University of Valladolid

25,000-year-old teeth reveal earliest known evidence of human drug use

- Analysis of two ancient skeletons from Sulawesi, Indonesia, found traces of the psychoactive compound arecoline in teeth, dating human drug use back as far as 25,000 years. - The individuals show distinctive tooth grooves consistent with repeatedly sucking on betel nuts, predating the oldest known drug-use evidence by at least 3,000 years. - Researchers confirmed the mechanism experimentally by soaking betel nuts in artificial saliva and testing the extract on frog egg cells engineered with human brain receptors. - The findings suggest betel nut sucking may have served as a painkiller, creating a self-perpetuating cycle of tooth damage and addiction.