A study published in the July edition of Psychosomatic Medicine, the official journal of the American Psychosomatic Society, reveals that parents have a lower risk of catching a cold, which could potentially be due to unknown "psychological or behavioral differences between parents and non-parents."
Research leader, Rodlescia S. Sneed, MPH, and Sheldon Cohen, PdD of Pittsburgh's Carnegie Mellon University discovered that the risk of contracting a cold, regardless of pre-existing immunity, after being exposed to cold viruses is 50% less in parents compared with those who have no children. The findings indicate that there are other, so far, unknown factors related to being a parent, which may affect susceptibility to illness.
The team examined data on 795 adults from three previous studies of stress and social factors that affect susceptibility to common colds. During these studies, healthy volunteers were administered with nose drops containing either the rhinovirus or influenza viruses, which cause colds.
One-third of volunteers subsequently developed clinical colds, i.e. typical symptoms of a cold plus confirmed infection with one of the study viruses. In their study, the researchers wanted to determine whether being a parent affected the risk of developing a cold.
The findings revealed that parents developed a lower rate of colds than volunteers who were not parents. After adjusting for variables, the result showed that parents had a 52% lower risk of developing a cold.
The finding may be expected considering that when children get colds, the parents may develop protective antibodies against the specific viruses that cause these colds. However, the findings revealed that based on levels of antibodies to the study viruses, the lower risk of colds in parents could not be explained by pre-existing immunity as volunteers that were parents tended to develop less colds irrespective of whether or not they had protective levels of antibodies.
The researchers also discovered that the protective effect of parenthood increased with the number of children, even though the data on parents with three or more children was limited. Furthermore, the findings revealed that the risk of parents contracting a cold was even lower when the parents did not live together with any of their children. The risk reduction of parents whose children did not live at home, was even greater, i.e. 73%.
The findings showed that the risk of colds was lower for parents in most age groups, apart from those in the youngest age group (18 to 23 years) who had the same risk as non-parents. The researchers also observed no difference in the risk of colds between married and unmarried parents.
The researchers state: "We found parenthood predicted a decreased probability of colds among healthy individuals exposed to a cold virus."
The results show that the effect is independent of parental immunity, which indicates a potential involvement of psychological or behavioral factors. However, the researchers cannot draw any conclusions in terms of what these protective factors might be.
One possible explanation may be that being a parent improves regulation of immune factors (cytokines) that are triggered in response to infection. According to earlier research, cytokine responses explain the protective effects of psychological factors, such as lower stress or a positive attitude against the risk of colds.
The researchers suggest that more research is required to establish the exact reasons why 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."
Written by Petra Rattue