Study leaders Sheldon Cohen and Rodlescia S. Sneed of Carnegie Mellon University, Ronald B. Turner of the University of Virginia Health Center and William J. Doyle of the University of Pittsburgh School of Medicine exposed 795 healthy adults ages 18-55 to a virus that causes a common cold.
Participants reported their parenthood status, and analyses were controlled for immunity to the experimental virus, viral strain, season, age, sex, race, ethnicity, marital status, body mass, employment status and education.
The study, published in Psychosomatic Medicine, found parents with one or two children were 48 percent less likely to get sick while parents with three or more children were 61 percent less likely to develop a cold.
Both parents with children living at home and away from home showed a decreased risk of catching a cold, the researchers said.
However, only parents older than age 24 were protected from the cold virus, parenthood did not influence whether those ages 18-24 became ill with the cold, the study said.