MONDAY, Oct. 20, 2008 (HealthDay News) -- A large Dutch study finds no link between acrylamide and the risk of developing gastrointestinal cancer.
Acrylamide is a chemical commonly found in French fries, cakes, snacks and even coffee. The substance forms naturally when certain carbohydrate-rich foods are cooked at high temperatures.
"No association was observed between dietary acrylamide intake and risk of cancer of the gastrointestinal tract, consistent with the few other epidemiological studies on this topic," said Janneke Hogervorst, lead author of the study in the November issue of The Journal of Nutrition.
But previous reports have provided conflicting evidence, added Hogervorst, a doctoral candidate at Maastricht University in the Netherlands, who urged "other research groups to investigate these relationships also."
Despite the complicated science, however, the public health message is surprisingly simple.
"People should limit consumption of foods which are important sources of acrylamide for general health reasons," said Dr. Michael Thun, vice president of epidemiology and surveillance research at the American Cancer Society. "They tend to be low in nutrition, high in fat and high in calories."
The International Agency for Research on Cancer classified acrylamide as a "probable" human carcinogen in 1994, based largely on animal studies in which animals were exposed to levels of the chemical up to 100,000 times higher than normally consumed in food.
Human studies have shown a possible association between acrylamide and cancers of the uterus, ovaries and kidneys, though no association for breast, bladder and prostate cancer, Hogervorst said.
Even though the data on human health has remained unclear, food safety authorities in Europe have started to curb acrylamide in foods.
The authors of this paper prospectively looked at more than 120,000 men and women aged 55 to 69 participating in the Netherlands Cohort Study on diet and cancer.
In this study, Dutch spiced cake and coffee were the largest dietary sources of acrylamide.
"Coffee beans naturally contain the necessary ingredients for acrylamide formation, which are carbohydrates and the amino acid asparagines," Hogervorst explained. "When coffee beans are roasted, temperatures [more than 120 degrees Celsius] necessary for the acrylamide-forming chemical reaction are reached. Then, when filtered coffee is prepared from the beans, acrylamide dissolves in the water and passes through the filter into the filtered coffee."
But coffee, Thun pointed out, has been studied extensively without any clear increase or decrease in cancer risk.
There was no positive or negative relationship between acrylamide and colorectal, gastric, pancreatic or esophageal cancer.
There were, however, significantly increased risks within certain subgroups when classified on the basis of obesity, physical activity and age, all factors which bear further scrutiny, the authors stressed.
Given that there have been associations between acrylamide intake and endometrial and ovarian cancer as well as estrogen-receptor positive breast cancer, there is a suspicion that acrylamide may cause cancer through a hormonal pathway, Hogervorst said.
The U.S. Food and Drug Administration has more on acrylamide.