Overcooking Meats Can Be Just As Harmful As Undercooking Them

It sounds like a flipflop, but it’s not.

For years, scientists have been warning us of the dangers of undercooked meat. Now studies suggest that the more we cook meat, the more harmful it is.

Actually, the truth is somewhere in between. You still must cook ground meat thoroughly to kill the deadly E coli bacteria, say researchers at the U.S. Centers for Disease Control and Prevention. But a new study says that the longer you grill or fry beef - cooking it at high temperatures for a long time - the greater the risk of stomach cancer.

In fact, according to the study conducted by the National Cancer Institute, Nebraska farmers were three times more likely to get stomach cancer if they ate their beef well done.

But researchers say that you don’t have to give up barbecue - or panic. There are steps you can take to minimize the risk. Precooking the meat briefly in a microwave, marinating it, or keeping it away from high heat all can help. And moist cooking, such as stewing or boiling, also appears to be safe.

“We’re not at a point where we’re going to say people should avoid (grilled meat),” said Kara Smigel, a spokeswoman for the National Cancer Institute.

Stomach cancer actually is on the decline in the United States. During the past 20 years, deaths from stomach cancer have dropped 34 percent, largely because of improvements in food storage methods. The lifetime risk of being diagnosed with stomach cancer in the United States is 1 in 81 for men and 1 in 127 for women, compared with 1 in 6 for prostate cancer in men and 1 in 8 for breast cancer in women.

The study of 679 Nebraska farmers showed that those who ate their beef cooked rare and in low quantities had the lowest risk of stomach cancer. The risk was 10 percent higher for those who had a high consumption of rare beef. However, it was 3.2 times higher for those who ate high quantities of medium beef and 3.3 times higher for those with a high consumption of well-done beef.

The culprits are chemicals called heterocyclic aromatic amines, or HAAs, which can be produced in all muscle meats. Scientists at the Lawrence Livermore National Laboratories in California have found that grilling and frying meat at temperatures above 212 degrees produces HAAs, while stewing and roasting creates almost none.

Mark Knize, a scientist at the Lawrence Livermore National Laboratories, said the highest levels of HAAs were found in bacon cooked over a high flame. The next highest were found in chicken cooked over a high flame, and the third highest levels were found in steaks cooked over an open flame. Cooking fish produces few HAAs and vegetables produce none.

The Nebraska study was designed to look specifically at the effects of HAAs and not of better known carcinogens known as PAHs (polycyclic aromatic hydrocarbons). PAHs are created when burning fat drips onto burning coals. The smoke, carrying the carcinogen, drifts back upward to coat the food. As a result, for years health authorities have warned against eating large amounts of charred meat.

“This isn’t a freaky result,” said Smigel. “It follows on what we do know about red meat in general.”

C.J. Valenziano, spokeswoman for the National Cattlemen’s Beef Association, questioned the validity of the study. Her advice was to use medium- to low-temperature charcoals when grilling. She said if you can hold your hand over the coals for 4 to 5 seconds, they’re medium to low.

“You don’t want to overcook or char your meat, poultry or fish,” she said. “It tastes better that way, anyway.”