We might think of children as "germ factories," but having kids may actually reduce an adult's risk of catching a cold, a new study says.
In the study, parents were half as likely as people without children to get sick after being exposed to a cold virus in a laboratory.
Surprisingly, the results could not be explained by the parents' pre-existing immunity to the cold viruses used in the study. In other words, while it could be easy to think that parents were less likely to get colds because their dear little ones had previously trucked these viruses home, the study didn't show this.
Instead, the researchers found that parents were less likely than people without children to get sick, regardless of whether they already had antibodies against a given virus.
The researchers aren't sure of the reason for the findings. It possible that, somehow, becoming a parent changes the regulation of the immune system so that the symptoms of a cold are actually less likely to appear, the researchers said.
Parenthood and health
Previous studies have found that parents have a reduced risk of dying over a given period, compared with nonparents, and tend to have better heart health.
In the new study, Rodlescia Sneed, of Carnegie Mellon University, and colleagues analyzed information from about 800 adults in the Pittsburgh area who participated in three studies conducted between 1993 and 2004. In those studies, healthy people were given nose drops containing one of three rhinoviruses (which cause colds), or a flu virus.
Participants were then quarantined and monitored for symptoms for five to six days.
In all, 337of the participants, or 42 percent, were parents.
About 30 percent of participants developed cold symptoms during the study. Parenthood was associated with a reduced chance of showing cold symptoms. For example, 25 percent of parents ages 24 to 36 became sick with a cold, compared with about 40 percent of non-parents in that age group.
Younger parents — those ages 18 to 23 — were the only parents who did not have a reduced risk of developing a cold, the researchers said. There may be psychological differences in people of this age that somehow translate to not reaping the same health benefits of parenthood, the researchers said.
Even having grown kids reduces risk
The findings held even after the researchers took into account factors that could affect the results, such as participants' age, sex, education level, marital status and certain personality traits. And parents still had a reduced risk of catching a cold regardless of whether their children lived at home, or had grown up and moved away.
"The lack of difference here suggests that daily and intensive contact with one’s children is not critical to the protective effect of parenthood," the researchers wrote.
Instead, physiological factors, such as a feeling regarding their purpose in life, or behavioral factors might be responsible for the link, the researchers said.
Because the study was conducted in a laboratory, it's not certain whether the results would apply to the real world, and so more research is needed to confirm them.
The study is published in the July issue of the journal Psychosomatic Medicine.
Pass it on: Parents may be less likely to develop cold symptoms after exposure to a cold virus.