Heterocyclic aromatic amines: An update on the science

Red meat is a high source of proteins, and essential micronutrients and minerals such as B vitamins and iron. The cooking of red meats improves the digestibility of meats, and the Maillard browning reactions produce desirable flavors and aromas in meat dishes and enhances sensory experience of dining. However, the cooking of meats at elevated temperatures also produce a series of more than 20 genotoxic heterocyclic aromatic amines (HAAs). These compounds are commonly formed at the parts-per-billion levels in cooked meats. All HAAs tested thus far are carcinogenic in long-term feeding studies in rodents. Some epidemiological studies have observed an association between frequent consumption of well-done cooked red meats and an elevated risk of colorectal cancer; positive associations also have been reported for the consumption of cooked red meat and cancers of the pancreas and the prostate. In this review article, we highlight the knowledge compiled on the chemistry of formation of HAAs in cooked meats and their metabolism, biological and toxicological effects in bacteria and mammalian cells, experimental laboratory animals, and humans.