Nutrition Action Healthletter
Stroke Signals
Pressure Points
Older and Higher
Beyond Blood Pressure
Not Ready for Prime Time
Who's At Risk?
Saving Brain Cells
Signs of a Stroke
Stroke Links
A stroke is essentially a heart attack in the brain.  If a blood clot or a hemorrhage cuts off the blood supply to brain cells, they die from lack of oxygen.
Every 53 seconds, another American has a stroke. More than a quarter of them are under age 65. Of those who survive, a third to half will be left permanently disabled or institutionalized.
A stroke is essentially a heart attack in the brain.  If a blood clot or a hemorrhage cuts off the blood supply to brain cells, they die from lack of oxygen.
   Yet most Americans don’t know how to recognize the signs of a stroke or how to lower their risk.

    “It’s tragic,” says Arthur Pancioli of the Department of Emergency Medicine at the University of Cincinnati College of Medicine. “Here we have the third leading cause of death and the leading reason for admission to a long-term care facility, and people don’t know the risk factors or warning signs.”

    The public’s inability to recognize the symptoms of a stroke is one reason why less than five percent of stroke victims get the best treatment available, say experts.

    “In the past, it wasn’t that important to know the warning signs of a stroke,” says John Marler of the National Institute of Neurological Diseases and Stroke (NINDS) in Bethesda, Maryland.

    “But now that we have drugs to dissolve the blood clots that cause most strokes, it’s important to get to the hospital in time to restore blood flow to the brain.”

    Knowing how to recognize and treat a stroke is only part of the equation. The other part: knowing how to prevent one.

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The older you get, the higher your blood pressure...and your risk of stroke. The proportion of people with high blood pressure jumps from 45 percent at age 50 to more than 60 percent at age 60, and to over 70 percent at age 70.

    “We used to think that older people needed higher blood pressures to push blood through their stiffer blood vessels,” explains Norman Kaplan of the University of Texas Southwestern Medical Center in Dallas. “Now we know without question that high blood pressure is a significant risk factor for stroke at any age.”

    That’s also true when only the higher number (systolic blood pressure) is elevated.1 “In the Framingham [Massachusetts] Heart Study, roughly 60 percent of people over age 65 had isolated high systolic blood pressure,” says Kaplan. That is, they had a systolic pressure over 160 but a diastolic pressure under 90.

    “If an older person has only high systolic pressure, doctors have to be cautious not to lower diastolic pressure too much,” he adds. That can cause postural hypotension—blood pressure that drops too low when the person stands up. If that makes them fall, it could lead to a broken hip or other serious injuries. But that’s no reason to let systolic pressure stay high.

    “We have trials in which the elderly were given low-dose diuretics, calcium antagonists, or, less often, ACE inhibitors,” says Kaplan. “Even after age 80, they achieve a 36 percent reduction in stroke. At all ages, the elderly respond to reductions in blood pressure.”

    That’s not to say that all older people need drugs to do it. “Eating less sodium is more effective in the elderly than in younger people,” says Kaplan. In the recent Trials of Nonpharmacological Interventions in the Elderly (TONE), he notes, people aged 60 to 80 were taken off their blood pressure medicine and told to eat less salt, lose weight, do both, or do nothing.2

    “Roughly 40 percent of those who cut salt—but only 23 percent of those who didn’t—were able to stay off anti-hypertensive drugs,” says Kaplan. “And they cut sodium by only about 1,000 mg a day. If you read labels and eat carefully, that’s practical.”

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1: Journal of the American Medical Association 265: 3255, 1991.

2: Archives of Internal Medicine 161: 685, 2001.
   “The especially sensitive brain cells are gone within 10 to 15 minutes,” says John Marler of the National Institute of Neurological Diseases and Stroke (NINDS). “But if the blood flow is only slowed down, not cut off completely, the less sensitive brain cells can ‘hold their breath’ for about three hours.”

       Strokes caused by a blocked artery are more likely than those caused by a hemorrhage to leave a trickle of blood flowing to brain cells. That’s good news, because 70 percent of strokes in the U.S. are due to blocked arteries. These “ischemic” strokes usually occur when a blood clot gets stuck in an already-narrowed artery. That leaves time to dissolve the clot...but not much.

       “On average, half the damage occurs within the first 90 minutes, 90 percent by three hours, and 99 percent by six hours,” explains Marler. Yet the average person waits 22 hours to get help.

       “Clot-dissolving drugs don’t save every neuron, but if you get to the hospital early enough, you can restore blood flow in time to resuscitate most neurons before they die.”

       Three hours may seem like a long time, but it isn’t. Once a patient gets to the hospital, it takes about an hour for doctors to do a CAT scan or other tests to make sure it was an ischemic stroke. (Clot-dissolving drugs can make a hemorrhagic stroke worse.) Then they have to administer the drug—which is called tPA (tissue plasminogen activator)—intravenously. “If you get the IV started at two hours, it might take an hour more to dissolve the clot,” says Marler. That leaves no room for delay.

       “People need to know that if they see the signs of a stroke, they shouldn’t call a relative, they shouldn’t call a doctor, and they shouldn’t wait to see what will happen,” he adds. “They need to call 911 immediately.”


Stroke Signals

    Would you recognize a stroke if you saw one? Most people couldn’t, according to a recent study by Arthur Pancioli of the University of Cincinnati.1 And people over 75—who are at greater risk—did worse than average.

       “Only 57 percent could identify one warning sign, 25 percent could name two, andIt's amazing how little blood pressure control it takes to lower the risk of stroke. eight percent could name three,” says Pancioli. “Yet this is a national health problem that affects nearly every family in the U.S.”

       Until people recognize that a stroke is a life-threatening emergency, they won’t feel compelled to learn the warning signs (see “Signs of a Stroke”).

       “People know that chest pain is a sign of a heart attack, but they don’t know what a stroke looks like,” says Marler.

    And for stroke, it’s even more important to recognize the signs in other people.

       “The person who has the stroke is often totally unaware of what’s happened,” Marler explains. “They’re often stunned. Their brain isn’t working.”

       But that shouldn’t stop others from taking charge. “We need to get bystanders to insist on calling 911, even if the victim is reluctant,” he says.

       Reluctance is more likely if the warning signs disappear after a few minutes. That’s what happens in a TIA, or transient ischemic attack (also known as a mini-stroke), but it’s still an emergency.

       “The symptoms may not have gone away as much as you think, or they may come back. And even if they don’t, you’re at extremely high risk to get another stroke,” cautions Marler.

       “If you had crushing chest pain and it went away by the time the ambulance arrived, you wouldn’t say ‘it doesn’t hurt now, so I’m fine.’ You still need to get to the hospital so doctors can determine the cause.”

       Sadly, many people get to the hospital in time and still don’t get the best stroke treatment.

       “Clearly, all hospitals aren’t set up to use tPA,” says Pancioli. “People can call their local hospitals to ask if they have a protocol up and running to rapidly evaluate and treat stroke using tPA.”

       That’s critical, because if tPA isn’t used correctly, it has serious side effects. “Even when used correctly, tPA causes bleeding into the brain in six percent of patients,” explains Pancioli. But in the vast majority, tPA can cut the odds that the victim will be left severely disabled.2

       “I have personally used tPA 96 times and have been very pleased with the results,” says Pancioli. “It’s a very powerful treatment.”

       The National Institute of Neurological Diseases and Stroke is trying to get hospitals to set up systems to use tPA. But until then, you’re on your own.

       “The time to find out which hospitals give tPA isn’t when you’re calling 911,” says Marler. “Call now.”


Pressure Points

    Now is also the time to gauge your risk of having a stroke (see “Who’s at Risk?”). Yet only 68 percent of people can name a single risk factor for stroke, and only a quarter can name at least two, says Pancioli. “Risk factors are the real deal,” he adds. “The more you have, the more likely you are to have a stroke.”

       High blood pressure is far and away the strongest risk factor for stroke. Higher pressure makes blood vessels more likely to rupture (causing a hemorrhage). It also damages the walls of the blood vessels, boosting the odds that plaque will block arteries or break off to form a clot.

       “It’s important to know your blood pressure and to get it checked every year, or more often if you have other risk factors,” says JoAnn E. Manson of Brigham and Women’s Hospital in Boston. Because blood pressure rises with age, don’t assume that if your pressure is low, it will stay that way (see “Older and Higher”).

       The good news: The recent DASH (Dietary Approaches to Stop Hypertension) study showed once and for all that, for some people, diet can lower blood pressure—or keep it from rising—as effectively as drugs. The DASH diet limits sodium, saturated fat, and cholesterol and loads up on fruits, vegetables, and low-fat dairy products. And it’s easy to follow (see Dec. 2000, cover story).

       Getting enough exercise, losing excess weight, and limiting alcohol to one drink a day (for women) or two a day (for men) can also lower blood pressure or keep it from rising.

       But if that doesn’t work, drugs make sense. “It’s great to keep blood pressure down without medication, but if it’s still high, people shouldn’t avoid drugs,” says Meir Stampfer of the Harvard School of Public Health. Unfortunately, most people on medication still have blood pressures that are too high, says Manson.

       “Some people don’t take their medicine, or they take one that isn’t fully effective,” she explains. “Sometimes patients don’t get re-checked to see how well the medicine is working, or they have side effects, so they don’t want to go to a higher dose.”

       But doctors can try different combinations of drugs to get optimal results. “If one medicine has side effects or doesn’t work, you can find another one that does,” says Stampfer.

       The bottom line is to do whatever it takes. “All the major trials find that lowering blood pressure reduces Walking 30 minutes a day can reduce the risk of stroke by about 40 percentthe risk of stroke by 35 to 40 percent in people with hypertension,” says Norman Kaplan of the University of Texas Southwestern Medical Center in Dallas. “And that’s by reducing blood pressure by only ten points over five points.”

       “It’s amazing how little blood pressure control it takes to lower the risk of stroke,” says Pancioli. “If your blood pressure is high, lower it.”


Beyond Blood Pressure

Lowering blood pressure is key, but researchers have come up with other steps you can take to prevent a stroke, regardless of your pressure. Treating some risk factors, like diabetes and atrial fibrillation, requires a doctor’s care (see “Who’s at Risk?. But others you can work on yourself:

1. Physical activity. Whether you are overweight or not, exercise helps.3 “Thirty minutes a day of moderate intensity exercise like brisk walking can reduce the risk of stroke by about 40 percent,” says Manson, co-author of The 30-Minute Fitness Solution: A Four-Step Plan for Women of All Ages (Harvard University Press; $22.95).

2. Obesity. In one of Manson’s studies, women who gained 24 to 44 pounds since their 18th birthday had a 69 percent increased risk of ischemic stroke compared to women who gained less than 11 pounds.4 Gaining more than 44 pounds doubled the risk of stroke. “The evidence is now compelling that obesity raises the risk of stroke,” says Manson.

3. Fruits & vegetables. In a study of more than 75,000 women and nearly 40,000 men, those who ate an average of five or six servings of fruits and vegetables a day had a 31 percent lower risk of ischemic stroke compared to those who ate less than three servings a day.5 The most protective: green leafy vegetables (like spinach and collards), citrus fruits and juices, and cruciferous vegetables (broccoli, cabbage, brussels sprouts, and cauliflower). Potatoes and chickpeas, pintos, and other beans offered no protection.

   “The results are fairly consistent,” says Stampfer. “But we don’t know what it is in fruits and vegetables that lowers the risk.” So don’t think you can take vitamins instead.

4. Folate, B-6, & B-12. “A number of studies have found that the higher the level of homocysteine in the blood, the higher the risk of stroke,” says Stampfer. Three B-vitamins—folate (folic acid), B-6, and B-12—can lower homocysteine, an amino acid that is found naturally in the body. “In most populations, folate is the biggest determinant of homocysteine,” he explains.

   Several clinical trials are testing whether those vitamins can lower the risk of stroke.6 But the evidence on homocysteine alone isn’t strong enough to send people to the drug store for folic acid, B-6, or B-12.

       “It’s reasonable to take folate because it’s safe and it may have other benefits—like lowering the risk of heart disease and colon cancer—though none is proven except preventing neural tube birth defects for babies,” says Stampfer. “But people should recognize that folate isn’t proven to lower the risk of stroke.”

5. Seafood. In a study of roughly 80,000 women, those who ate seafood two to four times a week It's not dying of a stroke, but surviving one with brain damage, that should convince people to lower their risk .had about half the risk of ischemic stroke compared to those who ate it less than once a month.7 Researchers suspect that the omega-3 fats in seafood are responsible, but don’t have data to show that fish oil pills work as well.

6. Whole grains & fiber. “Whole grains and fiber may be protective, while potatoes, sugar, white bread, and other foods with a high glycemic load may increase the risk,” says Manson.

   In large quantities, refined carbohydrates may boost insulin levels and insulin resistance, which are known risk factors for stroke.8


Not Ready for Prime Time

   Unlike those relatively harmless changes, it’s too early for people to take other means to prevent a stroke:

Antioxidants. Earlier studies suggested that high doses of antioxidants, especially vitamin E, could prevent stroke, but 400 IU of vitamin E a day had no effect in a large study of people who had already had a stroke or heart attack.9 And in a large study of Finnish smokers, 50 IU a day of vitamin E lowered the risk of ischemic stroke but raised the risk of hemorrhagic stroke, though only in men who had high blood pressure.10

    “The evidence on antioxidants is a mixed bag,” says Manson. She and colleagues have two major trials under way:

The Women’s Antioxidant and Cardiovascular Study (WACS) is testing vitamin E (600 IU of alpha-tocopherol every other day) plus vitamin C (500 mg a day) and beta-carotene (83,000 IU every other day) in 8,000 women who already have cardiovascular disease. The trial is also testing folic acid and vitamins B-6 and B-12. Results are expected in 2004.

   —The Women’s Health Study is testing vitamin E (600 IU of alpha-tocopherol every other day) and/or aspirin (100 mg every other day) on more than 40,000 female health professionals. Results are due in 2004.

   “I wouldn’t make any public health recommendations until we see the results of these and other trials,” says Manson. As for aspirin, she notes, “it’s been proven to protect people who already have had a TIA, stroke, or other cardiovascular event. But it hasn’t been proven to reduce the risk of ischemic stroke—and may increase the risk of hemorrhagic stroke—in healthy women or men.”

Saturated Fat. Last February, Harvard researchers reported that women who ate the least saturated fat had a higher risk of one kind of hemorrhagic stroke.11 “I was happy that the news media didn’t go crazy with the report, because it was a small percentage of all strokes,” says Stampfer.

   And the finding may be spurious, says Margo Denke of the University of Texas Southwestern Medical Center in Dallas, who wrote an editorial that was published with the study.

   “Other factors could explain why these people had a higher risk of stroke,” she says. “The data from one epidemiological study isn’t sufficient to make dietary changes.”

   That’s especially true when it’s clear that Americans need to eat less saturated fat. “Eating more saturated fat will raise LDL (‘bad’) cholesterol, which is a risk factor for ischemic stroke,” notes Denke. “People can cut saturated fat as far as possible. I don’t see any downside.”


Who's At Risk?

“If you don’t know the risk factors for stroke, you won’t get treatment for them,” says Arthur Pancioli of the University of Cincinnati Medical Center. Here are some key risk factors.

Risks You CAN Change

High Blood Pressure. The higher your blood pressure—systolic or diastolic—the higher your risk of both stroke and heart attack.

What to do: Keep your systolic blood pressure below 140 (ideally below 120) and your diastolic blood pressure below 90 (ideally below 80).

Smoking. Smoking doubles the risk of stroke, in part by making blood vessels stiffer.

What to do: Quit. Your risk starts to drop immediately.

Diabetes. The risk of stroke is two to six times higher in people with diabetes. That’s not surprising, given that diabetics are more likely to have high blood pressure, high LDL (“bad”) cholesterol, and clogged arteries. But lowering high blood pressure can help. In one study, the risk of stroke was 44 percent lower in diabetics whose blood pressure was tightly controlled (average: 144/82) than in those with blood pressure that was less-well-controlled (average: 154/87).

What to do: Make sure your blood pressure is under control. Lose excess weight. Get at least 30 minutes of exercise like brisk walking on most days.

High Insulin Levels. People with high insulin levels have a higher risk of stroke, even if their high insulin doesn’t lead to diabetes. High triglycerides, low HDL (“good”) cholesterol, and high blood sugar are signs of high insulin levels (which are difficult to measure).

What to do: Lose excess weight. Get at least 30 minutes of exercise like brisk walking on most days. If your triglycerides don’t fall and your HDL doesn’t rise, talk to your doctor about medication.

Clogged Neck Arteries (asymptomatic carotid stenosis). Up to ten percent of people over age 65 have carotid (neck) arteries that are more than half clogged, thanks to a lifetime of high cholesterol and other factors.

What to do: Talk to your doctor about taking aspirin or statins or, in severe cases, undergoing surgery to clear out neck arteries.

Atrial Fibrillation. Atrial fibrillation is an irregular heartbeat that allows blood to pool in the heart, making it more likely to clot. If your heart pumps the clot into the bloodstream, it can get lodged in an artery in your brain, causing a stroke. Twelve percent of people aged 75 or older have atrial fibrillation, which makes them six times more likely to have a stroke.

What to do: Talk to your doctor about taking aspirin or “blood thinners” like coumadin.

High LDL (“bad”) Cholesterol. A high LDL cholesterol raises the risk of stroke less than it raises the risk of heart disease. Statin drugs lower the risk of stroke, even in people with only slightly elevated LDL. It’s not clear whether that’s because statins lower LDL or because they curb inflammation, keep plaques from rupturing, and reduce the risk of blood clots.

What to do: Use diet or, if necessary, statin drugs to lower your LDL.

High hs-CRP. People with a high level of high-sensitivity C-reactive protein (hs-CRP) are at greater risk of stroke. People with a high hs-CRP have a strong inflammatory response. Whether that raises their risk—or whether it’s a marker for something else that does—is still unclear.

What to do: Talk to your doctor about getting your hs-CRP checked with a simple blood test. If it’s high, see if weight loss can lower it. If that doesn’t work, consider taking statins or aspirin (see September 2000, cover story).

Risks You CAN'T Change

Age. The risk of stroke doubles each decade after age 55.

Sex. Men are more likely to have a stroke, but women are more likely to die of one, in part because they’re usually older when the stroke occurs. One in 25 women will die of breast cancer, while one in six will die of a stroke.

Race. African Americans, Hispanic Americans, and Asian Americans have a higher risk of stroke than non-Hispanic whites.

Genes. People with a family history of stroke are at greater risk.

Prior Stroke. One in six ischemic stroke survivors will have another stroke within two years. A person who has had at least one TIA (mini-stroke) is almost ten times more likely to have a stroke than a similar person who hasn’t had a TIA.


Saving Brain Cells

   With so many known risk factors, experts are convinced that many strokes don’t have to happen.

   “Stroke kills 20 percent of its victims by three months, and 50 to 60 percent are left somewhere between mildly and horribly impaired,” says Cincinnati’s Arthur Pancioli. That’s the scary part.

   Roughly half of all stroke victims are partially paralyzed on one side of their bodies, a third are clinically depressed, between a quarter and a half are partially or completely dependent on others for daily living, a fifth cannot walk, and a sixth have difficulty reading, writing, or speaking. In fact, it’s not dying of a stroke, but surviving one with brain damage, that should convince most people to lower their risk. Yet the outlook could be much brighter.

   Says Pancioli: “Most strokes are preventable or put-offable. And when a stroke does occur, we can improve the outcome if people learn to treat it as a life-threatening emergency.

   “Remember: your brain cells are dying by the minute.”


Signs of a Stroke


    1: J. Amer. Med. Assoc. 279: 1288, 1307, 1998.
    2: Circulation 94: 1167, 1996.
    3: J. Amer. Med. Assoc. 283: 2961, 2000.
    4: J. Amer. Med. Assoc. 277: 1539, 1997.
    5: J. Amer. Med. Assoc. 282: 1233, 1999.
    6: Neuroepidemiology 20: 16, 2001.
    7: J. Amer. Med. Assoc. 285: 304, 2001.
    8: J. Amer. Med. Assoc. 284: 1534, 2000.
    9: New Eng. J. Med. 342: 154, 2000.
    10: Archives of Neurology 57: 1503, 2000.
    11: Circulation 103: 784, 856, 2001.

Click here for links to the most useful Web sites with information about stroke

Nutrition Action Healthletter Center for Science in the Public Interest September 2001 U.S. Edition Brain Attack Brain Attack What You Need to Know About Stroke by Bonnie Liebman If you don't know the risk factors for stroke, you won't get treatment for them, says Aurthur Pancioli of the University od Cincinnati Medical Center. Here are some key risk factors. Who's at Risk? .pdf 500k If you or someone else has one or more of these warning signs, don't wait. Call 911 immediately, even if the signs go away. Other, less common signs include double vision, drowsiness, nausea, or vomiting. .pdf 34KB Signs of a Stroke Subscribe Today! Customer Service