Non-smokers who are married to a smoker have a 42 percent greater chance of having a stroke than those married to someone who never smoked, according to a new study.

For former smokers, being married to a current smoker was associated with a 72 percent increase in risk.

However, being married to a former smoker was not associated with any increase in risk, which researchers said in a news release suggests that the risk is eliminated if your spouse stops smoking.

The results were based on studies of more than 16,000 people who were followed for an average of nine years.

A news release on the finding did not indicate the overall risk of stroke in the people studied.

"These findings indicate that spousal smoking increases stroke risk among nonsmokers and former smokers. The health benefits of quitting smoking likely extend beyond individual smokers to affect their spouses, potentially multiplying the benefits of smoking cessation," author M. Maria Glymour of Harvard University wrote in the September 2008 issue of the American Journal of Preventive Medicine.