New York [US]: A team of anthropologists discovered that reproduction permanently changes the bones of females in ways that were previously unknown. Its revelation, based on primatological research, gives fresh light on how giving birth might permanently alter the body. The findings of the study were published in the journal PLOS ONE.
"Our findings provide additional evidence of the profound impact that reproduction has on the female organism, further demonstrating that the skeleton is not a static organ, but a dynamic one that changes with life events," explains Paola Cerrito, who led the research as a doctoral student in NYU's Department of Anthropology and College of Dentistry.
Specifically, the researchers found that calcium, magnesium, and phosphorus concentrations are lower in females who have experienced reproduction. These changes are linked to giving birth itself and to lactation. However, they caution that while other clinical studies show calcium and phosphorus are necessary for optimal bone strength, the new findings do not address overall health implications for either primates or humans. Rather, they say, the work illuminates the dynamic nature of our bones.
"A bone is not a static and dead portion of the skeleton," notes NYU anthropologist Shara Bailey, one of the study's authors. "It continuously adjusts and responds to physiological processes." The other authors of the study, which appears in the journal PLOS ONE, are Timothy Bromage, a professor in NYU College of Dentistry, Bin Hu, an adjunct professor at NYU College of Dentistry, Justin Goldstein, a doctoral candidate at Texas State University, and Rachel Kalisher, a doctoral candidate at Brown University.
It's been long-established that menopause can have an effect on females' bones. Less clear is how preceding life-cycle events, such as reproduction, can influence skeletal composition. To address this, the researchers studied the primary lamellar bone--the main type of bone in a mature skeleton. This aspect of the skeleton is an ideal part of the body to examine because it changes over time and leaves biological markers of these changes, allowing scientists to monitor alterations during the life span.