January 9, 2014

Some of the earliest evidence of severe tooth decay and bad breath in a population of prehistoric hunters and gatherers has been recovered by a team of British scientists from a cave in Morocco. The team, led by paleoanthropologist Louise Humphrey of the British Museum of Natural History in London, examined the skeletal remains of at least 52 individuals found in a North African cave known as the Grotte des Pigeons (Cave of the Pigeons). The remains date from 13,700 to about 15,000 years ago. The scientists found evidence of tooth decay in all but three of the individuals and severe tooth decay in about half. The evidence of decay in some of the individuals was so severe that the people were likely suffering from constant discomfort or pain. The hunters also almost certainly suffered from severe halitosis (bad breath) due to the rotten condition of their mouths.

The poor oral health of the Grotte des Pigeons population surprised the scientists. Prehistorians can usually identify hunter-gatherer populations in the archaeological record simply by examining their teeth. The teeth of these people are often in excellent condition, and tooth decay, periodontis (gum disease), or dental caries (cavities) are rarely seen.  Early farming communities are equally easily identified by the amazingly poor oral health seen in their remains.

Before agriculture was developed about 12,000 years ago in the Middle East, Stone Age peoples survived by hunting game and gathering wild plant foods. Such foods are low in simple carbohydrates (sugars) that cause tooth decay and dental caries that plague modern agricultural societies. Once people began cultivating wheat, barley, and rice, they began preparing the grains into soft, gummy, carbohydrate-rich foods, including bread, porridge, and beer. Bacteria in the mouth digest the simple sugars from such foods and release acid that breaks down tooth enamel, causing decay and caries. Modern advances in dental care, including brushing, flossing, and fluoridation, have done much to improve oral health. But nearly all people in modern societies still suffer from tooth decay, gum disease, and caries due to a grain-based diet rich in the simple sugars that oral bacteria thrive on.

Sweet acorns are produced by certain oak trees, including the cork oak, which grows in northern Morocco, western Spain, and Portugal. The acorns are still prized today. (World Book illustration by Chris Skilton)

The scientists linked the prehistoric hunters’ dental woes to a large amount of sweet acorns found in a nearby refuse pile that contained the remains of wild plant foods the people of Grotte des Pigeons consumed. The people most likely boiled the sweet acorns and ground them up to make a sticky flour. Although they never cultivated any crops, the diet of the Grotte des Pigeons people was more similar to a modern agricultural population, rich in sticky, decay-causing, carbohydrates from wild sources. Although the population appears to have been robust and well-fed, the pain in their jaws and bad breath almost certainly made life miserable for all. Unfortunately for the Grotte des Pigeons residents, the evidence for dentistry in the archaeological record does not appear until about 6,500 years ago.

Additional World Book articles:

• Dental hygiene
• Controlling the Causes of Bad Breath (a Special Report)
• Healthy Gums