(Reuters Health) - Children whose parents separate and are not on speaking terms may be more vulnerable to catching colds as adults than kids whose parents stay together or go through an amicable breakup, a recent study suggests.
"There is evidence that children whose parents divorce are at increased risk for illness both during their childhood and as adults," said lead study author Michael Murphy, a psychology researcher at Carnegie Mellon University in Pittsburgh.
"However, our study indicates that parental separation itself may not account for this increased risk," Murphy said by email. "This is important because parental divorce is a common experience, affecting more than a million children annually in the United States alone."
For the study, researchers quarantined 201 healthy adults, exposed them to a virus that causes a common cold and monitored them for five days to see how their immune systems reacted and if they developed a respiratory illness.
Adults whose parents lived apart and never spoke during their childhood were more than three times as likely to develop a cold as participants who grew up in two-parent households, the study found. However, adults whose parents separated but communicated with each other were no more likely to catch a cold than people who came from intact families.
People whose parents separated and stopped speaking were 3.3 times more likely to develop a cold than people whose parents remained together during their childhood, the study found. These people also had higher levels of a marker of inflammation, which might help explain why they were more susceptible to catching a cold, the researchers speculate.
Participants in the study were about 30 years old on average, and 92 of them, or 46 percent, reported that their parents had divorced or separated during their childhood. Among the people with separated parents, 51 said their parents weren't on speaking terms.
All of them were given nasal drops containing rhinovirus 39 (RV39), a virus that causes the common cold.
Then, for the next five days, researchers collected nasal secretions to check for evidence of the virus and inflammation as well as to assess how much mucus people produced and how congested they were.
Overall, 149 participants, or 74 percent, developed an infection with RV39 and 60 people met the criteria for a cold based on having both an infection and objective symptoms, researchers report in the Proceedings of the National Academy of Sciences.
Limitations of the study include its reliance on participants to accurately recall and report on whether their parents communicated after a separation, the authors note. Even though researchers accounted for a number of factors that can influence the odds of catching a cold such as medical and psychiatric history and prescription use, it's still possible something other than divorce or parents' communication influenced the results.
"Although it's natural to suggest there's a causal process in play here from early parental divorce to later health, it's just as likely that the children of adults who never spoke with each other after their separation share many of the same personality dispositions as their parents - perhaps hostility, addiction or depression - and it is these variables that actually place the young adults at greater risk for colds," David Sbarra, a psychology researcher at the University of Arizona who wasn't involved in the study, said by email.
Even so, the findings add to growing evidence linking divorce-related stress to an increased risk of physical health problems, said Sharlene Wolchik, a psychology researcher at Arizona State University who also wasn't involved in the study.
"The good news is that we know a fair amount about the protective factors that reduce this risk," Wolchik said by email. "When divorce is followed by a new family structure in which parents have high quality relationships with their children, children spend sufficient time with each parent so their relationships can be meaningful and children are not directly or indirectly exposed to conflict between the parents, children can be resilient and thrive despite the stress of divorce."
SOURCE: bit.ly/2u2zLwn Proceedings of the National Academy of Sciences, online June 5, 2017.
(The story refiles to correct journal name in paragraph 10)