by Jennifer Novakovich
You may have heard the word “acrylamide” popping up, even featured in popular shows such as Dr. Oz. Acrylamides are a chemical commonly found in many of the foods we eat at variable concentrations; the highest concentrations are found typically in white potatoes and cereal products, presenting a difficult issue for the food industry to manage. Acrylamides are thought to be potentially carcinogenic, with both neurological and reproductive effects. Are acrylamides something we should be concerned with? Should we consider reducing or eliminating acrylamide rich foods from our diets? Read on for more information on this controversial topic.
Acrylamides are used industrially to primarily produce polyacrylamide, but they are also used as grouting agents. Polyacrylamide is used in water treatment, soil treatment, paper production, ore processing, and gel electrophoresis. Acrylamide in foods was first reported by the Swedish National Food Authority and the University of Stockholm in April 2002. These scientists, who were originally studying the exposure of acrylamides on tunnel workers after spilling grouting agents, began seeking a reason to why people who were never exposed to these situations had levels of acrylamide in their blood. This ultimately led to the discovery of acrylamide in cooked (above 120 degrees Celsius) potatoes (carbohydrate rich). Foods were then collected from Stockholm stores and acrylamides were ultimately found in many carbohydrate-rich plant foods.
The Swedish report was quickly verified by a number of other countries, attracting worldwide attention for its potential adverse health effects in humans. Acrylamide toxicity has been subject to a number of studies including high-dose animal studies (primarily rodents), where acrylamides were demonstrated to be both a carcinogen and genotoxin. In humans, acrylamides are primarily neurotoxic, but are currently considered “probably carcinogenic to humans” by the International agency for Research on Cancer. This statement is largely based on acrylamide’s documented carcinogenic, neurological, and reproductive effects on rodents. As a result, The Food and Agricultural Organization and the World Health Organization speedily had an expert consultation about acrylamides in food in June 2002. A number of recommendations were given, including ones for more research, leading to a worldwide collaborative effort still in process today.
The food industry quickly reacted to the discovery of acrylamides and initiatives to reduce acrylamides, including new crop varieties with lower amounts of asparagine and/or less sugar. While the levels of acrylamides have been reduced in some products, it is much harder in other products (effects taste or is just not currently possible). With the lack of plausible evidence, no country is yet to take regulatory action but world-wide food industries have made efforts to reduce acrylamides to “as low as reasonably achievable.”
Major acrylamide contributors in human diets include fried potato products, coffee, soft bread, and cookies. In the United States, the major contributors are French fries (10–60%), chips (10–22%), bread and toast (13–34%), and cookies (10–15%). While animal studies have shown a strong relationship between acrylamides and detrimental health effects, epidemiological studies on humans have been less conclusive. There are, however, a small number of studies that have shown a weak link between acrylamides and endometrial cancer. While acrylamide is a well-known toxin to the central nervous system at high doses, these high doses are not thought to occur by dietary exposure and the majority of studies have failed to show an association between detrimental health effects and acrylamide-containing foods. Regardless, the WHO has recommended a reduction of acrylamides and the European Commission issued indicative acrylamide levels in 2011. It is now classified by the U.S. National Toxicology Program’s (NTP) Report on Carcinogens as “reasonably anticipated to be a human carcinogen,” and by the U.S. Environmental Protection Agency (EPA) as “likely to be carcinogenic to humans.”
How are acrylamides formed in the foods we eat? Acrylamides are formed when asparagine and sugars are exposed to high-temperatures (above 120 degrees Celsius) while cooking or processing (frying, baking, and roasting, but not boiling). Asparagine is an amino acid that tends to accumulate in plants at very high concentrations; potatoes are particularly high in asparagine (and carbohydrates, i.e. sugars). The accumulation in plants can be directly related to their exposure to environmental stresses, e.g., toxic metals, pathogens, salt, nutrient deficient soil, or drought. Acrylamide formation occurs by a series of reactions with the umbrella name “the Maillard reaction.” The reaction only occurs when heat is present and therefore raw plant foods do not have acrylamides, and neither do foods produced by low temperature cooking or boiling. On a side note, the Maillard reaction is also a source for melanoidin, which gives cooked products their color and much of their aroma and flavor. When looking for ways to reduce acrylamides, the above fact makes it difficult for the food industry to remove them without compromising the taste and quality of foods.
And that brings me to the question, should we worry about acrylamides in the first place? Cereal and potato products are currently major contributors to the nutritional needs of many. In the United States, it has been estimated that acrylamide containing foods contribute to about 38% of daily calories, 36% of fiber, 33% of carbohydrates and more than 25% of many micronutrients. At the same time, after a decade since the discovery of acrylamides in foods, we are yet to even confidently say that there is any risk at all with consumption.
With that said, I personally think it wouldn’t hurt to reduce the major acrylamide forming foods and replace them with with more fresh fruits, vegetables, nuts, and legumes and also to opt for cooking at lower temperatures or using a dehydrator. Easy things to do would be to reduce the amount of cookies, white potatoes (especially French fries and potato chips), and toast (especially darkly browned) we consume. With the given state of overconsumption of calories, reducing these foods, even if acrylamides are not something we need to be concerned with, could go a long way in terms of weight management. As a result, there could also be reduced risks for many chronic diseases including diabetes and heart disease.
With the history and evidence of acrylamides above, what are your thoughts on the current initiatives to reduce their presence in the foods we eat? Do you think they are something we should be concerned with?Halford NG, Curtis TY, Muttucumaru N, Postles J, Elmore JS, Mottram DS. (2012) The acrylamide problem: a plant and agronomic science issue. J Exp Bot. 63(8):2841-51.Lineback DR, Coughlin JR, Stadler RH. (2012) Acrylamides in foods: a review of the science and future considerations. Annu Rev Food Sci Technol. 3:15-35.See this and other articles on Jennifer Novakovich’s website JennovaFoodBlog.com