Love can sometimes break a heart but marriage seems to do it a lot of good.
A study of more than 3.5m Americans found that married people are less likely than singles and those divorced or widowed, to suffer any type of heart or blood vessel problem.
This was true at any age, and regardless of other heart disease risk factors such as high cholesterol or diabetes, researchers found.
"It might be that if someone is married, they have a spouse who encourages them to take better care of themselves," said Dr Jeffrey Berger, a preventive cardiologist at NYU Langone Medical Centre in New York.
Previous studies mostly compared married to single people and lacked information on divorced and widowed ones.
Researchers used health questionnaires that people filled out when they sought various types of tests.
The results are from people who sought screening from 2003 to 2008.
Their average age was 64 and nearly two-thirds were female.
The study found:
* Married people had a 5pc lower risk of any cardiovascular disease compared to single people. Widowed people had a 3pc greater risk of it and divorced people, a 5pc risk, compared to those who were married.
* Marriage seemed to do the most good for those under 50; they had a 12pc lower risk of heart-related disease than single people their age.
* Smoking, a major heart risk, was highest among divorced people and lowest in widowed ones. Obesity was most common in those single and divorced. Widowed people had the highest rates of high blood pressure, diabetes and inadequate exercise.
"We don't really have a clear explanation for why marriage may be protective," Dr Vera Bittner, a cardiologist at the University of Alabama, said.
"You may be more willing to follow up with medical appointments, take recommended drugs, diet and exercise if you have a spouse."