Foods that contain acrylamide are unlikely to cause breast cancer in women, according to preliminary results of a study presented Tuesday at the national meeting of the American Chemical Society.
Acrylamide made headlines a few years ago when Swedish scientists discovered high levels of it in such foods as french fries, potato chips, cookies and crackers. The chemical is a natural byproduct of cooking starchy food at high temperature. Studies have shown it causes cancer in lab mice and rats but its effect on human health is still being explored.
This latest epidemiological study is the largest to date exploring the possible link between the "probable human carcinogen" and cancer in humans, and involved 100,000 U.S. women.
A team led by Lorelei Mucci, an epidemiologist at Harvard School of Public Health in Boston, followed a group of 100,000 U.S. nurses over 20 years, from 1980 to 2000, and asked them to complete periodic questionnaires about their dietary habits, including the type of foods eaten and their frequency of consumption.
The researchers used the data to estimate daily acrylamide intake, while collecting information on the incidence of breast cancer among the women.
They identified more than 3,000 cases of breast cancer among the group, but the incidence of cancer among women with high acrylamide intake was about the same as that among women with low intakes.
"At levels consumed in the diet, it appears unlikely that acrylamide in foods is related to breast cancer risk," says Mucci.
"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."
In previous studies, Mucci has also found no link between dietary acrylamide and risk of cancer of the colon, rectum, bladder and kidney.
Mucci has several theories as to why acrylamide appears to be a carcinogen in animals but not in humans. The animals in the previous studies were exposed to acrylamide levels 1,000 to 100,000 times higher than found in the human diet.
It's also possible that humans may detoxify acrylamide at levels found in the diet.
Mucci does not rule out the possibility that dietary acrylamide can cause other health problems, but only breast cancer was explored in the current study.
"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," she says.
