CARIES and CAVEMEN Dental caries and gum disease have been with us since the beginning. But why? Is it simply our diet? Or is our environment changing faster than we can evolve?

by Sara Hamed-Negahdar, DDS

Dental caries were found in the skulls of ancient man-apes more than 800,000 years ago. It is evident that tooth decay existed in ancient humans, but it was very rare. Research shows that changes in the human diet from ancient times to our modern era has resulted in a change in our oral ecosystems. This, consequently, gave rise to the development of dental caries and gum disease at much higher rates in the human population. Scientific evidence shows a pattern of increased dental caries throughout archeological history as humans have adapted new ways of living. Oral health problems have increased steadily from our beginnings as hunter-gatherers through our progression into farmers and finally to modern humans.

Photo by Kinez Riza

Most of the studies on the cause and prevalence of dental caries reveal an increase in tooth decay as humans started farming and consuming starchy crops that fed sugar-loving bacteria on our teeth. Records of Egyptian times show the advent of eating bread as a daily staple and a higher caries rate than other less-civilized cultures of the time. Microbiology shows that oral bacteria like streptococcus mutans are particularly adapted to attaching to our teeth and converting carbohydrates into enameldestroying acids, thus causing dental caries.

Image: Slab stele from mastaba tomb of Itjer at Giza. 4th Dynasty, 2543-2435 BC. Itjer is seated at a table with slices of bread, shown vertical by convention. Other offerings described in the text near the table are incense, fruit, and wine. Excavations 1903 by Schiaparelli, S. 1849. Egyptian Museum, Turin.

Photo by Ian Alexander

On the other hand, different studies argue that an agricultural diet is not the only type that can cause tooth decay. Such studies show that the increase in the amount of dental caries is also due to the improvement of social productivity and development of the food processing industry. These studies suggest that human teeth, jaws and mouth are not adapted to the diet of a modern industrial society because of our past evolution of eating coarse seeds, nuts, fruit and meat. These studies show that the mismatch between our adaptation and our environment causes dental cavities, overcrowding of teeth, overbite and gum disease.

This happened as humans switched from their traditional diet to an industrial-age diet of refined sugars and easy-to-masticate processed foods. Although, there are other factors such as bacterial flora and host defense involved in susceptibility to caries, the prevalence of dental caries is more affected by cultural factors such as dietary habits, nutrients, frequency/availability of food and food processing techniques.

The bottom line is that the world and environment of modern man has changed over the eons, but we can learn from the past historical record and use that knowledge to bring ourselves into better synchrony with our environments for our health's sake. Our profession has the opportunity to recognize the importance of human nutrition and our modern diet’s impact on our patient’s caries rates. If we can become more knowledgeable about changing human nutrition patterns and their impact on disease, we will likely not only lower the caries rates of our patients but also potentially improve the general health of modern man.


1. Prevalence Profile of Oral Disease in Ancient Population X. Zhang1 , J. Dai1 , Y.X. Han2 and J.L. Shao

2. Traci Watson, Special for USA TODAY Published 3:03 p.m. ET Jan. 6, 2014 | Updated 10:27 a.m. ET Jan. 9, 2014

3. Adler, C. J., Dobney, K., Weyrich, L. S., Kaidonis, J., Walker, A.W., Haak, W., ... Cooper, A. (2013). Sequencing ancient calcified dental plaque shows changes in oral microbiota with dietary shifts of the Neolithic and Industrial revolutions. Nature Genetics. Doi: 10.1038/ng.2536

4. An Evolutionary Theory of Dentistry, Ann Gibbons

5. The Open Anthropology Journal, 2010, Volume 3 Zhang et al.

Originally featured in SCCDS The Cutting Edge Vol. 55, No. 5

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