Health problems can put a strain on a marriage at any age. But as we get older, chronic illnesses can make it even tougher to keep the spark alive.
Scientists at the University of Chicago have uncovered one way couples can offset the stresses of illness and aging: more physical intimacy.
Couples who continue to be sexually active over the years report higher levels of satisfaction in their marriages, the sociologists reported last month.
And it doesn't take much to give a relationship a boost. Going from essentially no sexual activity during a year to sex once each month or so was associated with an increase in marital quality, according to those surveyed.
"To protect marital quality in later life, it may be important for older adults to find ways to stay engaged in sexual activity, even as health problems render familiar forms of sexual interaction difficult or impossible," sociologists Adena Galinsky and Linda Waite write in The Journals of Gerontology B.
And intercourse wasn't necessary to maintain intimacy. "As individuals age, the means of sexual expression may change," the researchers write. "Our measure of sexual behaviors was designed to be inclusive; it asks explicitly about any activities with one's partner that were sexually arousing, noting that they did not need to result in orgasm."
To figure out the relationship between sex, marital happiness and health, Galinsky and Waite analyzed data from nearly 500 couples between ages 58 and 85. Most of the couples had been married for at least 40 years.
The team measured marital quality through a series of questions about how close each partner felt to his or her spouse. They asked, for example, "How often do you open up about your feelings?" and "How often do you feel your spouse puts too many demands on you?"
They also checked each person's mental and physical health. And they asked each couple how frequently they engaged in some type of sexual activity from simple caresses to intercourse.
A link between marital quality and frequency of intimacy was clear. But how big was the effect?
That's difficult to summarize, says Amelia Karraker, a psychologist at the University of Michigan who wasn't involved in the study.
"Prior research has found that people that are physically ill are more likely to have a lower-quality marriage," she says. "This paper examines why that might be: Illness sometimes results in a cessation of sexual activity, and less sex may lead to you being less satisfied in your marriage."
Of course, the study's findings are averages over an entire population. "Other research has found that for some people and couples, sex just isn't important," Galinsky wrote in an email to Shots. "Our study does not show that sex is necessary for a high-quality marriage. Only that, on average, those who have sex more frequently report ... higher levels of marital quality."