John R. Lukacs Current Anthropology Vol. 49 (5):901-914 (Oct. 2008)

Some of my students may remember that Dr. John Lukacs presented this work at ASU in a guest lecture on September 22, 2008. The abstract summarizes the gist of this paper:

The transition from foraging to farming is associated with a
widespread and well-documented decline in oral health,
wherein women experience a more rapid and dramatic decline
than men. Historically, anthropologists have attributed this
difference to behavioral factors such as sexual division of labor
and gender-based dietary preferences. However, the clinical
and epidemiological literature on caries prevalence reveals a
ubiquitous pattern of worse oral heath among women than
men. Research on cariogenesis shows that women’s higher
caries rates are influenced by changes in female sex hormones,
the biochemical composition and flow rate of saliva, and food
cravings and aversions during pregnancy. Significantly, the
adoption of agriculture is associated with increased sedentism
and fertility. I argue that the impact of dietary change on
women’s oral health was intensified by the increased demands
on women’s reproductive systems, including the increase in
fertility, that accompanied the rise of agriculture and that
these factors contribute to the observed gender differential in
dental caries.

Of course, my comments should be prefaced with a statement that Dr. Lukacs was my Ph.D. advisor, our research interests are similar, and so I am not exactly an impartial observer. That being said, this paper is an important contribution to bioarchaeology because it provides a new set of proximate causes for sex differences in caries rates. Dr. Lukacs reviews cross-cultural evidence for sex differences in caries rates for contemporary and paleo-populations. His research demonstrates that in agricultural societies, female caries rates are significantly higher than males throughout their life history. He documents an association between agriculture and increase in both caries and fertility rates and suggests a causal relationship. To support this, he reviews aspects of female physiology related to oral health. Female life history and hormonal variation can lead to increased susceptibility to caries, which is exacerbated during the reproductive cycle. Ultimately, if the Neolithic transition led to an increase in fertility, Lukacs argues that is partially responsible for accentuated sex differences in caries rates.

It seems to me, this paper’s significance for bioarchaeology is analogous to the impact of the Osteological Paradox (Wood et al., 1992). It confirms the primacy of the demographic profile in the interpretation of skeletal assemblages. This time, it is fertility (rather than mortality) shaping morbidity. This paper supports the particular importance of demographic variables related to fertility (McCaa, 1998, 2002). Fertility is preeminent in shaping the demographic profile. It outweighs mortality in its contribution to the age structure of a population as it is concentrated at a single moment in the age pyramid, while mortality is diffuse. It appears in this paper as though fertility’s impact on morbidity is exactly opposite. While mortality is a force focused at a moment in the life of an individual, fertility (and related issues of pubescence and reproduction) is spread across the female lifespan- leading to increased caries rates in this case. This paper provides a lot to think about for sure…