Married men are less likely to die from heart disease and women with “satisfying relationships” live longer, two recent studies suggest. The findings add to a widening strand of evidence that people in long-term relationships live longer and are less likely to suffer from conditions ranging from depression to diabetes. But does this all point towards a bleaker flipside that being single is bad for your health – and, if so, why?
It turns out that this question is harder to answer and there are also indications that the health benefits of partnership may be different for men and women and are also shifting over time.
“It’s well established across many studies that people who are married tend to have better health than people who are not married,” said Prof Kristi Williams of Ohio State University. “But I’d argue that it’s not always well-established that it’s a causal effect on health.”
One crucial factor, sometimes unaccounted for, is the health trajectory people were on before they got married or entered a long-term relationship.
“Where you run into trouble is that these are observational studies – we obviously can’t randomly assign some people to marry and others to stay single,” said Williams. “We do know that being unhealthy reduces your chances of marriage.”
Another confounder is introduced when divorced people are included in the “single” category – although many studies do account for this. “That’s already selected out a lot of the people who were most unhappy,” she said. “You can’t take that and say: ‘Get married and you’ll have the same benefits.’ It’s worse for your health to be in an unhappy, high-conflict marriage than to be unmarried.”
One recent US study that controlled for the pre-existing trend in individuals’ health, concluded that the benefits of marriage are more limited than is sometimes implied. There are also notable exceptions to the associations between health and partnership – those in long-term relationships tend to gain more weight in middle-age.
Bella DePaulo, a psychologist at the University of California, Santa Barbara and author, also highlighted the need for cautious interpretation, saying that a common, but misguided assumption was that “if only those single men would get married, they would be healthier”, she said. “But studies like the one about heart failure do not tell us the answer to that question.”
Caveats aside, many believe there are compelling reasons to expect partnership to have health benefits. “Generally, the scientific consensus is that long-term relationships are good for health,” said Prof George Ploubidis, a population health researcher at University College London whose work on UK demographic data has linked being in a relationship to better cardiovascular and respiratory health.
Wealth and income are very strong determinants of health and there are substantial benefits in being able to combine salaries and share living costs. Social isolation is also strongly associated with worse health and mortality and having a partner can make isolation less likely.
“This doesn’t mean there aren’t positive things about being single – I’m totally against demonising single-dom,” said Ploubidis. “This is about averages across a population and long-term trends.”
Some studies also highlight gender differences, with men often appearing to gain the most health benefits from partnership. This could be down to women tending to play a greater role in improving their partner’s health, by encouraging them to engage with screening programmes and take medication, for instance. There is also evidence that women are better at fostering close relationships with friends and relatives, so are potentially less likely to feel isolated when single.
“When they are single, many women are not at all isolated or alone or lonely – they have their friends and other people who matter to them,” said DePaulo. “Heterosexual men have traditionally not been as good at that.”
A final consideration is the extent to which marriage, or having a partner, provides a unique health benefit. “Would the results be any different if the participants had become close friends with someone, or had built a whole social network of people they cared about and who cared about them?” said DePaulo.
The recent study that tracked 8,000 women in Australia, suggested that a far wider range of interpersonal relationships are important when it comes to health. The researchers followed the women, aged 45 to 50 when the study began, for 20 years to see if they developed diabetes, hypertension, heart disease, stroke, chronic obstructive pulmonary disease, asthma, osteoporosis, arthritis, cancer, depression or anxiety. Those who were most satisfied with interpersonal relationships were least likely to develop multiple chronic health conditions. Crucially, this did not just apply to spouses or long-term partners, but across each type of social relationship, including partners, family, friends and colleagues.
