If you have high cholesterol, high blood pressure, or diabetes—or if you smoke—you probably know that you’re at increased risk for dangerous complications such as heart disease or stroke. Likewise, if you have family members who have suffered from heart disease or stroke, your risk of having a stroke goes up as well.
Stroke is the third leading cause of death in the United States; about 137,000 Americans die from them each year. A stroke occurs when the blood supply to the brain is blocked or a blood vessel bursts, damaging part of the brain.
Although many causes of stroke can be prevented by practicing a healthy lifestyle, your risk is also partly hereditary. A 2003 University of Utah study found that out of all strokes that occurred early, before age 75, 86% of them occurred in just 11 percent of families.
This shows just how much stroke can be passed down from generation to generation, and how important it is for members of vulnerable families to be screened and to adopt lifestyle changes to reduce their risk. If someone in your family has had a stroke or a transient ischemic attack (TIA)—also known as a mini-stroke—take some time to think about how it might affect your own health.
Your Genetic Risk for Stroke
High blood pressure, high cholesterol, and diabetes all have genetic components, so if you have a parent or close relative who had these conditions and also had a stroke, it’s likely you could share those risk factors.
Even without these stroke-related conditions, however, a parent’s stroke seems to be a significant risk factor alone. In a 2010 Boston University study, researchers found that children with parents who had suffered a stroke by age 65 were more likely to also have had a stroke themselves.
When the researchers ruled out cases where traditional risk factors (such as high blood pressure, diabetes, smoking, and other cardiovascular conditions) were present, these participants still had double the risk of having a stroke at any age—and four times the risk of having a stroke by age 65—than those whose parents had not reported a stroke before 65.
The study also found that a parent’s stroke was a significant risk factor for adult children, regardless of gender. Fathers’ strokes were just as likely to impact both their sons' and daughters' future stroke risk. When mothers suffered strokes, however, the risk of future stroke was strongest in their daughters.
A 2011 study from Oxford University researchers found that a mother’s history of stroke can also help predict her daughter’s heart attack risk, as well. (Researchers aren’t sure why the female-to-female connection was stronger in this case than female-to-male or male-to-male, but they suspect it has to do with sex-specific genetics and the way genes are passed from parent to child.)
In less common cases, stroke can occur as a complication of a genetic condition such as sickle cell disease—a blood disorder that mainly affects people of African-American and Hispanic descent—and a rare disorder called CADASIL (Cerebral Autosomal Dominant Arteriopathy with Sub-cortical Infarcts and Leukoencephalopathy). Because these conditions tend to run in the family, so does the associated stroke risk in those affected by them.
Your Environmental Risk for Stroke Stroke can also appear to be hereditary because of lifestyle and environmental factors your family shares. If a parent or close relative has had a stroke, ask yourself the following questions to determine if any of these factors could also put you in danger.
- Does your family tend to lead a sedentary lifestyle?
- Are many of your family members overweight?
- Does your family follow a diet that is full of saturated fats, cholesterol and sodium, which are often found in canned and packaged foods and fast food meals?
- Do you and/or your family members smoke?
- Does your family have a history of drug use or excessive alcohol consumption? (Current guidelines recommend no more than two drinks a day for men and one drink a day for women.)
Research also suggest that strokes affect low-income populations more severely than affluent ones, and that they are more common in the southeastern United States—the "stroke belt" states—than in other areas. (This region’s high prevalence of stroke has been attributed to factors such as education level, income, and high rates of smoking, obesity, and chronic diseases like hypertension, diabetes, and heart disease.)
By Amanda MacMillan
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