Does childbirth slow the aging process?

25 January 2016

The number of children you have may influence how your body ages, according to a new MSFHR-supported study.

A team co-led by Simon Fraser University researchers Dr. Pablo Nepomnaschy (2012 MSFHR Scholar) and Dr. Cindy Barha (2015 MSFHR Trainee) found a correlation between the number of surviving children born to a woman and the length of her telomeres. Telomeres are caps at the end of each chromosome that protect the rest of our DNA and are argued to be linked to cellular age. While telomeres tend to shorten as a natural consequence of aging, the study’s findings suggest that having more children may act as a protective factor, slowing the pace of telomere shortening.

The researchers studied a group of 75 Indigenous Kaqchikel Mayan women from Guatemala over a 13-year period. Each woman was assessed for telomere length at the start and end of the study. This population represents a good model to study because they are more similar to each other than those women who live in industrialized communities in terms of genetics and lifestyle factors, including physical activity, education, and socio-economic status,. These similarities increased the researchers’ ability to detect the relationship between telomere length and the number of children women have.

In this specific population and environment, women with more surviving kids were found to have longer telomeres than women with fewer children. One hypothesis for the longer telomeres is the action of the steroid estradiol, which increases dramatically during pregnancy.

Estradiol is known to protect telomeres from the effects of oxidative stress and increase the activity of telomerase, an enzyme that maintains telomere length. Women who have more pregnancies are exposed to higher estradiol levels, which indirectly protect telomeres from shortening.

In order to better understand the relationship between telomere length and pregnancy, Nepomnaschy and Barha plan to carry out additional studies with women of different ethnicities in different social and physical environments. Improving our understanding of the factors that influence changes in telomere length can provide useful information to help improve our management of well-being, morbidity, and mortality during the aging process.

The study was published in PLoS ONE on January 5, 2016, and has garnered much media attention, including interviews on Roundhouse Radio, The Simi Sara Show, and CBC’s The Early Edition.