Ancient Hunter-Gatherers Suffered Tooth Decay from Starchy Foods

It turns out that our ancient ancestors probably needed a dentist. Scientists have discovered that a diet rich in starchy foods may have led to high rates of tooth decay in ancient hunter-gatherers. The findings challenge the long-held view that dental disease was linked to the advent of farming.

In order to better understand the diets of hunter-gatherers, the researchers analyzed 52 sets of adult teeth from hunter-gatherer skeletons found in Morocco. These samples dated between 15,000 and 13,700 years ago. In the end, they found evidence of tooth decay in more than half of the surviving teeth.

So what was causing this decay if not crops from farming practices? The scientists turned to the soil. The site where the skeletons were discovered had a deep ashy layer with exceptionally well preserved charred plants. The researchers found evidence of the systematic processing of wild foods such as sweet acorns, pine nuts and land snails.

"The 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," said Nick Barton, one of the researchers, in a news release. "It is clear changes happened on a very wide scale and we must now consider whether climate change was the major contributory factor."

It's like that the reliance on edible acorns as a staple food source could have accounted for the high prevalence of cavities. Eating fermentable carbohydrates in particular is a key factor for the initiation and progression of tooth decay.

"The acorns may have been boiled or ground to make flour; cooking the acorns would have added to their stickiness, and abrasive particles from grindstones contributed to rapid tooth wear so that caries started to form on the roots of the teeth," said Louise Humphrey, one of the researchers, in a news release.

The findings are published in the journal Proceedings of the National Academy of Sciences.