

                [Reprinted from Nature, May 4, 1935, pp, 716-718]

The twenty-five years of His Majesty's reign which are now being celebrated
correspond remarkably closely with the establishment of a new era in the science
of nutrition. At the opening of the twentieth century, attention was being focused
on the quantitative relations of the energy exchanges of the body and on the
metabolism within the body of the proteins, fats and carbohydrates of the food.
The physiologists and chemists working at these problems were making most
valuable contributions to the body of knowledge concerning the processes of nutri-
tion, but such contributions were for the most part not of such a nature as to
afford obvious clues either to the origin of or to the treatment of disease. The
second decade of the twentieth century witnessed the rapid development of the
view that the adequate nutrition of an animal depended on the presence in its food
of hitherto unsuspected elements. The absence of such essential elements from a
diet was proved to result regularly in the appearance of predictable signs of
disease and the fundamentally new idea of deficiency diseases became gradually
established in current medical teaching.

Before mentioning any of the effects which this new conception of nutrition
has had on the problems of the prevention and treatment of disease, it will be useful
to hark back to the 'pre-Georgian' era to review the current teaching of the medical
profession regarding the relation of diet to disease. The fact that faulty diets
are often the direct or indirect cause of disease was of course fully recognised, as
it had been for many centuries. But there was little precise knowledge available
to enable definite diseases to be ascribed to specific dietetic errors. Over-eating
was regarded as predisposing to many gastro-intestinal diseases, gout and raised
blood pressure, and under-eating was considered to render the body more liable to
invasion by harmful bacteria. The idea of lack of balance between the various
classes of foodstuffs, for example, relative excess or deficiency of protein, carbohy-
drate or fat was looked upon as at least an important contributory cause of disease.
In the case of scurvy, it was already taught that the absence from the diet of some
principle which was present in fresh foods but not in stale foods contributed largely
to the production of the disorder. Otherwise the production of disease by faulty
diet was largely related to the presence of toxins, pathogenic bacteria or living para-
sites in food which had become accidentally contaminated.

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