To hear baby boomers talk, their greatest health fear associated with aging is Alzheimer's disease. The benefit of adding 20 years to the lifespan in the past century is overshadowed, they say, by an awareness that one in two people will end up with some form of dementia.

But these boomers are ignoring a more serious health problem that they can control, says Dr. Orly Avitzur, medical adviser to Consumer Reports Health and a neurologist.

"Stroke is the No. 1 cause of disability in the United States and a more common condition to have," she says. "It is also the No. 3 cause of death and should be in the forefront of our concerns."

As Avitzur points out, little can be done, at this point, to stave off Alzheimer's. "But a person can make profound lifestyle and medical changes that will reduce the risk of stroke by 80 percent," she says.

Consumer Reports Health cites 11 strategies for stroke prevention as part of National Stroke Awareness Month in May.

About every 40 seconds, someone in the U.S. suffers a stroke and more than 77 percent are first events. (To read the complete report, go to www.consumerreportshealth.org.)

Stroke is caused by a sudden loss of blood flow to the brain or bleeding around the brain. Both incidents cause brain cells to die.

"Hypertension is the most important and treatable factor for stroke, yet more than half of Americans with high blood pressure don't have it under control," Avitzur says.

These medical and lifestyle changes can help prevent a stroke:

Lower blood pressure. High blood pressure damages arteries, so they clog or burst more easily, escalating the risk of both types of stroke: ischemic and the less common but deadlier hemorrhagic.

Improve cholesterol levels. LDL (bad) cholesterol, a fatty substance in the blood, builds up plaque on artery walls, causing arteries to narrow.

Rein in diabetes. High blood sugar levels damage blood vessels over time.

Consider low-dose aspirin. Aspirin wards off heart attack and stroke by preventing artery-blocking blood clots. But it's not for everyone, so a physician should be consulted.

Have your pulse checked. Arterial fibrillation, a heart-rhythm disorder, can lead to blood clots that travel to the brain, amplifying the risk of an ischemic stroke.

Think twice about neck surgery. Having surgery to remove blockages in the neck arteries (or carotid arteries) can reduce stroke for those who have already had a stroke. But for those with a narrowed carotid artery that hasn't triggered any symptoms, the risk of stroke is much lower and the benefit of surgery is small.

Follow a brain-healthy diet. What you eat has a strong influence on an individual's risk of stroke. In a study that assessed people's consumption of fruits and vegetables, each extra daily serving reduced stroke risk by 6 percent. Other studies have linked high-potassium diets with lower stroke risk and sodium-heavy diets with higher risk.

Be physically active. Excess fat, especially around the abdomen, raises blood pressure. Do at least 30 minutes of moderate-intensity aerobic exercise five days a week or more.

Drink alcohol moderately. Drinking is associated with a 64 percent increase in the risk of stroke, raises blood pressure, promotes clot formation and increases the risk of arterial fibrillation. Light drinking appears to reduce stroke risk.

Quit smoking. The most common diseases caused by smoking are lung cancer, heart disease and stroke.