[Dietary mutagenicity and stomach cancer epidemiology].

On the comparison of stomach cancer mortality between Akita and Iwate prefectures which locate neighboring in northern Japanese mainland shows marked difference, the former very high and the latter very low. Dietary mutagenicity of inhabitants in the two areas were assayed by Rec-assay using B. subtilis and by Ames test using Salmonella TA 100 and TA 98.

[The effect of mutagen-depressive substances in vegetables on benzo(a)pyrene metabolism].

Dietary mutagenicity which was observed as the regional differences corresponded to those of the stomach cancer mortalities seemed to be epidemiologically determined by the food components of the diet, especially those of fresh vegetables. Experimental studies were made on the mutagen-depressive effects of vegetables based upon the preceding observation. The mutagen-depressive substance suggested to be a kind of unsaturated hydrocarbon by two successive treatments using column chromatographic methods.