Happily married people who undergo major heart surgery are three times more likely to survive than those who 
are unmarried, according to a new study.
In addition, while women only enjoy the additional health benefit if they and their husband are happy together, men gained most of the benefit regardless.
Single women and unhappily married women have the same survival rates.
The study is the latest to show that intact marriages provide significant health advantages for couples, The Daily Telegraph reports.
Researchers from the University of Rochester in America found that 83 per cent of happily married women who had heart bypass operations lived on for another 15 years, compared with just 28 per cent in unhappy unions and 27 per cent of unmarried women.
For happy husbands the survival rate was also 83 per cent, but even those who were not content with their marriage stood a 60 per cent chance of survival, compared with just 36 per cent who were unmarried.
A 2009 study of more than 8,000 people, showed that those who divorce or whose spouse dies have 20 per cent more chronic health conditions such as heart disease, diabetes or cancer than married people.
Among the remarried, these problems still occur 12 per cent more frequently.
And a study from the Indiana University School of Medicine, also in 2009, showed that married cancer patients live longer than those who are divorced, separated or never married.
The study found that married cancer patients had the highest survival rates, with 63.3 per cent still alive five years after diagnosis and 57.5 per cent still alive after ten years.
Patients who were separated had the worst survival rates, with 45.4 per cent still alive after five years and 36.8 per cent still alive after ten.
Widowed patients had the next worst survival rates, followed by those who were divorced and then those who had never married.
Professor Kathleen King, who led the most recent research, said that having a supportive husband and wife encouraged people to live a healthier lifestyle, for example by taking more exercise or giving up smoking.
Being in a healthy marriage also motivates patients to take care of themselves after surgery because they have a reason to “stick around”, she said.
Professor Harry Reis, who co-authored the study in the Health Psychology journal, said a happy marriage was “every bit as important to survival after bypass surgery as more traditional risk factors like tobacco use, obesity, and high blood pressure.”
Earlier research has also shown that people with less hostility in their marriages had lower levels of a type of inflammation that is linked to heart disease.