For years, marriage has been so well linked to health that U.S. Department of Health and Human Services got $150 million a year to spend on marriage support through its Healthy Marriage Initiative.

So will newlyweds Brad Pitt and Angelina Jolie be better off, health-wise, as a married couple?

Not necessarily. While there are clear health benefits linked with healthy relationships (married people live longer, and are at less risk of everything from cardiovascular disease to dementia to pneumonia), researchers are now realizing that the strength of the relationship might be more important than a marriage certificate.

Short Men Divorce Less

“When we divide good marriages from bad ones,” marriage historian Stephanie Coontz told The New York Times, “we learn that it is the relationship, not the institution, that is key.”

Indeed, marital stress is much worse for your health than being single. Research at the University of Chicago shows that newly single people, whether divorced or widowed, suffer a 20 percent increase in chronic health issues.

Photos: Marriage’s Bumpy History

How could relationships have such a profound effect on health? “It encourages people to maintain good health behaviors and have good social support and a sense of purpose in life,” said researcher Hui Zheng, an assistant professor of sociology at Ohio State University who led a study that found marriage benefits to be more protective for couples who were already healthy.

Despite the risk of the negative impacts of failed relationships, “on balance it probably is worth making the effort,” David and John Gallacher pf Cardiff University wrote in Student BMJ.

Photo: Brad Pitt and Angelina Jolie arrive at the 18th Annual Screen Actors Guild Awards. The pair married in a secret wedding this week. Credit: ThinkStock