A potentially cancer-causing chemical found in some carbohydrate-rich foods appears to not raise the risk of breast cancer, the results of a large study suggest.

The chemical, acrylamide, gained notoriety several years ago when researchers discovered that the suspected human carcinogen is present in high levels in some popular snack foods, like potato chips, French fries and crackers. Other sources include teething biscuits, sweet potatoes, peanut butter, fast-food chicken nuggets, bottled prune juice and black olives.

Acrylamide appears to form when certain carbohydrate-rich foods are heated to high temperatures, through frying, baking or broiling.

Whether people’s diets typically contain enough acrylamide to promote cancer remains debatable. A number of studies have found no link between people’s acrylamide intake and their risk of cancer, but some have detected a relationship. Specifically, a significant association between acrylamide and the risk of estrogen receptor-positive breast cancer was detected by Danish researchers in 450 middle-age and older women.

In the latest study, published in the American Journal of Epidemiology, the investigators found no connection between long-term acrylamide intake and the risk of breast cancer.

The findings suggest that acrylamide from foods does not promote breast cancer - at least within the range that women in this study consumed, report Dr. Susanna C. Larsson and her colleagues at the Karolinska Institute in Stockholm.

The study included 61,433 women born before 1949 who were cancer-free at the outset. At the start of the study and again 10 years later, the women completed dietary questionnaires that asked them how often they usually ate specific foods.

The researchers used that information to estimate the women’s overall acrylamide intake.

During the study period, 2,952 women were newly diagnosed with breast cancer. Those with the highest acrylamide intake were no more likely to develop the disease than women with the lowest intake, Larsson’s team found.

“These findings for Swedish women do not support the hypothesis that dietary acrylamide is positively associated with risk of breast cancer, at least not within the ranges of acrylamide consumed by this population,” the researchers conclude.

They note, however, that acrylamide intake was fairly low in the study group as a whole. So, it’s not clear whether the findings apply to other groups of women as well.

SOURCE: American Journal of Epidemiology, February 1, 2009.