The short answer is yes, especially if you are a man–but there are plenty of caveats.
“Marriage, if you stay married, is wonderful social support,” says Peter Martin, a professor of human development and family studies at Iowa State University. Having a partner during middle age, which is when chronic diseases often first appear, is protective against premature death, according to a 2013 study that Martin and his co-authors published in Annals of Behavioral Medicine. They also found that people who never married were more than twice as likely to die early as people in stable marriages. “Being married is a big factor in survivorship,” Martin concluded.
Martin’s team isn’t the first to make the connection between marriage and longer life. A 2013 study of 15,330 cardiac events showed that married people have considerably better prognoses than singles. The effect has been observed beyond heart-disease patients. Other research indicates that married people are more likely to have their cancer detected early and less likely to die early from it.
Longevity researchers believe it’s tied to the live-in emotional and physical support. When you have someone around all the time, it means you have someone to remind you to take your meds and go to the doctor. And if you fall down or otherwise hurt yourself, there’s a good chance there will be someone around to help you. Married people are also more likely to adopt healthy behaviors like exercising and quitting smoking if their partner does. Martin, who interviews centenarians, says he’s heard many of them say they abide by healthy behaviors their long-deceased spouse used to remind them about. “Some of the marriage benefits seem to outlast the partner who doesn’t make it to very old age,” he says.
The so-called marriage effect doesn’t appear to benefit men and women equally, however. The Terman Life-Cycle Study–an ongoing project that started following more than 1,500 people in 1921–found that whereas steadily married men were likely to live substantially longer than divorced or remarried men, divorced women lived almost as long as their married peers.
“Women who thrived in a good marriage stayed especially healthy,” explains Howard S. Friedman, a professor of psychology at the University of California, Riverside, and author of The Longevity Project, which breaks down and continues to build on the Terman research. “But women who stayed single, got and stayed divorced or were widowed often lived quite long without the burdens of husband trouble. They had good friends instead.” (Plenty of research shows that whether people are married or not, strong social connections and friendship are especially important factors in healthy aging.)
Researchers are also learning that the quality of the marriage might matter–a lot. The husband-and-wife research duo Janice Kiecolt-Glaser and Ronald Glaser have conducted a number of experiments at Ohio State University on the topic. In one, they brought couples into their lab, inserted IV blood-collection catheters and then asked them to talk through an especially troublesome aspect of their marriage–things like finances, sex or their in-laws. They found that couples who are hostile toward each other tend to have more stress hormones in their blood, less adaptive immune systems and slower metabolic rates after eating high-fat meals. “The way people treat each other on a daily basis clearly impacts physical health,” says Kiecolt-Glaser. Poor marital quality and the stress associated with it are linked to differences in inflammation, a marker for disease, she adds. “That’s a great pathway to all the nastiness that comes with aging.”
Even the best-case scenario of a happy and long marriage can come with a sad, if darkly romantic, twist: couples who die in old age within days or months of each other. While it’s not completely understood, experts suggest that broken-heart syndrome could be to blame. Broken-heart syndrome–a colloquial name for something called stress-induced cardiomyopathy–can be caused by an emotionally stressful event like the death of a loved one or even a very tough breakup. It’s often mistaken for a heart attack, but instead of blocked arteries, the culprit is a tsunami of stress hormones that cause the heart to temporarily expand, limiting its ability to pump. Still, it’s probably a risk most lovebirds are willing to take for a satisfying relationship–and a longer life.
This appears in the February 23, 2015 issue of TIME.