Researchers have found evidence of tooth decay in hunter-gatherers. The team suspects that the rotten teeth were caused by the high-starch diet of early humans.

related study had earlier documented the rise of dental cavities and had found that they were linked with the popularity of agriculture. However, the latest study by researchers at Oxford and their colleagues, has found that dental problems existed even when humans were hunter-gatherers and followed a paleo diet.

For the study, researchers looked at 52 sets of adult teeth obtained from ancient human skeletons in Taforalt in Morocco. The teeth dated somewhere between 15,000 and 13,700 years ago. Researchers found that most of the teeth were decayed, with just three skeletons showing no signs of dental carries.

The scientists collected soil sample from the fossil site and found several charred remains of starchy foods such as sweet acorns and pine nuts. The team suspects that the starchy food could have  caused the decay. 

"This study reveals for the first time that at both ends of the Mediterranean, hunter-gatherers had started to eat a variety of different foods and were becoming more settled long before the advent of farming. It is clear changes happened on a very wide scale and we must now consider whether climate change was the major contributory factor," said Nick Barton of the Institute of Archaeology at the University of Oxford.

"These people's mouths were often affected by both cavities in the teeth and abscesses, and they would have suffered from frequent toothache," Dr Isabelle de Groote from the Natural History Museum, one of the study authors added, according to a news release.

The study is published in the journal Proceedings of the National Academy of Sciences.