Scientists unlocked a 4,000-year-old secret inside ancient human teeth. A woman’s clean smile in Thailand revealed surprising chemical proof of early betel nut chew habits

New chemical analysis of ancient dental plaque from a burial site in Thailand revealed preserved traces of betel nut alkaloids. Remarkably, the woman’s teeth showed no visible stains. This discovery provides the earliest direct biomolecular proof of betel nut consumption in Southeast Asia, proving humans were getting high off the plant millenia ago.