This is how motherhood influences life expectancy

In an increasingly long-lived society, where life expectancy continues to increase, science continues to look for the keys to aging better. Now, new research focuses on a factor that is unusual in this type of study: the number of children.

A work carried out by the University of Helsinki and the Minerva Foundation Medical Research Institute, published in the journal Nature Communications concludes that both Not having children like having large families could be related to faster biological aging and lower survival.

The study is based on the well-known Finnish Twin Cohort, one of the most complete databases in the world to study health and genetics. In total, the researchers analyzed nearly 15,000 women, whom they followed for decades through health records, demographic data and periodic questionnaires. This long-term follow-up made it possible to relate their reproductive history—number of children and age at birth—with their evolution in health and mortality.

Furthermore, in a part of the sample biological samples were collected that allowed aging to be measured at a molecular level, which provides a more precise view than studies based solely on age or diseases.

A U-shaped relationship

The researchers observed that women without children and those with more than four present worse aging indicators. Instead, Those who had two or three children showed, on average, a better evolution.

“The association between the number of children and mortality follows a U shape,” the authors explain, suggesting that extremes are less beneficial for long-term health.

Along the same lines, from the University of Helsinki they explain in a press release that “Women with two or three children tend to live longer”reinforcing the idea that there is a more favorable intermediate point.

This type of relationship had already been noted in previous studies, but is now reinforced with more precise biological data on aging.

Beyond age: biological aging

One of the keys to the study is that it is not limited to counting years of life, but rather analyzes the so-called biological age. That is to say, the real wear and tear of the organism. To do this, the scientists used epigenetic markerswhich allow us to measure how our cells age.

As detailed, “women at the reproductive extremes showed a more advanced biological age”, which is usually linked to increased risk of disease and mortality.

The moment of being a mother also influences

The work adds another relevant factor: the age at which you have children. The data indicate that mothering too young is associated with worse aging, while mothering at intermediate ages—approximately between 24 and 38 years old—is related to better outcomes.

“The timing of reproduction plays an important role in long-term health.””, the researchers emphasize.

To explain these results, the authors turn to evolutionary biology. Specifically, the so-called “disposable soma” theory, which states that the body has limited resources.

According to this idea, The organism must distribute its energy between reproducing and maintaining itself: “Greater investment in reproduction may come at the expense of body maintenance,” they point out.

Prudence in interpretation

Despite the forcefulness of the data, experts call for do not draw simplistic conclusions.

“These findings should not be interpreted as individual recommendations.“, they warn, remembering that health is influenced by multiple factors such as socioeconomic level, lifestyle habits or access to health care.