Humans have been using cannabis for its intoxicating properties for at least 2,800 years, according to a new study published in the journal Science. Scientists from the University of Bern discovered cannabis seeds and molecular traces of the drug in human hair within a tomb in Siberia, belonging to members of the Scythian society, a horse-riding culture of the Eurasian steppe.
Using radiocarbon dating, the team determined the cannabis seeds found in the grave date back to the early eighth century BC. Approximately 1,400 cannabis seeds were found, with six preserved well enough for dating. The presence of these seeds suggests cannabis played a significant role in the burial rituals surrounding the individuals interred.
Further analysis of human hair collected from inside the tomb revealed molecular traces consistent with cannabinol (CBN), a compound produced by the oxidation of THC, the primary psychoactive component of cannabis. Weak signals consistent with THC were also detected. This discovery strongly suggests that cannabis was inhaled or ingested by one of the tomb's residents for its intoxicating effects.
While cannabis has been cultivated in East Asia for at least 6,000 years, likely for its seeds, direct evidence of its use as an intoxicant has been scarce due to the perishable nature of plant parts like flowers and leaves. This new finding provides the earliest concrete proof of cannabis consumption for its psychoactive effects.
The researchers are now planning to conduct further analysis on the seeds to determine if they were specifically cultivated for higher concentrations of active compounds. DNA sequencing of the plant samples is underway, which is expected to shed more light on the domestication and historical spread of cannabis.