Dear Doctor: Our family loves the summer barbecue season, but the “take the fun out of everything” lobby keeps saying this can increase our risk of cancer. Just how unhealthy is grilled meat? Can we do anything to make it safer?
Dear Reader: The potential health threat of grilled meat is one of those cyclic news stories that pops up each spring as reliably as the first crocuses. The issue has its roots in decades of science, but the subsequent writing about the potential risks has ranged from measured and helpful to off-the-charts alarmist. To sort through the noise, let’s start with some basics.
When we cook meat over high heat, or to high temperatures, a number of chemical compounds, a few of them potentially dangerous, are formed. The grilling of beef, poultry, pork, fish and other muscle meats creates heterocyclic amines, or HCAs. These are formed not only in grilling, but during other high-heat cooking, such as broiling, pan frying and deep frying. When meat juices ignite on the hot coals beneath the grill, or when they come into contact with any surface hot enough to evaporate liquid and create smoke, that smoke contains chemical compounds called polycyclic aromatic hydrocarbons, or PAHs. When the smoke comes into contact with the meat -- and whatever else is on the grill -- it leaves behind potentially dangerous compounds. Lab experiments have shown that HCAs and PAHs have the potential to cause changes to DNA, which means that they may increase the risk of cancer.
So far this all sounds pretty grim, so it’s helpful to put things into context. In lab experiments, most of them conducted in test tubes and in animals, researchers use doses of HCAs and PAHs that are extremely high, the equivalent of thousands of times the exposure of a person eating a typical diet. By comparison, the levels of HCAs and PAHs generated by home cooking and grilling methods are quite low. However, ongoing population studies continue to find a link between grilling and a slight increase in cancer risk. The takeaway here, as with so many pleasures in life, is moderation.
When it comes to grilling, a few simple steps can make your meal safer. First, grill meat separately from other foods to limit exposure to PAHs, the compounds contained in rising meat smoke. Vegetables, fruit, bread and pizzas, all popular grilling options, should be cooked at a different time from the meat, or at the very least on their own side of the grill. When it comes to meat, it’s wise to avoid high cooking temperatures and prolonged cooking times. Turning meat frequently while it’s on the grill helps keep charred areas from forming. Be sure to remove any charred portions before serving and eating.
A final note -- studies have shown that acidic marinades that contain no sugar (but spices are fine) can significantly reduce the formation of PAHs. A marinade of lemon juice reduced the generation of PAHs by 70%, while lemon juice mixed with oil reduced PAHs by 57%. We hope this helps, and that you have an enjoyable and healthful grilling season.
(Send your questions to firstname.lastname@example.org, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10880 Wilshire Blvd., Suite 1450, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)