The risk is from natural carcinogens in the diet, because they overwhelm all the others," said Dr. Robert J. Scheuplein, director of the Office of Toxicological Sciences at the U.S. Food and Drug Administration.
Scheuplein said the clearest cancer-causing agent in ordinary food is fat, which has been linked with several kinds of tumors. However, he said most foods now eaten would not pass safety tests required for new food chemicals and additives.
Many spices contain questionable substances. There is estragole in tarragon, eugenal in cloves, cinnamaldehyde in cinnamon, myristicin in nutmeg and anethole in fennel. Several spices, including oregano, marjoram and bay leaves, may cause genetic damage.