(Reuters Health) - Married couples may be healthier than single, divorced or widowed adults at least in part because they have lower levels of the stress hormone cortisol, a recent study suggests.
Previous research has linked marriage to a longer life and other health benefits, which were thought to be due to factors such as higher household income, better medical insurance or improved access to care. The current study, however, offers fresh insight into another possible benefit of marriage: less stress.
For the study, researchers tested levels of cortisol in 572 healthy men and women aged 21 to 55. They found married individuals consistently had lower cortisol levels than people who never married or who were previously married.
"Our findings provide new and important initial insights into how our most intimate social relationships can ‘get under the skin’ to impact physical health," said lead study author Brian Chin, a psychology researcher at Carnegie Mellon University in Pittsburgh, Pennsylvania.
"We aren't able to draw any strong conclusions from our study about exactly how this happens, but we are able to make some educated guesses based on earlier research," Chin added by email.
It's possible, for example, that married people might have better access to care than single individuals because they have good health insurance through a spouse or more funds available to pay for care, Chin said. Being married might also help encourage people to stick to a healthier lifestyle or avoid behaviours that can lead to illness like smoking or excessive drinking.
Married people in the study had faster drops in cortisol levels during the day, a pattern that's associated with health benefits including a lower risk of heart disease and longer survival among cancer patients, researchers note.
Differences in cortisol during the day between married and unmarried people were not due to variations in participants' starting levels of cortisol at the beginning of the day.
Instead, it appeared that married people had a more rapidly accelerating decline in cortisol during the afternoons than people who were never married, though not individuals who had been previously married.
"This study is exciting because we know being married is associated with better health but we don't know why this association occurs," said Kira Birditt, a researcher at the University of Michigan in Ann Arbor who wasn't involved in the study.
– Medscape online