Charred meat contains several known cancer-causing chemicals, and many previous studies have linked these compounds with cancer risk, but this finding is one of the strongest yet linking very well-done meat, especially red meat, to cancer.

Study Details

Kristin Anderson, the study author said in a statement,

"Our findings in this study are further evidence that turning down the heat when grilling, frying, and barbecuing to avoid excess burning or charring of the meat may be a sensible way for some people to lower their risk for getting pancreatic cancer."

Anderson's team started with 62,000 healthy people and documented what they ate. Over nine years, 208 were diagnosed with pancreatic cancer. When divided into five groups based on how much charred meat such as hamburgers they ate, the people diagnosed with pancreatic cancer were far more likely to be in the top two groups.

"We found that those who preferred very well-done steak were almost 60 percent more likely to get pancreatic cancer as those who ate steak less well-done or did not eat steak," Anderson said.

"Those with the highest intake of very well-done meat had a 70 percent higher risk for pancreatic cancer over those with the lowest consumption."

Genotoxins

Some of the carcinogenic substances formed when meat is burnt include polycyclic aromatic hydrocarbons (PAHs) and heterocyclic amines (HAs). PAHs and HAs are formed when food is cooked at high temperatures (over 150°C), for example, by grilling, barbecuing or pan-frying. HAs only form in meat, poultry and fish, but PAHs may also be formed in other foods.

It is thought that these substances form by interacting with DNA in the body. Chemicals that act in this way are called genotoxins. Recent studies have associated these chemicals and cooked meat with the development of specific types of cancer. 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. Additional studies have shown that an increased risk of developing colorectal, pancreatic, and breast cancer is associated with high intakes of well-done, fried, or barbequed meats.

To reduce your exposure to these harmful chemicals, try to limit your intake of burnt and overcooked meat, or remove the burnt sections from the food. When cooking meat, to stop these genotoxins from being formed, don't let flames touch food when you're barbecuing or grilling, and cook the meat at lower temperatures for a longer time.

Although overcooking meat may produce harmful chemicals, it's very important to make sure you don't undercook meat, especially chicken. Otherwise, any bacteria in the meat could survive and cause food poisoning. Make sure the meat is steaming hot all the way through with no pink meat left, and any juices should run clear.

References

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• Bogen KT. Cancer potencies of heterocyclic amines found in cooked foods. Food and Chemical Toxicology 1994; 32(6):505-515.

• Muscat JE, Wynder EL. The consumption of well-done meat and the risk of colorectal cancer. American Journal of Public health 1994; 84(5):856-858.

• Sinha R, Rothman N, Brown ED, et al. High concentrations of the carcinogen 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) occur in chicken but are dependent on cooking method. Cancer Research 1995; 55(20):4516-4519.

• Snyderwine EG. Some perspectives on the nutritional aspects of breast cancer research. Food-derived heterocyclic amines as etiologic agents in human mammary cancer. Cancer 1994; 74(3 Supplement):1070-1077.

• Stavric B. Biological significance of trace levels of mutagenic heterocycylic aromatic amines in human diet: A critical review. Food and Chemical Toxicology 1994; 32(10):977-994.

• Wakabayashi K, Ushiyama H, Takahashi M, et al. Exposure to heterocyclic amines. Environmental health Perspectives 1993; 99:129-134.