New studies show that how people cook meats can have major health implications. For years, scientists have been investigating the conditions under which a family of carcinogens* known as heterocyclic amines (HCA’s) develop in cooked meats. Test tube studies have shown that several HCA’s can bind to DNA in breast cells, forming molecular structures called adducts a first step in cancer development. Whether such adducts appear and provoke cancer in people, however has remained uncertain. Even accounting for other cancer risks, such as a family history of this disease, use of hormone supplements, or a high waist to hip ratio, meat doneness preference remained an independent predisposing factor.

Exploring conditions that foster HCA’s showed that meats must be subjected to high temperatures for relatively long periods. That’s why blackening the exterior of a rare steak with a flash searing leaves meat relatively free of HCA’s, as does precooking it at relatively low temperatures in the microwave and then browning the surface quickly in a broiler.

Fat content can also prove important. When fried under the same conditions, hamburgers that start with five percent fat developed up to five times the concentrations of HCA’s as burgers starting with fifteen percent fat. The reason is that the fat has an insulating effect.

While this new data offer health conscious cooks some food for thought, they also are prompting a genetic probe. Not all people make equal amounts of the enzymes that activate HCA’s.

REFERENCES:

1) Journal of the National Cancer Institute Nov.18
2) Science News 4/23/94 p.264