Children of parents who are divorced are more likely to start smoking than their peers from intact families, according to a new study of 19,000 Americans.

The study, conducted by University of Toronto and published this month in the journal Public Health, concluded that men who experienced parental divorce before their 18th birthday were 48percent more likely to ever smoke 100 or more cigarettes than men whose parents did not divorce. Women from divorced families were also more likely to have smoked, with 39 percent higher odds of ever smoking 100 or more cigarettes than women from intact families.

"Finding this link between parental divorce and smoking is very disturbing," said lead author Esme Fuller-Thomson, Sandra Rotman Chair at University of Toronto's Factor-Inwentash Faculty of Social Work in a press statement.

"We had anticipated that the association between parental divorce and smoking would have been explained by one or more of three plausible factors, such as lower levels of education or adult income among the children of divorce; adult mental health issues, such as depression or anxiety among the children of divorce, or other co-occurring early childhood traumas, such as parental addictions or childhood physical, sexual or emotional abuse."

Fuller-Thompson said those characteristics had been linked with smoking in other studies, but that even when taking all the factors into account, "a strong and significant association between parental divorce and smoking remained."

While the study was able to determine a link between divorce and smoking, it was not able to establish why the link exists.

Joanne Filippelli, a co-author of the study, speculated that "children upset by their parents' divorce may use smoking as a coping mechanism to regulate emotions and stress. Some research suggests this calming effect may be particularly attractive to those who have suffered early adversities."

"These findings need to be replicated in longitudinal studies before causality can be established." said co-author Candace Lue-Crisostomo. "If the parental divorce-smoking link is shown to be causal in future studies, then smoking prevention programs targeted at children whose parents are going through a divorce might prove helpful."

Link to journal abstract: https://www.publichealthjrnl.com/article/S0033-3506(13)00007-3/abstract