Ice-Age Teeth Held Humanity's Oldest Known Drug Habit
Grooves in two Sulawesi skeletons looked like damage without a cause. Chemical traces and experiments point to habitual betel-nut use up to 25,000 years ago.
The Grooves
Two pre-agricultural foragers from Sulawesi carried the same strange damage: deep, rounded grooves worn into their teeth. One lived between 25,000 and 16,000 years ago. The other was buried thousands of years later.
Researchers reporting in Science Advances argue that the grooves record a behaviour archaeology had not recognised — repeatedly holding and sucking whole betel nuts. The seed of the areca palm contains arecoline, a stimulant still consumed across much of Asia and the Pacific.
A vanished habit survived as chemistry and damage inside the mouth.
The Chemical Check
Modern betel use usually combines chopped nut with slaked lime, which helps release the psychoactive compound. The ancient wear suggested something simpler. The team soaked intact nuts in artificial saliva and found that prolonged contact alone released enough arecoline to affect receptors.
Biomolecular analysis of the ancient dental tissue was also consistent with arecoline exposure. The two lines of evidence reinforced each other: a distinctive physical action explains the grooves, while the compound expected from that action appears in the teeth.
- Both individuals were hunter-gatherers, not farmers.
- The earliest dates reach the Late Pleistocene.
- The finding moves habitual betel use far earlier than the Neolithic and Bronze Age evidence previously known.
The paper calls this the earliest recorded evidence for habitual use of a neuroactive plant drug. That careful phrase matters. It is the oldest evidence recovered so far, not proof that no older practice existed elsewhere.
What It Changes
Psychoactive traditions are often tied to farming, fermentation and settled communities because those leave visible archaeological traces. Whole seeds held in a forager's mouth are much harder to find. Here, teeth became the archive.
The discovery also supplies a marker other researchers can search for in collections: the same rounded wear pattern, tested alongside surviving molecules rather than treated as ordinary chewing damage.
Humanity's relationship with mind-altering plants did not begin in a field or a brewery. In Sulawesi, it was already wearing through enamel during the Ice Age.