As the ground finally begins to thaw here in Wisconsin, folks are getting their grills out for BBQ season.
Most of us don’t give much thought to what happens when we cook foods at higher temperatures. We know that cooking food has some benefits:
- It can make food safer
- It can concentrate tastes and flavors
- It can reduce spoilage
- It can soften tough foods
- It increases the amount of energy our bodies can get from food
- It breaks starch molecules into more digestible fragments
- It denatures protein molecules
So, yes, cooking our food can be a good thing, but the modern diet can be extremely heat-processed. Higher cooking temperatures can create specific chemical reactions in meat among amino acids (the building blocks of protein) and creatine (substances in muscle) to form heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs). HCAs and PAHs are formed when muscle meat, including beef, pork, fish, or poultry is cooked using high-temperature methods, such as pan frying or grilling directly over a flame. PAHS are more specifically formed when fat and juices from meat grilled directly over a heated surface or open fire drip onto the surface or fire, causing flames and smoke. The smoke contains PAHs, which then adhere to the surface of the meat. PAHs can also be formed during the smoking of meats.
Since the 1970s, we have known that HCAs and PAHs can produce dangerous carcinogens and mutagens (compounds that damage our DNA). Along with heme iron and nitrates/nitrites, HCAs and PAHs may be the major reasons that “meat” is associated with cancer. Pickled, smoked, barbecued and processed meats (e.g., bacon, ham, sausage, hot dogs, salami, bologna, luncheon meats, corned beef, etc.) seem to cause the most health problems.
Even with this knowledge, we do not know how often or how much HCAs or PCAs a person needs to consume to increase cancer risk. Most studies have been conducted on animals receiving extremely high doses of HCAs. It has been difficult to determine the effect of HCAs and PAHs on cancer risk in humans for a number of reasons. Numerous epidemiologic studies have found a correlation between high consumption of well-done, fried, or barbecued meats and increased risks of colorectal, pancreatic, and prostate cancer. However, other studies have found no association with risks of colorectal or prostate cancer.
The formation of HCAs and PAH varies by meat type, cooking method, and “doneness” level (rare, medium, or well done). Whatever the type of meat, however, meats cooked at high temperatures, especially above 300 ºF (as in grilling or pan-frying), or that are cooked for a long time tend to form more HCAs. For example, well-done, grilled, or barbecued chicken and steak all have high concentrations of HCAs
Before you throw your grill off the deck, here are some tips for reducing HCA/PAH exposure.
- Avoid direct exposure of meat to an open flame or a hot metal surface and avoid prolonged cooking times at high temperatures.
- Turn meat over continuously when cooking on a high heat source. This can significantly reduce HCA formation.
- Remove charred portions of meat and refrain from using gravy made from meat drippings.
- Grill fruits, veggies, and potatoes on the grill more frequently and save grilling and smoking meat for special occasions
- Avoid overcooking beef and opt for rare or medium rare levels of doneness (if you are a healthy adult)