Being a parent reduces your risk of catching a cold by more than half, according to new findings, suggesting that "psychological or behavioral differences between parents and nonparents," may be the reason for the health benefit.

A new study, published in the July issue of Psychosomatic Medicine, found that the risk of becoming ill after exposure to cold viruses is reduced by about half compared to nonparents, regardless of their preexisting immunity.

Researchers at Carnegie Mellon University, Pittsburgh, analyzed data on 795 adults from three previous studies that looked at how stress and social factors affected susceptibility to the common cold.

Scientists had given healthy volunteers nose drops containing rhinovirus or influenza viruses that causes cold, and about a third of the volunteers had developed clinical colds after being exposed to the virus.

Researchers analyzed the results from the previous studies and found that parents were 52 percent less likely to develop colds compared to other healthy volunteers and the protective effect of parenthood appeared to increase along with the number of children.

Parents who were no longer living with their children were at an even lower risk of catching a cold, with a 73 percent reduction in risk after exposure.

Researchers the risk of colds was significantly lower for parents in all age groups except for parents between the ages of 18 to 23 years old, for whom there was no difference in the risk of colds compared to nonparents.

"We found parenthood predicted a decreased probability of colds among healthy individuals exposed to a cold virus," co-authors Rodlescia Sneed and Sheldon Cohen wrote.

Sneed and Cohen believe that the protective effect of parenthood is independent of parental immunity, when parents develop protective antibodies against specific viruses that are causing their kids to get colds.

Researchers explained that based on the levels of antibodies to the study viruses, parents were still less likely to develop colds whether or not they had protective levels of antibodies, suggesting that the psychological or behavioral factors could be involved.

Scientists suggest that being a parent may improve regulation of immune factors like cytokines triggered in response to infections. Past research found that besides lowering cold risk, cytokine responses explain the protective effects of psychological factors like having less stress and possessing a positive attitude.

However, scientists noted that more research will be needed to explain now being a parent could affect the body's response to cold viruses.

"Our results, while provocative, have left room for future studies to pursue how various aspects of parenthood (eg, frequency of contact with children, quality of parent/child relationships) might be related to physical health, and how parenthood could 'get under the skin' to influence physical health," researchers wrote.