Chemicals in High-Temperature Cooked Meat

This page is for anyone who grills, fries, or smokes meat and wonders about cancer risk. It explains which chemicals form, what the evidence shows, and which cooking changes have been measured.

Grilling and pan frying create two families of compounds. They are not the same, and they do not form the same way.

Heterocyclic amines, or HCAs, form inside the meat. Amino acids, sugars, and creatine or creatinine react with each other at high heat. Creatine is found in muscle, so HCAs form when muscle meat is cooked at high heat.

Polycyclic aromatic hydrocarbons, or PAHs, form outside the meat. Fat and juices drip onto a hot surface or an open fire. That causes flame and smoke. The smoke carries PAHs, which then settle back onto the surface of the food.

In animal studies, both groups of chemicals have been linked to cancer.

Heat is the main lever. NCI says meat cooked above 300 °F, as in grilling or pan frying, forms more HCAs. Cooking that exposes meat to smoke drives PAH formation instead.

Pan residues and drippings can hold these chemicals too, which is why NCI lists skipping gravy made from drippings as a way to cut exposure.

The animal evidence is strong and the human evidence is not. Both statements are true at once, and the gap between them is the whole story.

In rodents, these chemicals caused tumors. The doses used were very high compared with a normal diet.

In people, no definitive link has been established. Several large questionnaire studies found that high intake of well-done, fried, or barbecued meat was associated with higher risk of colorectal, pancreatic, and prostate cancer. Other studies found conflicting results.

NCI notes that it is hard to measure how much of these chemicals a person actually takes in from food. That is one reason the human evidence is unclear.

In 2015, an IARC expert panel classified consumption of red meat as probably carcinogenic to humans, Group 2A. That judgment rested largely on population studies and on strong mechanistic evidence.

That finding is about red meat as a whole. It is separate from the question of HCAs and PAHs. Our page on red and processed meat covers the 2015 evaluation in full.

NCI says there are no federal guidelines on eating foods that contain HCAs and PAHs. So there is no set limit to stay under. What exists is a set of cooking changes.

• Avoid direct flame and long cooking at high heat. Meat cooked above 300 °F, as in grilling or pan frying, forms more HCAs.
• Microwave first. Microwaving meat before high-heat cooking can cut the time it spends on the heat.
• Flip often. Turning meat often while it cooks lowers HCA formation.
• Skip the char and the drippings. Remove charred parts. Do not make gravy from meat drippings.

NCI notes several ongoing studies, including the NIH-AARP Diet and Health Study, the American Cancer Society's Cancer Prevention Study II, the Multiethnic Cohort, and studies from Harvard University.

Until those read out, the honest position is the one the evidence supports. These compounds caused tumors in animals, and their effect on human cancer risk at real dietary levels is unresolved. For the PAH side of the story on its own, see polycyclic aromatic hydrocarbons and cancer. For how any of this fits beside the rest of your plate, see diet and cancer risk.

• National Cancer Institute, Chemicals in Meat Cooked at High Temperatures and Cancer Risk, reviewed July 11, 2017; accessed October 2, 2026