With summer grilling season upon us, you may want to consider how “well-done” you like your poultry, meat, and fish. Research has shown that cooking certain meats at high temperatures creates chemicals that are not present in uncooked meats. A few of these chemicals may increase cancer risk, such as heterocyclic amines (HCAs). HCAs are carcinogenic chemicals formed from the cooking of animal muscle such as beef, pork, poultry, and fish.

Temperature is the most important factor in the formation of HCAs. Methods such as frying, broiling, and barbecuing produce the largest amounts of HCAs because the meats are cooked at very high temperatures. One study conducted by researchers from NCI's Division of Cancer Epidemiology and Genetics found a link between individuals with stomach cancer and the consumption of cooked meats:

The researchers assessed the diets and cooking habits of 176 people diagnosed with stomach cancer and 503 people without cancer. The researchers found that those who ate their beef medium-well or well-done had more than three times the risk of stomach cancer than those who ate their beef rare or medium-rare. They also found that people who ate beef four or more times a week had more than twice the risk of stomach cancer than those consuming beef less frequently.