Stroke: how to avoid a brain attack.

In the first minute of a stroke, your brain loses an estimated 1.9 million cells--what you'd lose in three weeks of normal aging.

But the loss continues every minute the stroke is left untreated. If a stroke runs its usual 10-hour course, it can kill 1.2 billion nerve cells--what a normal brain loses over the course of 36 years.

That doesn't have to happen. "Stroke is a highly treatable disease, but unfortunately, the time in which physicians can effectively reverse a stroke is short," says UCLA neurologist Jeffrey Saver.

"Precious tissue is lost every second," he explains. "Patients need to get to the hospital at the first sign a stroke is occurring."

If they get there within three hours, doctors can use a clot-busting drug like tPA (tissue plasminogen activator) to curb the damage. But many victims wait, hoping the symptoms will disappear.

"Don't try to tough it out, and don't waste time trying to get in touch with your primary physician or a neurologist," says Saver, who calculated the brain cell losses. "You need emergency help."

Each year, 700,000 Americans suffer a stroke, and 160,000 of them die. The human and economic toll is staggering.

"Many people don't realize that a stroke can change your life forever," says Stephen Havas, vice president for science, quality, and public health at the American Medical Association. "My father used to go mountain climbing and wrote papers in theoretical physics before he had a stroke. Afterwards, he had to move to a nursing home."

Nor do people realize how much they can lower their risk. "Most strokes are preventable by changes in lifestyle like not smoking, doing at least 30 minutes of moderate-to-vigorous exercise each day, maintaining a healthy weight, and eating a heart-healthy diet," says JoAnn E. Manson, professor of women's health at Harvard Medical School and chief of the Division of Preventive Medicine at Brigham and Women's Hospital in Boston. Here's how to cut your odds of having a stroke.

1. Keep a lid on your blood pressure.

Nine out of 10 strokes are like a heart attack, but in the brain. A blood clot gets stuck in an already-clogged artery, blocking the flow of blood to cells, which then die from lack of oxygen. (One out of 10 strokes is hemorrhagic, which means that a blood vessel in the brain bursts.)

But strokes may be easier to prevent than heart attacks. That's because 80 percent of the risk of stroke is due to high blood pressure.

"With heart disease, it's harder to separate the effect of cholesterol, blood pressure, diabetes, and other factors," explains Norman Kaplan, a hypertension expert at the University of Texas Southwestern Medical Center at Dallas.

"In the brain, blood pressure is a much greater factor," he notes.

It's easy to see how high pressure could cause a hemorrhagic stroke. "But it's also true for ischemic strokes, when a blood clot closes off blood vessels," says Kaplan, whose textbook, Kaplan's Clinical Hypertension, is now in its ninth edition.

Studies show that lowering blood pressure can cut your risk of stroke by about 40 percent. (1) Yet only one out of three patients has his or her blood pressure under control--that is, below 140 over 90.

"Overall, the percentage of people with hypertension who are getting treated is going up," says Kaplan. "But many people--especially the elderly and those with diabetes--are not being treated as intensively as they should be."

That's partly because doctors are hesitant to overmedicate people over age 85, especially when most studies on lowering blood pressure have few people in that age group.

"But it's clear that in people under 80, lowering blood pressure does reduce the risk of stroke by about 40 percent," says Kaplan. It also cuts their odds of a heart attack by 27 percent and heart failure by 54 percent.

2. Don't expect your blood pressure to stay normal.

Blood pressure rises with age. More than two-thirds of Americans over age 65 have hypertension--blood pressure of 140 over 90 or higher.

"If your blood pressure is normal at age 55, you have a 90 percent chance of developing high blood pressure as you get older," says the AMA's Stephen Havas.

Your risk of stroke (and heart disease) starts to climb as your blood pressure rises above normal. (Normal means below 120 over 80.) That's why blood pressure that's between normal and high is called pre-hypertension.

"In addition to the 65 million U.S. adults with hypertension, another 59 million have pre-hypertension," says Havas.

And high blood pressure now may mean an Alzheimer's-like mind later. In the Longitudinal Population Study in Sweden, the risk of being diagnosed with dementia between the ages of 79 and 85 was greater in people who had high blood pressure 15 years earlier. (2)

The good news: lowering high blood pressure seems to protect the brain. In the Honolulu Asia Aging Study of nearly 1,300 Japanese American men, the risk of Alzheimer's was 65 percent lower in those who had been treated for hypertension than in those whose blood pressures were untreated. (3)

"For every year of hypertension treatment, we found increased protection against dementia," says Rita Peila of the National Institute on Aging in Bethesda, Maryland.

Hypertension can damage the brain's blood vessels, she explains, and the brains of Alzheimer's patients often have tiny blood clots and the small areas of dead tissue they cause.

3. Don't assume that you can tell sodium by taste.

"We've estimated that approximately 150,000 lives could be saved each year --mostly from stroke and heart disease--if we could cut sodium by 50 percent in processed and restaurant foods," says Havas. "The needless loss of lives that is due to excess salt intake must stop."

Sodium raises blood pressure, but the salt shaker isn't to blame in most households. "Roughly 75 to 80 percent of sodium that people consume comes from processed and restaurant foods," Havas notes.

How does salt boost blood pressure?

"It causes an increase in fluid intake, which causes blood vessels to expand," explains Havas. "That creates a need for the kidneys to excrete extra salt and water. But over time, the continued extra pressure on the arterial wall leads to stiffness in the wall, and that leads to high blood pressure."

Cutting sodium isn't as easy as crossing potato chips and salted peanuts off your shopping list. A serving of each has less sodium (250 milligrams) than two slices of most breads (400 mg), two slices of turkey or a half cup of spaghetti sauce (500 mg), or a cup of canned soup (800 mg).

At McDonald's, a large fries has 330 mg of sodium--less than a Quarter Pounder (730 mg), Big Mac (1,010 mg), Grilled Chicken Sandwich (1,240 mg), 5-piece Chicken Selects Premium Breast Strips without sauce (1,550 mg), or Asian or Caesar Chicken salad (about 1,000 mg without dressing, 1,500 mg to 1,700 mg with). And sit-down restaurants are often worse than fast food, in part because their meals are larger.

Take-home message: you can't tell sodium by taste.

4. Load up on potassium-rich foods.

Sodium gets all the press, but potassium can protect against stroke. And it often gets ignored.

"Thirty or forty years ago, Louis Tobian of the University of Minnesota gave rats with hypertension increased amounts of potassium, and it lowered their stroke rates," notes Norman Kaplan.

Since then, researchers have found that potassium supplements can lower blood pressure in humans. (4) And people who consume more potassium have a lower risk of stroke. (5,6)

"The National Heart, Lung, and Blood Institute has recommended increasing potassium since 1993," says Havas.

The current target: 4,700 milligrams a day. That's not so easy to reach when even a potassium-rich food like a banana has only about 400 mg (see "Pass the Potassium").

But experts caution that potassium supplements or salt substitutes that contain potassium chloride aren't for everyone--and not just because some people find they leave a bitter aftertaste.

"Make sure you know that your kidney function is normal before you take them," says Kaplan. "If you have kidney damage, which increases with age, diabetes, hypertension, or congestive heart failure, your kidneys don't get rid of potassium as well."

That's also true if you're taking certain drugs to lower your blood pressure. "The safest way to get more potassium isn't through pills but by eating more fruits and vegetables," notes Havas.

And there's a bonus: potassium citrate--the kind you get in fruits and vegetables--also seems to protect against kidney stones and osteoporosis.

5. Eat 8 to 10 fruits and vegetables a day.

Potassium may help explain why fruits and vegetables seem to protect against strokes.

When Graham MacGregor, professor of cardiovascular medicine at St. George's Hospital Medical School in London, and colleagues pooled eight studies that included more than 250,000 people, the researchers found that those who reported eating at least five servings of fruits and vegetables a day had a 26 percent lower risk of stroke than those who ate fewer than three servings a day. (7)

Experts have known that fruits and vegetables lower blood pressure since the 1997 landmark DASH (Dietary Approaches to Stop Hypertension) study. (8)

"DASH showed that eating eight to 10 fruits and vegetables a day and increasing low-fat dairy foods in a diet that's low in saturated fat can lower blood pressure by about 10 millimeters of mercury," notes Havas. "That's as good as most single medications for blood pressure."

In 2005, the OmniHeart study pitted the original DASH diet (which gets about 60 percent of its calories from carbohydrates) against a higher-protein diet (which emphasized soy and other plant protein) and a Mediterranean-like diet (which was higher in unsaturated fat). All three had the same calories and were low in saturated fat, sodium, and cholesterol and were rich in fruits, vegetables, fiber, and potassium.

And after six weeks, all three diets lowered blood pressure and LDL ("bad") cholesterol. However, the protein and unsaturated fat diets cut blood pressure more, perhaps because they had fewer desserts and sweets than the higher-carb original DASH diet. (In some studies, sugars raise blood pressure.)

"The OmniHeart results should give people more flexibility to choose any of these three options," says lead author Lawrence Appel of Johns Hopkins University in Baltimore. "That should make it easier to eat a diet that can reduce risk of stroke and heart disease."

6. Eat fish twice a week.

Most studies find a lower risk of stroke in fish eaters.

For example, when researchers tracked 4,775 older men and women for 12 years, those who reported eating tuna or baked or broiled fish one to four times a week had a 27 percent lower risk of stroke than those who ate fish less than once a month. (9) (In contrast, people who ate fried fish or fish burgers more than once a week had a 40 percent higher risk of stroke.)

And in a study that tracked roughly 79,000 women for 14 years, those who ate fish at least twice a week had a 51 percent lower risk of ischemic stroke than those who ate fish less than once a month. (10)

It's always possible that it's not fish, but something else that fish eaters do, that lowers their risk. "Without clinical trials, we can't tell for sure that it's the omega-3 fats in fish that prevent stroke," says Harvard's JoAnn Manson.

Even so, there's good reason to think that fish might protect arteries. "The omega-3 fats in fish lower triglycerides, reduce clotting, and are associated with reduced inflammation," she notes.

7. Shoot for 30 minutes of exercise a day.

"Physical inactivity is associated with an increased risk of stroke," says the AMA's Stephen Havas.

In a study that tracked more than 72,000 nurses for eight years, those who were active for at least four hours a week had a 54 percent lower risk of ischemic stroke than those who were sedentary. (11)

It's not hard to imagine how staying active protects blood vessels in your brain. Exercise lowers blood pressure, curbs blood clotting, reduces insulin resistance, and keeps excess pounds from piling up, among other things.

"At least 30 minutes of moderate-to-vigorous exercise each day can cut the risk of stroke in half," says Manson. What's more, "exercise--and maintaining a healthy weight--can curb your risk of diabetes, which is a strong risk factor for stroke, especially in women."

8. Lose extra weight.

In a study of more than 20,000 male health professionals, the risk of stroke was 30 percent higher in those who were overweight and twice as high in those who were obese as in normal-weight men. (12)

More important than the number on your bathroom scale is whether you can see your toes. In one study, men with a waist larger than 42 inches had a 50 percent higher risk than those with a waist no larger than 34 inches. (13)

"Weight gain--especially around the abdomen--increases vascular trouble as you age," explains Norman Kaplan of the University of Texas. "It's that middle-aged spread that's so important to prevent as we grow older."

The good news is that losing weight has a clear-cut impact on your risk. "If you lose weight, blood pressure goes down," explains Havas. "Pressure drops about one millimeter of mercury for every two pounds you lose."

9. Don't pin your hopes on antioxidants or B vitamins.

In the 1990s, researchers had promising evidence that antioxidant vitamins could protect blood vessels from heart attacks and strokes.

So they gave more than 8,000 women with a high risk of cardiovascular disease vitamin C (500 milligrams daily), vitamin E (600 IU every other day), and/or beta-carotene (83,000 IU every other day).

After roughly nine years, the antioxidants had no impact overall. However, women who got both vitamins C and E did have a lower risk of stroke. (14) But that result may not matter.

"We looked at a lot of comparisons, so the results may be due to chance," notes Manson. The more you look, the greater the odds that something spurious turns up, say statisticians.

"Without further research, we're not making a big deal out of it," she adds.

In a second trial, more than 5,400 women with a history of cardiovascular disease took three B vitamins (2,500 micrograms of folic acid, 50 milligrams of B-6, and/or 1,000 micrograms of B-12) or a placebo. After seven years, there was no difference in the risk of stroke or heart disease. (14)

"It's perplexing," says Manson, because the B vitamins did lower blood levels of homocysteine, an amino acid.

"In earlier studies, homocysteine not only predicted strokes and heart attacks," she explains. "It was also linked to inflammation, thrombosis, and other biomarkers of cardiovascular disease."

It's possible, she speculates, that "the B vitamins may lead to other metabolic changes that counter the benefits of reducing homocysteine."

Another possibility: homocysteine could simply be an innocent bystander that has been wrongly singled out when something else in the blood is guilty.

"Right now, I don't think anyone has an answer," says Manson.

10. Talk to your doctor about low-dose aspirin.

Once you've had a stroke (or heart attack), taking low-dose aspirin (81 milligrams a day) makes sense unless you've had stomach ulcers or a history of other bleeding.

But what about taking aspirin to prevent a first stroke? It depends.

In men, low-dose aspirin cuts the risk of a first heart attack, but not a first stroke. In women, age matters.

"In the Women's Health Study, aspirin prevented a first stroke, but not a first heart attack," explains Manson. But when researchers looked only at women 65 or over, aspirin takers had a lower risk of both. (15)

"Women aged 65 and over should talk to their doctor about taking aspirin to reduce their risk of cardiovascular disease," says Manson. "The same holds for younger women at high risk."

But aspirin takers of all ages had a 40 percent higher risk of significant gastrointestinal bleeding, which can outweigh the benefits, especially when you have a low risk of stroke.

"The absolute rate of stroke is low in women in their 40s and 50s," explains Manson, "so aspirin is of minimal benefit to them."

Stephen Havas, JoAnn Manson, and Norman Kapian are members of Nutrition Action Healthletter's Scientific Advisory Board.

(1) Stroke 37: 1583, 2006.

(2) Lancet 347: 1141, 1996.

(3) Stroke 37: 1165, 2006.

(4) Hypertension 45: 571, 2005.

(5) Circulation 98: 1198, 1998.

(6) N. Engl. J. Med. 316: 235, 1987.

(7) Lancet 367: 320, 2006.

(8) N. Engl. J. Med. 336: 1117, 1997.

(9) Arch. Intern. Med. 165: 200, 2005.

(10) JAMA 285: 304, 2001.

(11) JAMA 283: 2961,2000.

(12) Ann. Intern. Med. 162: 2557, 2002.

(13) Am. J. Epidemiol. 144: 1143, 1996.

(14) Circulation 114: 2424, 2006.

(15) N. Engl. J. Med. 352: 1293, 2005.

WHO'S AT RISK?

"Many people don't realize that stroke is the third leading cause of death in both men and women in the United States," says Manson.

Here are some key risk factors.

Risks You CAN'T Change

* Age, Stroke risk 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 (ministroke) is almost 10 times more likely to have a stroke than a similar person who hasn't had a TIA.

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 pressure below 140 (ideally below 120) and your diastolic 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.

* Atrial Fibrillation. Atrial fibrillation is an irregular heartbeat that allows blood to pool in the heart, making the blood 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. Five percent of people aged 70 or older have atrial fibrillation, which makes them three to four times more likely to have a stroke.

What to do: Talk to your doctor about taking aspirin or blood-thinning drugs like Coumadin.

* Clogged Neck Arteries (asymptomatic carotid stenosis). Up to 10 percent of people over age 65 have carotid (neck) arteries that are more than half clogged, thanks to a lifetime of high blood cholesterol and other factors.

What to do: Talk to your doctor about taking aspirin or cholesterol-lowering statin drugs or, in severe cases, undergoing surgery to clear out neck arteries.

* Clogged Coronary or Leg Arteries. The risk of stroke is higher in people who have had a heart attack, angina (chest pain), heart failure, or peripheral artery disease (clogged leg arteries), which can cause intermittent claudication (severe leg pain, usually during exercise).

What to do: Use diet or, if necessary, drugs to treat cardiovascular disease.

* 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.

Source: Stroke 37: 1583, 2006.

WHAT'S YOUR RISK?

Want a rough idea of your odds of having a stroke? You can estimate your risk by following these steps, which researchers based on the participants of the Framingham Heart Study.

Women

Step 1
Find the points for your age.

Age         Women

54-56         0
57-59         1
60-62         2
63-64         3
65-67         4
68-70         5
71-73         6
74-76         7
77-78         8
79-81         9
82-84         10

Step 2
Find the points for your blood
pressure and other risk factors.

No BP Drugs          Taking BP Drugs

SBP         Points      SBP      Points   Diabetes;
under 95      0      under 95      0      No = 0 Yes = 3

95-106        1       95-106       1      Cigarette Smoker
107-118       2       107-113      2      No = 0 Yes = 3
119-130       3       114-119      3
131-143       4       120-125      4      CVD
144-155       5       126-131      5      No = 0 Yes = 2
156-167       6       132-139      6
168-180       7       140-148      7      AF
181-192       8       149-160      8      No = 0 Yes = 6
193-204       9       161-204      9
205-216      10       205-216      10     LVH
                                          No = 0 Yes = 4

Men

Step 1

Find the points
for your age.

Age          Men

54-56         0
57-59         1
60-62         2
63-65         3
66-68         4
69-72         5
73-75         6
76-78         7
79-81         8
82-84         9
   85        10

Step 2

Find the points for your blood pressure
and other risk factors.

No BP Drugs          Taking BP Drugs      Diabetes
                                          No = 0 Yes = 2
SBP         Points      SBP      Points
                                          Cigarette Smoker
97-105        0       97-105       0      No = 0 Yes = 3
106-115       1       106-112      1
116-125       2       113-117      2      CVD
126-135       3       118-123      3      No = 0 Yes = 4
136-145       4       124-129      4
146-155       5       130-135      5      AF
156-165       6       136-142      6      No = 0 Yes = 4
166-175       7       143-150      7
176-185       8       151-161      8      LVH
186-195       9       162-176      9      No = 0 Yes = 5
196-205      10       177-205      10

Step 3
Total the points for all
your risk factors.

Age          + --
SBP          + --
Diabetes     + --
Cigarette    + --
Smoker       + --
CVD          + --
AF           + --
LVH          + --

Total
Points        --

Find Your Risk
Here's your risk of having
a stroke within the next
10 years.

Points       Men       Women

1             3%         1%
2             3%         1%
3             4%         2%
4             4%         2%
5             5%         2%
6             5%         3%
7             6%         4%
8             7%         4%
9             8%         5%
10           10%         6%
11           11%         8%
12           13%         9%
13           15%        11%
14           17%        13%
15           20%        16%
16           22%        19%
17           26%        23%
18           29%        27%
19           33%        32%
20           37%        37%
21           42%        43%
22           47%        50%
23           52%        57%
24           57%        64%
25           63%        71%
26           68%        78%
27           74%        84%
28           79%        --
29           84%        --
30           88%        --

Your Risk Compare
Compare your stroke risk
to that of an average
person your age.

Age          Men       Women

55-59         3%         6%
60-64         5%         8%
65-69         7%        11%
70-74        11%        14%
75-79        16%        18%
80-84        24%        22%

Stroke Glossary

AF--Has a doctor ever told you that you have atrial fibrillation (irregular heart beats in the upper chambers of your heart)?

BP Drugs--Drugs to lower blood pressure.

CVD-Have you ever had any of these five conditions?

1. Heart attack.

2. Angina (chest pain during physical activity).

3. Unstable angina or coronary insufficiency (the symptoms of a heart attack, but with no increase in the enzymes that signal heart muscle damage).

4. Intermittent claudication (severe leg pain, usually upon exertion, that results from an inadequate blood supply).

5. Congestive heart failure (symptoms like breathlessness and severely swollen ankles caused by the heart's failure to pump enough blood and oxygen).

LVH--Has an electrocardiogram ever shown that you have left ventricular hypertrophy (an enlarged heart muscle)?

SBP--Your systolic blood pressure (the higher of your two blood pressure numbers).

Pass the Potassium

Experts recommend 4,700 mg of potassium a day, largely from fruits and
vegetables, not supplements. Bonus: in addition to lowering your blood
pressure and risk of stroke, potassium may also help strengthen bones
and prevent kidney stones.

Food                                    Potassium
(1/2 cup cooked unless noted)        (milligrams)

Potato, baked, with skin (1)                1,080
Pasta sauce, tomato (1 cup)                   940

Sweet potato, baked, with skin (1)            690
Edamame (boiled green soybeans)               490

Halibut (3 oz. cooked)                        490
Orange juice (1 cup)                          480
Swiss chard                                   480
Tuna (3 oz. cooked)                           480
Great northern beans                          460
Winter squash                                 450
Artichoke (1 medium--3/4 cup)                 430
Cantaloupe (1 cup)                            430
Banana (1)                                    420
Spinach                                       420
Apricots, dried (5)                           410
Yogurt, plain, nonfat (6 oz.)                 400
Honeydew (1 cup)                              390
Black beans, lentils, or navy beans           370
Milk (1 cup)                                  370
Papaya (1 cup)                                360
Split peas                                    360
Kellogg's All-Bran Original (1/2 cup)         350
Salmon (3 oz. cooked)                         350
Haddock (3 oz. cooked)                        340
Watermelon (2 cups)                           340
Kidney beans                                  330
Grapes, green or red (1 cup)                  310
Prunes (5)                                    310
Pistachios (50 nuts--1 oz.)                   300
Pork (3 oz. cooked)                           300
Flounder or sole (3 oz. cooked)               290
Parsnips                                      290
Yogurt, fruit on the bottom (6 oz.)           290
Beef (3 oz. cooked)                           280
Lima or pinto beans                           280
Nectarine (1)                                 270
Raisins (1/4 cup) or dates (5)                270
Sunflower seeds (1/4 cup-1 oz.)               270
Figs, dried (2)                               260
Mango (1 cup) or strawberries (1 cup)         260
Beets or Brussels sprouts                     250
Broccoli or zucchini                          230
Orange (1) or carrot (1)                      230
Almonds (25 nuts-1 oz.)                       210
Chicken (3 oz. cooked)                        210
Chickpeas                                     210
Salmon, red (sockeye), canned,
with bones (1/4 cup-2 oz.)                    210
Tomato (1/2 cup)                              210
Peach (1) or pear (1)                         190
Peanuts (30 nuts--1 oz.)                      190
Tuna, canned (1/4 cup--2 oz.)                 130

Sources: U.S. Department of Agriculture and companies.