Most people know the major advantage of being a grandparent—you get to spoil your progeny silly, then send them home and let their parents deal with the aftermath.

Now: New research reveals that some grandparents may even receive a hidden health benefit. Compared with grandparents who don’t help out, those who assist in the care of their grandchildren report less loneliness, which a growing body of scientific evidence now links to poor health outcomes.

Study details: As part of the German Ageing Survey, an ongoing study of adults ages 40 to 85, researchers recently went a step beyond the standard questions (occupational status, housing and health and life goals) to assess the study participants’ feelings of loneliness and social isolation. Along with that, participants were asked about the size of their social network (how many people with whom they have regular contact) and whether they helped care for their grandchildren.

Interestingly, research has shown that about half of grandparents in the US provide some level of care for their grandchildren—a percentage that is roughly equivalent to the number of European grandparents who also help out, though the exact number varies depending upon the country.

Results: In the German survey, about one-third of the 3,849 grandparents said they actively care for a grandchild. When responding to the questions about loneliness, the caregiving grandparents had a loneliness score of 1.7 (on a scale of 1 to 4, with 1 being the lowest), while the grandparents who were not actively caring for grandkids had a score of 1.8—a small but statistically significant difference.

Similarly, the caregiving grandparents had larger social networks. Those who help out with grandchildren reported being in contact with an average of six important people on a regular basis, while the grandparents who didn’t provide care were regularly in touch with four to five people (that’s a 50% or 20% increase, respectively). It should be noted, however, that the social network size included grandchildren that the grandparents cared for as well as the child’s primary caregiver.

Important: The size of one’s social network may be especially significant because previous research has linked reduced social interaction with worse mental and physical health, particularly as we get older.

“Assisting their families to balance work and family by providing supplementary grandchild care may boost grandparents’ self-esteem and may also facilitate ongoing positive relationships with their children and grandchildren,” the researchers noted. “Moreover, caring for grandchildren may also expand the social circle of grandparents and allow for further opportunities to establish relationships with other parents or grandparents.”

Caveats: The researchers warn that there may be a limit to how much active care is healthy for grandparents. Too much caregiving—especially if it interferes with the grandparents’ other activities or responsibilities—could produce less positive results.

As an observational study, the research also does not determine cause and effect. It’s possible that grandparents who felt less lonely before the study began were more likely to actively care for a grandchild. However, the findings held even after taking into account such factors as marital status, household income, self-rated health and activity levels—all of which could potentially affect the research findings.