Mothers may sometimes feel more aged than their childless counterparts. However, this may not simply be because the latter have more ‘me’ time and zero parenting stresses. A new study published in Human Reproduction claims that having children can make you age at a chromosomal level. 

In a bid to understand how childbirth and motherhood affects the genetic structure of women, researchers at George Mason University, Virginia, measured telomere, the end section of a chromosome associated with longevity, of women with children. On studying the data, they were able to surmise that mothers showed telomere shortening on par with childless women more than a decade older than them. 

 “We were surprised to find such a striking result. It is equivalent to around 11 years of accelerated cellular ageing,” said study author Dr Anna Pollack. “We found that women who had five or more children had even shorter telomeres compared to those who had none, and relatively shorter relative to those who had one, two, three or four, even.” 

Telomeres work as caps at the end of each strand of DNA that protect our chromosomes, like the plastic tips at the end of shoelaces. Just as the plastic ends prevent the shoelaces from getting frayed, DNA strands become damaged and our cells can’t duplicate if the telomeres are destroyed.

This is a typical part of the ageing process and is evident from immune system weakening with time and decrease in bone mineral density. 

The main implication of the present study suggests that history of live births may be associated with accelerated cellular aging. The shortening of telomeres due to motherhood was even greater than that of the impact of smoking or obesity. 

Information was gathered from over 1,900 women through the National Health and Nutrition Examination Survey (1999–2002). Because of the cross-sectional nature of the data collected, the authors were unable to factor in additional information like stress and fertility status. For this reason they warn that the results should be interpreted with caution and warrant further study. 

“Anecdotally, just chatting with my friends who have children, we all do feel that having kids has aged us,” Pollack said. “But scientifically, this does fit with what we understand pretty well. We know that having kids is associated with a higher risk of heart disease and diabetes. And some large studies have linked telomere length to mortality risk and risks of other major diseases.”