Acrylamide Not Linked to Breast Cancer

Acrylamide, a compound that can form in certain foods when heated, might not cause cancer--in particular, breast cancer--as originally speculated, according to preliminary results of a new epidemiological study. The results, presented at the 234th national meeting of the American Chemical Society in Boston, mirrored those in an earlier study by the group among Swedish women that also found no association between dietary acrylamide and cancer risk.

At levels consumed in the diet, it appears unlikely that acrylamide in foods is related to breast cancer risk, says study leader Lorelei Mucci, Sc.D., an epidemiologist at Channing Labs at Brigham and Womens Hospital and Harvard School of Public Health, Boston. Prior work done by her group also found no association between dietary acrylamide and risk of cancer of the colon, rectum, bladder and kidney. Although we do not rule out that very high levels of acrylamide could cause cancer, it appears that at the levels found in the diet, it is unlikely, she said.

The results of the study, which was funded by the National Institutes of Health, were based on a review of 100,000 U.S. women, making it the largest epidemiological study to date exploring possible links between acrylamide and cancer in humans. Researchers used frequency of consumption data to estimate daily acrylamide intake. Members of the study group developed over 3,000 cases of breast cancer, but the incidence among women with a high acrylamide intake was about the same as that among women with low intakes, leading the researchers to conclude no association exists between acrylamide intake and breast cancer.

Acrylamide has been detected in numerous foods, with the highest levels occurring in products subjected to heating, especially fried and baked products such as potato chips and other snack foods. It forms when the amino acid asparagine, which occurs naturally in many vegetables, especially some varieties of potatoes, is heated to high temperatures in the presence of certain sugars.

So far, no studies show acrylamide causes cancer in humans. However, because the compound has been shown to cause cancer in laboratory rats, the U.S. Environmental Protection Agency (EPA) and the International Agency for Research on Cancer (IARC) Lyon, France, consider it a probable human carcinogen. European food-safety authorities have been taking steps to reduce acrylamide ingestion.

Mucci proposes several theories for the different results in animals and humans. For one, the rats were exposed to acrylamide levels 1,000 to 100,000 times higher than those found in the human diet. In addition, she speculated that humans may detoxify acrylamide at levels present in their diet. However, she cautions, The story of dietary acrylamide and cancer risk in humans is still emerging, and additional epidemiological studies examining other cancers and in additional populations are warranted, including biomarker assessment of acrylamide exposure.