About every 40 seconds, someone in the United States suffers a stroke, and more than 77 percent are first events. Although deaths due to strokes have declined, a stroke — caused by the sudden loss of blood flow to the brain or by bleeding in or around the brain, either of which can cause brain cells to die — can still have a staggering impact upon lives. New guidelines from the American Heart Association and the American Stroke Association offer updated advice for preventing a first stroke.
High blood pressure damages arteries so they clog or burst more easily, escalating the risks of both types of stroke: ischemic, caused by blockage of a blood vessel that supplies part of the brain; and hemorrhagic, the less common but deadlier stroke that occurs when a blood vessel bursts inside the brain. Treatment to lower blood pressure, including lifestyle changes and medication, can reduce those risks by a third.
l Recommendations: Have your blood pressure checked at least once every two years, more often if you’re 50 or older. If your reading is high-normal — above 120/80 mmHg but below 140/90, the cutoff for hypertension — try to lower it by adopting the lifestyle measures listed below. If your reading is 140/90 or higher, talk with your doctor about adding an antihypertensive drug.
LDL (bad) cholesterol, a fatty substance in the blood, builds up plaque on artery walls, causing arteries to narrow. If plaque ruptures, a blood clot can form and block a blood vessel to the brain, causing a stroke.
l Recommendations: Get a fasting lipid profile every five years, and talk with your doctor about your cardiovascular risk based on family history, blood pressure readings and other factors.
High blood-sugar levels damage blood vessels over time. In addition, people with diabetes are likely to have hypertension, high cholesterol and excess weight. All told, diabetes increases the risk of ischemic strokes by as much as 600 percent.
Recommendations: Have your blood-sugar level tested every three years if you’re 45 or older and at least once a year if you’re pre-diabetic, which is defined as having a fasting glucose level between 100 and 125 milligrams per deciliter (mg/dL). If you have diabetes, keep your blood pressure below 130/80 mmHg with lifestyle approaches and medication if needed.
Atrial fibrillation, a heart-rhythm disorder, can lead to blood clots that can travel to the brain, amplifying the risk of an ischemic stroke. The blood thinner warfarin (Coumadin and its generic cousins) reduces that risk by 64 percent, yet it might be underprescribed.
l Recommendations: Your doctor should check your pulse for irregular rhythms at every visit and follow up with an electrocardiogram or other heart monitoring if necessary.
If either of the carotid arteries, located on each side of the neck, becomes clogged, a stroke can result. People with severe carotid narrowing that has caused a stroke or transient ischemic attack (TIA) — a strokelike episode that doesn’t cause permanent damage — are at high risk for a second stroke, and surgery to scrape out the blockage significantly reduces that risk. But those with a narrowed carotid artery that hasn’t triggered symptoms are at much lower risk, and the benefit of surgery is small.
l Recommendations: Screening for clogged neck arteries is not recommended for people without stroke risk factors because it generates many false-positive test results that can lead to further testing with angiography, which carries a small risk of triggering a stroke, or to unnecessary surgery.
What you eat affects your risk of a stroke. The Dietary Approaches to Stop Hypertension (DASH) diet stresses potassium-rich fruits and vegetables, low-fat dairy, and limited sodium and saturated fat.
l Recommendations: Though it can be difficult, try to consume no more than 1,500 milligrams of sodium (roughly two-thirds of a teaspoon of table salt) a day, the maximum recommended by the American Heart Association. A DASH-style diet is recommended, too. For the plan, search for “DASH diet” at www.nhlbi.
nih.gov, or call the National Heart, Lung, and Blood Institute at 301-592-8573.
Adults who are physically active generally have a 25 to 30 percent lower risk of strokes or death than the least active people.
l Recommendations: Do at least 30 minutes of moderate-intensity aerobic exercise, such as brisk walking or cycling, five days a week and preferably daily.
In a 2009 analysis of 900,000 adults, each additional five points in body mass index (BMI) was associated with a 40 percent increased risk of death from strokes among people who were overweight (a BMI of 25 to 29.9) or obese (a BMI of 30 or greater). A loss of just 11 pounds significantly reduced the predominant stroke risk factor — high blood pressure — in an analysis of 25 trials.
l Recommendations: To determine your BMI, multiply your weight in pounds by 703, then divide by your height in inches, squared. If your BMI is 25 or higher or your waist measures more than 40 inches for men or 35 inches for women, commit to regular exercise and a weight-loss diet such as the DASH plan.
Excessive drinking, associated with a 64 percent increase in risk of stroke, raises blood pressure, promotes clot formation and increases the risk of atrial fibrillation.
l Recommendations: Limit alcohol to no more than two drinks a day for men and one for women.
Cigarette smoking raises blood pressure, decreases exercise tolerance, promotes plaque buildup in arteries and makes blood more likely to clot.
l Recommendations: If you smoke, talk with your doctor about quitting.