Dietary Acrylamide and Cancer Risk

Acrylamide is a colorless, odorless compound frequently used industrially in polyacrylamide polymers, dyes, organic chemicals, fabrics, paper and textiles, cosmetics, sugar purification, contact lenses and soil stabilization. In 1994, the International Agency for Research on Cancer (IARC) listed it as an industrial chemical potentially posing a carcinogenic risk to humans: there is sufficient evidence of cancer in animals but limited human data (Group 2A carcinogen).

Acrylamide also occurs in dietary sources / foods. It forms during heating (from 120 degrees Celsius to 180 degrees), particularly when free amino acids (such as asparagine), sugars and certain dietary products are heated, resulting in variable concentrations. Defined as averaging above 200 micrograms / kg, foods with high acrylamide content include grain products, breads, pastries, crunchy snacks, potato and tortilla chips, French fries and sweet potato fries, instant or decaffeinated coffee, and cocoa products.

Concerns About Acrylamide

Concern about potential human health effects of food acrylamide began shortly after its first detection in heated foods in 2002.

Definitive evidence of an association between acrylamide and cancer in humans isnotavailable; nevertheless, based on animal model data, the World Health Organization’s Expert Committee on Food Additives concluded in 2010 that acrylamide was a human health concern. The US Food and Drug Administration (FDA) actively researches acrylamide and monitors food levels. It has also published industry guidance on reducing acrylamide levels in prepared foods.

• Related Topic: On the California Court Ruling Declaring "Coffee Causes Cancer" Because of Its Acrylamide Content

Acrylamide and Cancer Evidence

The US National Toxicology Program (NTP) conducted a comprehensive study and literature review of acrylamide-induced genotoxicity and carcinogenicity, published in 2012. Its carcinogenicity studies concluded that there was clear evidence of increased incidence of several cancers in experimental mice and rats exposed to acrylamide in drinking water. However, for human carcinogenicity, NTP noted that occupational acrylamide exposure, apart from a potential association with pancreatic cancer , showed no consistent dose-response relationship indicating increased incidence of any cancer type.

Population studies evaluated dietary acrylamide, mainly measured by questionnaires, and risk of different cancers. Most showed no association. A meta-analysis including large cohorts such as the European Prospective Investigation into Cancer and Nutrition (EPIC) and Nurses’ Health Study (NHS) found no association between high or low dietary acrylamide intake and cancer. This included multiple cancers: oral cavity and pharynx, esophagus, stomach, colorectal, pancreatic, laryngeal, lung, breast, endometrial (uterine), ovarian, prostate and bladder cancers, or lymphoid malignancies.

NOTE: Cohort can be understood as a group of people moving together from an exposure toward an outcome. It is also defined as a group of people of the same age.

The authors noted that 1 study finding a positive association with breast cancer risk was excluded because it used biological exposure markers rather than dietary intake and did not match cases and controls by smoking status. This matters because smokers are known to receive much higher acrylamide exposure than nonsmokers, and smoking is associated with breast cancer.

The meta-analysis found a significant association between acrylamide and a 20% increased kidney cancer risk (relative risk 1.20). However, the authors noted that the analysis included approximately 1800 kidney cancer cases, a small sample limiting the certainty of findings.

Many cohort studies published after the meta-analysis also found no association between acrylamide and cancer. For example, a Japan Public Health Center-based prospective study, with more than 15 years of follow-up, found no association between dietary acrylamide and esophageal, stomach or colorectal cancer.

Conclusion

Animal model data indicate that acrylamide has the potential to cause cancer; however, human studies to date show no association between dietary intake and the risk of developing different cancers. Human evidence is therefore insufficient. Nevertheless, regulatory agencies provide guidance documents to help industry reduce acrylamide levels in processed foods and help consumers understand the acrylamide content of their food and drinks.