NEW YORK (Reuters Life!) - Having a parent with a history of heart disease almost doubles a person's risk of also getting heart disease, regardless of ethnicity or country, according to an international study.
The study, which involved patients in 52 countries and appeared in the Journal of the American College of Cardiology, also suggested that if your parents had a heart attack, changing your behavior to more healthy patterns, while helpful, isn't guaranteed to protect you completely.
Previous studies have confirmed the relationship between a family history of heart disease and a person's own heart risk in certain populations, but the study also suggests the effect of family history is about the same in cultures across the world.
"This study reinforces the important role of family history as one of the very important risk factors, in addition to other known modifiable risk factors," said Christopher O'Donnell at the National Institutes of Health, who was not involved in the study, to Reuters Health.
"It reinforces the need to integrate the family history into the day-to-day practice of prevention and therapy for heart disease."
The findings are from the INTERHEART study led by Salim Yusuf of McMaster University in Ontario, Canada and involved 12,000 patients on every continent except Antarctica who were being treated for their first heart attack between 1999 to 2003.
The study also included about 15,000 age- and sex-matched controls.
About 18 percent of patients who had suffered a heart attack also had parents with a history of heart attack, compared to 12 percent of participants without heart disease.
When the researchers factored in the patient's age, sex and region of residence, those with at least one parent with a history of heart disease were still 1.8 times more likely to get heart disease themselves, a number consistent across ethnicities and world regions.
The risk was the same whether it was the father or mother who had the heart attack, but higher if both parents were affected, or if either or both had a heart attack before the age of 50.
Accounting for known heart disease risk factors including smoking and alcohol consumption, fruit and vegetable consumption and obesity didn't explain the increased risk that comes with having a parent with heart disease.
"We know that family history represents many things," said Themistocles Assimes at the Stanford University School of Medicine, the author of an editorial accompanying the study.
"A lot of those things are genetic. Some are almost certainly environmental (factors) that we don't know about that we can't measure."
Reporting by Genevra Pittman at Reuters Health; editing by Elaine Lies