PARIS • Parents, take heart. If you survive sleep deprivation, toddler tantrums and teenage angst, you may be rewarded with a longer life than your childless peers.
Fathers gained more in life expectancy than mothers, a team wrote in the Journal of Epidemiology and Community Health - and particularly in older age.
"By the age of 60, the difference in life expectancy... may be as much as two years" between people with children and those without, the team concluded in the report published on Monday.
Deep in sleep denial, new parents might sympathise with the old joke that they do not really live longer, it just feels like it. But the numbers prove otherwise, observed the Britain-based website IFLScience.
Many studies have confirmed that parents do actually have longer lives, on average, than adults who never procreate, but have not been able to explain why.
Dr Karin Modig of the Karolinska Institutet in Sweden led the research that sought to answer this question. The researchers tracked the lifespan of men and women born between 1911 and 1925 and living in Sweden - more than 1.4 million people in total.
The remaining life expectancy, in years, of 60-year-old women with children, compared with 23.1 for those who do not have children.
The remaining life expectancy, in years, of 60-year-old men with children, compared with 18.4 for those who do not have children.
They also gathered data on whether the participants were married and had children.
Men and women with at least one child had "lower death risks" than childless ones, the team concluded.
"At 60 years of age, the difference in life expectancy was two years for men and 1.5 years for women", compared with peers with no children, the researchers wrote.
By age 80, men who fathered children had a remaining life expectancy of seven years and eight months, compared with seven years for childless men, said the team.
For mothers, life expectancy at 80 was nine years and six months, while for childless women, it was eight years and 11 months.
The study merely pointed out a correlation, and cannot conclude that having children is the cause of the life expectancy gains, the researchers admitted.
But they theorised that parents may benefit from social and financial support from their children in older age, which childless people lose out on. The difference was about twice as large among unmarried men (including widowers and divorcees) as married men.
Dr Modig concludes that the difference is not just in the direct care children may provide, but also in helping aged parents deal with bureaucracies such as healthcare systems and housing providers.
It could also be that childless people live unhealthier lifestyles.
The association between having children and longer life was found in married and unmarried people, but appeared to be strongest in single, older men, said the study.
This could be because unmarried men relied more on their offspring in the absence of a partner.
The study did not echo previous findings that daughters are more beneficial for longevity than sons.
Fewer people are having children in Sweden as older people are spurning old-age institutions to receive care at home - often by their children. "Therefore, to further investigate health and survival consequences for childless older individuals is of importance," wrote the team.