(Reuters Health) – - Grandparents who help out occasionally with childcare or provide support to others in their community tend to live longer than seniors who do not care for other people, according to a study from Berlin, Germany.

Having full-time custody of grandchildren can have a negative effect on health, but occasional helping can be beneficial for seniors, the researchers write in the journal Evolution and Human Behavior.

“Having no contact with grandchildren at all can negatively impact the health of grandparents,” said lead author Sonja Hilbrand, doctoral student in the department of psychology at the University of Basel in Switzerland.

“This link could be a mechanism deeply rooted in our evolutionary past when help with childcare was crucial for the survival of the human species,” Hilbrand told Reuters Health by email.

The findings are drawn from data on more than 500 people over age 70 in the Berlin Aging Study.

The participants completed interviews and medical tests every two years between 1990 and 2009.

The researchers did not include any grandparents who were the primary caregivers for their grandchildren, only those who cared for grandchildren occasionally.

The study team compared this group with seniors who provided support for non-family members, such as friends or neighbors, and seniors who did not provide any care to other people.

Overall, after accounting for grandparents’ age and general state of health, the risk of dying over a 20-year period was one-third lower for grandparents who cared for their grandchildren, compared with grandparents who did not provide any childcare.

Half of the grandparents who cared for grandchildren were still alive ten years after the initial interview. The same was true for participants who did not have grandchildren but supported their adult children in some way, such as helping with housework.

In contrast, about half of the participants who did not help others died within five years of the start of the study.

Caregiving was linked with longer life even when the care recipient wasn’t a relative. Half of all childless seniors who provided support to friends or neighbors lived for seven years after the study began, whereas non-helpers lived for four years on average.

“Caregiving may give caregivers a purpose of life because caregivers may feel useful for the others and for the society,” said Bruno Arpino, an associate professor at Pompeu Fabra University in Barcelona, Spain who was not involved in the study.

“Caregiving may be thought also as an activity that (keeps) caregivers physically and mentally active,” Arpino said by email, adding that previous studies suggest that caregiving may improve cognitive functioning, mental and physical health.

Arpino noted, however, that caregiving is not the only activity that can improve health, and too many caring responsibilities can take away from other beneficial activities like working, being in social clubs, or volunteering.

“Children should take into (consideration) their parents’ needs, willingness and desires and agree with them on the timing and amount of childcare,” Arpino suggested.

“It is very important that every individual decides for him/herself, what ‘moderate amounts of help’ means,” Hilbrand said, adding, “As long as you do not feel stressed about the intensity of help you provide you may be doing something good for others as well as for yourself.”

SOURCE: bit.ly/2honXO9 Evolution and Human Behavior, online December 5, 2016.