BARBECUE definitely gives apple pie a run for its money in the competition for all-American food. More than 17 million barbecues were sold in 2006, according to the Hearth, Patio & Barbecue Assn. And 81% of Americans own a barbecue, more than half grill year-round, and 47% barbecue at least twice weekly in the summer months.
The truth is, pretty much anything tastes better hot off the grill. It's something about the flames, the smoke, the tongs, the-meat-on-metal sizzle that no broil or fry pan can reproduce. Even a tofu dog almost comes alive with a set of grill marks.
For The Record
Los Angeles Times Monday June 11, 2007 Home Edition Health Part F Page 5 Features Desk 1 inches; 68 words Type of Material: Correction
Grilling: A May 28 Health article on the health effects of eating barbecued meat incorrectly referred to a scientist as Zei Wheng. His name is Wei Zheng. The article also said that many processed meats contain nitrates and that these have been shown to increase cancer risk. The chemicals most commonly used in curing meat today, and which also have been shown to increase cancer risk, are nitrites.
Nothing that good can be good for us, of course. And yes, the natural chemicals that give barbecued foods their trademark crusty-brown smokiness are toxic and carcinogenic. Researchers have linked consumption of flame-grilled meat to all sorts of ailments: breast, prostate and colon cancer; diabetes; glaucoma; heart disease; and Alzheimer's disease.
Fumes from burning fat drippings, along with smoke from wood and charcoal, add another layer of carcinogenicity (as well as deliciousness) to grilled foods.
And let's not forget the foods themselves. A diet high in red meat -- a favorite of U.S. backyard cooks -- is a known cancer risk factor.
But you don't have to convert to a raw food diet yet. Barbecue chemicals may be potent toxins in petri dishes and mice, but the evidence that they do the same in humans, at the doses we're exposed to, is weaker.
Most studies find a significant increase in cancer risk only for people who eat several portions of well- or very well-done meat a week. And even then, the risk is often small. For example, a 2005 study in Cancer Research found a 21% increase in the risk of developing colon cancer precursors for people eating as much as 18 ounces of well-done red meat per day. The bottom line: A twice-weekly date with a medium-rare steak is unlikely to give you cancer any time soon.
What's more, in addition to reducing portion size and frequency of grilling or developing a taste for steak tartare, there are many simple changes you can make to your grilling techniques to drastically reduce the toxicity of your barbecue with little adulteration of taste (see sidebar). Which is good, because you won't find many takers in the "give up steak for summer" campaign.
The best-known toxic barbecue chemicals are heterocyclic amines, or HCAs, which form under high heat conditions -- such as grilling -- from amino acids, sugars and a muscle meat chemical called creatine. Almost any meat cooked above 300 degrees Fahrenheit, when it begins to brown, will have HCAs, but as a general rule, the levels increase sharply with higher cooking temperatures and longer cooking times.
For example a steak cooked until just rare -- about 15 minutes or so -- has just 2.5 nanograms of one common HCA per gram of food. Wait until that steak is black and crispy -- about 40 minutes -- and that value rises more than tenfold to 30 nanograms per gram.
Chicken breasts are even worse. A nicely blackened grilled breast, cooked for about 40 minutes, has 480 nanograms of the same cancerous HCA per gram of meat. Compared with other high-heat cooking methods such as pan-frying or oven broiling, grilling almost always leads to the biggest, baddest HCA numbers.
In laboratory tests, high doses of HCAs have proved to be potent carcinogens and tumor promoters. So, too, have tests on another class of cooking-related meaty carcinogens, PAHs, or polycyclic aromatic hydrocarbons. Whereas HCAs are generated by any high-heat cooking method, PAHs are specifically formed from the close relationship of food, fire and smoke in grilling and Southern barbecue.
PAHs are technically the incomplete combustion products of fuel and are best known as components in air pollution and cigarette smoke. However, the World Health Organization estimates that 80% to 90% of our exposure to PAHs comes through food. Smoke clouds from charcoal grills and those fat drip flare-ups are packed with PAHs. And, again, the longer the cooking or smoking time, the greater the coating of carcinogens.
The extra whammy of PAHs, in addition to HCAs, is probably why a high intake of grilled, well-done meats is worse than that of broiled or fried meat. One 1999 study led by cancer and cooking expert Rashmi Sinha, a senior investigator at the National Cancer Institute, found that for every 2.5 ounces of grilled meat consumed per week, colon cancer risk rises 26%. For frying, it was only 10%.
Still, the overall evidence of the malignant effects of PAHs and HCAs on people has been less than overwhelming.