"Marriage must be of a high quality to be advantageous" for blood pressure, the study states. "In other words, one is better off single than unhappily married."
The study included 204 married people and 99 single men and women. Participants were 20-68 years old (average age: 31).
Most of the singles -- 89% -- had never been married; none was living with a partner. Married participants had been married for eight years, on average, note the researchers, who included Julianne Holt-Lunstad, PhD, of Brigham Young University's psychology department.
Participants wore a blood pressure monitor that tracked their blood pressure around the clock for 24 hours. They also rated their marital satisfaction in a survey.
Happily married people had the best blood pressure. Singles ranked second. The unhappily married had the worst blood pressure of those three groups.
Having a healthy social network was a plus for singles' blood pressure. But it didn't equal the blood pressure advantage of being happily married.
Of course, other factors -- including diet, exercise, smoking, and stress -- also affect blood pressure. Those factors count for everyone, single or married, happy or not.
The study, published in the Annals of Behavioral Medicine, paints the big picture about blood pressure and marriage. It's not meant to describe every single or married person's blood pressure, since there are exceptions to every rule.
The study appears in the March 20 edition of the Annals of Behavioral Medicine.