Overcooked meat is twice likely to cause cancer than previously thought, scientists warn.
The warning comes after they found that the dark crust formed on the outside of a well-done steak or joint of red meat more than doubles the risk of intestinal tumors.
Frying and grilling are particularly risky because the intense heat turns the sugars and amino acids of muscle tissue into high levels of cancer-causing compounds.
Cancer-causing substances, so-called food mutagens, occur at high temperatures when frying or grilling.
It has long been known that cooking meat until it is very well done or even charred creates chemicals that are not present in uncooked meat. These compounds, called HCAs, are carcinogenic. Other cancer-causing substances, so-called food mutagens, occur at high temperatures when frying or grilling.
Previous research has used mice to assess the effects of the burnt meat on humans.
But now scientists at the Norwegian Institute of Public Health have inserted human enzymes into the mice to get a better idea of how it affects us.
They found that after the "human-like" mice ate the overcooked meat crust, their risk of developing a cancerous tumor soared.
"We 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 Daily Express quoted the researchers as saying.
"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," he added.