The Truth is in the Tooth: Braces, Cavities, and the Paleo Diet

Brush, floss, and forget: chances are, you only think about your teeth when they cause you trouble. But teeth have tales to tell, such as how old we are, how fast we grew, and how far we've traveled... But, most intriguingly, teeth can tell us both what we evolved to eat and what we actually have been eating. Paleo diet fans insist that our modern teeth troubles—all those pesky cavities—come from eating the wrong diet. If we only ate what our ancestors ate—meat, berries, and no grains—we'd be fine, they claim. But what do our teeth say? Tune in this episode to find out the toothy truth.

Our ancient ancestors had no teeth: they simply opened their mouths and filtered out food from the water. Evolutionary biologist Tanya Smith, author of The Tales Teeth Tell, told us there are two main theories as to where teeth came from: they migrated to the jaws either from bumpy skin armor on the heads of ancient fish, or from little pegs found in the throats of weird, eel-like creatures known as conodonts. Either way, "once teeth took over, they really took over," says Peter Ungar, paleo-anthropologist and author of Evolution's Bite. Teeth are ninety-five percent mineral, and so, for the earliest toothed creatures, these acquisition of these peg-like accessories represented a Stone Age-style leap forward—they literally acquired a set of stone tools in their mouths.

Smith and Ungar are dental detectives, and this episode, they help us examine teeth for the clues they hold to what our ancient ancestors ate. Using tooth shape and size, but also more high-tech forensics such as micro-wear and plaque chemistry, they help us tease out the nuances of early hominin diets, as well as the tell-tale marks that food processing and cooking have left on our choppers today. Is our modern diet to blame for the braces and cavities that are so common as to be a rite of passage in the developed world? And, if so, what should we be eating for a healthy smile? Listen in now for the surprising story of teeth.

Episode Notes

Tanya Smith and The Tales Teeth Tell

Tanya Smith is an associate professor in the Australian Research Centre for Human Evolution at Griffith University and author of the new book, The Tales Teeth Tell: Development, Evolution, Behavior. Her area of particular expertise is the study of tooth growth and structure.

Peter Ungar and Evolution's Bite

Peter Ungar is distinguished professor and chair of anthropology at the University of Arkansas, where he uses tooth wear and shape to understand the diet and ecology of human ancestors. His most recent book is Evolution's Bite: A Story of Teeth, Diet, and Human Origins.