There’s a lot to consider when designing a healthy diet, from ensuring you’re getting enough fiber and protein to limiting ultra-processed foods. But it’s not just the ingredients themselves—how food is prepared matters, too.
A new study highlights the potential pitfalls of high-temperature cooking. During this process—a feature of common methods like grilling and smoking—carcinogenic pollutants called polycyclic aromatic hydrocarbons (PAHs) can form.
Meet the expert: Tracy Proverbs-Singh, M.D., gastrointestinal medical oncologist at the John Theurer Cancer Center at Hackensack University Medical Center.
We’re well into barbecue season. Does this mean you should cut your cookouts short this summer? Here’s what to know.
What are PAHs, exactly?
“PAHs are a group of harmful chemical compounds formed from the incomplete burning of organic matter like coal, oil, and wood,” explains Tracy Proverbs-Singh, M.D., gastrointestinal medical oncologist at the John Theurer Cancer Center at Hackensack University Medical Center. “They are commonly created in our diet during high-temperature cooking, especially when grilling or smoking meat, as fat drips onto flames and produces PAH-rich smoke that coats the food. Other major sources of exposure include vehicle exhaust, industrial emissions, and tobacco smoke.”
The primary health risk associated with PAHs is their link to cancer. “Many are classified as carcinogenic because, when ingested or inhaled, they can be metabolized into substances that bind to and damage a cell’s DNA,” says Dr. Proverbs-Singh. “This DNA damage, if unrepaired, can lead to mutations that initiate cancer, with the strongest links being to lung, skin, and bladder cancers, though they can also weaken the immune system and disrupt hormones.”
Grilled meats are known to be a significant source of PAHs in the human diet—unsurprising, given how food comes in direct contact with flames and hot surfaces during the grilling process. However, the recent study, published in Scientific Reports, looked at other foods to assess their safety and potential PAH content, and found three additional potential PAH-dense ingredients to be aware of this barbecue season.
What did the study find?
Using a special method called QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe), researchers extracted and measured eight different PAHs from various foods to determine which had the highest PAH content. They found that the highest levels of the particular PAHs they chose to measure were in soybean oil, followed by duck meat and canola oil.
The bottom line
The study didn’t pose recommendations for the consumption of soybean oil, canola oil, or duck meat—in fact, the Food and Drug Administration (FDA) has not established standards to govern levels of PAHs in food, though there are federal limits placed on PAHs in drinking water by the Environmental Protection Agency (EPA).
“While identifying PAHs in soybean oil is important, the study’s core achievement is validating a method that is not only highly accurate and sensitive but also quick and cheap,” Dr. Proverbs-Singh explains, referring to QuEChERS. “This efficiency is critical, empowering regulatory agencies and food producers to conduct widespread, cost-effective surveillance for harmful contaminants. Ultimately, the study’s main contribution isn’t just a single finding, but a robust tool to better protect the public from harmful chemicals in the food supply.”
If you want to consciously limit your PAH exposure, you can likely do so by avoiding grilled or smoked foods, as well as the handful of high-PAH ingredients the study identified. However, methods and testing like the one highlighted by this study aim to prevent the contaminants from making it to our plates in the first place.
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