DNA from a type of “chewing gum” used by teenagers Sweden 10,000 years ago sheds new light on Stone Age diet and oral health, according to research.
The pieces of gum are made from pieces of birch bark, a tarry black resin, and bear clearly visible teeth marks.
They were found 30 years ago alongside bones at the 9,700-year-old Huseby Klev archaeological site north of Gothenburg in the west. Swedenone of the country’s oldest sites for human fossils.
Hunter-gatherers probably chewed the resin “to be used as glue” to assemble tools and weapons, said Anders Götherström, the co-author of the study published in Scientific Reports.
“This is a most likely hypothesis – they could have been chewed just because they liked it or because they thought they had some medicinal purpose,” he said.
“There was several chewing gum [samples] and males as well as females chewed it. Most of them were apparently chewed by teenagers. There was some age to it,” Götherström said.
A previous 2019 study on the pieces of chewing gum mapped the genetic profile of the individuals who chewed it.
This time, Götherström and his team of paleontologists at Stockholm University were able to determine, again from the DNA found in the gums, that the teenagers’ Stone Age diet included deer, trout and hazelnuts. Traces of apple, duck and fox were also detected.
“If we do a human bone, we get human DNA. We can do teeth and then we get a little more. But here we will get DNA from what they chewed before,” Götherström said. “You can’t get it any other way.”
Additionally, in one piece chewed by a teenage girl, researchers found a number of bacteria indicating a severe case of periodontitis, a serious gum infection.
“She will probably start losing her teeth shortly after chewing this gum. It must have hurt too,” Götherström said. “You have the imprint of the teenager’s mouth that chewed it thousands of years ago. If you want to put some philosophical layer to it, it connects for us artifacts, the DNA and people.”
