Assessment of the Conclusions of the Joint FAO/WHO Expert Meeting on Tropane Alkaloids.

The European Food Safety Authority (EFSA) was requested to assess the differences in the outcome of the risk assessment of tropane alkaloids (TAs) in food between the CONTAM Panel and the Joint FAO/WHO meeting (FAO/WHO) and to conclude if an update of the EFSA opinion on tropane alkaloids in food and feed would be appropriate. TAs are secondary metabolites occurring in several plants. The main TAs considered in the assessments of EFSA and FAO/WHO were (-)-hyoscyamine and (-)-scopolamine, which exert their pharmacological and toxicological effects by acting as competitive antagonists of the muscarinic acetylcholine receptors. Both EFSA and FAO/WHO considered a study in human volunteers as the key study to assess the effects of TAs. The CONTAM Panel established a group acute reference dose (ARfD) of 0.016 µg/kg body weight (bw) for the sum of (-)-hyoscyamine and (-)-scopolamine, based on decreased heart rate. FAO/WHO concluded that it was not possible to establish an ARfD and instead selected a point of departure of 1.54 µg/kg bw for the sum of the two substances, based on decreased salivary secretion, and applied it in a margin of exposure approach. A detailed assessment of the differences in the two approaches is provided in the report. Overall, it is not straightforward to compare quantitatively the differences emerging from the assessments of the CONTAM Panel and the FAO/WHO, in view of the different approaches applied and the different scopes of the assessments. Given the existing uncertainties, the ARfD established by the CONTAM Panel should be retained without modifications as protective towards the general population including susceptible subgroups. In conclusion, based on the comparison with the FAO/WHO assessment, an update of the CONTAM Panel assessment on the risks to human health related to the presence of tropane alkaloids in food is not considered necessary.