10 ways to reduce your risk of stroke

Our brains: We think of them as the “control centre” of our body — which is why the thought of a devastating event like a stroke is so frightening. Worldwide, strokes are the top cause of acquired disability in adults, often robbing people of their independence as well as their health — and the second leading cause of death. Strokes place a heavy burden not just on sufferers and their families, but also on entire countries.

The good news is that there’s a lot we can do to lighten that load. Research reveals that much of our stroke risk is determined by things we can control — like our everyday habits and choices. The INTERSTROKE Study, led by Canadian researchers at Hamilton’s McMaster University, investigated how certain lifestyle factors affect stroke risk.

The study involved over 3000 controls and 3000 participants from 22 countries — including Canada, Australia, China, India, Sudan and other developing nations — from March 2007 to April 2010. Participants not only completed questionnaires, but also under went physical examinations and clinic assessments. Using this data, investigators analyzed how certain factors affected the risk for ischemic stroke (caused by an interruption to blood flow in the brain from a clot) and intracerebral hemorrhagic stroke (uncontrolled bleeding caused by rupture deep in the brain) as well as overall stroke risk.

The results? The numbers might surprise you: 10 lifestyle factors account for 90 per cent of stroke risk, according to a report published in the June 18, 2010 online edition of the Lancet .

The 10 key factors

High blood pressure. As reported in previous studies, researchers found that hypertension (or a history of hypertension) is the most important risk factor for stroke.

Smoking. The more packs smoked per day, the higher the risk. However, it’s current smokers who are in danger. People who kicked the habit didn’t see an increased risk. In fact, their risks dropped substantially within the first year of quitting.

Waist-to-hip ratio. Here’s further proof that where you carry excess weight matters. While researchers note that Body Mass Index (BMI) doesn’t appear to be related to stroke risk, excess weight around the midsection (known as abdominal obesity) can have serious consequences. (For more information on what these measurements mean, see 10 tests that could save your life.)

Diet. We know a healthy diet is good for many reasons, but this study offers some specifics. Among all the food groups, fruit and fish are the top choices for reducing stroke risk. The usual suspects raise the risks — including red meat, organ meat, eggs, salty foods, fatty and fried foods and lard.

One finding that may surprise you: Eating plenty of vegetables didn’t appear to help reduce risk. While investigators note that this result isn’t unheard of, it certainly warrants further investigation.

Physical activity. There’s something to be said for getting the blood pumping: People who get regular exercise had a lower risk.

Diabetes. Consistent with previous heart studies, patients who reported a history of diabetes also had a higher risk of stroke. We also know lifestyle factors also play a major role in delaying and preventing type 2 diabetes. (For more information, see Put diabetes on hold.)

Alcohol. Once again, there’s something to be said for moderation. People who consumed more than 30 drinks per month or indulged in binge drinking had the highest risk.

Stress and depression. Perhaps we can’t escape these factors, but this study is further proof that attending to our mental and emotional well-being affects our physical well-being — especially our brains.

Heart conditions. Matters of the heart affect the head as well — especially atrial fibrillation (irregular heart beat). The heart risks were higher for people in high-income countries rather than developing countries.

Elevated levels of blood fats (cholesterol). While the numbers depend on the type of cholesterol and the type of stroke, overall researchers found that higher levels of “bad” cholesterol were associated with a higher risk of stroke.

What’s missing? The scope of the study didn’t include risks from medications and therapies that are known to increase stroke risk, or non-lifestyle related factors like age, sex, ethnic background or family history.

The take away message?

Essentially, we can significantly reduce the risk of having a stroke by eating a healthy diet, exercising regularly, maintaining a healthy weight and keeping our essential numbers in check. The researchers note that interventions and initiatives targeting habits like diet, exercise, smoking and alcohol — as well as controlling blood pressure and diabetes — will significantly reduce the burden of stroke.

Sounds familiar? Chances are you’ve seen this list before — it’s similar to previous research findings for other health conditions, such as the INTERHEART study which focussed on how lifestyle choices affected heart disease risk. Many of these lifestyle choices are also known to affect other chronic conditions like diabetes and cancer. The steps we take to reduce our risk of one health condition also reduce the risk of other problems — especially when one chronic disease increases the risk for another.

So if we can control all of these factors, we’ll live forever, right?

It’s important to remember that “risk factors” aren’t guarantees. Having them doesn’t necessarily mean we’ll be affected by a particular issue, just as reducing our risk doesn’t mean we’ll get a free pass. (For example, non-smokers can still get lung cancer, and “thin” people still develop heart disease.) We like to play the blame game when it comes to health, but the fact is there are limits on how much control we have.

Perhaps it’s true that “we’re all going to die of something”, but we’d still like to delay the onset of serious disease and enjoy as many healthy years as we can.


Stroke incidence in Canada

How common are strokes in Canada? Here’s an overview of the statistics:

– Over 50,000 strokes happen each year (that’s about one stroke every 10 minutes). Eighty per cent of these strokes are ischemic — that is, caused by a blood clot which interrupts the flow of blood to the brain. The remaining 20 per cent are hemorrhagic strokes caused by uncontrolled bleeding in the brain.

– Stroke is the third leading cause of death in Canada. Each year, more than 14,000 Canadians will die from a stroke — and more women will die than men.

– More than 300,000 Canadians are living with the effects of a stroke. More than half of stroke survivors are left with a moderate to severe impairment, and 10 per cent require long term care. Only ten per cent of stroke survivors experience a full recover.

– Survivors have a 20 per cent change of having another stroke within the next two years.

– After age 55, the risk of having a stroke doubles every decade. People over the age of 80 are at the highest risk.

– Strokes can strike at any age — even children. An average of 6.7 strokes occur for every 100,000 Canadians under the age of 19. Strokes can even happen before a baby is born, or within the first 28 days of life — affecting 1 in 4000 live births.

– For every hour that treatment is delayed, the brain loses as many neurons as if it had aged about three and half years.

* Source: The Heart and Stroke Foundation

– For more information about the study, read the full report in Lancet.
– To learn more about stroke — including how to spot the warning signs — visit the Heart and Stroke Foundation website .

(Note: As disclosed in the journal article, the study was funded by the Canadian Institutes of Health Research, Heart and Stroke Foundation of Canada and the Canadian Stroke Network, Pfizer Cardiovascular Award, Merck, AstraZeneca, and Boehringer Ingelheim. Researchers note that these organizations had no influence over the design, implementation or reporting of the study.)

Photo ©iStockphoto.com/ naphtalina

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