November 10, 2010 — Researchers at Harvard School of Public Health (HSPH) have found an increased risk of ovarian and endometrial cancer among non-smoking post-menopausal women who consume food and beverages containing high levels of acrylamide, a naturally occurring chemical found in grains, potato chips, pretzels and other common baked and snack foods. Acrylamide is generated during the heating process to produce these foods.
“Women shouldn’t change what they eat based on this study, but we do have intriguing findings of an increased risk of endometrial and ovarian cancer that require more research,” said lead author Kathryn Wilson, research fellow in epidemiology at HSPH and postdoctoral fellow in the Channing Laboratory at Brigham and Women’s Hospital in Boston.
The good news was that the researchers did not find an association between dietary acrylamide and breast cancer, which is consistent with other studies. However the findings for ovarian and endometrial cancers are important because there are very few modifiable risk factors for those cancers, Wilson said.
The study appears in the October 2010 issue of Cancer Epidemiology, Biomarkers, & Prevention.
Wilson and her colleagues studied data from 88,672 non-smoking women in the Brigham and Women’s Hospital-based Nurses’ Health Study. They were followed for 26 years and surveyed about their eating habits every four years. The major sources of acrylamide among the Nurses’ Health Study participants in this study were coffee (20%), breakfast cereal (15%), French fries (12%), potato chips (7%), pretzels (6%), and potatoes (baked/roasted/mashed) (6%).
There were 6,301 cases of invasive breast cancer, 484 cases of invasive endometrial cancer, and 416 cases of ovarian cancer between 1980 and 2006. The researchers used a statistical model to study the association between acrylamide and these cancer cases. They reviewed the food tracking information that the Nurses’ Health Study participants had supplied and estimated the amount of acrylamide consumed each day. The findings were corrected for such factors as age, BMI, physical activity, and alcohol intake.
While most previous acrylamide studies have not shown a link with other types of cancer, one study in the Netherlands also found a link with endometrial and ovarian cancer risk in nonsmoking women. In that study, high consumption of Dutch spiced cake containing acrylamide was believed to be a factor. Animal tests also have shown that acrylamide causes cancer in hormone-sensitive tissues, including cancerous tumors in mammary tissue in female rats, when drinking water containing acrylamide at levels 1,000 to 10,000 times higher than the amount of acrylamide in the typical human diet.
Prior to 2002, when acrylamide was discovered in food, the substance, classified by the World Health Organization as a probable human carcinogen, was thought to be found only in occupational settings (in substances like glue, printing ink and cosmetics) and in tobacco use. The food industry has made efforts in recent years to reduce acrylamide formation during food processing. However, it is still found in many popular foods in the U.S. diet.
Compounding the issue is that many foods containing acrylamide, such as high-fiber cereal and coffee, have beneficial ingredients. “We are not yet at the point of telling people that they should avoid acrylamide in their diet,” said senior author Walter Willett, chair of the Department of Nutrition and Fredrick John Stare professor of epidemiology and nutrition. “However the study results probably arereason enough for manufacturers to be prudent and continue to work to lower the acrylamide content of their products,” he said.
While research continues, there are things women can do to reduce their risk of ovarian and endometrial cancer, Wilson said. These include increasing physical activity, drinking alcohol in moderation or not at all, and not smoking. “Adopting these lifestyle habits would go a long way to reducing cancer rates,” Wilson said.
Support for the study was provided by the National Cancer Institute of the National Institutes of Health.
“A prospective study of dietary acrylamide intake and the risk of breast, endometrial, and ovarian cancers,” Kathryn M. Wilson, Lorelei Mucci, Bernard Rosner, and Walter C. Willett, Cancer Epidemiology, Biomarkers, & Prevention, October 2010, Vol. 19: 2503-2515.
Press Release on HSPH Study on Acrylamide and Breast Cancer (March 15, 2005)