Caring for a grandchild may be linked to a lower risk of loneliness and social isolation, suggests research published in the online journal BMJ Open.
Active grandparents have larger social networks, which include people who are important to them, than those who don't have this role, the findings show.
Previously published research suggests that social networks may be a key factor in health and wellbeing, particularly at older ages.
Grandparents are increasingly taking on the role of childcare, often in a supplementary role, to help out parents when other forms of care aren't available.
But to date, most of the research on grand-parenting has focused on those who act as surrogates and parent their grandchildren, and none has explored how grand-parenting might affect the size of that individual's social network, with the potential implications for health and wellbeing.
To try and address this, the researchers drew on the information collected in wave 5 of the DEAS survey.
This survey involves speaking to a nationally representative sample of older German adults (40-85 years old) every three years since 1996.
Wave 5 (2014) was the first time that respondents were asked questions designed to assess their feelings of loneliness and social isolation, using validated scales, i.e. a shortened version of the De Jong Gierveld Loneliness Scale, and the Bude and Lantermann scale for social isolation.
Both scales ranged from 1 to 4, with 1 representing strong agreement and 4 representing strong disagreement with specific statements.
Higher scores indicated a higher degree of perceived loneliness and social isolation.
Among the 3,849 grandparents included in this wave of the survey, 1,125 said they actively cared for a grandchild.
Just over half of them were women, and most were married and living with their spouse (80 per cent).
After taking into account potentially influential factors, including marital status, domestic arrangements, household income, self-rated health, physical activity levels and depressive symptoms, active grand-parenting was associated with lower scores on loneliness and social isolation, and a larger social network.
Among the active grandparents, whose average age was 66, the average loneliness score was 1.7 and the average social isolation score was 1.6, while the average number of people with whom they were in regular contact was six.
Grandparents who didn't have an active caring role had higher average loneliness scores (1.8) and were in regular contact with fewer people important to them (four to five, on average).
This is an observational study, and as such, can't establish cause.
And it may be that grandparents who felt less lonely and isolated to start with might have been more likely to actively care for a grandchild, note the researchers.
What's more, the study didn't collect information on how near to their grandchildren grandparents lived, how often they provided care or its quality, all of which might have influenced the findings.
But the researchers suggest: "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.
"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."
But they also suggest that the positive impact might wear off if grandparents are called on too often to step in and care for a grandchild, especially if this interferes with other aspects of their lives.