Couples may get health benefits simply from sleeping in the same bed, a burgeoning field of study is showing. In fact, some scientists believe that sleeping with a partner may be a major reason why people with close relationships tend to be in better health and live longer.
The new research runs counter to studies that show women do not sleep as well with a partner and both men and women move around more when sleeping together. Other bed battles that interrupt couples' sleep include sheet-stealing and differing bedtimes and room-temperature preferences.
Sleep experts suggest there are ways to address these couple-sleep problems -- without resorting to separate bedrooms.
"Sleep is a critically important health behavior that we know is associated with heart disease and psychiatric well-being," said Wendy M. Troxel, an assistant professor of psychiatry and psychology at the University of Pittsburgh. "It happens to be this health behavior that we do in couples."
In one of Troxel's studies, published in 2009, women in long-term stable relationships fell asleep more quickly and woke up less during the night than single women or women who lost or gained a partner during the six to eight years of the study.
While the science is in the early stages, one hypothesis suggests that by promoting feelings of safety and security, shared sleep in healthy relationships may lower levels of cortisol, a stress hormone.
Sharing a bed may also reduce cytokines, involved in inflammation, and boost oxytocin, the so-called love hormone that is known to ease anxiety and is produced in the same part of the brain responsible for the sleep-wake cycle.
So even though sharing a bed may make people move more, "the psychological benefits we get having closeness at night trump the objective costs of sleeping with a partner," Troxel said.