Despite the rebellious teenage years that give you gray hair…
Many people might assume that the stress and full-time job associated with having kids would lead parents to age faster, but science has found the opposite.
Researchers at Simon Fraser University suggest that the number of children a woman has influences the rate at which her body ages.
How? It all has to do with telomeres, which are the protective tips found at the end of each DNA strand. As T.A. Sciences puts it, “Telomeres are the caps at the end of each strand of DNA that protect our chromosomes, like the plastic tips at the end of shoelaces.”
Just like shoelaces become frayed without the plastic coatings, DNA strands become damaged and unable to do their job without telomeres. Telomeres are indicative of cellular aging and associated with longevity, according to the press release.
The study, led by health sciences professor Pablo Nepomnaschy and postdoctoral researcher Cindy Barha, found that women who give birth to more surviving children exhibit longer telomeres. It’s the first study to examine the direct association between the number of children and telomere length in humans over time.
The study looked at the number of children born to 75 women from two neighboring indigenous rural Guatemalan communities, as well as the women’s telomere lengths. The researchers measured the telomere lengths at two time points 13 years apart. The telomere lengths were tested through salivary specimens and buccal swabs.
Nepomnaschy says that the study findings contradict the life history theory which predicts that having more children speeds up the pace of biological aging. However, telomeres may not be the only biological factor at play.
"The slower pace of telomere shortening found in the study participants who have more children however, may be attributed to the dramatic increase in estrogen, a hormone produced during pregnancy," says Nepomnaschy, who also leads the Maternal and Child Health Laboratory at the SFU Faculty of Health Sciences. "Estrogen functions as a potent antioxidant that protects cells against telomere shortening."
So the telomeres and the estrogen could be working together in the age-slowing mechanisms, but social environment might also influence the relationship between reproduction and the pace of aging, the researchers say.
"The women we followed over the course of the study were from natural fertility populations where mothers who bear numerous children receive more social support from their relatives and friends," explains Nepomnaschy. "Greater support leads to an increase in the amount of metabolic energy that can be allocated to tissue maintenance, thereby slowing down the process of aging.”
While there are a few factors found in the study that could explain why having more kids seems to slow down the aging process, the findings pose an interesting contrast to the common view that people who have more kids age faster.
Perhaps the whole joke about parents getting gray hair from the rebellious teenage years is a myth after all.