Acrylamide: What We Have Learned So Far

In April 2002, Swedish researchers shocked the food safety world when they presented preliminary findings of acrylamide in fried and baked foods, most notably potato chips and French fries, at levels of 30–2,300 ppb. They also reported that foods cooked or processed at temperatures lower than about 120°C, such as boiled potatoes, did not contain detectable levels of acrylamide, and attributed this to the higher temperatures reached in Maillard nonenzymatic browning reactions required for desirable color, flavor, and aroma production.

The chemical, a well-known neurotoxicant, had never before been reported in foods or beverages, but it has surely been present in food since man first began cooking. Its critical safety importance is reflected in its classification by several regulatory agencies and health advisory bodies as a “probable human carcinogen” based on high-dose animal cancer bioassays.

Numerous academic, government, and industry research groups worldwide have initiated major acrylamide research programs on mechanisms of formation and mitigation, methods of analysis, dietary exposure and biomarkers, toxicology and metabolic consequences, and risk communication, to determine acrylamide intakes in various diets and whether acrylamide is a significant public health risk.

The Joint Institute for Food Safety and Applied Nutrition has played a major role in coordinating global acrylamide research and education. It serves as the  AO/WHO Acrylamide in Food Network, or Acrylamide Infonet (www.acrylamidefood.org), and its Food Safety Risk Analysis Clearinghouse maintains the most current and complete Web page (www.foodriskclearinghouse.umd.edu/acrylamide.cfm) listing key acrylamide Web links.

Five international research groups have separately confirmed a major Maillard reaction pathway for acrylamide formation. Using elegant radiolabeling experiments, they conclusively demonstrated in model systems that significant amounts of acrylamide are formed by the high-temperature reaction of glucose and the common amino acid asparagine. Since potato products are especially high in asparagine, it is now thought that this Maillard reaction is most likely responsible for the majority of the acrylamide found in potato chips and French fries. Research is underway to determine if this reaction may also be responsible for acrylamide formation in other foods and beverages, but it is unlikely that this reaction is the only one responsible, since other Maillard and non-Maillard reactions may also play a role.

At its December 4–5, 2002, meeting to review and evaluate its “Draft Action Plan for Acrylamide in Food,” FDA released Maillard reactions may also play a role. exploratory analytical data on acrylamide levels in about 300 food samples, and said that it plans to test an additional 1,500 samples over the next year. Besides the already known occurrence of acrylamide in fried potato products, cereals, breads, and bakery products, FDA reported significant concentrations of acrylamide in some baby foods, snack foods other than potato chips, nuts and nut butters, chocolate products, coffee, and various dried foods. Therefore, it is now apparent that a wide range of heated foods contain acrylamide, some at levels up to several thousand ppb, far higher than levels of other potential food carcinogens identified over the past 30 years.

Nowhere is the impact of the Swedish acrylamide discovery being felt more strongly than in California. Acrylamide is listed as a carcinogen under the Safe  drinking Water and Toxic Enforcement Act of 1986 (“Proposition 65”), a law requiring that a cancer warning be given to consumers on the food product label if the average daily consumption of acrylamide in that product exceeds the No Significant Risk Level (NSRL) of 0.2 µg/day. Two groups have already sued several food manufacturers and fast-food restaurant companies for failure to provide a cancer warning on acrylamide-containing products, and a coalition of food trade associations has asked the state to exempt acrylamide from such warning requirements because they believe acrylamide “poses no significant risk.” Because of the widespread presence of acrylamide in prepared foods consumed throughout the world, warning labels on products sold in California are not scientifically justified and will not have any meaningful public health value in reducing cancer risk to consumers.

The information currently available on acrylamide in foods is not sufficient to draw firm conclusions about cancer risk to humans. FDA, the World Health Organization, the European Union, and other bodies have stated that there is no indication at this time that consumers need to change their eating habits in response to the acrylamide findings, but instead advise consumers to follow established dietary guidelines and eat a healthful, balanced diet consisting of a wide variety of foods. A massive global research effort is underway to answer the outstanding questions about acrylamide’s safety, and an update will be presented at a symposium during the IFT Annual Meeting, July 12–16, 2003, in Chicago.