A strike against stroke: how to keep your brain in working order.
"He had symptoms throughout the day, but he was working at a high-tech company and he had deadlines, so he was toughing it out," says Richard's wife, Holly. "He came home and we had dinner. Around 8 p.m., he fell to the floor."
If Richard or his co-workers had known the signs of a stroke and had called 9-1-1 immediately, doctors might have been able to minimize the stroke's damage.
But warning signs are just part of the stroke story. Some "silent strokes" occur without any symptoms. And they often contribute to what we assume is Alzheimer's disease.
The answer isn't just to know a stroke when you see it, but to keep it from striking in the first place.
"We know how to prevent stroke." says hypertension expert Norm Campbell. "Why aren't we doing it?"
Every 40 seconds, someone in the United States suffers a stroke. That adds up to 795,000 strokes a year. And the number doesn't count invisible "silent" strokes.
Every four minutes, someone dies of a stroke. Though death rates have dropped, strokes still kill more than 137,000 Americans a year. That makes stroke the fourth-leading cause of death.
Here's what will--and won't--lower your risk of a stroke.
A typical stroke is essentially a heart attack in your brain.
Roughly nine out of 10 strokes are ischemic. That means they occur when arteries in or on the way to the brain get blocked by a blood clot. The trigger: a ruptured plaque in blood vessels in the brain or neck or near the heart--or a clot in the heart--that travels to the brain.
"The clot can block the blood vessel or it can break into little pieces that go all over the body, including the brain," explains Norm Campbell, professor of medicine, community health sciences, and physiology and pharmacology at the University of Calgary in Canada.
If the clot cuts off the blood supply to the brain, oxygen-starved brain cells near the blocked vessel die. Two million brain cells die every minute during a stroke, causing brain damage, disability, or death.
Six months after having an ischemic stroke, a fifth of survivors aged 65 or older have trouble speaking, a third can't walk without assistance, and a quarter are in a nursing home. (1)
"Hemorrhagic strokes are even more tragic," says Campbell, who chairs the Canadian Hypertension Advisory Committee. Hemorrhagic strokes--which occur when a blood vessel in or around the brain bursts--account for 13 percent of strokes in the United States, but 30 percent of stroke deaths.
One drug has revolutionized the treatment of ischemic strokes. In 1996, the Food and Drug Administration approved the use of tissue-plasminogen activator (tPA) to break up clots and restore the brain's blood supply. The catch: you don't have much time.
"The FDA's approval is for three hours, but our national guidelines allow us to go out to 4 1/2 hours in selected patients," says Larry Goldstein, director of the Stroke Center at Duke University Medical Center in North Carolina. "But what's very, very clear is that the sooner you get treated, the more likely that the drug is going to be of benefit."
That doesn't mean you have three hours to arrive at the hospital.
"The current national goal is one hour from arrival to treatment, but that's extraordinarily difficult to do in many settings," says Goldstein, who chaired the American Heart Association's 2011 Guidelines for the Primary Prevention of Stroke. (2)
"A variety of things slow things down."
Among them: "A CT scan and blood tests have to be taken, other potential reasons for the symptoms have to be excluded, and the patient has to agree to take the drug."
But the hospital isn't usually the problem. "The single most important reason people aren't treated with intravenous tPA is that they don't get to the hospital soon enough," says Goldstein.
It's not just that people fail to recognize the symptoms. "Denial is very important," notes Goldstein. "People don't believe that a stroke is happening or they dismiss it and the people around them dismiss it."
And time is brain, as they say.
"If you're too late, there are no treatment options available," says Campbell. "It's a true emergency. You need to call an ambulance."
Even if the warning signs disappear, call 9-1-1. You might be having a TIA, or transient ischemic attack.
"A TIA is one of the greatest predictors of having a true stroke"--that is, one that causes permanent damage, notes Campbell. "You may not need a clot-busting drug, but you need treatment," often with drugs to lower blood pressure or prevent clots.
"You don't want to have the stroke and then be treated. A TIA is a great opportunity to prevent a stroke. It shouldn't be squandered by delay."
Richard Dykema was eventually treated with tPA, "but it didn't turn things around," says Holly. "I've heard so many stories about people who go into the hospital and can't move their limbs, can't talk, and walk out of the hospital totally fine. The drug is amazing."
TPA may not have helped because Richard had a carotid dissection, which can start with a small tear in the lining of the carotid artery in the neck. That allows blood to enter the space between the inner and outer layers of the artery wall, narrowing or completely blocking the blood vessel.
"I didn't even know what a stroke was when he had it," says Holly. "One day I had had problems seeing out of one eye, and it wasn't serious. So I said, 'Don't worry about it.' Silly me."
The urgent need to treat stroke symptoms has led to campaigns to publicize a stroke's warning signs (see "Signs of a Stroke"). But knowing the warning signs can't help with strokes that have no symptoms.
"In silent strokes, people can speak normally and have normal power and feeling in their limbs," says Campbell. "They don't get the warning signs of stroke so they don't go to the hospital." Nevertheless, silent strokes cause brain cells to die.
"What's emerging is that silent strokes are probably precursors of dementia," says Campbell. "People become cognitively impaired as the burden of silent strokes increases."
Scientists used to distinguish Alzheimer's disease from vascular dementia caused by clogged blood vessels, but no longer. (3)
"There's a big overlap between vascular dementia and Alzheimer's disease," explains Goldstein. "Finding pure Alzheimer's or pure vascular dementia is the rarity, not the rule. Most people have at least some components of both."
And the number of Americans suffering from dementia is climbing. So is the cost.
"We're an aging population," says Campbell. "When you look at hospitalizations, physician visits, and drugs to treat strokes and heart attacks, the cost is essentially bankrupting the health care system."
The answer isn't just to get people to act when they see warning signs or to. come up with better treatments for strokes.
"I view those as waiting-for-a-stroke programs," says Campbell. "Society needs to be more proactive to prevent strokes from occurring in the first place. We know how."
"We know that people who follow a healthy lifestyle have a dramatically lower risk of stroke than people who don't," says Goldstein.
For example, in a study that tracked some 44,000 men and 71,000 women for 16 years, five aspects of lifestyle made a difference. (4)
"People who don't smoke, who are not overweight, who don't drink alcohol in excess, who exercise regularly, and who eat a healthy diet have about an 80 percent lower risk of a first stroke," explains Goldstein. "And the risk decreases for each of those lifestyle habits."
(In the study, a "healthy" diet meant higher intakes of vegetables, fruits, nuts, soy, grain fiber, chicken, and fish and lower intakes of red meat, saturated fat, and trans fat.)
And in studies on some 257,500 people, those who ate more than five servings of fruits and vegetables a day had about a 25 percent lower risk of stroke than those who ate less than three servings a day. (5)
Those studies weren't trials so they can't prove cause and effect. It's possible that people who eat healthier diets also do other things that lower their risk.
But odds are that a healthy lifestyle means fewer risk factors for stroke (see "What's Your Risk?" p. 5). Some risk factors--like age and family history--you can't change. Of those you can, one stands out: "The single most important risk factor for a stroke is high blood pressure," says Goldstein.
Keep Blood Pressure Low
"An optimal blood pressure is less than 115 systolic over 75 diastolic," says Campbell. "As long as a disease hasn't caused blood pressure to go low, that's healthy."
(The target for people who are taking blood-pressure drugs is 140 over 90, notes Campbell. "I wouldn't want those people to ask their does to lower their pressure to 115 over 75," he says.)
Why is lower better? "As blood pressure rises, all of the blood vessels in the body are damaged," says Campbell. "And that causes strokes, heart attacks, heart failure, kidney failure, dementia, impotence, and difficulty with walking."
Doctors diagnose patients with high blood pressure, or hypertension, when either the upper number reaches 140 or the lower number hits 90.
"Doctors and patients like having goal numbers, but it's not like at 139 over 89 you have no risk and at 141 over 91 suddenly you have risk," says Goldstein.
In fact, the risk starts to rise well before 140 over 90. "Around 60 to 70 percent of clinical strokes are caused by increased blood pressure," explains Campbell. "Half of those strokes occur in people with high blood pressure and half strike those with increased-but-not-high blood pressure."
Increased-but-not-high blood pressure--or prehypertension--ranges from 120 to 139 systolic over 80 to 89 diastolic. "Normal" is less than 120 over less than 80.
"We use different names but the reality is that as blood pressure increases, the damage increases," says Campbell. Here's how you can keep your pressure low, according to a report by the Institute of Medicine, the health arm of the National Academy of Sciences: (6)
* Lose excess weight. If you're overweight, losing about 10 pounds could trim systolic blood pressure by an average of six points.
* Eat a DASH-like diet. A DASH diet is built around vegetables, fruit, low-fat dairy, and unsaturated fat instead of added sugars, refined starches, and saturated fat (see "What to Eat"). A DASH diet can lower systolic blood pressure by about six points. (That doesn't count the drop in pressure from the cut in sodium that's usually recommended as part of the DASH diet.)
* Scale back salt. Cutting sodium in half (that means trimming about 1,700 milligrams a day for the average American) could cut systolic blood pressure by around four points.
* Eat more potassium. Potassium-rich fruits and vegetables can lower systolic blood pressure by about three points. (That accounts for half of the six-point drop you can expect from the DASH diet.)
* Exercise. Regular aerobic exercise like brisk walking can lower systolic blood pressure by two to four points.
* Limit alcohol. No more than two drinks a day for men or one drink a day for women can cut systolic blood pressure by an average of three points.
It's not hard to see the food industry's role in raising our blood pressure.
"Sodium is added during food processing, by restaurants or in packaged foods," notes Campbell. "Both have too little potassium due to lack of fruits and vegetables. And obesity is due to calorie density due to sugars and saturated and trans fats.
"Food companies are killing us, but we're not supposed to demonize them,"
Don't Give Up
Richard Dykema hasn't fully recovered from his stroke. "We used to be very active," says his wife, Holly. "He used to ride a motorcycle, scuba dive, and hang glide. Now he's in a wheelchair most of the time. Walking is difficult.
"He was hit on many levels. He has absolutely no use of his arm. His leg was paralyzed, but it's come back some. And he has a communication disorder and cognitive issues."
But Holly still has hope.
"For many years, the theory was that what you see at six months is what you get for the rest of your life," she says. "I've been going to support groups for six years, and I've seen many people continue to make improvements years after their stroke.
"You may not be climbing mountains again, but that doesn't mean you'll never be able to walk out your front door. You have to reinvent your life."
For Holly, that meant starting the Stroke Association of Florida (SAF) to help other survivors and caregivers in Sarasota and Manatee counties.
At first, she explains, "I barely knew when my next shower was going to come, let alone who would care for Richard when I went back to work."
The SAF offers information on support groups and a local resource guide.
"When Richard first came home, I needed a transfer board to get him in and out of the car," says Holly. "A couple of months down the road, he no longer needed that.
"Then he needed a device to help him go fishing one-handed. How do you open a jar or operate a zipper with one hand? Your needs are going to change."
The SAF's second goal is to educate the local community.
"People need to know about the lifestyle changes that can prevent strokes," says Holly. "And they need to know that they should call 9-1-1 immediately, because waiting to see if symptoms go away can mean the difference between complete recovery and disability."
SIGNS OF A STROKE
Sudden weakness or numbness on one side of the face, arm, or leg
Sudden trouble speaking or understanding, confusion
Sudden trouble seeing in one or both eyes
Sudden trouble walking, dizziness, loss of balance or coordination
Sudden headache of no known cause
WHAT'S YOUR RISK?
Want a rough idea of your odds of having a stroke within the next 10 years? You can estimate your risk by following these steps, which researchers based on the participants in 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 under 95 0 under 95 0 95-106 1 95-106 1 107-118 2 107-113 2 119-130 3 114-119 3 131-143 4 120-125 4 144-155 5 126-131 5 156-167 6 132-139 6 168-180 7 140-148 7 181-192 8 149-160 8 193-204 9 161-204 9 205-216 10 205-216 10 Diabetes No=0 Yes=3 Cigarette Smoker No=0 Yes=3 CVD No=0 Yes=2 AF No=0 Yes=6 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 SBP Points SBP Points 97-105 0 97-105 0 106-115 1 106-112 1 116-125 2 113-117 2 126-135 3 118-123 3 136-145 4 124-129 4 146-155 5 130-135 5 156-165 6 136-142 6 166-175 7 143-150 7 176-185 8 151-161 8 186-195 9 162-176 9 196-205 10 177-205 10 Diabetes No=0 Yes=2 Cigarette Smoker No=0 Yes=3 CVD No=0 Yes=4 AF No=0 Yes=4 LVH No=0 Yes=5
Total the points for all your risk factors.
Age + -- SBP + -- Diabetes + -- Cigarette Smoker + -- CVD + -- AF + -- LVH + -- Total Points --
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).
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% -- Compare Your Risk Compare your stroke risk to that of an average person your age. Age Men Women 55-59 6% 3% 60-64 8% 5% 65-69 11% 7% 70-74 14% 11% 75-79 18% 16% 80-84 22% 24%
(1) Circulation 125: e2, 2012.
(2) Stroke 42: 517, 2011.
(3) Stroke 42: 2672, 2011.
(4) Circulation 118: 947, 2008.
(5) Lancet 367: 320, 2006.
WHAT TO EAT
Here's a variation of the DASH (Dietary Approaches to Stop Hypertension) diet that gave people the best blood pressure, triglycerides, and HDL ("good") cholesterol levels (see Oct. 2009, cover story). It has about 2,000 calories a day. If you eat more, just up the servings proportionally. * The diet provides roughly 4,700 milligrams of potassium, 500 mg of magnesium, 1,200 mg of calcium, 30 grams of fiber, and 2,300 mg of sodium per day. * The fruits and vegetables may seem overwhelming, but the servings are small. If you don't want to measure, just make sure they fill at least half your plate. (Adapted from JAMA 294 2455, 2005.)
A DAY'S FOOD
VEGETABLES & FRUIT 11 servings per day 1 serving: 1/2 cup cooked vegetables 1/2 cup raw vegetables 1 cup salad greens 1 piece fruit 1/2 cup fresh fruit 1/4 cup dried fruit GRAINS 4 servings per day 1 serving: 1 slice bread 1/2 cup cereal, pasta, or rice OILS & FATS 2 servings per day 1 serving: 1 Tbs. oil 1 Tbs. margarine or mayo LOW-FAT DAIRY 2 servings per day 1 serving: 1 cup milk or yogurt 1 1/2 oz. cheese WILD CARD 1 serving per day of OILS & FATS or POULTRY, FISH, & MEAT or GRAINS or DESSERTS & SWEETS POULTRY, FISH, & MEAT 1 serving per day 1 serving: 1/4 lb. cooked DESSERTS & SWEETS 2 servings per day 1 serving: 1 small cookie 1 tsp. sugar LEGUMES & NUTS 2 servings per day 1 serving: 1/4 cup nuts 1/2 cup cooked beans
What Else May Prevent a Stroke
* Vitamin D. When it comes to vitamin D, "the jury is still out," says JoAnn Manson, chief of preventive medicine at Brigham and Women's Hospital in Boston.
"A higher intake of vitamin D and higher blood levels of 25-hydroxy-D are linked to a lower risk of stroke," she explains. But until researchers test vitamin D supplements compared to a placebo, they won't know if the vitamin makes a difference.
"There are so many sources of potential bias," says Manson, who is also professor of medicine at Harvard Medical School. For example, "lower blood levels of vitamin D are correlated with obesity and being sedentary, because those people are less likely to be outdoors exercising and getting sun exposure that would raise blood levels." (1)
To find out if vitamin D--rather than a healthier body weight or more exercise or something else about people with higher vitamin D levels--lowers the risk of stroke and heart disease, Manson is leading the VITamin D and OmegA-3 Trial (VITAL), which is giving men and women either vitamin D (2,000 IU a day) or a placebo. Results should be out in 2017.
* DHA and EPA. "There are now several studies suggesting that people who eat more fish have a reduced risk of stroke," says Manson. "However, the trials that randomly assigned people to take fish oil or a placebo have not clearly documented that." Why the discrepancy? "Eating fish may replace less healthful forms of protein such as red meat, and it also tends to track with more physical activity and healthier body weight and generally healthier diets," notes Manson. These differences, not DHA and EPA (the two omega-3 fats in fish oil), may explain why fish eaters have a lower risk of stroke. (2)
Another possibility: most randomized trials have studied people at high risk for stroke or heart attacks. "They're often on statins, aspirin, or antihypertensive medications like ACE inhibitors and beta-blockers," explains Manson. Those drugs may work through similar pathways and lower the risk of stroke so much that "it may be difficult to see a benefit of the omega-3s."
The VITAL trial should clear up the confusion. It's giving 1,000 mg a day of DHA plus EPA to people who are taking fewer drugs because they're at average risk.
What Doesn't Work
* Antioxidant vitamins, "The randomized trials of antioxidant vitamins have been disappointing," says Manson. In trials with thousands of people, those who were given high doses of beta-carotene or vitamins E or C had no lower risk of stroke than those who got a placebo. (1)
In fact, vitamin E promoted strokes in some trials. Among the 14,600 men in the Physicians' Health Study, those who took 400 IU of vitamin E every other day for eight years had a 74 percent higher risk of hemorrhagic stroke than those who took a placebo. (3)
"Mega-doses of vitamin E can increase the risk of bleeding," says Manson. (And 400 IU isn't an outlandish dose. Most multivitamins have 30 IU, but some have 100 to 400 IU.)
* B vitamins. "Homocysteine had been linked to an increased risk of stroke," says Manson. And three vitamins (B-6, B-12, and folic acid) can lower homocysteine. "But B-vitamin supplements have not reduced the risk of stroke in randomized trials," she notes. (1) "That's been a surprising finding." What went wrong?
Higher homocysteine may be a sign that people have other risk factors for stroke, like obesity. "Correlation doesn't prove cause and effect," cautions Manson.
(1) Stroke DOI: 10.1161/ST.ROKEAHA.111.639930.
(2) Arch. Intern. Med. 172: 697, 2012.
(3) JAMA 300: 2123. 2008.
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|Publication:||Nutrition Action Healthletter|
|Article Type:||Cover story|
|Date:||Nov 1, 2012|
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