World Cancer Research Fund/American Institute of Cancer Research 1997 recommendations: applicability to digestive tract cancer in Japan

Objectives: This paper reviewed analytic epidemiological studies of the maj or Japanese digestive tract cancers, i.e. esophageal, stomach, colon and re ctal. The applicability of the recommendations for prevention of these canc ers by the World Cancer Research Fund/American Institute of Cancer Research (W&A) to Japan is considered. Methods: Papers were searched by the MEDLINE for the period 1966 through 19 97. Among them, 43 relevant papers including data from Japan were reviewed. Results: Results for 11 lifestyle-related factors were considered. Cigarett e smoking was a strong and consistent, thus, convincing, risk factor for es ophageal cancer, and a possible risk factor for stomach and colorectal canc er. Excessive consumption of alcohol was a convincing risk factor for esoph ageal cancer, and a possible risk factor for stomach and colorectal cancer. Excessive salt intake was a risk factor supported by some strong evidence but inconsistent; therefore, it is a probable risk factor for stomach cance r and a possible risk factor for colorectal cancer. Low physical activity w as a probable risk factor for colorectal cancer. On the other hand, suffici ent intake of vegetables, including green-yellow vegetables, and fruits was regarded as a possible protective factor for these cancers. Conclusions: These observations were mostly consistent with those reported by W&A; therefore the recommendations by W&A for prevention of these cancer s may be considered applicable to the current Japanese population.