A new study from the Karolinska Institute in Sweden revealed that older adults who have children are more likely to live a little longer than those who don't have any children.

The study, published in the Journal of Epidemiology and Community Health, showed that parents have up to two years increase in their lifespan when they reach the age of 60, while non-parents don't experience the same increase in longevity.

"Parents live longer than non-parents, even in the oldest ages," said Karin Modig, an assistant professor of epidemiology at Karolinska Institute and lead author of the study, in a report from CBS News. "The absolute difference in death risk between parents and non-parents increases with age between age 60 and 100."

For the study, the researchers tracked all men and women born between 1911 and 1925 and living in Sweden using national registry data. The researchers gathered the data of 704,481 men and 725,290 women. The researchers also gathered registry data on marital status and the number and sex of any children they have.

They then compared their subjects' life expectancy with their marital status and parenthood to identify any linked between having children and longer life.

The researchers found that men, at the age of 60, were most likely to live two years longer than men with no children. The same is true with women. Mothers were expected to live 1.5 years longer than non-mothers. At 80, fathers and mothers are expected to live eight months and seven months longer, respectively, than non-parents.

At 90, the difference in the one-year risk of death reached 1.5 percent among men and 1.1 percent among women. The researchers were not able to explain the reason behind the increase in lifespan among those with children.

They noted that it is possible that parents tend to live healthier than non-parents. A more plausible explanation is parents have adult children to take care of them when they grow old, while the presence of grandchildren will increase their social interaction, all leading to longer life.