A new study published in Science Advances suggests that hunter-gatherers in modern-day Indonesia may have used betel nuts as a mind-altering substance as early as 25,000 years ago. Researchers led by Adam Brumm, an archaeology professor at Griffith University, identified distinctive grooves in ancient teeth that they believe resulted from habitually sucking on the seeds of palm trees. The findings indicate that the use of betel nuts, which are currently consumed by approximately 600 million people, may have originated for pain relief or stimulant effects long before modern chewing practices.
The research focused on human remains excavated from two sites in Sulawesi. The first set of remains belonged to a hunter-gatherer from 25,000 years ago, while the second set dated to 8,000 years ago. Both sets exhibited deep grooves in the teeth. Brumm reported that the wear was so significant in the 8,000-year-old remains that it exposed the pulp cavity and nerve centers. After ruling out use of the teeth as tools or for processing fibers, the team compared the marks to dental wear patterns seen in historical clay pipe smokers and concluded the grooves were consistent with sucking hard, abrasive objects over decades.
To test their hypothesis, the researchers soaked betel nuts in artificial saliva and applied the extract to frog egg cells engineered with human brain receptors. Adam Brumm stated that the process successfully extracted arecoline, a chemical found only in betel nuts that triggers brain receptors. Furthermore, chemical testing of the ancient dental tissues revealed traces of arecoline. Brumm, who personally tested sucking the nuts, described a numbing and astringent effect, suggesting that ancient users may have become caught in a cycle of using the nut to relieve the pain caused by the tooth wear it created.
For the scientific community, the findings provide a rare glimpse into the sensory and cultural lives of Pleistocene-era hunter-gatherers. Because tropical heat and humidity often destroy ancient remains, the discovery of well-preserved teeth with traceable chemical signatures offers a new method for tracking drug history. The study suggests that the instinct to experiment with mind-altering substances is a long-standing trait in human nature, echoing similar findings of thousand-year-old drug use in South America. It shifts the understanding of betel nut history from a modern addiction to a potentially ancient cultural practice.
However, some outside experts maintain that the small sample size of two skeletons limits the study's conclusions. Anthropologists such as José Capriles of Penn State University noted that while the chemical evidence is strong, more direct evidence—such as finding the actual seeds in a burial or hearth—would be necessary to confirm the context of use. Additionally, researchers like Agustín Fuentes of Princeton University cautioned against applying modern concepts of public health to ancient cultures, suggesting there may have been social or ritual reasons for the practice that are not yet understood. The researchers stated that they plan to continue investigating the vast unknowns associated with early human plant use.