Arecoline in ice-age teeth pushes habitual drug use back before farming on Sulawesi

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 ^[9][5]. Specialists in prehistoric dental wear sent images of the first find had not seen the pattern before ^[23].

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 ^[22], falls between 25,000 and 16,000 years old ^[2]. That is a 9,000-year window in which 25,000 is the ceiling and not the measurement ^[28]. 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 ^[15] and the roughly 12,500-year-old start of Fertile Crescent agriculture that Brumm cites ^[16][30].

The second individual, dated to between 7,600 and 6,300 years ago ^[3], follows the first by at least 8,400 years and possibly by 18,700 ^[29]. 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 ^[13]. Betel is, on Brumm's account, the fourth most widely used psychoactive substance in the world today ^[26].

On motive, the team notes that arecoline is a natural analgesic and that foragers on the island had generally poor teeth ^[19]; New Scientist reports Brumm's view that people began sucking the nuts for toothache, became addicted, and worsened their teeth in the process ^[20]. The grooves cannot arbitrate that order. They record abrasion by a hard, roughly spherical object moved back and forth in the mouth ^[9], 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 ^[12]. 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 ^[6], and Matheson's biochemical analysis then found arecoline in the dental tissues ^[7]. 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 ^[21].

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 ^[16].