Mutagens and Carcinogens in Cooked Foods: Concentration, Potency and Risk

Abstract

The cooking of foods derived from muscle generates heterocyclic amines that are very potent bacterial mutagens and carcinogens in mice, rats, and monkeys. Presently 12 mutagenic compounds have been found in cooked foods derived from the Western Diet. Only 6 of these compounds have been definitely identified. Specifically designed monoclonal antibodies can detect nanogram amounts each of 2-amino-1-methyu1-6-phenylimidazo[4,5-f]pyridine(PhIP), 2-amino-3-methylimidazo[4,5f] quinoline(IQ), and 2-amino-3,4-dimethylimidazo[4,5-f]quinoline (MeIQx) in the meat matrix, but specific quantitation requires a prior HPLC separation before use of antibodies for identification. Modeling of PhIP (20 ppb in beef) formation under dry heating conditions using heavy isotope incorporation coupled with MS and NMR shows that all the C and N atoms in the PhIP are contributed by creatin(ine) and phenylalanine. PhIP is both a potent frameshift mutagen in Salmonella bacteria and a potent inducer of mutations, sister chromatid exchange and chromosomal aberrations in Chinese Hamster Cells in culture, and of chromosome damage in mouse bone marrow. Using accelerator mass spectroscopy, we can measure in a linear fashion one MeIQz DNA adduct per 10¹¹nucleotides. N-OH-PhIP which is generated by both IA1 and IA2 forms of cytochrome P-450 appears to be a proximal mutagen.