Concerns about the safety of cooking meat and fish over high, dry heat relate primarily to the creation of two kinds of potentially carcinogenic compounds:
- Heterocyclic amines (HCAs).
- Polycyclic aromatic hydrocarbons (PAHs)
PAHs form when fat drips onto a flame, heating element, or hot coals.
PAHs rise with the smoke and are deposited on the food. They can also form directly on the food when it is charred.
Heterocyclic amines (HCAs) can form in grilled, broiled and pan-fried meats and fish.
HCAs are by-products of the Maillard (browning) reaction … which gives grilled meat or fish some of its characteristic flavor. The hotter the temperature and the more well done the meat or fish, the more HCAs get formed.
The hotter the temperature and the more well done the meat or fish, the more HCAs get formed.
Concerns about the HCAs that form during grilling of meat or fish are legitimate, but may be overblown by the media.
In fact, there is no evidence that low-to-moderate consumption of foods containing these heat-generated chemicals presents serious health risks.
An evidence review from Japan – where people eat far more fish than meat and where grilled fish constitute the single greatest source of HCAs – produced reassuring conclusions:
“…the content of HCAs in dishes consumed in ordinary life is low and not sufficient in itself to explain human cancer…” (Sugimura T 2004).
In addition to HCAs, browning of animal foods or baked goods creates less troublesome compounds called advanced glycation end products (AGEs).
Once consumed, AGEs generate cell-damaging free radicals, stiffen collagen (creating wrinkles), and promote unhealthful “silent” inflammation.
Though they're not causily connected to cancer or other diseases, AGEs accelerate aging of cells and tissues, and consumption of them should be minimized.
Keeping grilled seafood safe
You can reduce formation of these compounds during grilling, broiling, and pan-frying by keeping meat, poultry, and fish moist (e.g., use marinades), and by removing any charred parts from poultry and fish.
And the negative impacts of grilled, broiled or pan-fried meats and fish can be mitigated very considerably by enjoying them with antioxidant-rich fruits, herbs, and vegetables.
In addition to any free-radical-quenching effects, the antioxidants in produce tend to switch off the body’s gene-controlled inflammatory response to dietary free radicals and AGEs.
It's substantially safer to grill fish compared with chicken or red meats, especially if you observe these three preparation and cooking caveats, in descending order of importance:
- Minimize cooking time (which yields the best results anyway).
- Before serving grilled fish, remove the skin and its fatty under layer, and any charred portions.
- Use Cedar or Alder Grilling Planks to protect fish from charring on the high heat of the grill.
- Marinate fish before grilling. Like PAHs, the HCAs formed during grilling concentrate in the fat drippings, and marinating food reduces their formation (Johansson MA 1994, Salmon CP 1997).
As the table below shows, one test of grilled skin-on salmon produced concentrations of HCAs 86 times lower than the levels that occurred in a test of grilled chicken, and almost five times lower than the HCA levels that occur in a test of grilled steak.
In fact, in a Swiss study published in 1993 (Gross GA), researchers found no detectable levels of HCAs in grilled fish. It is reasonable to assume that fish grilled lightly (i.e., until just done), without the skin and its fatty under layer, will contain the lowest levels of HCAs.
To ensure the lowest intake of HCAs and PAHs, remove the skin and its fatty under layer from grilled fish before consuming it, trim fat before grilling meat, and keep a spray bottle of clean water handy to prevent the fiery flare-ups that occur when fat drips onto hot coals or surfaces.
|Grilled Food||HCA content (nanograms per 100 grams/3.5 oz)|
|Chicken breast skinless-boneless, grilled||14,300 ng1|
|Steak, grilled, well done||810 ng2|
|Pork, barbecued||470 ng3|
|Salmon, grilled with skin||166 ng4|
- Sinha R, Rothman N, Brown ED, Salmon CP, Knize MG, Swanson CA, Rossi SC, Mark SD, Levander OA, Felton JS. High concentrations of the carcinogen 2-amino-1-methyl-6-phenylimidazo- [4,5-b]pyridine (PhIP) occur in chicken but are dependent on the cooking method. Cancer Res. 1995 Oct 15;55(20):4516-9.
- Sinha R, Rothman N, Salmon CP, Knize MG, Brown ED, Swanson CA, Rhodes D, Rossi S, Felton JS, Levander OA. Heterocyclic amine content in beef cooked by different methods to varying degrees of doneness and gravy made from meat drippings. Food Chem Toxicol. 1998 Apr;36(4):279-87.
- Murray S, Lynch AM, Knize MG, Gooderham MJ. Quantification of the carcinogens 2-amino-3,8-dimethyl- and 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine in food using a combined assay based on gas chromatography-negative ion mass spectrometry. J Chromatogr. 1993 Jul 2;616(2):211-9.
- Kataoka H, Nishioka S, Kobayashi M, Hanaoka T, Tsugane S. Analysis of mutagenic heterocyclic amines in cooked food samples by gas chromatography with nitrogen-phosphorus detector. Bull Environ Contam Toxicol. 2002 Nov;69(5):682-9.
- Sugimura T, Wakabayashi K, Nakagama H, Nagao M. Heterocyclic amines: Mutagens/carcinogens produced during cooking of meat and fish. Cancer Sci. 2004 Apr;95(4):290-9. Review.
- U.S. Department of Health and Human Services, Public Health Service, National Toxicology Program. 2005. 11th Report on Carcinogens. Available at http://ntp.niehs.nih.gov/ntp/roc/toc11.html.
- Gross GA, Turesky RJ, Fay LB, Stillwell WG, Skipper PL, Tannenbaum SR. Heterocyclic aromatic amine formation in grilled bacon, beef and fish and in grill scrapings. Carcinogenesis. 1993 Nov;14(11):2313-8.
- Salmon CP, Knize MG, Felton JS. Effects of marinating on heterocyclic amine carcinogen formation in grilled chicken. Food Chem Toxicol. 1997 May;35(5):433-41.
- Johansson MA, Jagerstad M. Occurrence of mutagenic/carcinogenic heterocyclic amines in meat and fish products, including pan residues, prepared under domestic conditions. Carcinogenesis. 1994 Aug;15(8):1511-8.
- Oak Ridge National Laboratory. Fourth of July no picnic for the nation's environment. Accessed online May 14, 2007 at http://www.ornl.gov/info/press_releases/get_press_release.cfm?ReleaseNumber=mr20030703-00