What may be the earliest known evidence of human drug taking has been traced to ancient Indonesian foragers. Researchers suggest these individuals may have sucked on mind-altering nuts as long as 25,000 years ago.
Analysis of two rare skeletons from the Indonesian island of Sulawesi revealed significant tooth wear and traces of a psychoactive substance in the remaining teeth. This suggests the foragers routinely sucked on hard, abrasive betel nuts.
One of the skeletons was dated to approximately 7,000 years old, while the other was more ancient, estimated to be between 16,000 and 25,000 years old. Prof Adam Brumm of Griffith University's Australian Research Centre for Human Evolution noted the deep, rounded grooves in the adults' teeth, some of which were deep enough to have exposed the dental pulp.
Betel nuts are the seeds of the Areca catechu palm and are the world's fourth most widely used psychoactive substance. Scientists found that soaking betel nuts in artificial saliva released enough of the psychoactive compound arecoline to induce a high. Traces of arecoline were also found in the foragers' teeth tissues.
Prof Brumm suggested that the individuals might have initially used the nuts as a traditional remedy for toothache. However, prolonged sucking could have worn down their teeth, potentially leading to worse dental pain and a cycle of continued nut-sucking to alleviate the discomfort.