DNA from a type of “chewing gum” used by Swedish teenagers 10,000 years ago sheds new light on Stone Age diet and oral health, according to a study.
The gum blobs are made from fragments of birch bark pitch, a tar-like black resin with clearly visible tooth impressions.
They were discovered 30 years ago next to bones at the 9,700-year-old Huseby Kleb site north of Gothenburg in western Sweden, one of the country's oldest fossil hominin sites.
Hunter-gatherers likely chewed the resin “as a glue” to build tools and weapons, said Anders Goeterström, co-author of the book. The study was published in Scientific Reports.
“This is the most likely hypothesis. They could have chewed it just because they liked it or because they thought it had some medicinal value,” he says.
“There was some chewing gum. [samples] And both males and females bit it. Most of them appear to have been bitten by teenagers. It kind of had its time,” Goetelstrom said.
A previous study in 2019 on a piece of gum mapped the genetic profiles of individuals who chewed it.
Now, Goeterström and a team of paleontologists from Stockholm University have been able to determine from DNA, also found in the gum, that the diets of Stone Age teenagers included deer, trout and hazelnuts. . Traces of apples, ducks and foxes were also detected.
“If you take human bones, you get human DNA. If you can prepare their teeth, you get a little bit more. But here, we get DNA from what they were chewing before. ,” Goetelstrom said. “You can't get it any other way.”
Additionally, researchers found numerous bacteria in some of the teen's bites, indicative of severe periodontitis, a severe gum infection.
“She'll probably start losing her teeth soon after chewing this gum. It must have been painful, too,” Goeterstrom said. “You still have the imprint from the mouth of a teenager who chewed it thousands of years ago. If you want to add some kind of philosophical layer to it, for us it's an artifact, It connects DNA and humans.”
