For many people, charred burgers or extra crispy veggies are mealtime favorites. But can eating grilled or charred foods or foods cooked at high temperatures affect your risk for cancer?
Several types of chemicals are found in grilled, charred, and well-done meats, as well as some baked, roasted, or fried plant-based foods when cooked at high temperatures. Here, learn what these chemicals are, how they can impact your cancer risk, and what you can do to reduce your exposure to chemicals when cooking.
What are the chemicals found in grilled food or food cooked at a high temperature?
Two chemicals, polycyclic aromatic hydrocarbons (PAHs) and heterocyclic amines (HCAs), develop naturally when cooking meat. When you grill meat, fat and juice drip into the grill’s drip pan below, causing flames and smoke that contain PAHs. This then, in turn, coats the meat with PAHs. PAHs are also found in smoked foods, tobacco smoke, and car exhaust. Meanwhile, HCAs occur naturally when you heat meat, such as beef, chicken, pork, or fish, at high temperatures.
Another chemical called acrylamide develops naturally when baking, roasting, or frying potatoes or other plant-based foods at a high temperature. Acrylamide is a chemical formed when sugars react with amino acids in the food that you bake, fry, or roast. You can find acrylamide in baked or fried potatoes, cookies and other baked goods, and coffee. Drinking water and tobacco smoke also contain acrylamide, and people who smoke have higher levels of biomarkers for acrylamide in their blood than non-smokers, according to a 2010 study in Environmental Health Perspectives.
If you would like to know more about which food items contain acrylamide, the acrylamide content in thousands of foods is published online by the U.S. Food and Drug Administration (FDA).
Can PAHs and HCAs cause cancer?
In animal studies, rodents fed diets with high doses of PAHs and HCAs developed several different types of cancer. For example, in a study published in the journal Carcinogenesis, rodents fed HCAs in their diet were more likely to develop breast cancer and colon cancer. However, studies in humans have not found that PAHs or HCAs cause cancer, and this remains an ongoing area of research.
Studying these chemicals in humans is particularly difficult because it is hard to pinpoint the exact amount of PAHs or HCAs that a person consumes based on questionnaires about their daily food intake. Plus, levels of PAHs and HCAs can vary by the type of meat, length of cooking, and cooking temperature. Finally, the way your body metabolizes these chemicals or your exposure to these chemicals in your environment can differ from someone else’s. For some people, this could likely impact their risk for cancer.
“There’s not a clear recommendation on what’s a safe amount [to consume],” says Julie Lanford, MPH, RD, CSO, LDN, a registered dietitian and the author and creator of CancerDietitian.com. But Lanford does not recommend avoiding grilled meats altogether. Instead, she advises people who grill more frequently, such as once or twice a week, to select a variety of foods, including vegetables, fish cooked in a foil packet, or low-fat meats, to reduce their exposure to PAHs and HCAs.
Other ways to possibly reduce exposure to these chemicals include:
Trying to avoid flare-ups that can char meat
Partially pre-cooking meats to lessen their time on the grill
Marinating meat beforehand to provide a protective layer against these chemicals
“Eat plenty of fruits, vegetables, whole grains, beans, nuts, and seeds. If you can balance foods that might be higher in risk for carcinogens with lots and lots of good, healthy, nourishing foods, then you get the right balance.” – Julie Lanford, MPH, RD, CSO, LDN, a registered dietitian and the author and creator of CancerDietitian.com
Can acrylamide cause cancer?
Acrylamide was first identified in food in 2002, and although it probably isn’t a new chemical, studies of its health effects have ramped up since then.
In animal studies, high levels of acrylamide have been found to cause several types of cancer, according to the FDA. However, studies in people are inconclusive. This could be due to the difficulty in estimating the intake level of acrylamide in a person’s diet. And, levels of acrylamide in foods can vary by cooking temperature, length of cooking, food storage, and other factors.
The European Food Safety Authority Panel and the Joint Food and Agriculture Organization of the United Nations/World Health Organization Expert Committee on Food Additives categorize acrylamide as a concern, and they recommend further study of the potential cancer risk in people. Meanwhile, the International Agency for Research on Cancer considers acrylamide a probable human carcinogen, and the U.S. National Toxicology Program classifies acrylamide as “reasonably anticipated to be a human carcinogen.”
The FDA does not publish what acceptable levels of acrylamide in a diet are and does not advise against eating foods with acrylamide. Instead, it recommends eating a balanced, healthy diet that contains a variety of vegetables, fruit, grains, fat-free or low-fat dairy, and proteins.
However, if you want to reduce acrylamide in your diet, the FDA offers these tips:
Toast bread to golden brown rather than dark brown.
Follow the food label’s instruction for frying or cooking frozen foods, such as french fries, and avoid overcooking.
Store potatoes in a cool, dry area but not in the refrigerator, which can increase acrylamide during cooking.
The information in this post is based on the current research and expert opinions available today. These findings may change as more research into this topic emerges.