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Publication #FCS8759

Acrylamide in Foods: A Review and Update1

Amy H. Simonne and Douglas L. Archer2

Introduction

The presence of acrylamide in many fried and baked foods surfaced in 2002 following publications of research done in Sweden. These news reports raised concerns among consumers and professionals because acrylamide is known to be toxic and can cause cancer in animals. This publication provides background information on acrylamide along with its content in foods. This publication will be revised periodically to include new information as it becomes available.

What is acrylamide?

Acrylamide is a versatile organic compound that finds its way into many products in our everyday life. Acrylamide exists in two forms: a monomer (single unit) and a polymer (multiple units joined together by chemical bonds) (1). The single unit form of acrylamide is toxic to the nervous system, a carcinogen in laboratory animals, and a suspected carcinogen in humans. The multiple unit or polymeric form is NOT known to be toxic.

Acrylamide Uses

The monomeric form of acrylamide is primarily used in research laboratories for gel preparation. The acrylamide gel is used for electrophoresis, a technique for protein separation. It is also used to produce grout, dyes, contact lenses, and in the construction of dams, tunnels, and sewers.

Acrylamide polymers are used as additives for water treatment, flocculants, paper making aids, thickeners, soil conditioning agents, textiles (permanent-press fabrics), production of organic chemicals, and ore and crude oil processing. Although the polymer polyacrylamide is not toxic, a small amount of the acrylamide monomer may leach from the polymer.

Acrylamide Exposure

Traditionally, human exposure to acrylamide (monomeric form) was thought to occur only in workplaces or other environments with little relevance to the public at large. However, it is now known that acrylamide can be absorbed through skin contact, inhalation, or consumption of contaminated foods or water. The World Health Organization (WHO) has set a maximum limit for acrylamide in water to be 0.5 microgram per litre for a lifetime of consumption (http://www.who.int/foodsafety/publications/chem/acrylamide_faqs/en/index3.html), while the US Environmental Protection Agency (EPA) have set the maximum contaminant levels for acrylamide in drinking water is 1 mg/L per liter (http://water.epa.gov/drink/contaminants/index.cfm#8). Smokers absorb the chemical from tobacco smoke, as can those exposed to second hand smoke. Currently, data on acrylamide intake from foods and its fate in the body after the intake are limited.

Once inside the body, acrylamide binds to red blood cells. Potential symptoms of overexposure to monomeric acrylamide include numbness of the limbs, and weakness and lack of coordination in the legs. Long-term exposure to small doses of acrylamide causes nerve damage in the extremities. Some tunnel construction workers have experienced neurological damage from exposure to acrylamide in grout. Animal studies have shown acrylamide to be a carcinogen, although evidence supporting increased cancer in humans following occupational exposures to acrylamide remains controversial.

Why the sudden concern about acrylamide in fried and baked foods?

A group of Swedish researchers found that some fried or baked high-carbohydrate foods such as potato chips and french fries contain high levels of acrylamide. Because these foods are widely consumed in significant amounts, much interest and concern was generated from the report published in April 2002 (2).

The researchers reported moderate levels of acrylamide (5-50 ppb) in heated protein-rich foods and higher contents (150-4000 ppb) in carbohydrate-rich foods such as potato, beetroot, and selected commercial potato products. Median levels of acrylamide were found at 1,200 ppb in potato chips, 450 ppb in french fries, and 410 ppb in biscuits and crackers. The same group of researchers also stated that acrylamide was not found in the same foods in the raw state or in foods prepared by boiling(2). The researchers examined the heated foodstuffs for acrylamide because they have consistently found acrylamide in red blood cells of some Swedish adults who apparently had no known sources of exposure to acrylamide.

Based on these findings, the Swedish National Food Administration and the researchers at Stockholm University estimated an average intake of acrylamide from food in Sweden to be 35-40 micrograms per day.

How is acrylamide formed in foods?

Acrylamide has been found in certain foods that have been cooked or processed at high temperatures. The levels of acrylamide appear to increase with the time of heating. However, the mechanism of acrylamide formation in foods is not well understood. Acrylamide appears to be formed as a byproduct of the Maillard reaction. The Maillard reaction is best known as a reaction that produces the tasty crust and golden color in fried and baked foods. This reaction can occur during baking or frying when there is a proper combination of carbohydrates, lipids, and proteins in foods (3). The FDA recently proposed that one mechanism may involve the amino acid asparagine which, when heated in the presence of glucose, forms acrylamide.

Because the asparagine content of foods within a certain category (e.g., potatoes) varies greatly, this asparagine-dependent reaction may explain the tremendous variability in acrylamide levels even within one food category. There may be more than one way that acrylamide forms in foods. An understanding of how acrylamide forms in various foods may lead to the development of methods to prevent or limit its formation (4, 5).

Based on current stage of knowledge, acrylamide is a natural byproduct that forms when certain carbohydrate-rich foods are fried, baked, or roasted at high temperatures above 120° (7). Acrylamide can cause cancer in laboratory animals at high doses, although it is not clear whether it causes cancer at the much lower levels found in food.

What has been done?

The Swedish study prompted the United Nations WHO and the United Nations Food and Agriculture Organization (FAO) to convene an Expert Consultation to examine the issue. On June 25-27, 2002, a panel of 23 experts met and prepared a report on behalf of the FAO and WHO. The report notes that information on the presence of acrylamide in food is incomplete and that the magnitude of cancer risk for humans has not been quantified. The report suggests further studies in areas such as dietary intake and the toxicology of acrylamide, the modes of formation, fate and levels of acrylamide in foods, and the development of sensitive, reliable, and low-cost methods of analyses.

The US Food and Drug Administration has recently made available its methodology for the determination of acrylamide. Since the discovery of acrylamide in food in 2002, the FDA has initiated many research studies on acrylamide including the carcinogenicity and neurotoxicity studies and the toxicology modeling work cited in the Joint Expert Committee on Food Additives (JECFA), and the results are expected in 2007.

According to the FAO/WHO report, which is based on the available published data, food is estimated to make a significant contribution to the total exposure of acrylamide. Average intakes of acrylamide were estimated to be 0.3-0.8 microgram acrylamide per kilogram of body weight per day in diets of people in developed countries. Dietary intakes of acrylamide may vary greatly from person to person. The FDA recently initiated a survey for acrylamide in foods in the U.S. and also created an Action Plan for Acrylamide in food in March 2004. This information can be found at http://www.fda.gov/Food/FoodborneIllnessContaminants/ChemicalContaminants/ucm2006782.htm [23 March 2013].

Further, the FDA has created a database for the acrylamide content in foods as well as conducted a total diet study. In 2004, the FDA identified foods that are high in acrylamide content per portion. Some examples of these foods include french fries, potato chips, canned black olives, and breakfast cereals. The results can be viewed at http://www.fda.gov/Food/FoodSafety/FoodContaminantsAdulteration/ChemicalContaminants/Acrylamide/ucm053549

What consumers can do?

Many potentially harmful chemicals are present at extremely low levels in both the environment and our foods. In many cases the levels of these are far below those expected to have an effect on human health. In recent years, analytical methods and instrumentation have advanced considerably, allowing detection of every small levels of chemicals that may or may not have adverse effects on human health (6). Although the information on acrylamide in foods and its implications for human health is not yet complete, the FAO and WHO have issued interim advice based on current knowledge to minimize existing risks.

Despite research implications that exposure to acrylamide from food is safe, some consumers may choose to take measures to further reduce their acrylamide exposure. The FDA provides the following tips for consumers who would like to minimize acrylamide in food.

  • In comparing frying, roasting, and baking potatoes, frying causes the highest acrylamide formation, followed by roasting, and then baking. Boiling potatoes and microwaving whole potatoes with skin on to does not produce acrylamide. Soaking raw potato slices in water for 15-30 minutes before frying or roasting helps reduce acrylamide formation. To avoid splattering or fire, potatoes should be drained and blotted dry after soaking.

  • Storing potatoes in a cool, dark place in the kitchen instead of in the refrigerator will prevent sprouting and reduce acrylamide formation.

  • The brownness of a potato or bread after cooking is correlated with increased amounts of acrylamide formation.

  • Acrylamide forms in coffee when coffee beans are roasted, not when it is brewed. There is no known way to reduce the acrylamide that forms when coffee beans are roasted, however, the amount of acrylamide in coffee is still safe to consume on a regular basis.

(http://www.fda.gov/Food/FoodSafety/FoodContaminantsAdulteration/ChemicalContaminants/Acrylamide/ucm151000.htm)

Sources and References

  1. The Merck Index, 12 ed. 1996. p.132.

  2. Tareke, E., Rydberg, P., Karlsson, P., Ericksson, S., and Törnqvist, M. 2002. Analyses of acrylamide, a carcinogen formed in heated foodstuffs. . 50:4998-5006.

  3. Tareke, E., Rydberg, P., Karlsson, P., Ericksson, S., and Törnqvist, M. 2000. Acrylamide: A cooking carcinogen? . 13, 517-522.

  4. Janet Raloff. 2002. FDA Launches Acrylamide Investigations. 162(15).

  5. Mottram, D.S., Wedzicha, B.L. and Dodson, A.T. 2002. Acrylamide is formed in the Maillard reaction. 419:448-449.

  6. AOAC International. Inside Laboratory Management. September/October 2002. Pp. 8-9.

  7. International Food Safety Authorities Network (INFOSAN), 2005. Acrylamide in food is a potential health hazard. INFOSAN Information Note No. 2/2005 - Acrylamide. Pp. 1-5.

  8. Pelucci, C. 2012. Exposure to acrylamide and human cancer—a review and meta-analysis of epidemiologic studies. Annals of Oncology 22(7): 1487-1499.

Pertinent reports and additional information on the subject can be found at:

http://www.who.int/foodsafety/publications/chem/en/acrylamide_summary.pdf

http://www.fda.gov/Food/FoodborneIllnessContaminants/ChemicalContaminants/ucm2006782.htm

http://www.acrylamide-food.org/

http://www.who.int/foodsafety/chem/chemicals/acrylamide/en/

Footnotes

1.

This document is FCS8759, one of a series of the Department of Family, Youth and Community Sciences, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Publication October, 2002. Revised April 2006 and March 2013. Please visit the EDIS website at http://edis.ifas.ufl.edu.

2.

Amy H. Simonne, Ph.D., assistant professor, Department of Family, Youth and Community Sciences; Douglas L. Archer, Ph.D. , professor, Food Science and Human Nutrition Department, Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, 32611. Reviewed by Linda B. Bobroff, Ph.D., RD, LD/N, professor, Department of Family, Youth and Community Sciences; R. Elaine Turner, Ph.D, RD, associate professor, Food Science and Human Nutrition Department.


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U.S. Department of Agriculture, UF/IFAS Extension Service, University of Florida, IFAS, Florida A & M University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Nick T. Place, dean for UF/IFAS Extension.