"Three out of four American households own a barbecue grill, according to the Health, Patio, & Barbecue Association. Yet many consumers are unaware that grilling some popular food items can produce cancer-causing compounds called heterocyclic amines (HCAs). HCAs, a family of mutagenic and cancer-causing compounds, are produced during the cooking of many animal products, including chicken, beef, pork, and fish. In January of 2005, the federal government officially added HCAs to its list of known carcinogens. The Cancer Project determined the level of HCAs found in commonly grilled foods."
[Check out the list, and more, in "continued"]
Food - HCAs ng/100g*
Chicken breast, skinless, boneless, grilled, well done - 14,300 ng/100g2
Steak, grilled, well done - 810 ng/100g3
Pork, barbecued - 470 ng/100g4
Salmon, grilled with skin - 166 ng/100g5
Hamburger, grilled, well done - 130 ng/100g3
*100g portion equals about 3.5 ounces grilled
Safer Alternatives for Grilling:
"Other foods produce undetectable levels or negligible concentrations of
HCAs when they are grilled. These include soy-based veggie burgers,
veggie brochettes, and portabello mushroom “steaks.” These healthy
vegetarian alternatives are also low in fat and cholesterol.
Grilled Meat High in HCAs
Grilled meat yields some of the highest concentrations of heterocyclic
amines (HCAs).6 These compounds form when a combination of creatine (a
specific amino acid found in muscle) and sugars, which are both found
naturally in meats, are heated during cooking.7 Grilling is
particularly carcinogen-forming because the process involves high heat
and long cooking times. Nearly all meats, including chicken and fish,
produce significant amounts of HCAs when tossed on the grill.
Meat that is grilled, fried, or oven-broiled often produces large
quantities of HCAs.8,9,10 The longer and hotter the meat is cooked, the
more these compounds form. The major classes of HCAs include
amino-imidazo-quinolines, or amino-imidazo-quinoxalines (collectively
called IQ-type compounds), and amino-imidazo-pyridines. Within these
families, MeIQx and PhIP are the members most abundantly found in
cooked meats.
High meat intake has been correlated with increased risk of cancer,
particularly of the breast and colon.11 While the fat in meat is most
commonly associated with cancer risk, HCAs also play a role. As known
mutagens, HCAs can bind directly to DNA, cause mutation, and promote
cancer initiation.12
Because HCA concentration increases with heat and time, it would be
expected that well-done meat would increase the risk of cancer. This is
exactly what researchers have found. In a recent review of 30
epidemiologic studies investigating the link between well-done meat
consumption and cancer at various sites, 80 percent showed a positive
correlation.13
Plant-Based Foods Yield Negligible HCAs
Since creatine, one of the ingredients for the formation of HCAs, is
mostly found in muscle tissue, it is not surprising that grilled veggie
burgers and other vegetarian foods contain either no HCAs or negligible
levels.6
Choosing plant-based foods instead of meat also lowers cancer risk in
other ways. Not only are vegetables low in fat and high in fiber, they
also contain many cancer-fighting substances. Carotenoids, the pigment
that gives fruits and vegetables their dark colors, have been shown to
help prevent cancer. Beta-carotene, present in dark green and yellow
vegetables, helps protect against lung cancer and may help prevent
cancers of the bladder, mouth, larynx, esophagus, breast, and other
sites. Many studies have found that diets rich in fruits and vegetables
and low in animal fat cut cancer risks.
Other Dangers of Grilled Meat
Grilling meat also produces other types of food mutagens. Grilling or
broiling meat over a direct flame results in fat dropping on the hot
fire and the production of polycyclic aromatic hydrocarbon-containing
flames. Polycyclic aromatic hydrocarbons (PAHs) adhere to the surface
of food; the more intense the heat, the more PAHs are present.14 They
are widely believed to play a significant role in human cancers.15 A
fairly consistent association between grilled or broiled, but not
fried, meat consumption and stomach cancer implies that dietary
exposure to PAHs may play a role in the development of stomach cancer.11
Hotdogs Contain Other Carcinogens
While HCAs do not form in grilled hotdogs, these highly processed meat
products contain other carcinogens. Nitrates and N-nitroso compounds,
preservatives found in processed foods such as hotdogs and sausages,
have long been recognized as potent carcinogens.16 Increased dietary
intake of processed meats have been linked to increased cancers at
various sites, including the colon,17 the pancreas,18 and the
gastrointestinal tract.19
Red Meat Increases Cancer Risk
Red meat increases the risk of cancer. Recent studies show that red
meat can increase colon cancer risk as much as 300 percent.20 While
dietary factors such as the fat content and the lack of protective
fiber in red meat are considered significant contributors, HCAs were
specifically found to increase colon cancer risk.21
Chicken and Fish Increase Cancer Risk
Many people switch to chicken and fish, believing these to be healthier
alternatives to beef. But that is not the case. On the grill, chicken
produced more than 10 times the amount of the carcinogenic heterocyclic
amines found in grilled beef. Furthermore, nearly all the HCAs detected
were in the form of PhIP, which has specifically been implicated in
breast cancer risk.12 This increased PhIP formation is likely due to
the fact that chicken contains a large amount of phenylalanine,
tyrosine, and isoeucine, amino acids that contribute to HCA formation.
Fish also contains significant amounts of creatine, one of the other
main ingredients for the formation of the carcinogens; not
surprisingly, fish showed significant HCA formation as well.
What Should Go On the Grill?
Consumers who want to reduce their cancer risk need not give up
grilling. Reducing exposure to carcinogens is as simple as grilling
veggie burgers instead of hamburger, or a thick portabello mushroom
instead of a steak. Steering clear of animal products is a key step in
avoiding heterocyclic amines, polyaromatic hydrocarbons, nitrosamines,
and other cancer-promoting substances. For healthy recipes, go to
PCRM's great recipes for the grill and picnic basket.
[references and footnotes edited out]
The Cancer Project is a collaborative effort of physicians,
researchers, and nutritionists who have joined together to educate
individuals, families, and the public about the benefits of a healthy
diet for cancer prevention and survival. Based in Washington, D.C., The
Cancer Project is an affiliate of The Physicians Committee for
Responsible Medicine."
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