Did you know stroke is the leading cause of long-term disability? Stroke comes in two main types: ischemic and hemorrhagic. Ischemic stroke is more common the hemorrhagic stroke. An ischemic stroke is where blood flow to the brain is reduced to the point that it damages, delicate brain tissues. A stroke usually happens when a blood clot forms in a vessel that feeds into the brain, although anything that interferes with blood flow to the brain can cause an ischemic stroke. Around 87% of strokes are ischemic.
In contrast, hemorrhagic stroke is bleeding into the brain. This is often caused by a ruptured blood vessel due to an aneurysm, an abnormal dilation or weakening in the wall of a blood vessel. They can also be brought on by abnormally formed blood vessels, called AV malformations, that leak. The blood from the leaky or ruptured vessel enters the tight cavity that encloses the brain and causes the brain tissue to swell. Hemorrhagic strokes are commonly fatal.
It all sounds frightening, doesn’t it? Well, here’s some good news. According to the Stroke Association in the U.K, thirty minutes of exercise daily can slash the risk of an ischemic stroke by 25%. It also lowers the risk of transient ischemic attacks. Studies also show that exercise is important for preventing another stroke after suffering an initial one.
Just as encouraging is a 10-year study of more than 16,000 men. It showed a link between greater cardiovascular fitness and a reduced risk of dying of a stroke. With this type of “link” study, you have to worry that some other factor is causing the lower risk that’s unaccounted for, but the study controlled for other health habits, like body mass index, lifestyle habits, diet, high blood pressure, diabetes, and family history and the link persisted.
There’s even more evidence: A meta-analysis of 23 studies published in the journal Stroke found physically active people who engage in moderate to high amounts of physical activity have a lower risk of all types of stroke, both ischemic and hemorrhagic.
What’s the Mechanism By Which Exercise Lowers Stroke Risk?
Although it’s not clear exactly how exercise reduces the risk of a stroke, research suggests it likely works by controlling risk factors that increase the likelihood of stroke. These include abnormal lipids, high blood pressure, and abnormal blood glucose levels. Exercise even improves the way blood vessels behave, a phenomenon called the endothelial function. This may reduce the risk of a clot forming in a blood vessel leading to the brain and cutting off blood flow. For example, studies show aerobic exercise can reduce blood pressure, improve lipids, help with blood glucose control, and even reduce inflammation, another contributing factor to stroke.
Even among people who have had a stroke, exercise is beneficial. Supervised exercise helps stroke survivors recover deficits due to the stroke such as difficulty using the limbs and balance. Many stroke survivors also suffer from fatigue and depression and exercise can help with these symptoms too.
Lower Your Risk of Stroke
Although staying physically active appears to lower stroke risk, there are other things to do to reduce your likelihood of developing a stroke. The strongest risk factor for stroke is high blood pressure. No surprise here! Chronically elevated blood pressure damages the inner lining of the blood vessel. How can you lower your risk?
Keep an eye on your blood pressure and make sure it stays within the normal range. Recently, the guidelines for what constitutes a normal blood pressure has changed, as studies suggest that even tighter blood pressure control lowers the risk of heart failure, heart attacks, and stroke over a three-year period. So, know your blood pressure readings and discuss them with your physician. Even better, check them at home at different times of the day and record them. Monitor for morning spikes in blood pressure, readings that are 20 points or more higher than evening readings. Morning surges in blood pressure is a risk for heart attack and other cardiac events.
Also, follow your blood sugar and lipids levels. Elevated LDL-cholesterol is linked with a higher risk of stroke, but studies also correlate high blood triglycerides with an elevated risk. High blood glucose, even in the pre-diabetic range, boost the odds of developing a stroke. Fortunately, these problems can often be addressed through lifestyle modifications.
Of course, you should also eliminate unhealthy habits like smoking and excessive alcohol use. These habits raise the risk of stroke as well. Be aware that many of these prevention strategies apply to ischemic stroke. However, controlling blood pressure and staying physically active may also lower the risk of hemorrhagic stroke as well.
Watch your diet too. Obesity is a risk factor for stroke and eating a diet of ultra-processed foods, junk food, and sugar makes it harder to control your rate. Previously, doctors warned that a diet high in saturated fat increases the risk of stroke and heart disease, but more recent studies call this into question. However, adding more fiber-rich fruits and vegetables may reduce the risk by helping with weight control, lipids, and blood pressure control. Fruits and vegetables are an excellent source of potassium. A number of studies link high intake of potassium with a lower risk of ischemic stroke. In fact, research shows a spot urine test that measures the ratio of potassium to sodium is predictive of stroke risk. One study found that a ratio of potassium to sodium in the urine greater than 1 is linked with a 47% higher risk of stroke.
The Bottom Line
The most important things you can do to lower your risk of stroke is to control blood pressure. Aerobic exercise can help you do that. Plus, exercise may offer benefits for stroke prevention independent of its impact on blood pressure. Keep moving for the health of your brain and blood vessels!
· Stroke Association. “Exercise and Stroke”
· Stroke. 2018;49:820–827
· Int J Epidemiol, 2004, vol. 33 4(pg. 787-798)
· Stroke. 2003;34:2475-2482.
· Heart.org. “Hypertension guidelines, one year later: monitoring the change”
· Pharmacy Times. “What’s Up with Morning Blood Pressure?”
· HealthLine.com. “What Are the Different Types of Strokes?”
· Cochrane Database Syst Rev. 2015 Jun 10;(6): CD011737. doi: 10.1002/14651858.CD011737.
· National Institutes of Health. “Potassium”
· Renal and Urology News. “Spot Urine Sodium-to-Potassium Ratio Predicts Stroke Risk”
· Centers for Disease Control and Prevention. “Stroke Facts”