Cancer Link Cooks Up Doubt: Heating may form potential carcinogen in food

Foods cooked at high temperatures contain large concentrations of acrylamide, report researchers at Sweden’s National Food Administration (NFA) in Uppsala. Animal tests hint that this chemical may cause cancer in people. Although widely publicized following an April 24 press conference, the finding of acrylamide in foods is not altogether new nor a cause for alarm, according to critical observers.

Two years ago, a separate team of researchers at Stockholm University, led by Margareta Törnqvist, reported that rats’ blood cells show elevated concentrations of a form of acrylamide after the animals consumed fried feed. The researchers then found that acrylamide forms in the feed during heating. At high doses, acrylamide can cause cancer and neurological damage in animals.

Previously, researchers had considered acrylamide to be exclusively a synthetic compound, says Manfred Luetzow of the United Nation’s Food and Agriculture Organization (FAO) in Rome. In industry, acrylamide is used to make products such as plastics and to filter water.

Törnqvist and her colleagues found earlier this year that some foods commonly eaten by people also form acrylamide when heated, but Törnqvist declines to elaborate on the finding before its formal publication.

After learning of Törnqvist’s results, the NFA researchers developed a new technique to measure acrylamide concentrations in various foods. Many products can contain surprisingly high amounts of the compound, says Leif Busk, who led the team.

The researchers tested mainly starchy foods and found the highest acrylamide concentrations—an average of more than 400 micrograms per kilogram—in potato chips, french fries, cookies, and crackers. Breakfast cereals and breads also contain substantial quantities of the chemical.

High temperatures may cause the compound to form. Boiling, which never heats foods to more than 100°C, produces little or no acrylamide, the NFA reports. Luetzow stresses that the specific chemical reactions that produce the acrylamide need to be unraveled.

By releasing the new findings before publication, Busk says, NFA hopes to push food manufacturers and regulators to identify baking and frying methods that minimize acrylamide production.

However, some scientists not directly involved in the research discourage consumers and public health officials from taking action on the basis of the available data.

“This is extremely preliminary and has been seriously oversensationalized,” says Walter C. Willett of Harvard School of Public Health in Boston.

U.S. government officials were circumspect about the finding, and Luetzow described FAO’s response as “cautious.” Nevertheless, he adds, FAO will convene an expert panel, probably this June, to analyze the Swedish findings.