Preserved foods as possible cancer hazards: WA rats fed salted fish have mutagenic urine

Abstract

Six batches of food traditionally and commonly consumed by southern Chinese, including two samples of dried shrimps and four samples of different species of salted fish, were tested for mutagenic properties using Salmonella typhimurium TA98 and TA1000. Mutagenic activities toward both tester strains were found in all preparations. In most cases, these activities were enhanced by liver microsomal activation. Urine collected from experimental rats regularly fed salted fish also showed mutagenic activity. The level of this activity decreased markedly when the experimental rats were transferred from a salted fish diet to Purina rat chow. Our data suggested the presence of mutagenic/carcinogenic substances in some local preserved foods and at least one of them, salted fish, has been suspected on epidemiological and experimental evidence to be a possible co-carcinogenic factor in the development of nasopharyngeal carcinoma in southern Chinese. Our finding is compatible with this hypothesis.