Dietary and nutritional influences on cancer: A review of epidemiologic and experimental data

Abstract

The recent epidemiologic data relating high dietary fat and breast or colon carcinoma are less consistent with a direct association than the data reviewed in the National Academy of Sciences-National Research Council report. The recent experimental data are consistent with an effect of certain fats on mammary and pancreatic tumorigenesis but are inconsistent in studies of colon tumor models. In both epidemiologic and experimental studies, consideration of the effect of total caloric intake has reduced somewhat the magnitude of the apparent specific effect of fat. The recent experimental data directly relating caloric intake and mammary and colon carcinogenesis are consistent. The epidemiologic data on caloric intake are inconsistent but may become clearer as the independent effects of determinants of caloric intake on cancer risk are considered. Epidemiologic data on the association of breast cancer risk with alcohol intake support the addition of breast to the cancer sites previously related to alcohol consumption. Conclusions about the relations between other nutrients or foods and cancer risk discussed are not substantially changed from the 1982 publication. The effects of nutrients and diet on cancer risk in people or laboratory animals are generally subtle. However, because of the great morbidity and mortality due to cancer, even small changes in incidence or latency due to dietary changes may be highly significant. Large international variations in cancer rates suggest that the effects of diet on cancer in humans may be more marked than in the data reviewed. Additional studies are warranted to: (a) refine current dietary guidelines; (b) support efforts in chemoprevention using foods, and related nutrient compounds; (c) identify other components of foods that may be anticarcinogenic; (d) examine interactions between nutrients that may influence carcinogenesis.