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
Another interesting observation, is that dental caries aren’t unique to humans. Evidence for caries has been seen in Paleozoic fish, which lived 570 million years ago.14 A review of populations throughout time, shows that hunter-gatherers, as a whole, show roughly a rate of 0-5% of dental caries.15 That is astoundingly low, especially when compared to modern day populations. Today we roughly experience a rate of 92% of dental caries,16 and that percentage is only a survey of those with teeth left.
So, what is the best way to avoid dental caries? A diet low in sugar, and subsequently carbohydrate, like the Paleo Diet, would be a great idea. The literature shows obvious links between dental caries and fermentable carbohydrate ingestion.17,18 Though hunter-gatherers may not have needed them, good oral hygiene would be a good idea as well. And it is interesting to note, that different refined items, such as wheat, corn and sugar, may produce different rates of dental caries.19 Avoid all three, and you are well on your way to dental perfection, like your ancient ancestors may have had.
References
1. Southward K. The systemic theory of dental caries. Gen Dent. 2011;59(5):367-73.
2. Touger-decker R, Van loveren C. Sugars and dental caries. Am J Clin Nutr. 2003;78(4):881S-892S.
3. Utturkar SM, Klingeman DM, Land ML, et al. Evaluation and validation of de novo and hybrid assembly techniques to derive high quality genome sequences. Bioinformatics. 2014;:201318176.
4. Bagramian RA, Garcia-godoy F, Volpe AR. The global increase in dental caries. A pending public health crisis. Am J Dent. 2009;22(1):3-8.
5. Available at: //www.history.com/news/for-perfect-teeth-start-hunting-and-gathering. Accessed June 16, 2014.
6. Dental anthropological indications of agriculture among the Jomon people of central Japan. X. Peopling of the Pacific. American Journal of Physical Anthropology. 51(4):619.
7. Dental health and disease in ancient Egypt. British Dental Journal. 2009;206(8):421.
8. Rateutschak-Pluss E M, Guggenheim B. Effects of a carbohydrate-free diet and sugar substitutes on dental plaque accumulation. J Clin Periodontol 1982; 9: 239–244.
9. Cassidy CM. Nutrition and health in agriculturalists and hunter-gatherers: a case study of two prehistoric populations. in Nutritional Anthropology. Eds Jerome NW et al. 1980 Redgrave Publishing Company, Pleasantville, NY pg 117-145
10. L. T. Humphrey, I. De Groote, J. Morales, N. Barton, S. Collcutt, C. Bronk Ramsey, A. Bouzouggar. Earliest evidence for caries and exploitation of starchy plant foods in Pleistocene hunter-gatherers from Morocco. Proceedings of the National Academy of Sciences, 2014
11. Utturkar SM, Klingeman DM, Land ML, et al. Evaluation and validation of de novo and hybrid assembly techniques to derive high quality genome sequences. Bioinformatics. 2014;:201113050.
12. Smith BH. Patterns of molar wear in hunger-gatherers and agriculturalists. Am J Phys Anthropol. 1984;63(1):39-56.
13. Klaus HD, Tam ME. Oral health and the postcontact adaptive transition: A contextual reconstruction of diet in Mórrope, Peru. Am J Phys Anthropol. 2010;141(4):594-609.
14. Luis Pezo Lanfranco and Sabine Eggers (2012). Caries Through Time: An Anthropological Overview, Contemporary Approach to Dental Caries, Dr. Ming-Yu Li (Ed.), ISBN: 978-953-51-0305-9, InTech, DOI: 10.5772/38059.
15. Forshaw R. Dental indicators of ancient dietary patterns: dental analysis in archaeology. Br Dent J. 2014;216(9):529-35.
16. Raner E, Lindqvist L, Johansson S, et al. pH and bacterial profile of dental plaque in children and adults of a low caries population. Anaerobe. 2014;27:64-70.
17. Guggenheim B, Ben-zur E. [Fermentable carbohydrates in teething preparations as a cause of caries in small children]. Schweiz Med Wochenschr. 1982;112(7):232-4.
18. Bokhout B, Hofman FX, Van limbeek J, Prahl-andersen B. A 'sufficient cause' model for dental caries. J Epidemiol Biostat. 2000;5(3):203-8.
19. Utturkar SM, Klingeman DM, Land ML, et al. Evaluation and validation of de novo and hybrid assembly techniques to derive high quality genome sequences. Bioinformatics. 2014;88(6):490.
