According to the June, 2009, Nutrition Action Healthletter, it is possible to cook or grilling meat at too high a temperature for safety. The high heat creates heterocyclic amines (HCAs) and polycyclic aromic hydrocarbons (PAH) from substances in the meat. These chemicals are mutagens—they change the body's DNA and could lead to colorectal cancer. While scientists are still trying to unravel the “why” of this association between charred meats and cancer, the research evidence for a link between the two is strong.

Studies have been published over the past ten years, but public awareness of this hazard has grown slowly. We may be even more prone to overook meat now due to recent concerns over bacterial contamination.

Does the backyard chef have to hang up his tongs and apron? Not at all. Just take a few precautions.

Remember moderation. Minimize the number of red-meat grilled meals. Do you really need to make hamburgers every night all summer long? Try chicken, fish, or veggie kabobs on the grill instead. Nutrition Action Healthletter states these alternative grill candidates produce little if any HCAs. Consider limiting the grilling to a few days a week. Explore crisp summer salads, cool soups, and fancy sandwiches if you don't want to heat up the kitchen.

Marinade your beef in beer or wine. According to the Tufts University Health & Nutrition Letter, June, 2009, some research indicates this practice might reduce the risk of mutagenic compounds forming during the grilling process.

Nutrition Action Healthletter also suggests microwaving the meat for just a few minutes before grilling. Discard the drippings. This practice will rid the meat of most of the HCAs.

Take the meat's temperature. Invest in a good meat thermometer and use it. That way you can cook just to the point of safety from bacteria, without burning the meat.

What about indoor cooking of red meats? Is that safe? Moist cooking seems to best to guard against carcinogen production. Steam, poached, or stewed, meats cooked in fluid cannot exceed water's boiling point, thus the high temperatures that produce HCAs are never reached.

References:
Liebman, B: The Real Cost of Red Meat. Nutrition Action Healthletter Vol 36 (5), pg 1-7, June 2009.
Tufts University: Meat Lovers' Mortality Risk Is Higher. Health & Nutrition Letter Vol 27 (4), pg 1-2, June 2009.