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A marvel of biology, pregnancy, however, has a price to pay: women affected by one or more pregnancies show more signs of aging than those who have never given birth, according to a new study.
Being a mother doesn’t just result in a few gray hairs… According to a new study freshly published in Proceedings of the National Academy of Sciences, it would be the whole body that would look a little old. Indeed, scientists found that pregnant women showed more signs of biological aging than women who had never been pregnant before. A process which would accelerate over the course of pregnancies.
Faster aging from four months to more than a year
The researchers analyzed data from more than 1,700 people in the Philippines from a large health and nutrition survey. The participants, who were all ages 20 to 22 in 2005 when the study began, provided blood samples and answered questions about their histories, including how many times they had been pregnant.
A smaller group of women provided additional blood samples between 2009 and 2014 to allow researchers to compare changes over time. All blood samples were analyzed for a number of biological factors associated with aging, including changes in DNA called epigenetic modifications, or here “epigenetic clocks.” This is how they observed this phenomenon: overall, women who had been pregnant at least once were biologically older than women of the same age who had not been pregnant.
Pregnancy led to faster aging by four months to more than a year, at a rate about 3 percent higher per year than that of women who had never been pregnant.
Cumulative aging with the number of pregnancies
The researchers then looked at how being pregnant more than once might affect measures of aging. Women who had more pregnancies aged up to five months faster than women who had fewer pregnancies, an acceleration in the rate of aging of almost 2% per year per pregnancy.
Finally, to ensure that this effect was not related to other factors that may affect aging, (such as exposure to air pollution, smoking and socioeconomic status), the group used the same six epigenetic clocks on the men in the study. They found that the number of children fathered by men had no relationship with the rate of their biological aging. “I“There appears to be something about the pregnancy of young women in the Philippines that affects biological aging.” explains Ryan Calen, first author of the study.
But why would pregnancy make women age a little faster? Researchers consider a link with the physical impact of pregnancy in terms of energy and resources for the woman. “The idea is that the body performs certain functions, but is always forced to optimize one of those functions, which creates a trade-off.”, Ryan explains. “Thus, energy intended for reproductive function can be diverted from body maintenance.”
In another recent paper, researchers led by Kieran O’Donnell of the Yale School of Medicine reported in Cell Metabolism that while they saw a similar acceleration of aging factors during pregnancy, they also saw signs encouraging evidence that these changes are reversed after pregnancy, particularly when mothers breastfeed.
In this study, O’Donnell found that pregnancy increased biological age by one to two years, but the rate of aging decreased by 16 percent three months after childbirth. This raises the idea that pregnancy may be associated with the potential for rejuvenation.
NO to diets, YES to WW!
Epigenetics opens new doors
Ryan Colen’s team now wants to know a little more about these mysterious processes.”We have evidence that pregnancy can accelerate biological aging. And we have proof that there is healing after pregnancy. What we don’t know precisely is to what extent this healing compensates for pregnancy, and how much this varies from person to person or country to country.” New research must therefore be undertaken. Especially since researchers are just beginning to harness the power of epigenetic studies.