People who have never married are more likely to die -- at all ages -- than people who are married and live together, U.S. data show.
It's the "never-married penalty," suggest University of California researchers Robert M. Kaplan, PhD, and Richard G. Kronick, PhD, in the August issue of the Journal of Epidemiology and Community Health.
Kaplan and Kronick extracted data from two sources: a 1989 national health interview survey, and the 1997 U.S. national death index. They had sufficient data to analyze information on more than 80,000 Americans.
Their main findings:
--Never being married has a greater risk of "poor health outcome" than being divorced or widowed.
--For men, the never-married penalty is stronger early in life.
--The never-married penalty affects both men and women.
"The risks of being never married … rival the risks of having increased blood pressure or high cholesterol," Kaplan and Kronick conclude.
The researchers found that never-married people, compared with their married peers, are:
--5 times more likely to die of infectious disease
--Twice as likely to die in accidents, homicides, or suicides
--38 percent more likely to die of heart disease
Social Isolation to Blame?
What's going on? Kaplan and Kronick suggest that people who never marry are isolated from other people. People who are divorced or widowed, they say, are more likely than the never-married to have children or other family relationships that offer social support.
"Accumulated evidence suggests that social isolation increases the risk of premature death," they note. "Marriage is a rough proxy for social connectedness."
The data strongly argue against other explanations. For example, it wasn't true that people with poorer health tended to be unmarried. In fact, the never-married penalty was strongest among people who said they were in excellent health. Moreover, never-married people reported better health habits than married people.
There are some drawbacks to the study. The researchers excluded people who were unmarried but living together. And the survey questions did not ascertain a person's sexual preference. Given the study period -- 1989 to 1997 -- a disproportionate number of deaths due to AIDS may have affected young men in the never-married group.
By Daniel J. DeNoon, reviewed by Louise Chang, MD
SOURCES: Kaplan, R.M. and Kronick, R.G. Journal of Epidemiology and Community Health, August 2006; vol 60: pp 760-765.