Obesity Increases the Risk of Stroke
Stroke is defined as any interruption to the blood supply of the brain. (1) Related conditions are aneurysm, arteriovenous malformation and cerebral hemorrhage. If blood flow to any part of the brain is interrupted, because a blood vessel in the brain is blocked or bursts open, then a stroke can occur. (2) If the blood flow is interrupted for just a few seconds, then the brain cannot get oxygen and this will cause the brain cells to die, causing permanent brain damage. (3) The two main types of stroke are ischemic stroke and hemorrhagic stroke.
Ischemic stroke takes place when a blood vessel that supplies blood to the brain undergoes a blood clot. (4) This is usually a result of cardiovascular disease, in the form of atherosclerosis, which takes place as due to excess fat, cholesterol and other substances which collect on the wall of the arteries, forming a sticky substance known as plaque. This plaque builds up over time and makes it difficult for the blood to flow properly, thus causing the blood clot. (5)
Hemorrhagic stroke can take place when a blood vessel in the brain becomes weak and bursts open, which causes blood to leak into the brain. (6) This can be genetic as some people have defects in the blood vessels of the brain that can make this more likely to take place. (7)
The link to obesity
People who are obese are generally defined as having a body mass index greater than 30 kg/m2. (8) Some 25-30% of Americans are currently considered obese. (9) Most media outlets report correctly that obesity is a major risk factor for a number of life-threatening conditions, such as heart disease, stroke, type 2 diabetes and even some types of cancer. (10) The actual link is through what is known as abdominal or visceral obesity and people who suffer from this condition have a high chance of developing an ischemic stroke. (11) Since obesity is a known risk factor for coronary heart disease, it has often been thought that stroke is related to obesity in some way.
Cholesterol and obesity link to ischemic stroke
Cholesterol is a substance that is normally present in the body and which is created largely by the liver. (12) In a person with a well-functioning metabolism, the different types of cholesterol are regulated by insulin released from the pancreas. However, in persons with a poor diet that results in high blood cholesterol, more insulin is created in order to attempt to regulate this cholesterol in the blood vessels. When too much insulin goes into the blood, the body can become immune to its effects and this is the first stage of type 2 diabetes. (13) Insulin resistance can let cholesterol levels get out of control. Cholesterol is a fatty substance that is used to bind cells together and to form their outer membranes which are permeable. (14) When the cells of a blood vessel become damaged, then cholesterol is used to repair the damage and make new cells. Therefore, cholesterol has a beneficial function in the body, but too much of it can still be bad for you. Insulin is the main regulator of the cholesterol in the body. Cholesterol is synthesized by the liver from the nutrition that is consumed. Therefore, if blood clots develop in the blood vessels in the brain due to cholesterol, an ischemic stroke can occur.
Obesity and angina – link to stroke
Angina is caused by a reduced blood flow to the heart muscle. (15) Blood is carried to the heart to feed it with oxygen, but if plaque builds up around the various blood vessels in the body less oxygen can get to the heart and this causes heart palpitations or angina. (16) If the blood is not traveling around the body fast enough, then the brain can become starved of oxygen and this can lead to stroke or brain damage. Again, angina and heart disease are linked to obesity through excess body-fat and cholesterol levels in the blood vessels.
Obesity, hypertension, diabetes and cardiovascular disease
The four conditions are highly interrelated. According to the Framingham experiment, a direct link can be observed between higher BMI levels and cardiovascular diseases such as angina, atherosclerosis and stroke. (17)
Hypertension, or high blood-pressure, is also a significant risk factor in strokes. (18) High blood pressure, especially when blood is in the brain, can cause blood vessels to burst and cause a hemorrhagic stroke. (19) Of course, genetic factors may come into play in this situation as well, because of blood vessels which are not strong enough. But generally, being overweight or obese with high cholesterol and triglycerides in the bloodstream does not help the situation either and can make things worse as the blood volume is greater in already weak blood vessels. (20)
Problems with insulin can lead to type 2 diabetes. (21) When the body becomes desensitized to the effects of insulin, triglyceride and cholesterol levels go out of control and diabetes can develop. Diabetes is a life-threatening condition. People with diabetes also have a greater chance of developing both ischemic and hemorrhagic stroke if they do not monitor their diet and live a lifestyle that is conducive to good health.
Treatment of stroke and obesity
Obese people need to consider losing weight in a frontline defense against stroke and atherosclerosis. Losing weight reduces the amount of excess body-fat in the body, which balances out insulin levels. Furthermore, balancing the amount of cholesterol in the body becomes easier for the insulin as it can now travel more efficiently around the body to regulate triglycerides. Triglycerides can also be lessened by eating less foods that are converted into sugar (carbohydrates and sucrose). When there are less triglycerides in the bloodstream, insulin can work on regulating cholesterol instead. Losing weight and eating a balanced, healthy diet can be the frontline preventative defense against strokes.
Regular exercise also promotes blood to move more efficiently, getting insulin, cholesterol and white blood cells to the right places to repair any arterial damage that has been caused by the buildup of plaque through atherosclerosis.