Studies have long shown that married couples tend to have better health and decreased risk for heart disease, cancer, and other health risks, than unmarried people. Now, studies from Ohio State University throw a more nuanced light on the link between marriage and health, showing that the quality of a marriage and the nature of marital stress can have a profound effect on our health.

Married researcher-couple Ronald Glaser and Jan Kiecolt-Glaser studied the effects of marital stress on the immune function of 76 women. Using questionnaires related to their degree of happiness in their marriage, as well as blood tests, the researchers found that women who were in unhappy relationships and women who were struggling with the emotional effects of a divorce or separation had reduced immune response and produced lower amounts of antibodies.

In another study, the Kiecolt-Glaser team monitored blood samples from 90 newlywed couples as they argued about their most contentious areas of marital conflict. The study showed that couples who exhibited the most hostile and negative behavior during marital conflict had weakened immune systems, in real-time, during the 24 hours they were monitored. These studies suggest that marital stress can have a negative effect on our physical health.

Furthermore, the Glasers conducted another study monitoring how quickly the body healed itself during periods of marital stress in contrast with period of happy companionship. 42 couples (who were offered compensation) were subjected to a procedure where a small blister was produced on their skin. After sessions where couples argued or had some kind of conflict, the blister took a full day longer to heal than when the couples discussed something pleasant. In couples that exhibited pronounced levels of hostility while arguing, the blisters took a full 2 days longer to heal. This study offers compelling evidence that marital conflict, and in particular, conflicts that are especially negative or hostile, can cause our bodies to heal more slowly. This may potentially have serious effects on people recovering from surgery or other injuries.

The Kiecolt-Glaser study is supported by numerous other studies that suggest that marital stress contributes to higher health risks. One study from the University of Utah suggested that women who often had marital conflicts that lacked warmth and affection (i.e. arguments that were particularly nasty and hostile) were at higher risk for heart disease. Men, on the other hand, were at higher risk for heart disease when they had marital conflicts that involved controlling language.

More details on these and related studies can be found at Tara Parker-Pope's excellent article at the New York Times.

These studies all point to growing evidence that our emotional health, especially as it relates to our spouse or life companion, is closely linked to our physical health. Spending the effort to work on our relationships is also an important investment in the physical well-being of yourself and your loved one. Finding less hostile ways of resolving conflict and reducing relational stress may, in fact, help us to live longer.