Nutrition in the prevention of neoplastic disease in the elderly

In this review we have described the effects of certain dietary factors on cancer risk by considering the impact of these dietary factors on two distinct stages of carcinogenesis, initiation and promotion. Both initiators of carcinogenesis (mutagenic carcinogens) and cocarcinogens, which can enhance initiation by modifying the metabolism of initiators, occur in the diet, and ingestion of these agents should be minimized. This can be accomplished by avoiding foods which are diseased, contaminated, overcooked, or fried and foods which contain high levels of nitrates, nitrites, or fat. Dietary fats may also function as tumor promoters, so that a person who reduces his dieraty fat intake may reduce his risk of both the initiating and the promoting events of carcinogenensis. Colon, breast, and prostate cancer account for the majority of cancers occurring in the American population over the age of 75. Colon cancer exemplifies the current model of multistage carcinogenesis since it appears to proceed slowly through the stages of initiation and promotion. Since tumor promotion is a reversible process, the elderly may reduce their cancer risks through dietary modifications. There is evidence that dietary calcium, vitamin C, and fiber can antagonize colon carcinogenesis and that dietary fat can enhance it. There is also evidence that a high-fat diet may also increase the risk of breast and prostate cancer.