The oldest evidence of human drug use has been discovered in Indonesia, dating back 25,000 years to the last Ice Age. Scientists from Griffith University identified an ancient hunter-gatherer who consumed betel nuts, a practice previously thought to have begun much later.
Betel nuts, still widely consumed in the Asia-Pacific region, induce mild euphoria and heightened alertness. Professor Adam Brumm, the study's lead author, noted that betel nut is the world's fourth most widely used psychoactive substance, following alcohol, caffeine, and nicotine. Until this finding, the earliest evidence of human drug use was believed to be from the Neolithic period, around 13,000 years ago. This new discovery extends that timeline by more than 10,000 years.
The research involved analyzing the remains of two early human foragers found on the Indonesian island of Sulawesi. One individual dated between 25,000 and 16,000 years ago, while the other lived between 7,600 and 6,300 years ago. Both individuals exhibited unusual dental wear patterns, characterized by deep, rounded grooves in their teeth, suggesting they habitually sucked on whole betel nuts.
Previous understanding held that betel nuts needed to be chewed to release their psychoactive compound, arecoline. However, the research team conducted experiments that demonstrated sucking alone is sufficient to release the compound in physiologically significant amounts. The experiments involved soaking betel nuts in artificial saliva and testing the resulting liquid against cloned human receptors.
The researchers hypothesize that the practice may have initially served as a remedy for toothache. Sucking on the hard seeds could have provided temporary relief. However, over time, the abrasive nature of the nuts led to severe dental problems, including exposed pulp chambers, pain, difficulty eating, and chronic infections, potentially creating a cycle of continued use to manage the resulting discomfort.
These findings suggest that humans have sought out psychoactive compounds for a much longer period than previously assumed. The emergence of betel nut use by 25,000 years ago, predating agriculture, may represent the earliest evidence of drug use globally. The study implies that some modern drug-taking behaviors have deep roots in ancient foraging traditions.
