A recent study has established a connection between women’s reproductive history and their lifespan, along with biological aging. Conducted by researchers at the University of Helsinki and the Minerva Foundation Institute for Medical Research, this research utilized data from the Finnish Twin Cohort, tracking nearly 15,000 participants since their initial questionnaire in 1975.
The findings indicate that women with larger families, those who remain childless, or those who have their first child at a young age tend to exhibit signs of accelerated aging. This suggests that both the number of children and the timing of pregnancies significantly influence women’s health and longevity.
Key Insights from the Research
The study revealed that women who have two to three children generally enjoy the longest lifespans. In contrast, those with more than four children displayed a correlation with shorter lifespans and expedited biological aging. The timing of pregnancies is also crucial; the research indicates that having children between the ages of 24 and 38 is linked to more favorable health outcomes as women age.
According to Mikaela Hukkanen, a doctoral researcher involved in the study, “From an evolutionary biology perspective, organisms have limited resources such as time and energy. When a large amount of energy is invested in reproduction, it is taken away from bodily maintenance and repair mechanisms, which could reduce lifespan.” This perspective aligns with the principles of life history theory developed in the 20th century.
Interestingly, the study also found that childless women showed faster aging compared to those with a few children. Researchers suggest that this may stem from unmeasured lifestyle or health factors that could not be fully accounted for in the analysis.
Implications and Limitations
While the study offers valuable insights, the authors caution that the findings apply only at the population level. They do not establish cause-effect relationships or provide individualized recommendations for women regarding family planning. Dr. Miina Ollikainen, the study lead, emphasized that the family dynamics have changed since the time of the research, with family size decreasing and the age of first births rising. Therefore, individual women should not alter their reproductive plans based solely on these findings.
The research also introduced an innovative approach by measuring biological aging through epigenetic clocks derived from blood samples of over a thousand participants. These clocks assess the gradual deterioration of cells and tissues, indicating biological age, which can precede death by years or even decades. The results affirmed earlier mortality-based conclusions, revealing that women with either many children or none at all were biologically older than their chronological age.
According to Miina Ollikainen, “A person who is biologically older than their calendar age is at a higher risk of death. Our results show that life history choices leave a lasting biological imprint that can be measured long before old age.” The study also suggested that early pregnancies could relate to biological aging, as evolutionary theory posits that natural selection may favor earlier reproduction, despite potential health costs.
Published in the journal Nature Communications, this research adds to the ongoing discourse surrounding reproductive choices and their long-term implications on health and aging. The findings underline the complexity of biological aging and invite further investigation into how reproductive history shapes women’s life courses.
