Does how often you see your grandkids affect how long you live?

In the first study of its kind, a team of scientists has found that grandparents who provide regular care for their grandchildren have an edge on survival over those who don’t.

The study, which was based on a population of Germans ages 70 and over and excluded grandparents who provided full-time care for grandchildren, builds on previous research showing that a moderate amount of grandchild care is linked to better physical and mental health.

People who provide care for others experience neuronal and hormonal changes that may act as a bulwark against death. 

While the scientists established only that survival is correlated with—rather than caused by—providing care for grandkids, in a recent journal article they posit that a causal relationship does in fact exist. People who provide care for others experience neuronal and hormonal changes that may act as a bulwark against death, the article states.

In all likelihood, according to the article, these health benefits evolved originally in parents caring for young children but eventually extended to grandparents, whose help may have given kids an advantage in the harsh early days of our species. (Here‘s more on the potential role of grandmothers in early human evolution.)

The scientists, who are based at the Max Planck Institute for Human Development and the University of Basel, used data from the Berlin Aging Study, which tracked the health and wellbeing of 516 older Germans from 1990 to 2009.

At the onset of that study, participants were surveyed about whether they were grandparents and, if so, how often they saw any of their grandchildren without the child’s parents.

In the current study, researchers used those responses to divide the Berlin subjects, most of whom are now dead, into three categories: “caregiving grandparents” (15.5 percent), “non-caregiving grandparents” (45 percent), and “non-grandparents” (39.5 percent). The team then looked at how long after the initial interview the members of each of these three groups survived.

On average, caregiving grandparents survived longer than both non-caregiving grandparents and non-grandparents, the team found.

Ten years into the Berlin study, half of the caregiving grandparents were still alive. By contrast, half of the members of both other groups died within five years of the study’s launch.

After adjusting their calculations for age, gender, health, proximity to grandchildren, and other factors that are known to influence mortality, grandparental investment, or both, the research team found that a significant association between caring for grandchildren and survival still held.

They also compared the survival of non-grandparents who said they provided help to kin or friends with the survival of non-grandparents who said they didn’t. On average, the helpers significantly outlived the non-helpers.

“It seems plausible that the development of parents’ and grandparents’ prosocial behavior toward their kin left its imprint on the human body in terms of a neural and hormonal system that subsequently laid the foundation for the evolution of cooperation and altruistic behavior towards non-kin,” the article says.