"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 Center in New York.
—Married people had a 5 percent lower risk of any cardiovascular disease compared to single people. Widowed people had a 3 percent greater risk of it and divorced people, a 5 percent greater risk, compared to married folks.
—Marriage seemed to do the most good for those under age 50; they had a 12 percent 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.
Researchers don't know how long any study participants were married or how recently they were divorced or became widowed. But the results drive home the message that a person's heart risks can't be judged by physical measures alone — social factors and stress also matter, said Dr. Vera Bittner, a cardiologist at the University of Alabama at Birmingham.
She heads the heart disease prevention committee of the American College of Cardiology. The study results were released on Friday ahead of presentation this weekend at the group's annual meeting in Washington.
"We don't really have a clear explanation" for why marriage may be protective, Bittner said.
"You may be more willing to follow up with medical appointments," take recommended drugs, diet and exercise if you have a spouse, she said.