Acrylamide in Food: What Are the Health Risks?
Most people consuming typical Western diets ingest at least small amounts of acrylamide every day from the food they eat and the beverages they drink. But how bad is that for your health, really? In this article, we take a look at the current knowledge about the potential health risks associated with ingesting acrylamide from food.
Acrylamide is a chemical compound that is formed in starchy foods when they are heated to high temperatures. It is usually found in high amounts in coffee, chips, and many other foods and drinks that have gone through a heat treatment (such as baking or roasting) at some point during the preparation. You may also be surprised to learn that this potentially harmful substance is not only found in junk food, such as chips and fries, but it also occurs in many 'health foods' such as prunes, rye bread and unsweetened cocoa (see Acrylamide Food List for more information).
Effects on the Nervous System and Fertility
Acrylamide is a cumulative neurotoxin. Based on animal studies, repeated and/or high exposure exceeding the safety limits may decrease fertility and cause serious damage to the central and peripheral nervous systems. A 2008 study published in the Journal of Agricultural and Food Chemistry suggests that the neurotoxic effects of acrylamide may be linked to its ability to inhibit the transmission of nerve impulses by disrupting a signal sent by nitric oxide.
Neurotoxicity resulting from exposure to acrylamide may cause a range of symptoms, including feeling of numbness in the hands and feet. It has also been proposed that the neurotoxic effects of acrylamide might play a role in the pathogenesis of Alzheimer's disease.
Although acrylamide has known neurotoxic effects, a June 2002 report by the Food and Agriculture Organization (FAO) of the United Nations and the World Health Organization (WHO) concluded that the no observed adverse effect level (NOAEL) for acrylamide neuropathy is likely to be 0.5 mg/kg body weight/day, which is 500 times higher than the estimated average dietary intake of acrylamide (1 µg/kg body weight/day). For negative effects on fertility, the NOAEL is about 2,000 times higher than the average dietary intake.
As a result, the FAO/WHO report concluded that no neurotoxic effects are to be expected from the levels of acrylamide present in food. It is worth noting, however, that this risk assessment was derived from data obtained from studies carried out on rodents and monkeys due to a lack of dose-response data for human neurotoxicity.
Note: If you suffer from a nervous system disease, ask your doctor whether you should follow an acrylamide avoidance diet.
Cancer Risk from Acrylamide in Food
The 2002 FAO/WHO report on the potential health risks associated with the ingestion of acrylamide from food raised major concerns over the potential to acrylamide to increase the risk of cancer in humans. These concerns are based on the known ability of acrylamide to induce cancer and heritable mutations in rats. In rodents, high doses of acrylamide have been shown to increase the risk of tumors in the nervous system, mammary gland, uterus, oral cavity, peritoneum, and thyroid gland. However, according to the Carcinogenic Potency Database (CPDB) there is a 900-fold margin between the dose that gave cancer to 10% of rodents and human exposure to acrylamide from an average diet.
To better assess the actual cancer risk in humans associated with the ingestion of acrylamide from food, researchers from all over the world have carried out extensive studies using food frequency questionnaires. However, most of these studies have failed to show a link between dietary intake of acrylamide and risk for different types of cancer.
Some critics have pointed out, however, that food frequency questionnaires are not a very good measure of actual acrylamide exposure. Consequently, a 2008 study using blood acrylamide levels after adjusting for smoking did find a 2.7-fold increase in risk for estrogen receptor-positive breast cancer for every 10-fold increase of acrylamide. For more in-depth information, see Acrylamide and Cancer Risk.