Could marriage, and associated companionship, be one key to a longer life? According to new research, not having a permanent partner, or spouse, during midlife is linked to a higher risk of premature death during those midlife years.

The work, by Dr. Ilene Siegler and colleagues from Duke University Medical Center in the US, is published online in Springer’s journal Annals of Behavioral Medicine.

Survival through middle age to become elderly is expected; therefore understanding who does not survive to become elderly and why is important.

Siegler and colleagues looked at the effect of marriage history and timing of marriage on premature death during midlife. They were also interested in testing the role of pre-marital personality and quantifying the role of health behaviors.

The researchers analyzed data for 4,802 individuals who took part in the University of North Carolina Alumni Heart Study (UNCAHS) – an ongoing study of individuals born in the 1940s.

The authors were particularly interested in stability and change in patterns of marital and non-marital status during midlife, controlling for personality at college entry (average age 18), socioeconomic status and health risk behaviors.

They found that having a partner during middle age is protective against premature death: those who never married were more than twice as likely to die early than those who had been in a stable marriage throughout their adult life.

Being single, or losing a partner without replacement, increased the risk of early death during middle age and reduced the likelihood that one would survive to be elderly.

Even when personality and risky behaviors were taken into account, marital status continued to have a major impact on survival.

The authors conclude: “Our results suggest that attention to non-marital patterns of partnership is likely to become more important for these Baby Boomers. These patterns appear to provide different levels of emotional and functional social support, which has been shown to be related to mortality. Social ties during midlife are important to help us understand premature mortality.”