If you're like me, right about now you're thinking about the first barbecue of the season. Whether your taste runs to baby back ribs, beer can chicken, or you're keeping it light with shrimp skewers, before you tear open your first bag of charcoal, there's something you should know. That delicious substance formed by grilling animal proteins could be carcinogenic.

The National Institute of Health has placed heterocyclic amines (HCAs), or chemicals produced during the grilling of meat, on its list of "reasonably anticipated to be human carcinogens." Although that list is one step down from the scarier list of "known to be human carcinogens," the risks are worth bearing in mind. The NIH says "MeIQ, MeIQx, and PhIP are heterocyclic amine compounds formed when meats and eggs are cooked or grilled at high temperatures." These compounds are also found in cigarette smoke. They are listed in the report as "reasonably anticipated to be human carcinogens" because oral studies in animals showed they caused cancer in multiple organs including the forestomach, colon, liver, oral cavity, mammary gland, skin, and cecum. Several human studies suggest "there is an increased risk for breast and colorectal cancers related to consumption of broiled or fried foods that may contain these or other similar compounds."