In April 2002 scientists at the Swedish Food Administration first reported unexpectedly high levels of the chemical acrylamide in carbohydrate-rich foods, including crisps, chips, and some breads. Since then, acrylamide has been found in a range of cooked and heat-processed foods in other countries, including the Netherlands, Norway, Switzerland, the United Kingdom and the US.
Teams of scientists, both government and industry-funded, in the western world are currently working to learn more about how acrylamide is formed in foods. At the national meeting of the American Chemical Society this week in Anaheim, California, international scientists will bring into the forum their latest data.
Lorelei Mucci at Harvard University's School of Public Health, and colleagues, are currently examining the risk of cancer among people who consume foods with acrylamide. So far, the team has conducted four studies within Swedish populations.
Data from two of the studies found no link between dietary acrylamide and risk of bladder, kidney or colorectal cancer. Two larger ongoing studies, each of more than 50,000 women, are examining colorectal and breast cancer risk.
Hubert Vesper from the US government's Centers for Disease Control and Prevention found in a small pilot study that people who snack heavily on potato chips may experience an increase in acrylamide exposure.
These results will be verified in a larger feeding study, in which acrylamide biomarkers - in particular, haemoglobin adducts of acrylamide and its primary metabolite glycidamide - will be measured after people eat food containing naturally occurring acrylamide.
Peter Sadd, Colin Hamlet and other researchers at RHM Technology in High Wycombe, UK, have found a surprising lack of acrylamide in some bakery products, reports the ACS.
"Contrary to popular assumption, certain richly flavoured and coloured foods, such as fruitcake and crumpets, reveal low levels of acrylamide," say the researchers. An ongoing study, funded by the UK's Food Standards Agency (FSA) is measuring acrylamide in a wide range of cereal products and exploring the biochemical basis behind its variation.
From the food industry, David Zyzak at Procter and Gamble is looking at the biochemistry behind acrylamide formation in heated foods. They have found evidence that the chemical emerges from the reaction of the amino acid asparagine with carbonyl compounds at typical cooking temperatures. Studies, says the ACS, using the enzyme asparaginase have been shown to significantly reduce acrylamide levels in lab models of heated foods.
Varoujan Yaylayan and colleagues at McGill University in the US are looking at the chemistry behind acrylamide in heated foods. Researchers have generally pointed to asparagine as the major amino acid that yields acrylamide during certain cooking conditions. However, the McGill team identified other amino acids that may, under the right conditions, also produce acrylamide or its derivatives. Studies may lead to strategies for lowering acrylamide in heated foods, say the researchers.
Concerns over the presence of acrylamide in processed foods flared up again earlier this week after the US FDA detected levels of this carcinogenic chemical in a new batch of foods.
The FDA study of 740 food samples released on Sunday adds black olives, teething biscuits and prune juice to the growing list of food products containing levels of acrylamide.
"The new data are consistent with previous findings showing higher levels of acrylamide in potato-based and other carbohydrate-rich products processed at high temperatures and lower levels of acrylamide in dairy foods and infant formulas," said the FDA in a statement.