In a tale they got married and lived happily ever after. Well, maybe the "ever after" is a bit of an exaggeration, but a happy marriage can bestow certain benefits.
I've just finished a book called "The Case for Marriage" by Dr. Linda Waite. She's a sociology professor at the University of Chicago, and talks about a phenomenon sometimes called the "marriage benefit." Demographers have been tracking this now for forty years, and it is a well-established observation: people in good marriages lead healthier lives. It's not even a subtle effect, either. In developed countries, middle age men have been found to cut their risk of dying in half by being happily married.
Unfortunately, the reverse is also true. People in unhappy marriages fare much worse on health-related issues, such as heart disease. In one study printed in the American Journal of Cardiology, researchers found that subjects who argued the most with their spouses were one point eight times as likely to die within four years as those who argued the least. That's a big finding!
Of course, there is debate over what causes these effects. Is it that healthy people tend to marry or people who marry stay healthy? Any relationship is complex, and scientists are still teasing these things out. But it isn't surprising to find that regular emotional stress would wear down the body, while regular emotional support allows it to take care of itself.