Arecoline in ice-age teeth pushes habitual drug use back before farming on Sulawesi
A Griffith University team found the alkaloid arecoline in two sets of grooved prehistoric teeth from Sulawesi and showed that sucking a whole betel nut releases enough of it to act on human receptors, from a sample of two people.
The Scientist · Science desk
What happened
- A study published in Science Advances on 9 September attributes deep tooth grooves in two prehistoric hunter-gatherers from the Indonesian island of Sulawesi to habitual sucking of whole betel nuts.
- The older of the two was a man who died aged between about 40 and 50 and lived between 25,000 and 16,000 years ago, around the coldest part of the last ice age, though Sulawesi itself carried no ice.
- To test the mechanism, the team soaked nuts in artificial saliva and applied the broth to cloned human receptors expressed in frog egg cells, finding that intact nuts release enough arecoline to alter brain function.
- Separate biochemical analysis detected arecoline in the dental tissues of both foragers, linking the wear pattern to the drug rather than to some other hard object in the mouth.
- The finding places betel nut use up to 25,000 years ago, against previously suggested Neolithic or Bronze Age origins of roughly 3,500 years ago.
Why it matters
- What's now possible capability The rounded groove gives bioarchaeologists a wear signature they can screen existing skeletal collections for, which matters because areca seeds themselves almost never survive in the ground.
- What it limits constraint The marker only shows up in mature, heavy users by the team's own account, so it can date the behaviour but cannot yield an estimate of how many people on the island were doing it.
- What doesn't add up contradiction Live Science has plain sucking producing only a numb mouth, while the team's assay is reported as altering brain function, and the difference decides whether this is the origin of a drug habit or of a folk anaesthetic.
- What it sets up precedent If detecting an alkaloid in dental tissue holds up, the fermentation-first story of drug origins becomes an argument about what preserves rather than about what people did, and other pre-Neolithic candidates get reopened.
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The word doing the work in this study is "habitual", and wear is what carries it rather than any tally of users. In one of the two individuals the grooves deepened over a lifetime until they opened the tooth's pulp cavity [10], and nerve exposure of that kind would have been severely painful, according to Adam Brumm, who led the work at Griffith University with colleagues there and Indonesian archaeologists from the University of Hasanuddin and BRIN [8][14]. Specialists in prehistoric dental wear sent images of the first find had not seen the pattern before [22].
The dating deserves the same care as the wear. The older specimen, a jaw fragment with three teeth recovered from a cave at Maros-Pangkep about ten years ago [13], falls between 25,000 and 16,000 years old [4]. That is a 9,000-year window in which 25,000 is the ceiling and not the measurement [21]. The pre-farming argument survives the young end of it anyway: even at 16,000 years, this man precedes both the 13,000-year-old barley beer in Israel that anchors the current fermentation-first account of drug origins [6] and the roughly 12,500-year-old start of Fertile Crescent agriculture that Brumm cites [7][20].
The second individual, dated to between 7,600 and 6,300 years ago [24], follows the first by at least 8,400 years and possibly by 18,700 [23]. Two points that far apart show the behaviour recurring on one island, not a tradition running unbroken between them, and the team's own reconstruction has the modern slaked-lime quid arriving only in the Neolithic, about 4,000 years ago on Sulawesi, as a by-product of adding lime to pottery clay [18]. Betel is, on Brumm's account, the fourth most widely used psychoactive substance in the world today [15].
On motive, the team notes that arecoline is a natural analgesic and that foragers on the island had generally poor teeth [11]; New Scientist reports Brumm's view that people began sucking the nuts for toothache, became addicted, and worsened their teeth in the process [12]. The grooves cannot arbitrate that order. They record abrasion by a hard, roughly spherical object moved back and forth in the mouth [8], which fits decay preceding the habit as readily as the reverse.
The chemistry is what shifts the prior assumption, since arecoline release was thought to depend on slaked lime converting the alkaloid into a free base [17]. Soaking whole nuts in artificial saliva and applying the broth to cloned human receptors expressed in frog egg cells showed release sufficient for a physiological effect with no lime involved [2], and Matheson's biochemical analysis then found arecoline in the dental tissues [3]. What that pairing does not give you is a dose in a living mouth, or any measure of the experience; the nearest thing to that on record is Brumm rolling a whole nut around his own mouth and reporting a bitter astringency that left it numb [9].
What survives the caveats is narrow and worth having. Two people on Sulawesi, thousands of years apart, put an arecoline-bearing seed in their mouths often enough to wear through their own teeth, and the older of them did so before the Neolithic reached either Sulawesi or the Fertile Crescent [7].
What to watch
- Whether the same rounded grooves appear in other curated tooth collections from Sulawesi and island Southeast Asia, which would turn two individuals into a prevalence figure.
- Whether the second individual's sex and age get settled in print: Live Science reports the sex as undetermined, while New Scientist describes a middle-aged or older man.
- Whether independent labs detect arecoline in prehistoric dental tissue elsewhere, which would test the method rather than this one site.
Clarity's read
What the record supports and how the coverage leans. The claims behind it follow.
Reality
- Evidence60
- Adoption
- Not scored
- Hype gap+30
- Incentives35
- Confidence58
Perspective Coverage
4 publishers- Builder
- Builder 55%
- Operator
- Operator 40%
- Investor
- Investor 5%
Claim ledger
Ranked by verification strength, evidence, and original report placement.
- [1]
A study published in Science Advances on Wednesday 9 September reports that deep grooves in the teeth of two prehistoric hunter-gatherers from the Indonesian island of Sulawesi were caused by regularly sucking betel nuts (Areca catechu), palm seeds containing a neuroactive substance, likely for relief from toothache.
- [2]
The team soaked betel nuts in artificial saliva and tested the resulting broths against a panel of cloned human receptors expressed in frog egg cells, which showed that just sucking on intact betel nuts releases arecoline in sufficient amounts to have a physiological effect, altering brain function.
- [3]
Biochemical analyses carried out by Matheson detected the presence of arecoline in the dental tissues of the foragers, providing strong evidence for betel nut ingestion.
- [4]
One individual, a man who died between about 40 and 50 years of age, lived between 25,000 and 16,000 years ago, roughly corresponding to the Last Glacial Maximum, although Sulawesi was not covered with ice at that time.
- [5]
The research shows betel nut use as a drug emerged among some Indonesian communities up to 25,000 years ago, predating the previously suggested Neolithic or Bronze Age origins of about 3,500 years ago.
- [6]
Present thinking holds that the world's first traditions of psychoactive drug use arose after the Neolithic advent of farming, beginning with fermented alcoholic drinks (barley beer) about 13,000 years ago in Israel.
- [7]
Brumm said the earlier betel-sucking man predated the Neolithic period not only in Sulawesi but also in the Fertile Crescent, where people began practising agriculture around 12,500 years ago.
- [8]
The rounded grooves were consistent with repetitively moving a hard, spherical object back and forth inside the mouth; the teeth were so worn in places that their nerve centres were exposed, which Brumm says would have caused severe pain.
- [9]
As a preliminary test Brumm rolled a whole betel nut around inside his own mouth, gently sucking and gnawing, and found "there was a bitter, astringent taste that made my mouth go numb".
- [10]
The grooves became progressively deeper and in one individual exposed the tooth's inner pulp cavity; Brumm said "The more they sucked on the nut to relieve toothache, the worse that the damage to their teeth became" and that it would have been excruciatingly painful.
- [11]
Ancient foragers on Sulawesi generally had bad teeth, and arecoline is a natural analgesic; the team suggested the habit was significant enough to cause severe periodontal disease.
- [12]
Arecoline has both stimulatory and pain-relieving effects, and Brumm believes people may have started sucking betel nuts to relieve tooth pain and then became addicted, ultimately causing more damage to their teeth.
- [13]
About 10 years ago Brumm and colleagues excavating a cave in Maros-Pangkep on Sulawesi found a fragment of human jaw bone with three teeth, dated to 16,000 to 25,000 years old.
- [14]
The work was led by Professor Adam Brumm of Griffith University's Australian Research Centre for Human Evolution, with Associate Professors Carney Matheson and Michelle Langley, in collaboration with Indonesian archaeologists from Makassar's University of Hasanuddin and the National Research and Innovation Agency (BRIN).
- [15]
Brumm said betel nut is the world's fourth most widely used psychoactive substance, after alcohol, caffeine and nicotine, and is used by about one in 10 of the modern global population.
- [16]
Brumm said it is likely people of all ages used betel nuts as a toothache remedy in prehistoric times, but the grooves only became apparent in mature people who had become addicted to the practice.
- [17]
Previous reports held that arecoline was released by chewing the processed nut in a quid with slaked lime, the lime converting arecoline into a free-base form and increasing its bioavailability.
- [18]
The researchers speculate that the use of slaked lime with betel nuts originated much later, during the Neolithic, about 4,000 years ago on Sulawesi, when slaked lime was added to pottery to prevent shrinking and cracking during firing.
- [19]
The early history of betel nut use had remained uncertain largely because areca seeds were rarely preserved at archaeological sites.
- [20]
Even at the youngest bound of its date range, 16,000 years, the older individual predates both the 13,000-year-old barley beer in Israel and the roughly 12,500-year-old start of Fertile Crescent agriculture.
- [21]
The date range for the older individual spans 9,000 years, so 25,000 years is the oldest bound of that range rather than a point estimate.
- [22]
The team sent images of the grooves to some of the world's leading experts in prehistoric dental wear, and they had not seen anything like it.
- [23]
The two individuals are separated by at least 8,400 years and at most 18,700 years.
- [24]
The second person, around the same age at death, lived on Sulawesi between 7,600 and 6,300 years ago; their sex could not be determined.
- [25]
New Scientist reports that the second set of teeth, about 6,000 to 8,000 years old, was part of a more complete skull that appeared to have belonged to a middle-aged or older man.
- [26]
Live Science reports that betel nuts chewed with slaked lime have a powerful stimulant effect, while the early method of directly sucking betel nuts would have only made the mouth numb.
Sources
3 independent publishers whose own reporting we read for this story.
- livescience.comWorld's oldest evidence of habitual drug use traced back 25,000 years to Indonesia
1 article · September 9, 2026
- newscientist.comEarliest evidence of habitual drug use found in teeth in Indonesia
1 article · September 9, 2026
- phys.orgIce Age origins of one of humanity's oldest drug habits discovered
1 article · September 9, 2026
- sciencedaily.comAncient teeth reveal humans were getting high 25,000 years ago
1 article · September 10, 2026
Topics and entities
Topics
- Sulawesi archaeology
- Dental bioarchaeology
- Prehistoric drug use
Entities
- Australian Research Centre for Human Evolution
- National Research and Innovation Agency (BRIN)
- Griffith University
- Areca catechu (betel nut)
- Hasanuddin University
- Science Advances
- Elisa Guerra Doce
- Michelle Langley