Ancient Indonesians habitually used betel nuts for pain relief

Archaeologists in Indonesia discovered teeth dating from 16,000 to 25,000 years old showing evidence of regular betel nut use.

Adam Brumm at Griffith University in Brisbane, Australia, and his colleagues found the teeth in caves on the island of Sulawesi. The teeth displayed unusual rounded grooves, prompting the team to investigate possible causes. They compared the wear patterns to those found on the teeth of 19th-century clay pipe smokers.

Researchers determined the grooves resulted from people repeatedly rolling whole betel nuts, seeds from areca palm trees, around their mouths. They tested the idea by soaking betel nuts in artificial saliva and exposing the resulting liquid to human brain receptors, confirming the nuts release arecoline, a compound with physiological effects. The team also found traces of arecoline on the ancient teeth. Brumm suggests early humans may have initially used betel nuts to alleviate tooth pain, later developing an addiction.

This habit ultimately worsened dental health due to the constant friction. Betel nut use is now the fourth most popular form of psychoactive substance consumption worldwide, after alcohol, caffeine, and nicotine, but modern preparation methods differ and carry their own health risks. This discovery pushes back the earliest known evidence of habitual drug use by thousands of years, exceeding previous findings of ancient beer brewing and coca leaf chewing.