Dissolving a marriage is hard on everyone, but researchers say the psychological stress of a divorce can have serious physical effects on the heart, especially for women.

Women who divorced at least once were 24% more likely to experience a heart attack compared to women who remained married, and those divorcing two or more times saw their risk jump to 77%.

In the study published in the journal Circulation: Cardiovascular Quality and Outcomes, Matthew Dupre of Duke University and his colleagues found that men weren’t at similar risk. Men only saw their heart attack chances go up if they divorced two or more times compared to men who didn’t split with their spouses. If men remarried, their heart risk did not go up, while for women who remarried, their chances of having a heart attack remained slightly higher, at 35%, than that of divorced women.

These findings remained strong even after Dupre’s team adjusted for other potential contributors to heart attack, including age, social factors such as changes in occupation and job status and health insurance coverage, and physiological factors including body mass index, hypertension and diabetes. Previous studies have found links between divorce or widowhood and heart disease that were explained, at least in part, by changes in people’s access to health care and their ability to keep up healthy eating and exercise habits.

But these are the first results from tracking people over a longer period of time—18 years—to capture the cumulative effects of changes in marital status, says Dupre. “We looked at lifetime exposure to not only current marital status, but how many times someone has been divorced in the past. What we found was that repeated exposure to divorce put men and women, but particularly women, at higher risk of having a heart attack compared to those who were married.”

And it wasn’t simply changes in health insurance coverage or financial status resulting from the divorce that explained the higher heart risk. Even after Dupre’s group accounted for these, the relationship held. While he admits that the trial did not investigate exactly how divorce is seeding more heart attacks, other studies hint at a possible explanation. Dramatic life changes such as divorce, which signal an end to not only a significant relationship but potentially to stable financial and social circumstances as well, can lead to spikes in the stress hormone cortisol, which in turn can push blood pressure, cholesterol and blood sugar to unhealthy heights.