Life-style and cancer: from epidemiological evidence to public behavior change to mortality reduction of target cancers.

Cigarette smoking, alcohol consumption, and diet are of essential importance in modulating risks of cancer of selected sites, as demonstrated by various epidemiological methods. Examples include demographic studies on changing cancer risk, correlation studies on dietary fat and cancers of breast and colon, and case-control studies on highly salted food and gastric cancer. Evidence was also obtained by cohort studies including a census-population-based large-scale prospective study in Japan. Results included elevated risk from cigarette smoking for cancers of most sites; from alcohol consumption for cancers of the upper and lower digestive tract, liver, and prostate; and from daily meat consumption for cancers of the pancreas, colon, lung, and breast. Daily consumption of green-yellow vegetables reduced risk for cancer of the stomach, colon, lung, cervix, and prostate. Reports of these results and intensive public education and public guidance by governmental and nongovernmental organizations such as cancer societies, consumer groups, and mass media resulted in a notable change in public behavior in most cases in Japan.