Here is a smell that our German and Luxembourg neighbors will have to get used to. Since the relaxation of cannabis laws in these two countries (home cultivation authorized in Luxembourg since July 2023, German cannabis law in force since April 1, 2024), the scent of this controversial plant will regularly hang in the air above our European friends. Repulsive for some, pleasant and synonymous with freedom for others, the very particular smell of cannabis was of mysterious origin, until American scientists managed to identify the molecules that make it up.
Scientists with a good nose
The results of this research show that the smell of cannabis is highly complex: it is made up of more than 200 aromatic compounds. It is this multitude of molecules called terpenes that gives cannabis its smell. Terpenes are molecules with odorous properties; they give plants their flavors and their scents. These scents play an important role for plants: they attract pollinating insects to the flowers and repel predators. Once isolated by certain processes, terpenes are widely used in perfumery and in the food industry. Each plant has 4 to 6 main terpenes, but also several dozen or hundreds of others called minor terpenes. Moreover, there are said to be more than 60,000 different terpenes in nature, enough to produce an endless range of scents and flavors.
But let us come back to our Californian scientists working for Abstrax Tech, a company specializing in the production of terpenes. During the study, part of the team focused on another family of molecules found in the plant's flowers: volatile sulfur compounds. These compounds are present in small quantities, much smaller than terpenes. After selecting a cheerful group of olfactory experts, more commonly known as noses, the scientists had them smell 13 cannabis varieties, then asked them to rate the intensity they perceived from 0 to 10. The 13 cannabis varieties were then analyzed by various machines with very complicated names (mass spectrometer, flame ionization detector and sulfur chemiluminescence detector). All this work made it possible to identify, and also to quantify, the different substances involved in creating the smell of cannabis. Some of the compounds identified were previously unknown.
The study was able to show that it is not only terpenes that are responsible for the smells of plants, but that volatile sulfur compounds also play a part. So we now know why cannabis smells like cannabis.
A compound also found in garlic
One of the sulfur compounds found in cannabis, prenylthiol, has a molecular structure also found in another well-known plant: garlic. This molecule contributes to the taste of this food. Research is looking at the sulfur compounds in garlic, but nothing allows any effect of cannabis on health to be inferred from this: the discovery is first and foremost about the plant's aroma. Cannabis and CBD are not medicines.
