Food and cancer.

There are good reasons to suspect that the quantity and quality of food influence both the overall risk of development of many forms of cancer and the types of cancer which occur most commonly. The evidence is briefly reviewed and the kinds of mechanisms that may be responsible listed. The striking effects of dietary restriction on cancer risk in laboratory rats and mice and the possibility that dietary restraint may be beneficial in man are discussed. Recent laboratory evidence that carcinogens may be formed in food during cooking is mentioned. Finally, the importance of avoiding mineral imbalance when conducting animal studies designed to evaluate the safety of food constituents and additives is stressed in relation to urinary-calculus formation and bladder-tumour risk.