New research into the controversial substance acrylamide, cited as a possible cancer-causing agent found in some fried and baked foods, suggests that it can damage DNA by causing mutations.

The California-based study discovered that acrylamide mutates DNA in mouse cells. In tests, those cells exposed to the substance showed more adducts - specific types of mutations in the DNA - than unexposed cells.

However, acrylamide experts Fredrik Granath and Margareta Tornqvist say that the risk to any one person from eating acrylamide remained small and they would not recommend changing nutritional guidelines. Nonetheless, vulnerable groups, such as pregnant women and children, have been advised to treat foods with high concentrations of acrylamide with caution.

Swedish researchers sparked worldwide interest in 2002 when they reported that acrylamide, used to purify water and in other industrial processes, could be found in a range of baked and fried foods, prompting fears of a food safety problem.

Subsequent research has questioned this theory, with several studies concluding there is no link between acrylamide consumption and the risk of bladder or kidney cancer, but the effects of the substance remains a source of debate.

The new findings have been published in the latest issue of the Journal of the National Cancer Institute .