In south-east Asia, betel nut chewing has been practiced since antiquity. The vegetation comprise compounds that improve the patron’s alertness, power, euphoria, and leisure. Though the follow is changing into much less widespread in trendy instances, it has been deeply embedded in social and cultural traditions for hundreds of years. Chewing betel nuts sometimes leads to darkish, reddish-brown to black stained tooth.
But, tooth with out staining could not imply that individuals did not chew betel nuts. Now, utilizing a brand new technique, a world group of researchers examined historical dental plaque from Bronze Age Thailand and located proof of betel nut chewing.
“We recognized plant derivatives in dental calculus from a 4,000-year-old burial at Nong Ratchawat, Thailand,” mentioned first writer of the Frontiers in Environmental Archaeology examine Dr Piyawit Moonkham, an anthropological archaeologist at Chiang Mai College in Thailand. “That is the earliest direct biomolecular proof of betel nut use in south-east Asia.”
“We exhibit that dental calculus can protect chemical signatures of psychoactive plant use for millennia, even when typical archaeological proof is totally absent,” added Dr Shannon Tushingham, the senior writer, who’s the affiliate curator of anthropology on the California Academy of Sciences. “In essence, we have developed a method to make the invisible seen — revealing behaviors and practices which were misplaced to time for 4,000 years.”
Hidden in plaque
At Nong Ratchawat, an archaeological web site in central Thailand that dates again to the Bronze Age, 156 human burials have been unearthed since 2003. For the current examine, the group collected 36 dental calculus samples from six people.
Again within the lab, they eliminated tiny quantities of plaque from the samples and the chemical residues discovered therein underwent evaluation. The group additionally used betel liquid samples they produced themselves to make sure psychoactive compounds could possibly be reliably detected by way of their evaluation and to grasp the advanced biochemical interactions between elements. “We used dried betel nut, pink limestone paste, Piper betel leaves, and typically Senegalia catechu bark and tobacco. We floor the elements with human saliva to duplicate genuine chewing circumstances,” Moonkham mentioned. “Sourcing supplies and experimentally ‘chewing’ betel nuts to create genuine quid samples was each a enjoyable and attention-grabbing course of.”
The outcomes confirmed that three of the archaeological samples – all stemming from a molar of the identical particular person, Burial 11 – contained traces of arecoline and arecaidine. These natural compounds, present in betel nuts but additionally vegetation like espresso, tea, and tobacco, have pronounced physiological results on people. This means that betel nuts had been chewed as early as 4,000 years in the past in Thailand.
‘Archaeologically invisible’ proof
“The presence of betel nut compounds in dental calculus does recommend repeated consumption, as these residues turn out to be included into mineralized plaque deposits over time by way of common publicity,” defined Tushingham. Accordingly, the absence of tooth-staining raises questions. It could possibly be the results of totally different consumption strategies, the group identified. It may be because of post-consumption tooth cleansing practices, or autopsy processes affecting stain preservation over 4,000 years.
Whereas traces of betel nut chewing had been present in samples from just one particular person, there may be presently no proof that Burial 11 acquired particular therapy or was of elevated social standing or distinctive ritual significance in comparison with the opposite burials at Nong Ratchawat. The presence of stone beads as grave items, nevertheless, may present hints as to the person’s identification or lived expertise. Learning extra people at Nong Ratchawat and different native websites to study when and to whom such grave items got may present worthwhile proof, the group mentioned.
The strategies the researchers utilized can be utilized to look at the remaining burials at Nong Ratchawat and at different websites, they mentioned. “Dental calculus evaluation can reveal behaviors that depart no conventional archaeological traces, doubtlessly revolutionizing our understanding of historical lifeways and human-plant relationships,” Tushingham mentioned. “It may open new home windows into the deep historical past of human cultural practices.”
“Understanding the cultural context of conventional plant use is a bigger theme we wish to amplify — psychoactive, medicinal, and ceremonial vegetation are sometimes dismissed as medication, however they signify millennia of cultural data, religious follow, and neighborhood identification,” Moonkham concluded. “Archaeological proof can inform modern discussions by honoring the deep cultural heritage behind these practices.”
