Nutrition and Cancer

Abstract

A SYMPOSIUM arranged by the New York Academy of Sciences and held in December 1946 on "Nutrition in Relation to Cancer"covered a wide field and included a number of interesting articles which have now been published*. The paper by Dr. E. L. Tatum on chemically induced mutations and their bearing on carcinogenesis deals mainly with mutations induced in Neurospora and Escherichia coli, where the mutations have made the organisms more exacting in their nutritional requirements. Dr. W. J. Bobbins, dealing with the botanical contributions to the cancer problem, suggests that the autonomous growth of plant tumours induced by Phytomonas Pumefaciens is due to their ability to produce indole-acetic acid. In discussing the nutrition of tissue cultures, Dr. P. R. White indicates that if mammalian cells could be grown in controlled synthetic media, then the nutritional techniques used in the study of mutations in Neurospora could be applied to cancer tissue and carcinogenesis. This might give more insight into the relation of carcinogenesis and mutations involving changes in nutritional requirements. The induction of cancer in animals is often greatly affected by diet. Dr. A. Tannenbaum describes how the restriction of the calorific intake of animals reduces the incidence of spontaneous mammary tumours, lung adenomas, hepatomas, sarcomas, and skin tumours, in mice treated with 3: 4-benzpyrene. Restriction of calorific intake, however, has little effect on growth of established cancer. Perhaps the most interesting results of the effect of diet on carcinogenesis are seen in the experiments on hepa-toma induction with azo dyes. Such experiments, carried out at Wisconsin, are described by Dr. J. A. Miller, and results obtained at the Memorial Hospital by Dr. C. J. Kensler. A high content of ribofiavin in the liver reduces the chance of tumour development. Treatment with carcinogenic azo dyes tends to reduce the riboflavin content of the liver; but the carcinogenic action can be neutralized by adding riboflavin to the diet. Dr. J. White, Dr. F. R. White and Dr. G. B. Mider find that the incidence of leukaemia in mice treated with methylcholanthrene is not reduced if the dietary lysine or tryptophane is reduced to levels which prevent growth. On the other hand, reduction of the cystine intake to such a level did reduce the incidence of leukaemia in mice treated with methylcholanthrene.