Commentary on “Analyses of human dentine and tooth enamel by laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) to study the diet of medieval Muslim individuals from Tauste (Spain)” by Guede et al. 2017, Microchemical Journal 130, 287–294

The study of trace element (TE) distribution within human and animal teeth is crucial to decrypt information about their diet, ecology and behaviours in the past. Thanks to several efforts TE applications have spread also to the study of modern environments, with repercussions in medicine and forensic contexts. However, the use of TE analysis to infer eating habits of our ancestors has been used for decades without the proper theoretical basis. After the paper of Ezzo Ezzo (1994) that demonstrated the non-validity in the use of bioessential TE elements in bones and teeth as palaeodiet markers this trend has decreased. However, still some recent papers continue to ignore that portion of the literature that strongly contrasts the use of TE analysis for palaeodiet. With this commentary, we would like to share our remarks on the paper of Guede et al. Guede et al. (2017), where, in our opinion, there is a lack of literature review and thus a misinterpretation of the TE dataset.