Our Paleo Ancestors and Their Perfect Teeth
I remember my first trip to the orthodontist back when I was in grade school. Something about it didn’t sit well with me. The entire concept seemed warped. Why would teeth grow crookedly? By that time, I understood the basic tenets of evolution, and to my mind, crooked teeth made no sense whatsoever.
I got my braces, retainers, and obligatory embarrassment, promptly forgetting about the origins of this curious predicament. However, I started thinking about it again recently. A new study suggests that having crooked teeth only became part of the human experience relatively recently, starting around 12,000 years ago when we shifted from being hunter-gather to sedentary farmers.
An international team of scientists from University College Dublin, Israel Antiquity Authority, and the State University of New York studied the lower jaws and teeth crown dimensions of 292 archeological skeletons ranging from 28,000 to 6,000 years old. These skeletons consisted of European hunter-gatherers, Levant/Anatolian transitional farmers, and European farmers. In other words, the skeletons represented three different groups of people living distinctly different lifestyles and, most importantly, eating distinctly different diets.
The scientists, who published their study in PLOS ONE, found significant differences among the three groups with respect to malocclusion. Malocclusion, also known as dental crowding, is a misalignment or incorrect relationship of the teeth. Malocclusion can promote chewing, breathing, and speech problems, as well as psychological/emotional stress based on physical appearance. Described as “a malady of civilization,” malocclusion affects roughly 20 percent of the world’s population.
You might be surprised to learn that orthodontics originated in ancient Egypt. The Egyptians used crude metal bands and catgut, a cord prepared from natural fibers extracted from animal intestines, to straighten teeth. In the US, the modern orthodontics industry generates an estimated $13 billion annually. If modern orthodontists were transported back to Paleo times, however, they’d have precious few clients. That’s because Paleolithic humans, according to this new study, enjoyed an “almost perfect harmony” regarding tooth size and jaw alignment.
Only with the introduction of agriculture and its associated dietary changes did malocclusion become an issue. “Our analysis,” explains the study’s lead author, Professor Ron Pinhasi, “shows that the lower jaws of the world’s earliest farmers in the Levant, are not simply smaller versions of those of the predecessor hunter-gatherers, but that the lower jaw underwent a complex series of shape changes commensurate with the transition to agriculture.”
The authors explain that hunter-gather diets were based on “hard” foods, including uncooked vegetables and meats. Sedentary farmers, on the other hand, ate “soft,” processed foods, including cooked cereals and legumes. With soft foods come fewer requirements for chewing. Over several generations, this reduces the size of the jaw, but without corresponding reductions in teeth sizes. Without adequate space in the jaws for standard “Paleo” size teeth, malocclusion and dental crowding ensues.
So what can we take away from this study with respect to the modern Paleo diet? It seems our teeth and jaws evolved according to a “use them or lose them” logic. In other words, if we subsist only on soft, cooked foods, whether those foods are Paleo or not, we should expect future generations to experience dental/orthodontic problems.
In modern Paleo cooking, we sometimes favor “processed” foods, meaning high-quality Paleo foods that we “process” with blenders and other machines. It’s unlikely that modern humans will ever adopt diets involving the degree of chewing done by our Paleo ancestors, but we shouldn’t neglect the importance of chewing. And while introducing more hard, crunchy foods into your diet probably won’t change your own jaw structure, it certainly could benefit the jaws and teeth of your progeny.