Comment on Lachenmeier et al (2020) “Are side effects of cannabidiol (CBD) products caused by tetrahydrocannabinol (THC) contamination?”: disputation on various points in the publication

Abstract

This Correspondence article is a counterstatement to a Brief Report published by Lachenmeier and co-workers on 17th February 2020 in F1000Research: “Are side effects of cannabidiol (CBD) products caused by tetrahydrocannabinol (THC) contamination?”. This counterstatement proposes that the authors of that article neither present proof or evidence for the alleged side effects of CBD products (no case reports presented with utilisable data), nor do they show that side effects are due to the presence of THC. Primarily, there is no clear definition of THC because the authors do not explain whether they mean Delta9-THC only (without its precursor tetrahydrocannabinolic acid (THCA)) or total-THC (the sum of Delta9-THC and its precursor THCA, normalised to THC); indeed EU Recommendation 2016/2115 on the monitoring of cannabinoids in food requires the measurement and documentation of the precursor acids complementary to the decarboxylated cannabinoids. The key part of the authors’ work – Table 2 with the assessment of the CBD products – leaves the reader in the dark about the nature of “THC”. This is all the more concerning because acid-free Delta9-THC is psychotropic but THCA is not. Additionally, the classification of the CBD products (“toxicity assessment”) presented is based on the assignment of the quantitative relation to the LOAEL (lowest observed adverse effect level) of THC (2.5 mg of acid-free Delta9-THC per adult and day as assigned by EFSA, 2015). However, many assumptions by Lachenmeier et al. on daily intake of CBD products are questionable, in particular food supplements, where the recommended daily consumption was missing on the label. Finally, the authors of the paper also compare their findings with the German recommendations on maximum levels of total-THC in food, ignoring that those limits refer to total-THC and the ready-to-eat products, and not to the food ingredient itself – in particular hemp tea products.