Mutagenic activity of nitrite-treated foods: human stomach cancer may be related to dietary factors.

By the Salmonella typhimurium test, extracts of Japanese raw fish treated in the laboratory with nitrite showed mutagenic activity which is prevented by addition of ascorbate. Extracts from similarly treated beef and hot dogs were nonmutagenic. The data conform to a working concept that the high stomach cancer incidence in Japanese and certain other populations may be due to specific dietary factors of an alkylnitrosamide type.