What is acrylamide and why is it found in food products?
Acrylamide is an organic compound that is formed specifically when certain foods are prepared at low moisture and at temperatures usually above 120 °C, such as in the case of baked, roasted or fried foods including French fries, potato crisps, breads, biscuits and coffee beans. It results from a reaction between sugars and certain amino acids (the constituents of proteins) such as asparagine. This is called the ‘Maillard reaction’, and it is what gives browned food a distinctive color and taste. Acrylamide is also formed and present in cigarette smoke.
What are the adverse effects that acrylamide can produce?
In both laboratory animals and humans, acrylamide passes through the gastro intestinal tract and reaches the bloodstream. It can cross the placenta and is transferred to a small extent into human milk.
To facilitate its excretion the body transforms acrylamide into other molecules, one of them being glycidamide, which is considered to be the molecule that causes the genotoxicity and carcinogenicity of acrylamide. Glycidamide can bind itself to DNA or to proteins such as haemoglobin. Acrylamide and glycidamide can be further broken down into mercapturic acids that are excreted into urine and the analysis of their presence can be used as a marker to determine exposure to acrylamide.
In laboratory animals, exposure to acrylamide at high enough doses can have a variety of effects, but the main effects are toxicity to the nervous system, mutations and damage to chromosomes, and carcinogenicity.
In humans, studies of people who are exposed to acrylamide through their work did not indicate an increased cancer risk. There is also no consistent indication from available studies for an association between acrylamide exposure through food and an increased risk of most cancers. A few studies suggested an increased risk for renal , endometrial (in particular in never-smokers) and ovarian cancer but the evidence is limited and inconsistent.
Two studies reported an inverse relationship between acrylamide exposure and weight at birth and other markers of fetal growth but it has not been established whether or not this association is causal.
Studies among workers occupationally exposed to acrylamide showed an increased risk of neurological alterations, including mostly the peripheral but also the central nervous system. However in most cases these symptoms were reversible.
Is there a risk of adverse effects from acrylamide from food or other types of exposure?
By comparing the estimated exposure calculated from diet with the highest levels of exposure at which no health effects were observed, a margin of exposure (MOE) can be calculated. In this case, the margins of exposure ranged from 50 to 425 depending on the population groups. Since the EFSA Scientific Committee considers that for substances that are both carcinogenic and genotoxic, a margin of exposure of 10 000 or higher would be the level of low concern from a public health point of view, a concern remains with respect to the risk of cancer, even if there is no clear experimental or epidemiological (human) evidence that acrylamide causes cancer in humans.
The CONTAM Panel also noted that acrylamide is a mutagen for germ cells and that there are at present no established procedures for risk assessment using this endpoint. Finally the Panel made a series of recommendations to improve the risk assessment related to the exposure to acrylamide in the future.
How was dietary exposure evaluated?
In order to evaluate the exposition of the population to acrylamide through food, a large number of measurements of acrylamide in food was compiled and combined with survey data on the diet consumed across Europe. The highest concentrations were found in coffee and potato crisps. Estimation of human exposure to acrylamide revealed that infants, toddlers and other children were the most exposed population groups, with the highest exposures at 3.4 µg/kg b.w. per day, whereas the highest exposures in other groups were at 2.0 µg/kg b.w. per day. Scenarios were designed in order to assess the influence of specific behaviours (e.g. preference for particular products, places of consumption, home-cooking habits) on the total dietary exposure to acrylamide, and the highest variation came from conditions of potato frying from which the total dietary exposure to acrylamide could be increased up to 80 %.