The Introduction of Agriculture and Its Effects on Women's Oral Health:
A Study of Neolithic Women from La Playa, Mexico
August 2010
James T. Watsona, Misty Fieldsb and Debra L. Martinb
a Arizona State Museum, University of Arizona
b Department of Anthropology and Ethnic Studies, University of Nevada Las Vegas
The prehistoric transition to agricultural dependence has been well studied for a number of regions of the world; yet the effects on maternal health have been largely overlooked. A massive population expansion associated with the advent of agriculture, referred to as the 'Neolithic demographic transition' (Ndt), has largely been considered a consequence of higher fertility rates associated with decreased birth intervals. These processes would have imposed considerable biological demands on the bodies of Neolithic women. In a research article recently accepted for publication in the American Journal of Human Biology, we explore what this would have meant for oral health among women undergoing the Neolithic transition in the Sonoran Desert.
Archaeological research has shown that, in general, the shift to agriculture caused a global decline in human health related to two broad phenomena:
1) Larger sedentary communities led to poor sanitary conditions and the spread of communicable disease.
2) Significant changes in diet led to nutritional deficiencies, developmental problems and diminished immune response.
In addition, prehistoric agriculturalists were seen to develop more oral disease when compared with foraging societies. Much of the dental decay experienced among agriculturalists has been associated with the consumption of softer, processed domesticated plants, which tend to stick to tooth surfaces and between teeth and gums.
Demands of reproductive biology have long been recognized to add an additional health burden to women's bodies (i.e., osteoporosis), and oral health is no exception. The American Academy of Periodontology (2006) states that women are at increased risk for oral health problems over age-matched men due to physiological changes associated with hormonal fluctuations that occur throughout their lifespan. The vast majority of hormonal changes in women are associated with the female reproductive cycle. Clinical research indicates that pregnancy-related changes to the oral environment can affect dental health, so that without proper care, oral health can decline, leading to lifelong health problems specific to women.
Our study focused on testing the relationship between women's dental health and agriculture in a prehistoric skeletal sample from the archaeological site of La Playa in northwest Mexico. The residents of La Playa were sedentary forager-farmers undergoing the Ndt between about 1600 B.C.E. and 200 C.E. Their diet included wild animals, wild plants such as cactus fruits and pads and mesquite tree beans, and domesticated maize, squash, and beans-all of which can contribute to causing cavities.
We identified that both men and women equally suffered from cavities at La Playa, but that women lost far more teeth than men as they aged, losing up to three times as many teeth by the final decades of life. Although more cavities in women could have contributed to this tooth loss, we hypothesize that a stronger contributing factor was the loss of supporting bone structure from an overall reduction in bone mineral density (linked to factors that contribute to osteoporosis) and possibly periodontal disease. In this case we argue that physiological changes associated with hormonal fluctuations, accentuated by increased fertility rates associated with the Ndt, modified the supporting bony structures of women's teeth at La Playa to produce greater tooth loss.
The revelation that female reproductive physiology negatively affects oral health is an essential consideration for examining oral disease epidemiology. The results of our study also demonstrate that there are more complex processes involved in the development of long-term health trends during the childbearing years in the life history of a woman.
