Want To Live Longer? Scientists Say The 'Ideal' Number Of Children May Be 2 Or 3

A new long-term study suggests that the number of children a woman has and the age at which she becomes pregnant may be linked to how long she lives.

Researchers from the University of Helsinki and the Minerva Foundation Institute for Medical Research followed the lives of nearly 15,000 female twins to examine how reproduction relates to ageing and longevity. The findings have been published in the journal Nature Communications.

Participants first completed a questionnaire in 1975, and researchers have tracked their life course ever since. According to the analysis, women who had two to three children tended to live the longest. The timing of pregnancy also appeared to play a role.

The study found that pregnancies between the ages of 24 and 38 were linked with healthier ageing patterns and longer life expectancy.

However, women who had more than four children were found to have shorter lifespans on average and showed signs of faster biological ageing. Scientists say this may be explained by evolutionary biology theories which suggest that the body has limited energy resources. Investing heavily in reproduction may leave fewer resources for bodily maintenance and repair.

Interestingly, the study also found that women who had no children showed slightly faster ageing compared with those who had a small number of children. Researchers say this could be linked to lifestyle or health factors that were not fully measured in the study.

Scientists also examined biological ageing using "epigenetic clocks", which analyse blood samples to estimate how quickly a person's cells are ageing. The results showed that women with either many children or no children were biologically older than their actual age. Researchers stressed that the findings apply to population trends and should not influence personal decisions about family planning.