Though there are many widely recognized benefits of The Paleo Diet®, many people assume that modern dental advances likely improved our teeth. However, anyone familiar with the scientific literature, will know that, in fact, the exact opposite is the case. Hunter-gatherers exhibited low levels of dental caries, often had wisdom teeth that fit into their jaw, and, despite a complete lack of toothbrushes, toothpaste and dental floss – had good periodontal and gum health. How can this be? Well, in one word, the answer: carbohydrates. Or, more accurately, lack of carbohydrates.
Dental caries are also known as tooth decay, or cavities. One proposed mechanism, explained as simply as possible, is that bacterial and other acids in the oral environment can erode enamel and potentially initiate an inflammatory response in the dentin.1 So then, to avoid dental caries, mechanistically, it would make sense to limit bacteria and other acids, in your mouth. So how does one go about this? Well, a starting place is limiting sugar.2 The high prevalence of dental caries in recent times is directly attributed to more frequent consumption of plant foods rich in fermentable carbohydrates,3 as cannot be overstated, since caries are increasingly common, worldwide.4
Scientists have long theorized that when hunter-gatherers moved towards agriculture — and subsequently changed their diet, that this affected the development of the skull and jaw.5 Along with this change, came a well-documented rise in dental caries.6 The ancient Egyptians are an interesting case to look at, for example. Although dental caries are commonplace in today’s society, ancient Egypt lacked caries, for the most part, due to the lack of fermentable carbohydrates in the diet.7 Another factor would be the fiber in their diet, which helped to avoid some plaque retention.8 Then we have the case of the Hardin Villagers. They had rampant tooth decay, due to their high carbohydrate diet.9
However, there are some studies that conflict this observation. For example, this study10 shows that starchy foods may have led to high rates of tooth decay in Morocco - several thousand years before the dawn of agriculture. But dental caries are not the only issue here. Research shows that hunter-gatherers had consistently longer and narrower mandibles than those practicing agriculture.11 Then there is the observation that hunter-gatherers developed flatter molar wear due to the mastication of tough and fibrous foods.12 Agriculturalists develop oblique molar wear, which is a result of an increase in the proportion of ground and prepared food which they consume.13
