Acrylamide: A cooking carcinogen?

Exposure to acrylamide (AA) has been monitored by mass spectrometric detect ion of the adduct, N-(2-carbamoylethyl)valine (CEV), to the N-termini of he moglobin (Hb), according to the N-alkyl Edman method. In these studies, a c onspicuous background level, about 40 pmol/g of globin, of apparently the s ame adduct was regularly observed in Hb from persons without known exposure to AA. For testing of the hypothesis that this adduct originates from AA f ormed in cooking, rats were fed fried animal standard diet for 1 or 2 month s. These animals exhibited a strong increase of the level of the studied Hb adduct, compared to control rats fed unfried diet. By gas chromatography/t andem mass spectrometry, the identity with CEV was confirmed by the concord ance of the product ion spectrum of the studied adduct with that of a verif ied standard and by interpretation of the fragment ions. Further support of the chemical structure, at the same time pinpointing AA as the causative r eactive factor, was obtained through the demonstration that AA is formed in the heating of the feed and that the level of AA in the fried feed is comp atible with the measured levels of the CEV adduct. The raised CEV adduct le vels observed in experimental animals are of a magnitude that is similar to the background level in nonsmoking humans. These data render it likely tha t cooking of food is a major source of the background dose of AA also in hu mans. An evaluation of cancer tests of AA and available data for its metabo lism leads to the estimation that the background dose of AA is associated w ith a considerable cancer risk.