NEW YORK • Had a barbecue over the weekend? Many people would be surprised to hear that grilling carries potential cancer risks.
But each year, the American Institute for Cancer Research publishes guidance for "cancer-safe grilling", cautioning consumers to avoid two types of compounds that have been tied to cancer.
These compounds - polycyclic aromatic hydrocarbons and heterocyclic amines - get generated when food, especially meat, is cooked on a grill. They have not been proven to cause cancer in people, but laboratory studies have shown they alter DNA in a way that could lead to cancer.
Polycyclic aromatic hydrocarbons form when any organic matter, primarily fat that drips off meat and down into the grill grates, "gets burned, because the carbon inside is being combusted in the flames".
The hydrocarbons are carried up in the smoke, said senior investigator Rashmi Sinha at the National Cancer Institute. The smoke can envelop the meat, coating it with the potentially carcinogenic compounds.
The black char on grill grates and grilled food? That is the heterocyclic amines (HCAs), which occur when high temperatures meet muscle meat - which includes red meat (pork, beef, lamb), poultry (turkey, chicken) and fish.
"Grilling - or even pan-frying - at these high temperatures causes amino acids in the meat to react with another substance in meat called creatine," said Ms Colleen Doyle, managing director of nutrition and physical activity at the American Cancer Society.
As with most lifestyle choices related to dialling up or down cancer risk, the dosage makes the poison.
Which means if you are grilling once or twice a year, do not sweat it.
But if you plan to grill often, experts suggest taking steps to lower exposure to these compounds.
Think outside the burger: Grill fish, seafood, poultry or plant-based foods rather than red meat and especially processed meats like hot dogs.
While HCAs are still formed while grilling fish and seafood, Ms Doyle noted that you do not have to cook seafood as long as beef and chicken, which reduces the accumulation of the compounds.
Marinate first: Research suggests that marinating for at least 30 minutes can reduce the formation of HCAs on meat, poultry and fish.
"If you put a barrier of basically sugar and oil between the meat and the heat, then that is what becomes seared instead of the meat," said Mr Nigel Brockton, vice-president of research at the American Institute for Cancer Research.
Make produce the star: Many fruit and vegetables are protective as far as cancer risk is concerned, and do not form HCAs when grilled.
Several experts recommend using meat as a condiment.
Think of alternating cubes of chicken with peppers and onions or peaches and pineapple on a skewer.
This trick, which also works when pan-frying, reduces the surface area of meat exposed to the hot surface, Mr Brockton said, since the meat is also touching other ingredients throughout the cooking process.
Leverage on herbs and spices: According to Mr Brockton, cooking meat with herbs, spices, tea and the like - ingredients with phenolic compounds - can be helpful because "it seems they quench the formation of the potentially carcinogenic compounds because of the antioxidant properties of those ingredients".
Avoid char: The black, crispy crust on the bony edges of ribs or steak is more likely to contain a higher concentration of potentially carcinogenic compounds.
Ms Doyle also recommends cleaning the grill grates ahead of time.
Flip often: According to guidance from the National Cancer Institute, fewer HCAs are formed if you turn meat over frequently while cooking it on high heat.