The study, which was published in the journal of Psychoneuroendocrinology, said it discovered that married individuals had lower levels of cortisol, a stress hormone.
A recent study has found that married people are healthier than their unmarried/bereaved counterparts because they face less psychological stress.
Prolonged stress is associated with increased levels of cortisol, which can interfere with the body’s ability to regulate inflammation, which in turn promotes the development and progression of many diseases.
“It is exciting to discover a physiological pathway that may explain how relationships influence health and disease,” said one of the researchers, Brian Chin from Carnegie Mellon University in Pittsburgh, Pennsylvania, US.
For three non-consecutive days, researchers collected saliva samples from 572 healthy adults aged 21 to 55. Multiple samples were taken during each 24-hour period and tested for cortisol.
Results showed that the married participants had lower cortisol levels than the never-married or previously-married couples across the three-day period.
The researchers also compared each person’s daily cortisol rhythm. Typically, cortisol levels peak when a person wakes up and declines during the day.
Those who were married showed a faster decline, a pattern that has been associated with less heart disease, and longer survival among cancer patients.
“These data provide important insight into the way in which our intimate social relationships can get under the skin to influence our health,” said co-author, Sheldon Cohen, professor at Carnegie Mellon University.
Other researchers on the team were Michael L.M Murphy from Carnegie Mellon University and Denise Janicki-Deverts from the University of Pittsburgh were also part of the research team