Archaeologists recently reported that 2000-year-old skeletons of farmers excavated in Sudan were found to have remarkably healthy teeth. They discovered that the reason for this was a rather strange item in the Sudanese diet: the bad-tasting tuber of a noxious weed called purple nutsedge (Cyperus rotundus). The tuber is known to have antibacterial properties, and it appears to have protected ancient Sudanese farmers from cavities.
As National Geographic Daily News reported:
Early humans generally had relatively few cavities, thanks in part to meals that were heavy on the meat, light on the carbs.
Then humans invented farming and began eating more grain. Bacteria in the human mouth flourished, pouring out acids that eat away at the teeth. The first farmers tended to have much more tooth decay than hunter-gatherers did.
But when scientists looked at the teeth of people buried roughly 2,000 years ago in an ancient cemetery called Al Khiday 2, they found that fewer than one percent of the teeth had cavities, abscesses, or other signs of tooth decay, though those people were probably farmers, says study co-author Donatella Usai of Italy’s Center for Sudanese and Sub-Saharan Studies.
Analysis of hardened bits of plaque on the teeth showed those interred at the cemetery had ingested the tubers of the purple nutsedge, perhaps as food, perhaps as medicine. People buried at Al Khiday at least 8,700 years ago—before the rise of farming there—also consumed the tubers, probably as food.
The scientists published their findings in the online, peer-reviewed journal PLOS ONE. Their paper was entitled “Dental Calculus Reveals Unique Insights into Food Items, Cooking and Plant Processing in Prehistoric Central Sudan.”
As Geographic noted:
The purple nutsedge tuber may have many virtues, but a nice flavor isn’t one of them. People might have tried to tame the tubers’ bitterness by cooking them, says study co-author Karen Hardy of the Catalan Institution for Research and Advanced Studies at the Autonomous University of Barcelona, or they may have just tolerated the bad taste.
“They might have been using it for some medicinal purpose,” Hardy says. “Medicine always tastes horrible, so it would be par for the course.”
The report also quoted a biological anthropologist unconnected with the study as saying that no other example has been reported of a specific plant that kept tooth decay in check among ancient people.
This is actually an error. A well-known and quite ancient tooth-cleaning plant is the arak or toothbrush tree (Salvadora persica), from which comes the natural toothbrush known as the miswak, a chewing stick prepared from the tree’s root. It has antiseptic and astringent properties that help clean and protect the teeth and gums. For more on the arak tree, see Natural Remedies of Arabia by Robert Lebling and Donna Pepperdine.