Cooking meat at high temperatures creates toxins called heterocyclic amines, which have been linked to cancers. Studies show that adding rosemary to meat prior to grilling, frying, broiling or barbecuing reduces heterocyclic amines.
In one study, researchers tested extracts of rosemary on ground beef patties. The higher the concentration of the extract, the greater the reduction in heterocyclic amines -- sometimes by over 90 percent.
According to the New York Times:
“Scientists attribute this to specific antioxidants in rosemary: rosmarinic acid, carnosol and carnosic acid. Another study two years ago compared several marinades and found that the one that was most protective was a Caribbean mixture, which, they wrote, ‘contained considerable amounts’ of the same three antioxidants.”