?Why Do Women Get More Cavities Than Men

من طرف amalgam 17/10/2008, 11:58 pm

Reproduction pressures and rising fertility explain why women suffered
a more rapid decline in dental health than did men as humans
transitioned from hunter-and-gatherers to farmers and more sedentary
pursuits, says a University of Oregon anthropologist.

The conclusion follows a comprehensive review of records of
the frequencies of dental cavities in both prehistoric and living human
populations from research done around the world. A driving factor was
dramatic changes in female-specific hormones, reports John R. Lukacs, a
professor of anthropology who specializes in dental, skeletal and
nutritional issues.

His conclusions are outlined in the October issue of Current Anthropology.
The study examined the frequency of dental caries (cavities) by sex to
show that women typically experience poorer dental health than men.
Among research reviewed were studies previously done by Lukacs. Two
clinical dental studies published this year (one done in the
Philippines, the other in Guatemala) and cited in the paper, Lukacs
said, point to the same conclusions and "may provide the mechanism
through which the biological differences are mediated."

A change in food production by agrarian societies has been
associated with an increase in cavities. Anthropologists have
attributed men-women differences to behavioral factors, including a
sexual division of labor and dietary preferences. However, Lukacs said,
clinical and epidemiological literature from varied ecological and
cultural settings reveals a clear picture of the impacts on women's
oral health.

"The role of female-specific factors has been denied by
anthropologists, yet they attain considerable importance in the model
proposed here, because the adoption of agriculture is associated with
increased sedentism and fertility," Lukacs said. "I argue that the rise
of agriculture increased demands on women's reproductive systems,
contributing to an increase in fertility that intensified the negative
impact of dietary change on women's oral health. The combined impacts
of increased fertility, dietary changes and division of labor during
the move into agricultural societies contributed to the widespread
gender differential observed in dental caries rates today."

Lukacs' meta-analysis looked at both prehistoric
anthropological and modern health records. He repeatedly found that
increases in cavities go in favor of women in adulthood. Lukacs' review
found that women's higher rates of cavities are influenced by three
main changes:

Female sex hormones. Citing his own research published in
2006, he notes that these hormones and associated physiological factors
can significantly impact cavity formation. A study on animals published
in 1954 found that female estrogens, but not male androgens, were
correlated to cavity rates. He argues for a cumulative effect of
estrogens, including fluctuations at puberty and high levels during
pregnancy that both promote cavities and dietary changes.
The biochemical composition and flow rate of saliva.
Women produce less saliva than do men, reducing the removal of food
residue from the teeth, and that during pregnancies the chemical
composition changes, reducing saliva's antimicrobial capacity.
Food cravings, immune response and aversions during
pregnancy. Lukacs points to findings that women crave high-energy,
sweet foods during the third trimester, as well as an aversion to meat
in first trimesters.

How the factors combine to contribute to higher risk of
cavities in women as they age is not fully documented or understood, he
wrote. "However, if hormonal and physiological factors work in an
independent or additive manner, their impact on women's oral health
could be significant. The fact that women's caries experience increases
with age at a greater rate than men's in diverse ethnic groups from
different ecological and cultural settings supports this
interpretation."