TUESDAY, Feb. 14, 2017 (HealthDay News) -- A new study finds that married people have less of a stress hormone called cortisol, which may explain why they tend to be healthier than people without partners.
Researchers at Carnegie Mellon University in Pittsburgh measured cortisol levels in saliva samples of 572 healthy adults. Those participants who were married had consistently lower levels of the stress hormone than those who were never wed or were previously married.
It's "exciting to discover a physiological pathway that may explain how relationships influence health and disease," study author Brian Chin said in a university news release. Chin is a Ph.D. student in the department of psychology at Carnegie Mellon.
The researchers also compared participants' daily cortisol rhythm. Typically, levels of the hormone peak when a person wakes up, then decline during the day. Married people had a faster decline -- a pattern linked to reduced heart disease risk and longer survival among cancer patients, the researchers said.
The findings suggest unmarried people may have more mental stress than marrieds do, according to the researchers. Chronic stress boosts cortisol levels, which, in turn, impairs the body's ability to regulate inflammation. Inflammation plays a role in development of many diseases, the researchers said.
Study co-author Sheldon Cohen said, "These data provide important insight into the way in which our intimate social relationships can get under the skin to influence our health."
Cohen is a professor of psychology at the university.
The study appears in the April issue of the journal Psychoneuroendocrinology.
The U.S. National Institute of Mental Health has more on stress.