"Clearly, there is a strong genetic component to stroke risk," Seshadri said. "The Framingham Heart study, in conjunction with three other large collaborating studies, recently described a new gene for stroke risk, but this needs confirmation and other genes and genetic variants clearly remain to be found," she noted.
However, the biggest effect of a parental stroke by age 65 is on offspring who have a high stroke risk factor such as high blood pressure, Seshadri said.
"So, a positive family history should motivate one towards better control of blood pressure, blood sugar, quitting smoking, exercise and keeping an ideal weight," she added.
Dr. Larry B. Goldstein, director of the Duke Stroke Center at Duke University Medical Center, said these finding are consistent with the results of other studies.
Goldstein agreed that there are modifiable and non-modifiable risk factors for stroke.
"The non-modifiable ones are important to recognize, because they alone put you at increased risk," he said. "That means you really have to pay attention to all the things you can do to modify risk, and be quite aggressive about those."
Of the modifiable risk factors for stroke, blood pressure is the most important, Goldstein said.
"But studies have also shown that people who follow a healthy lifestyle can have up to an 80 percent lower risk of a first stroke, compared to people who don't," he said.
Controlling blood pressure, not smoking, staying lean, eating a healthful diet, not drinking too much alcohol, exercising and keeping your cholesterol low are all ways to help reduce the risk of having a stroke, Goldstein said.
All rights reserved