A Harvard University study has found that non-smokers who are married to a smoking partner find themselves at substantially increased risk of suffering a stroke, BBC News reported July 28.

Examining health records for more than 16,000 people over age 50, a research team found that a person who had never smoked incurred a 42 percent greater risk of stroke if they lived with a smoker. The increased risk soared to 72 percent for non-smoking spouses who had previously smoked at some point in their lives. The findings were adjusted for other factors that might affect stroke risk.

The researchers also found that being married to a former smoker did not increase stroke risk, suggesting that a spouse's move to quit smoking could yield an important benefit for the other partner.

"The health benefits of quitting smoking likely extend beyond individual smokers to affect their spouses -- potentially multiplying the benefits of quitting smoking," said researcher Maria Glymour, D.Sc., with the Harvard School of Public Health.

The research results are scheduled to be published in the September issue of the American Journal of Preventive Medicine.