Clinical Abstracts: The Chocolate Defense

With Comments by Charlea T. Massion, MD, and John McPartland, DO, MS

Source: Tytgat J, et al. Cannabinoid mimics in chocolate utilized as an argument in court. Int J Legal Med 2000;113:137-139.

Chocolate consumption has been used as a creative defense in a drug case. A 46-year-old prisoner whose urine tested positive for cannabinoids was accused of smoking and dealing marijuana. The defendant’s lawyer argued that the accused had supposedly eaten a massive amount of chocolate, causing a false-positive test for Cannabis in the urine immunoassay. To investigate this possibility, N-oleoyl- and N-linoleoyl-ethanolamide (cannabinoid-like substances in chocolate) were synthesized and spiked together with the endogenous cannabinoid anandamide (N-arachidonoylethanolamide) in urine. At concentrations of 300 mmol and 1 mmol, immunoassay for cannabis was negative, indicating that no cross-reactivity occurs between cannabinoids in Cannabis and cannabinoid-like substances in chocolate. As a result, the lawyer’s claim could be refuted and the accused was convicted.

Comments: "Cannabinoids" come in two varieties: the "exogenous" kind produced by marijuana plants, such as tetrahydrocannabinol (THC), and the "endogenous" cannabinoids, including anandamide. The two compounds are structurally dissimilar—THC is a tricyclic compound, while anandamide is a fatty acid derivative of arachidonic acid. It astonishes scientists that both compounds can activate the same brain receptors.

The lawyer’s suggestion that an immunoassay would cross-react between the two compounds is really a stretch, similar to saying chocolate would cross-react with capsaicin (chili peppers). But then again, there are lots of stretches in the cannabinoid field: Saying anandamide is found in chocolate (even cocoa) is amazing, because its metabolic source, arachidonic acid, is not produced by plants. And just when you think you have it figured out: Scientists have discovered that vanilloid receptors, the receptors that are activated by capsaicin, also are activated by anandamide.1 Keep tuned to these pages for updates!


1. Szallasi A, Di Marzo V. New perspectives on enigmatic vanilloid receptors. Trends Neurosci 2000;23:491-497.