A happy marriage could signal a healthy heart a new study has found.

A study of some 204 married and 99 single adults, who wore portable blood pressure monitors for 24 hours, found that unhappily married adults have higher blood pressure than both happily married and single adults.

Previous studies found that married people tend to be healthier than singles, but those studies didn’t measure the marital quality.

In addition to wearing the blood pressure monitors, participants also filled out questionnaires about their marriage.

The study was conducted by Professor Julianne Holt-Lunstad, of Brigham Young University and was published today in the Annals of Behavioral Medicine.

“There seem to be some unique health benefits from marriage.  It’s not just being married that benefits health — what’s really the most protective of health is having a happy marriage,” said Professor Holt-Lunstad.

She said it would take further study to sort out what the results mean for long-term health.

The research measured blood pressure levels about 72 times over the 24 hour period, even when participants slept.  They found that blood pressure for married adults — especially those happily married — dipped more during sleep than happens with singles.  “People whose blood pressure remains high throughout the night are at much greater risk of cardiovascular problems than people whose blood pressure dips,” Professor Holt-Lunstad said.