Fatty Food Fumes Could Be Dangerous : Discovery News

Even the smoke generated from cooking unhealthy food could be a hazard to your health.


- Commercial cooking produces fumes that pollute air and may harm our health.

- Some restaurants have already changed the way they cook as a result of the findings.

- To protect yourself at home, you might want to bake and steam instead of broiling or deep-frying.

Cooking smoke contains particles known to both pollute air and cause cancer, scientists reported this week at a meeting of the American Chemical Society in San Francisco. The study zeroed in on the dirtiest emitters: broiled hamburgers and wok-fried chicken.

Some major restaurant chains have already changed the way they cook as a result of the research, and parts of California have enacted new emissions standards for commercial kitchens. The findings should also help experts to develop better filtering technologies and consumers to make healthier, more environmentally sound choices in the kitchen.

People have been cooking food for more than 100,000 years, said Tim Farrell, a chemical engineer and independent consultant in St. Paul, Minn. Ventilating windows and chimneys have likewise been around since the Dark Ages. Yet, it wasn't until the mid-1990s that scientists started probing the contents of cooking smoke and how that smoke might contribute to air pollution.

The first comprehensive study looked at a handful of appliances commonly used in restaurants, hospitals, schools and other commercial settings. That study, conducted about a decade ago, found that the most and the dirtiest emissions came from broiling hamburgers under high heat. Other methods lagged far behind, including cooking French fries in a deep fryer or baking pizza in an oven.

In the new study, Kuehn and colleagues used state-of-the-art analytical equipment to examine in even more detail the vapors and particles that come out of a larger variety of cooking methods and foods. They found that the dirtiest smoke by far came from diced chicken cooked with peanut oil in a wok. Broiled hamburgers came next.

With chemical analyses, the researchers identified compounds called polycyclic aromatic hydrocarbons (PAHs) in both particle and vapor released in cooking plumes. PAHs are known carcinogens.

So far, there are no proven health risks to breathing in cooking fumes, but it's a hard link to make. As with cigarette smoke, though, the worry is that tiny particles in cooking smoke could get lodged deep into our lungs, where they might cause cancer or other problems.

One study conducted more than a decade ago found that cooking was by far the largest contributor to air pollution inside homes, Kuehn said. Another study in China, also conducted more than 10 years ago, found the highest rates of lung cancer in women, even though men smoked the most tobacco. Women do more of the cooking there, and the researchers speculated that their exposure to food fumes explained the trend.

Based on the new research, home cooks can make healthier choices in their own kitchens, Kuehn said. Because greasy foods cooked over extra-high heat produce the dirtiest emissions, stick with low-fat foods. Steam or bake food instead of broiling or frying. If you want to grill, do it outside, and make sure the hood in your kitchen forces air outside instead of recirculating it indoors.

As a hungry consumer, Farrell added, you might want to avoid restaurants with particularly strong food smells, as odor indicates the presence of emissions. If you see grease dripping out of outdoor exhaust fans, that's a bad sign, too. The good news is that advances in ventilation are coming.

"Any engineer will tell you that defining the problem is half the battle, and the problem has been defined here," Farrell said. "Good solutions are on the way."