Health risk from eating well-done meat may be underestimated. Mice are not men. Mice are often used to test whether substances in food are harmful to humans. This requires that mice and humans metabolize substances in the same way. But they don’t.
Humans have certain enzymes in more parts of the body than mice. The health risk associated with harmful substances in food may therefore be underestimated, explains a November 1, 2011 news release, “Health risk from eating well-done meat may be underestimated.” The studies have focused on any links between intestinal cancers and charred meats or ‘meat’ crusts formed by heat.
Researchers at the Norwegian Institute of Public Health have adopted a mouse type where human enzymes have been inserted to examine whether people may be more sensitive to certain carcinogenic substances from heat-treated foods. They have obtained a better model to assess negative health effects in humans from substances in food using these mice.
The results show that the incidence of intestinal tumors increased from 31 per cent to 80 per cent in “human-like” mice who consumed substances from meat crust, which usually is the surface formed during heat-treatment. But meat crust can form anywhere on the meat where it’s heated to a high enough temperature. One problem is if the meat is undercooked, the bacteria on it survives. But if the meat is heated so that a meat crust forms such as charred meat, the carcinogens form.
The problem lies in a wide variety of heat-processing of foods. Is dehydration of any food that can’t be eaten raw, dehydration at low heat healthier than high heat processing if the bacteria is destroyed in the cooking process when foods can’t be eaten raw because of bacteria, viruses, or their not digestible or toxic when raw? You need to be aware of food mutagens that form from cooking — or in the case of plant foods, are already in the food to protect it from predators. The main problem is the eating of meat crust.
With bread crust, the issue is what happens when the crust absorbs the toxins from the pan it’s baked in, such as aluminum or other chemically-treated surfaces of pans, certain types of nonstick pans, or other issues forming from high heat exposure. Another problem is the heat processing that causes food to mutate creating carcinogenic substances called food mutagens.
Heat-processing of food can lead to the formation of carcinogenic substances. The formation of carcinogenic substances – so-called food mutagens – usually occurs at high temperatures when frying or grilling.
There are enzymes called sulfotransferases (SULT) in several places in the human body. These are only found in the livers of normal laboratory mice. SULT-enzymes can make some substances in food less harmful, but they can also transform harmless substances into carcinogenic substances.
Humans have SULT-enzymes in many organs while normal mice only have them in the liver. Using results from laboratory mice to predict health risk to humans consuming food mutagens can therefore be underestimated. Researchers at the NIPH used laboratory mice with the same amount of SULT-enzymes in the intestines as humans in their experiments.
The mice received the food mutagen often found in highest quantities in the crust of meat and fish. The researchers wanted to study tumor development in the intestines of the “human-like” mice, and compare this with tumor development in normal mice given the same food mutagen.
The results showed that the incidence of intestinal tumors increased from 31 per cent to 80 per cent in “human-like” mice after consuming substances from the meat crust
This shows that normal laboratory mice are not a good model for assessing the health risk to humans following ingestion of food mutagens from well-done meat and fish. The Norwegian Research Council funded the study.
You can check out the original article or its abstract, “Intestinal carcinogenesis of two food processing contaminants, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine and 5-hydroxymethylfurfural, in transgenic FVB min mice expressing human sulfotransferases.” Authors are Svendsen C, Meinl W, Glatt H, Alexander J, Knutsen HK, Hjertholm H, Rasmussen, and T, Husøy. Mol Carcinog. December 2012. Epublished, Oct 17, 2011.