FOOD-DERIVED MUTAGENS AND CARCINOGENS

Cooked food contains a variety of mutagenic heterocyclic amines. All t he mutagenic heterocyclic amines tested were carcinogenic in rodents w hen given in the diet at 0.01-0.08%. Most of them induced cancer in th e liver and in other organs. It is noteworthy that the most abundant h eterocyclic amine in cooked food, 2-amino-1-methyl-6-phenylimidazo[4,5 -b]pyridine, produced colon and mammary carcinomas in rats and lymphom as in mice but no hepatomas in either. 2-Amino-3-methylimidazo[4,5-g]q uinoline induced liver cancer in monkeys. Formation of adducts with gu anine by heterocyclic amines is presumably involved in their carcinoge nesis. Quantification of heterocyclic amines in cooked foods and in hu man urine indicated that humans are continuously exposed to low levels of them in the diet. These low levels of heterocyclic amines are prob ably insufficient to produce human cancers by themselves. However, a l inear relationship between DNA adduct levels and a wide range of doses of a heterocyclic amine was demonstrated in animals. It suggests that even very low doses of heterocyclic amines form DNA adducts and may b e implicated in the development of human cancer under conditions in wh ich many other mutagens-carcinogens. tumor promoters, and factors stim ulating cancer progression exist.