Researchers analysing two exceptionally rare skeletons recovered from the Indonesian island of Sulawesi report tooth damage and chemical residues that point to repeated use of hard, abrasive betel nuts about 25,000 years ago. The combination of distinctive dental wear and traces of a psychoactive substance in the individuals’ remaining teeth led the team to conclude the foragers may have routinely sucked on or chewed the nuts.
What the evidence shows
The published analysis identified dramatic wear patterns on the front teeth of both skeletons along with detectable traces of a psychoactive compound preserved in dental material. Those observations together are consistent with prolonged, habitual contact between the teeth and an abrasive plant product, the researchers say, rather than isolated or accidental exposure.
Broader implications
If the interpretation holds, the findings push back the earliest documented instances of humans consuming psychoactive substances by thousands of years and add to evidence of complex behavioural practices among Pleistocene forager groups. The results also suggest that the use of mind‑altering plants formed part of daily or ritual life for at least some ancient communities in the region.
Cautions and next steps
The authors describe the evidence as suggestive rather than definitive and note that further study of skeletal remains and archaeological context is needed to confirm the behaviour and understand its social significance. Additional chemical analyses and comparisons with other sites will be required to establish how widespread such practices may have been among prehistoric populations.
The report highlights how advances in microscopic and chemical analyses of teeth can reveal aspects of past human behaviour that are not preserved in other parts of the archaeological record, offering new windows on ancient lifeways in island Southeast Asia.