The Carcinogen Glycidol and Use of N-(2,3-Dihydroxypropyl)-valine in Hemoglobin as a Biomarker of Exposure

Abstract

Fatty acid esters of glycidol (glycidyl esters, GE) are processing contaminants in vegetable oils and fats. GE release the carcinogenic glycidol in the gastrointestinal tract. The assessment of health risks associated with dietary GE uptake is hindered by the inaccuracy of exposure estimations based on consumption and food content data. Alternatively, the internal exposure can be approximated by monitoring of human biomarkers of glycidol, for example, the hemoglobin adduct N-(2,3-dihydroxypropyl)-valine (DHP-Val). The quantification of DHP-Val levels in blood samples showed that human adults are exposed principally by foodstuffs and tobacco smoke. Reverse dosimetry allowed calculating the mean oral exposure for 11 German adults (0.94 μg/kg body weight) and 50 Swedish adolescents (1.4 μg/kg body weight). These values exceeded the median chronic exposure estimated from dietary surveys for the adult population (0.2 μg/kg body weight) and for adolescents (0.3 μg/kg body weight), which may be due to hitherto unknown sources of glycidol/GE. Data on DHP-Val in strict raw food eaters, who do not consume food heated to more than 42 °C, suggests that DHP-Val is also formed independently from the oral exposure to GE.