A. Joel B. Mason, MD, Tufts professor of medicine and nutrition, answers, Although the existing evidence falls short of being proof positive, scientific studies continue to be published on a regular basis that suggest that regular consumption of red meats (usually defined as beef, pork, lamb and goat) that are prepared well-done, using very high temperature methods (such as grilling, barbecuing and pan-frying) is associated with increases in the risk of developing several common cancers, such as those of the colorectum, pancreas, post-menopausal breast and aggressive forms of prostate cancer. The increase in risk that has been observed is generally around 15-40% with weekly servings of red meats prepared in this manner. The chemical agents that are usually implicated are heterocyclic amines and polycyclic hydrocarbons, both of which are produced when meat is charred, and both of which are known to be mutagens. Interestingly, there is typically NO increase in risk associated with consumption of charred poultry meat.
On the other hand, there is little evidence to my knowledge that an occasional meal with these offending meats is going to produce any substantial degree of risk. There are too many other things in life that warrant far greater justification for worry than consuming a few barbecue meals over the summer, so if you savor these foods, an occasional meal with them is fine from my perspective. The operative words here are modest and occasional intake.