Don’t we all love BBQs? The smoked flavor is just such a come-on!
Beware, though, as there are two (2) chemicals formed when muscle meat, including beef, pork, fish, or poultry is cooked using high temperature methods, such as pan-frying or grilling directly over coals or an open flame.
In laboratory experiments, heterocyclic amines (HCAs) and polycyclic aromatic carbons (PAHs) have been found to cause changes in DNA that may increase the risk of cancer.
HCAs, though not found in significant amounts in foods other than meat, are formed when the amino acids (the building blocks of proteins), sugars, and creatine or creatinine (substances found in muscle) react to high temperatures.
PAHs, however, are formed:
- as fat and juices from meat grilled directly over a heated surface, or open fire, drip onto the surface or fire, causing flame and smoke that then adhere to the surface of the meat;
- when roasting over coals and smoking of meats;
- when tobacco is burned – as in cigarette smoke;
- in car exhaust fumes – from gas; and
- also when wood and garbage are burned as the PAH generated from these sources can bind to, or form small particles in the air, and stay in the environment for long periods of time.
The formation of HCAs and PAHs varies by:
- meat type;
- cooking method; and
- “doneness” level (rare, medium, or well done).
Whatever the type of meat, all have high concentrations of HCAs:
- when cooked at high temperatures, especially above 300 ºF (as in grilling or pan frying);
- when cooked for a long time as they tend to form more HCAs – like well-done, grilled, or barbecued chicken and steak; and
- when exposed to smoke as it contributes to PAH formation.
Even though no specific guidelines for HCA/PAH consumption exist, concerned individuals can reduce their exposure by:
- avoiding direct exposure of meat to an open flame or a hot metal surface, and avoiding prolonged cooking times (especially at high temperatures) to help reduce HCA and PAH formation;
- continuously turning meat over on a high heat source to substantially reduce HCA formation instead of just leaving the meat on the heat source without flipping it often;
- removing charred portions of meat; and
- refraining from using gravy made from meat drippings to reduce HCA and PAH exposure (29).
HCAs and PAHs become capable of damaging DNA only after they are metabolized by specific enzymes in the body, a process called “bioactivation.” Studies have found that the activity of these enzymes, which can differ among people, may be relevant to the cancer risks associated with exposure to these compounds.