Exposure assessment of process-related contaminants in food by biomarker monitoring.

Exposure assessment is a fundamental part of the risk assessment paradigm, but can often present a number of challenges and uncertainties. This is especially the case for process contaminants formed during the processing, e.g. heating of food, since they are in part highly reactive and/or volatile, thus making exposure assessment by analysing contents in food unreliable. New approaches are therefore required to accurately assess consumer exposure and thus better inform the risk assessment. Such novel approaches may include the use of biomarkers, physiologically based kinetic (PBK) modelling-facilitated reverse dosimetry, and/or duplicate diet studies. This review focuses on the state of the art with respect to the use of biomarkers of exposure for the process contaminants acrylamide, 3-MCPD esters, glycidyl esters, furan and acrolein. From the overview presented, it becomes clear that the field of assessing human exposure to process-related contaminants in food by biomarker monitoring is promising and strongly developing. The current state of the art as well as the existing data gaps and challenges for the future were defined. They include (1) using PBK modelling and duplicate diet studies to establish, preferably in humans, correlations between external exposure and biomarkers; (2) elucidation of the possible endogenous formation of the process-related contaminants and the resulting biomarker levels; (3) the influence of inter-individual variations and how to include that in the biomarker-based exposure predictions; (4) the correction for confounding factors; (5) the value of the different biomarkers in relation to exposure scenario's and risk assessment, and (6) the possibilities of novel methodologies. In spite of these challenges it can be concluded that biomarker-based exposure assessment provides a unique opportunity to more accurately assess consumer exposure to process-related contaminants in food and thus to better inform risk assessment.

A free fatty acid tolerance test identifies patients with coronary artery disease among individuals with a low conventional coronary risk profile.

This study investigated whether the presence of coronary artery disease (CAD) in patients with a low conventional coronary risk profile is associated with perturbations of free fatty acid (FFA) metabolism. All patients studied were non-smokers, normoglycemic, normotensive, nonobese, and had triglycerides, low-density lipoprotein and high-density lipoprotein (HDL) cholesterol in the reference ranges. An FFA tolerance test was designed, consisting of a heparin injection 4h after an oral fat load which induced a marked increase in plasma FFA concentrations. Measurements were made before the fat load, after 4 h (immediately before heparin injection), and after 4.5, 8, and 10 h. The test was carried out in 28 male CAD patients and in 25 male controls free of CAD as verified by coronary angiography. In the fasting state the two groups showed no differences in conventional risk factors with the exception of HDL cholesterol (patients 0.97 +/- 0.04 mmol/l, controls 1.13 +/- 0.05 mmol/l, P = 0.013). During the test the best discriminator found was FFA at 8 h (P = 0.0009) and, very pronounced, at 10 h (P = 0.000). We conclude that perturbed FFA metabolism in an FFA tolerance test can indicate the presence of CAD in men with a low conventional coronary risk profile, possibly as an early indicator of the metabolic syndrome.