A loving spouse might spur you on to look after yourself better, researchers told a heart conference, based on their study of nearly a million UK adults.
They found that people living with any of the three biggest risk factors for heart disease have higher survival rates if they are married.
The married ones fared much better than those who were single.
Dr Paul Carter and colleagues, who carried out the work, have already shown that marriage is linked to a better chance of surviving a heart attack.
They suspect marriage helps buffer against big heart disease risk factors, including cholesterol and high blood pressure.
The study looked at deaths from all causes, including heart disease.
They found that people with high cholesterol were 16% more likely to be alive at the end of the study if they were married compared to those who were single.
Meanwhile, married people with diabetes had a 14% higher chance of survival compared to those who were single.
And married patients with high blood pressure were 10% more likely to be alive at the end of the study period compared to singletons.
“Our research suggests that marriage offers a protective effect, which is probably down to having support in controlling the key risk factors for heart disease,” said Dr Paul Carter, lead study author based at the Algorithm for Comorbidities, Associations, Length of stay and Mortality (ACALM) study unit.
“The findings shouldn’t be seen as a reason to get married, but rather as encouragement for people to build strong support networks with their families and friends.”
The same was true for diabetes and high blood pressure, with married people having a survival advantage.
The picture was less clear for people cohabiting, separated, divorced or widowed.
Also, the researchers did not test if the wedded people were in happy marriages.
They suspect having someone special in your life is what’s important, rather than simply getting hitched.
Dr Carter said: “We need to unpick the underlying reasons a bit more, but it appears there’s something about being married that is protective, not only in patients with heart disease but also those with heart disease risk factors.
“We’re not saying that everyone should get married though.
“We need to replicate the positive effects of marriage and use friends, family and social support networks in the same way.”