Dietary habits and cancer epidemiology.

Data indicate that most cancers appear to be related to environmental factors and that diet is one of these factors which appears to play a vital role. Epidemiologic evidence has increasingly implicated nutritional factors in the etiology of several forms of cancer in man. The effect of specific nutritional deficiencies, as well as unbalanced metabolism from dietary excesses, is discussed in relation to colon and breast cancer development. The possibility that excessive alcohol consumption among smokers, with its associated nutritional deficiencies, could act as a tumor promoter is discussed. It is timely to integrate the work of related specialties in cancer research, for cancer can no longer be viewed as a single disease with a single etiology.