The research team is in the throes of a multiyear study examining how humans' closest personal relationships are associated with health, monitoring married couples' levels of stress hormones and wound-healing progress as partners carry on discussions about their lives. The prediction: Positive feelings about one's marriage can contribute to overall better health.
"There's growing evidence that the quality of marriage is related to health," said Dr. Janice Kiecolt-Glaser, director of health psychology in Ohio State's College of Medicine and Public Health. "The question is, how? If you have a good marriage, do you sleep better? Eat better? Probably so. But what we're finding is that the quality of interaction shows in the way the body responds through stress hormones and immune function."
The principal research team includes a marital partnership of its own. Kiecolt-Glaser is a longtime collaborator with husband Dr. Ronald Glaser, director of the Institute for Behavioral Medicine Research at Ohio State, and Dr. William Malarkey, an OSU Medical Center endocrinologist and director of the Clinical Research Center.
The Ohio State scientists are building upon numerous findings from more than two decades of research exploring how stress can alter the levels of certain hormones in the blood and weaken the immune system, increasing a person's vulnerability to disease. Their studies have determined that such experiences as marital fighting and being diagnosed with cancer or other debilitating diseases can weaken immunity, with consequences that include reducing the effectiveness of proven vaccinations and slowing the rate of wound healing.
In the marriage study, the researchers videotape the couples' interactions as they discuss a trait each partner wants to change about himself or herself, such as a desire to lose weight or become more organized, and determine whether the couples' behavior is positive, negative or neutral.
"We're finding the social interaction tends to be positive. We're asking the couples to talk about something they want to change, yet there's a degree of positivity to the discussion," Kiecolt-Glaser said. That positivity translates into lower levels of the stress hormone cortisol in the blood at that time. The lower the cortisol, the faster compounds are delivered to a wound to begin the healing process.
The wounds in question are a series of pea-sized blisters created by a vacuum in the lab on each partner's arm, which are monitored for wound-healing activity. "We can actually study what's going on at the wound site during the social interaction," Glaser said.
The researchers are looking for concentrations of cytokines, compounds that start the healing process, and cells called neutrophils, which are essential for repairing injured tissue. The scientists' previous studies have demonstrated that stress hormones can slow the delivery of cytokines to the site of injury, delaying the healing process.
"We combine the cortisol values and immune values with the behavioral measures and come up with very interesting relationships," Glaser said.
For example, a study of 90 newlywed couples showed that arguments between husbands and wives weaken their immune system, making them more susceptible to illness. In revisiting those couples 10 years later, the scientists discovered that elevated hormone levels from the earlier studies had been the best predictors of divorce - 19 percent of the couples had parted, all of whom had higher levels for three of four stress hormones monitored: epinephrine (adrenaline), norepinephrine, ACTH and cortisol.
"There's no doubt different kinds of emotions produce different physiological changes in the body, and they vary to some degree depending on the emotion," Glaser said. "And there's no doubt about the fact that people really play off each other. That can be good or bad, depending on the relationship."