A population-based dietary inventory of cooked meat and assessment of the daily intake of food mutagens

Frequent consumption of meat has been associated with an increased risk of colorectal cancer. Such a risk may be due to naturally occurring compounds in the meat, substances added to the meat, or agents formed during cooking. Concerning the latter alternative, mutagenic heterocyclic amines are multi-site animal carcinogens, but their relevance to human cancer has yet to be determined. In the present study, we made a population-based inventory of cooked meat dishes consumed in the county of Stockholm, ranked dishes according to cooking method and frequency of consumption and, in addition, determined levels of mutagenic activity in six commonly consumed fried meat dishes. Meat was consumed, on average, 493 times per year, giving 1.4 daily servings. Frying was the most common way to cook meat. When ranking meat dishes according to in take frequency, the top eight dishes were as follows: sausage, steak casserole, meatballs, pork chops, pork belly, bacon, ground beef patties, and, finally, mince meat sauce. The frying sessions were performed under controlled conditions at four different temperatures, and we documented the degree of surface browning and measured mutagenic activity in six frequently eaten dishes (sausage, meatballs, pork chops, pork belly, ground beef patties, and minute beef). We found extracts from all six dishes to be mutagenic, and a mean daily dose of exposure was calculated, giving 862 revertants. This investigation leaves no doubt that a major portion of the total meat consumption is fried before ingestion and that fried meat dishes frequently consumed by elderly population in Stockholm contain mutagenic substances. Furthermore, the study provides usable information for the future epidemiological research in which it is necessary to disentangle the effect of meat per se from the effect of potentially carcinogenic heterocyclic amines.