Scientists at Stockholm University have extracted DNA from a type of "chewing gum" teenagers in Sweden ate 10,000 years ago.
The lumps of gum bearing teeth marks are made from birch bark pitch, a tar-like black resin. The find sheds new light on Stone-Age Swedes' diet and oral health, according to a paper published by Nature.
The pieces of discarded prehistoric gum were discovered three decades ago close to human remains found at the Huseby Klev archeological site in Gothenburg, western Sweden.
"This is a most likely hypothesis - they could have been chewed just because they liked them or because they thought that they had some medicinal purpose...Both males and females chewed them. Most of them seem to have been chewed by teenagers," said Anders Gotherstrom, the study's co-researcher.
Upon close examination of the DNA found in the gum pieces, the research team detected traces of apples, deer, duck, fox, hazelnuts and trout in the teenagers' diet.
Another discovery was that of a teenage girl, who the study team found to have suffered from a severe dental gum infection (periodontitis) caused by mouth bacteria. “She would probably start to lose her teeth shortly after chewing this gum. It must have hurt as well,” Gotherstrom noted.