WHO officials have stressed that, although many pieces of information about acrylamide and its effects in animals do exist, a full picture of the levels in food and effects on humans does not, and therefore WHO will be looking to fill in relevant gaps in knowledge.
In 1994, the International Agency for Research on Cancer of WHO evaluated acrylamide as "probably carcinogenic to humans" (Group 2A). This evaluation was based on sufficient evidence of carcinogenicity in experimental animals and extensive supplementary evidence that acrylamide has a chemically reactive mode of action as a toxicant, causing DNA adducts, gene mutations and chromosome abnormalities in animal cells and haemoglobin adducts (a biomarker of exposure) in both exposed animals and exposed humans. The few epidemiologic studies of acrylamide that were available at that time were inadequate to establish that occupational exposures to acrylamide had increased cancer risks in exposed workers.
In announcing the discovery of high levels of acrylamide in food by research teams at Stockholm University and the Swedish National Food Administration (NFA), the NFA said that: "Present knowledge does not allow for a balanced analysis of risks and benefits of staple foods containing acrylamide. The Swedish NFA can currently only issue general advice regarding the risk management of acrylamide to the food industry and consumers… More knowledge is needed before the dietary advice issued by the NFA can be changed." The level of acrylamide produced during food preparation was reported in the Swedish studies to increase with the temperature at which the food is cooked.
WHO emphasized that several questions still need to be resolved before more definitive advice can be given. For example, is acrylamide taken up from food as readily as it is from water? If it is, what is the risk that this uptake will lead to harmful effects in humans?
The WHO informal expert consultation, planned to take place before the end of June, will look at these questions. Other topics that the consultation will consider are epidemiological data, levels in food in other countries, processing conditions that either increase or reduce those levels, and development of appropriate guidance to reduce exposure to acrylamide.
None of the results announced 24 April in Sweden would cause WHO to change its basic dietary advice. WHO recommends eating more fruits and vegetables and less fat-containing foods.