A study of teeth from Sulawesi, Indonesia, dated roughly 25,000–16,000 years ago, provides the oldest direct evidence of habitual betel nut use in humans, suggesting repeated exposure rather than a one-off event.

Biochemical tests show that soaking betel nuts in saliva and interacting with frog-egg–derived neural receptors indicate arecoline altered neural activity, implying mild, detectable psychoactive effects from simple nut exposure.

Researchers propose a dual role for arecoline: potential analgesic effects for toothache may have driven initial use, followed by habit formation and corresponding dental wear from abrasive seeds.

While 25,000 years ago represents the earliest evidence found so far, researchers caution it is not the definitive start of human drug use and possible older undiscovered instances may exist.

Experts emphasize the significance of these findings for understanding the prehistoric roots of addiction and pain management in human history.

The study, published in Science Advances, marks a notable shift in how we view the origins of drug use in human history.

Brumm notes the difficulty of finding archaeological evidence for early drug use and highlights this discovery’s importance for tracing humanity’s interaction with psychoactive substances.

Researchers stress that the term habitual denotes repeated behavior over long periods, not isolated usage.

The findings push back the timeline of psychoactive drug use to the Late Pleistocene, predating agriculture and suggesting a forager-based tradition of substance use.

This research challenges the idea that beer (about 13,000 years ago) is the oldest intoxicant, placing betel nut use earlier in the human timeline.

Overall, the discovery extends the history of human interaction with plant-based drugs by at least 3,000 years and shows a long-standing relationship with psychoactive substances.

Leading researchers call this the oldest known evidence of psychoactive plant use and highlight Areca nut consumption as a millennia-old practice.