Heat‐processed Carcinogens: What Can We Learn from the “Coffee ‐ Cancer Paradox”?

Abstract

Trace level animal carcinogens in heated foods, including acrylamide, furan, various aldehydes and 4‐methylimidazole, result from the Maillard Browning Reaction, and California's Proposition 65 law has targeted these carcinogens in coffee. While we must evaluate the toxicological risks of these individual carcinogens, it is equally important to fully evaluate the safety of whole foods containing them using modern clinical, toxicological, nutritional and epidemiological techniques. Currently there is little human epidemiologic evidence linking these trace level carcinogens with the risk of disease, including cancer. The health benefits of a food such as coffee, including numerous health‐protective compounds found naturally and those produced by heat, are often neglected by public health and regulatory authorities. In fact, coffee consumption has been shown to reduce the risk of several human cancers, in spite of the fact that coffee contains many animal carcinogens, a situation I call the Coffee ‐ Cancer Paradox. Therefore, it is critical to evaluate the beneficial health effects of heated foods/beverages and to undertake a thorough risk‐benefit evaluation of the whole food. For carcinogens, this evaluation must carefully consider how best to interpret animal cancer bioassays for individual chemicals, as well as epidemiological information that the whole food itself may actually be cancer protective.