Men with divorced parents are significantly more likely to suffer a stroke than men from intact families, shows a new study from the University of Toronto.

The study, to be published this month in the International Journal of Stroke, shows that adult men who had experienced parental divorce before they turned 18are three times more likely to suffer a stroke than men whose parents did not divorce. Women from divorced families did not have a higher risk of stroke than women from intact families.

"The strong association we found for males between parental divorce and stroke is extremely concerning," says lead author Esme Fuller-Thomson, Sandra Rotman Chair at University of Toronto's Factor-Inwentash Faculty of Social Work and Department of Family and Community Medicine. "It is particularly perplexing in light of the fact we excluded from our study individuals who had been exposed to any form of family violence or parental addictions. We had anticipated that the association between the childhood experience of parental divorce and stroke may have been due to other factors such as riskier health behaviors or lower socioeconomic status among men whose parents had divorced," explains University of Toronto recent graduate and co-author Angela Dalton. "However, we controlled statistically for most of the known risk factors for stroke, including age, race, income and education, adult health behaviors (smoking, exercise, obesity, and alcohol use) social support, mental health status and health care coverage. Even after these adjustments, parental divorce was still associated with a threefold risk of stroke among males." Researchers cannot say with certainty why men from divorced families had triple the risk of stroke, but one possibility lies in the body's regulation of cortisol, a hormone associated with stress.

Fuller-Thomson explains the elevated rate of stroke could be linked to a process known as biological embedding. "It is possible that exposure to the stress of parental divorce may have biological implications that change the way these boys react to stress for the rest of their lives," says Fuller-Thomson.

As with all scientific research, it is essential for many researchers to replicate findings from this study in prospective studies before it is safe to draw any conclusions about causality. Fuller-Thomson notes that eventually, the results of this study could potentially affect current stroke education policy. "If these findings are replicated in other studies," says Fuller Thomson, "then perhaps health professionals will include information on a patient's parental divorce status to improve targeting of stroke prevention education."

Internationally, stroke and other cerebrovascular diseases account for 10 per cent of deaths, making stroke the second leading cause of death.