Cognitive health: Stroke

Of all the problems that can affect the brain, stroke is probably the one most of us will have heard of or know something about. It is, after all, the largest cause of disability in the UK and the third most common cause of death after heart disease and cancer. In fact every year 120,000 people in the UK have a first stroke and around 30,000 people have a stroke that isn’t their first (i).

Age is a major factor in how likely you are to have stroke, with most cases affecting people aged 65 or older. Indeed every year around one in 100 people over the age of 75 has a stroke (i). But it isn’t just a problem that affects the elderly. You can have a stroke at any age, and according to the Stroke Association more than 400 strokes a year in the UK happen in children and even babies (ii).

A stroke is when the blood supply to part of the brain is suddenly cut off, damaging the brain in the process. Brain cells need a constant supply of blood delivered via the right and left carotid and vertebrobasilar arteries and the smaller arteries that branch off them. But when that blood supply is cut off and the cells don’t get the oxygen they need, the affected cells can become damaged or die.

This can cause a range of complications or after-effects – including problems with your speech, movement or thinking – depending on the particular blood vessel and part of the brain that have been affected.

What are the 3 types of strokes

There are two main types of stroke plus a related condition you may know of as a mini-stroke. The two main types are:

Ischaemic stroke

This is usually caused by a blood clot blocking the flow of blood in the brain. According to the National Institute of Health and Care Excellence (NICE), approximately 85 per cent of strokes are ischaemic strokes (iii).

Often the blood clot forms within an artery in the brain, typically in an area where there’s a patch of fatty substances called atheroma or plaques (this process, known as atherosclerosis, is also sometimes referred to as furring or hardening of the arteries). Atherosclerosis can make most people’s arteries become narrower as they get older. However, if a patch of atheroma becomes particularly big or thick, it can cause a clot. According to the NHS, some of the things that can speed up this process include (iv):

• Smoking

• Diabetes

• High Blood Pressure

• High Cholesterol

• Obesity

• Drinking too much alcohol

Sometimes, however, a blood clot that forms in another part of the body can travel to the brain via the blood stream. For instance, a condition called atrial fibrillation – which is a type of irregular and often very fast heart rate – can cause blood clots to form in the heart. Clots like these can then find their way into the brain, where they can get stuck and block an artery.

Other causes of ischaemic stroke include small vessel disease, where tiny blood vessels deep within the brain become damaged. Another is a condition that tends to happen in younger people, sometimes caused by an injury to the neck, called arterial dissection (this is when the lining of an artery becomes damaged and blood leaks between the layers of the artery walls).

Haemorrhagic stroke

Around 15 per cent of strokes are haemorrhagic strokes (iii). A haemorrhagic stroke – also sometimes called a brain haemorrhage – is caused by a bleed in or around the brain when a damaged or weakened artery bursts. The most common is a primary haemorrhage (or intercranial haemorrhage), which causes around 10 per cent of strokes (iii). This is when an artery busts inside the brain, which makes the blood spill into the surrounding brain tissue and stops cells in that area getting their oxygen supply.

The other main type of haemorrhagic stroke is a subarachnoid haemorrhage, which happens when an artery bursts in the narrow space between the brain and the skull (this is called the subarachnoid space). According to NICE around five per cent of strokes are caused by a subarachnoid haemorrhage (iii).

The main cause of a haemorrhagic stroke is High Blood Pressure, which can weaken the arteries in the brain and make them more susceptible to bursting. Other causes can include brain aneurysms (where a blood vessel expands like a balloon) and abnormal blood vessels in the brain.

According to NICE, a haemorrhagic stroke is 35 - 40 per cent more likely to be fatal than an ischaemic stroke (v).

Mini-strokes

The medical name for a mini-stroke is a transient ischaemic attack or TIA. According to NICE, each year 50 out of 100,000 people in the UK have their first mini-stroke (vi). The difference between a mini-stroke and a full stroke is that the symptoms – which are similar in both – are far more temporary in a mini-stroke and tend to last between a few minutes and a few hours (or anything less than 24 hours).

Most mini-strokes are caused by a tiny blood clot getting stuck in an artery in the brain, but the blood clot either breaks up quickly or the blood supply is re-routed through other blood vessels nearby, which means the brain is only starved of oxygen for a few minutes and soon recovers.

While this may not seem like an emergency, it’s still important to see a doctor or call an ambulance straight away if you think you’ve had a mini-stroke. That’s because people who have mini-strokes have a higher-than-normal risk of having a stroke in the near future. Indeed according to the NHS, a mini-stroke should never be ignored as it’s a serious warning of a problem with the blood supply to your brain (vii).

What are the complications from a stroke?

A stroke can be deadly: according to NICE, seven per cent of all deaths in the UK are caused by stroke – though it’s reassuring to know the number of people dying of a stroke decreased by 46 per cent between 1990 and 2010 (v). For those who survive it, however, stroke can cause a range of complications that vary from one person to the next. How it affects each individual depends on which part of their brain has been damaged. Some people may not be affected significantly or in the long term, but others will be left with more severe and long-lasting problems, such as:

• Speech, language and communication difficulties

• Muscle weakness, sometimes on one side of the body (hemiparesis)

• Balance and co-ordination problems

• Vision difficulties

• Pain (often from muscle weakness or stiffness, for example)

• Changes in sensation (such as reduced sensitivity to touch, pins and needles, reduced sensitivity to temperature)

• Cognitive problems (such as difficulties with memory, learning, concentration etc)

• Emotional problems (for instance crying or laughing for no reason, or getting annoyed really quickly)

• Fatigue

• Swallowing problems (if you can’t swallow after having a stroke, you may have to be fed through a tube)

Some of the less common effects of stroke include hallucinations – which is when you see something that isn’t there – and delusions, which can be described as strong beliefs about something that aren’t true.

If you’ve had a stroke you also have a higher risk of developing vascular dementia. According to the Alzheimer’s Association, an estimated one in five people who has a stroke develops post-stroke dementia within six months (viii).

What are the signs of a stroke?

The sooner someone gets treatment after having a stroke, the less their brain will become damaged. This is why it’s important to know what to look out for should you or someone else have a stroke. If you suspect you are having a stroke, call 999 straight away and ask for an ambulance, even if you start to feel better. This will help get you the treatment you need as soon as possible.

Most of us will have seen the adverts on TV that raise awareness of the signs and symptoms of a stroke, but it’s worth taking another look at them. The main symptoms can be remembered through the word FAST:

• F is for face: someone who is having or just had a stroke may not be able to smile, their face may have dropped on one side or their mouth or eye on one side may be dropping.

• A is for arms: can they lift both arms and keep them there? If one arm is too weak or numb to be lifted, it could be a sign of a stroke.

• S is for speech: people who are having or just had a stroke may find their speech is slurred or garbled, or they may not be able to talk at all. It’s also common for someone having or who’s just had a stroke to be confused about what someone else is saying to them.

• T is for time: that is, it’s time to call 999 if you notice any of these signs or symptoms in anyone, particularly someone who’s in a high-risk group for stroke such as an elderly person or someone with diabetes or high blood pressure.

Sometimes a stroke can also cause other symptoms while it’s happening – though these can sometimes be a result of other things – such as:

• Completely paralysis of one side of the body

• Swallowing difficulties

• Sudden loss of vision or blurred vision

• Confusion and difficulty understanding what other people are saying

• Dizziness and/or problems with balance and co-ordination

• Sudden and very severe headache

• Loss of consciousness

If you experience any of these symptoms, and even if the symptoms don’t last, it’s important to go to a hospital for an assessment. After your initial assessment you should be referred to a specialist within 24 hours of the start of your symptoms. Meanwhile if you think you may have previously had a mini-stroke but you didn’t get any medical advice at the time, see your GP as soon as possible, even if you feel completely better.

Stroke treatments

How a stroke is treated will depend on whether it was caused by a clot (ie an ischaemic stroke) or bleeding in or around the brain (haemorrhagic). Most people are treated with medication, but sometimes surgery may also be necessary.

Ischaemic stroke treatments

The main aim of medicines used to treat ischaemic strokes is to prevent another stroke from happening. These medicines include drugs that dissolve blood clots, improve blood flow and prevent new clots from forming. They include:

• Alteplase injections: this clot-dissolving medicine is best when given within a few hours of having a stroke (it’s not usually recommended if more than four and a half hours have passed).

• Aspirin: best known for its painkilling capabilities, aspirin also helps reduce the risk of another blood clot forming. In this capacity, it is known as an antiplatelet medicine. Other types of antiplatelet medicines may also be used.

• Warfarin and other anticoagulants: these are drugs that prevent clots from forming by changing the chemical composition of the blood.

Other medicines may also be used too, including blood pressure medicines if you’ve been found to have high blood pressure, and statins to reduce cholesterol if the level of cholesterol in your blood is too high.

Meanwhile surgical procedures used to treat an ischaemic stroke include a thrombectomy, which removes blood clots from the brain, and a carotid endarterectomy, which unblocks arteries that have become too narrow (this may help prevent a further ischaemic stroke).

Haemorrhagic stroke treatments

There are fewer medicines available to treat haemorrhagic strokes. If you’ve been found to have high blood pressure or high cholesterol you may be given medicines to lower them. Meanwhile if you were taking any beforehand you may have to stop taking some medicines – anticoagulants, for instance – and you could be given treatment to reverse their effects, as this may reduce the risk of any more bleeding.

An operation to fix any leaking arteries may be an option if you’ve had a stroke caused by a subarachnoid haemorrhage. Emergency surgery can also be performed to remove blood from the brain and repair burst blood vessels.

These, and other, treatments can help you recover. However while some people get back on their feet again fairly quickly, others need a long period of rehabilitation before they regain as much independence as they can.

Indeed, recovering from a stroke for many can involve getting help from a number of health specialists, including specialist nurses and doctors, physiotherapists, occupational therapists, dietitians, psychologists and speech and language therapists – all of whom are on hand to help you achieve the best quality of life as possible after your stroke.

What increases your risk of a stroke?

While anyone can have a stroke at any age, there are certain things that can make it more likely to happen to you. Some of the things you can’t do much about include:

• Your age (people aged 55 and older are more likely to have a stroke than those who are younger, though strokes can strike younger people too (iv)).

• Your gender (men are more likely than women to have a stroke at a younger age (ix)).

• Your family history (if one of your close relatives had a stroke, your risk could be higher too).

• Your ethnic background (people originating from south Asia, Africa or the Caribbean have a higher risk).

• Your health history (if you’ve already had a stroke, mini-stroke or heart attack, your risk is higher).

How to reduce risk of a stroke?

The good news, however, is there are risk factors you can improve, including:

• Smoking: giving up can reduce your risk of having a stroke significantly.

• Weight: if you’re overweight or obese losing some of those excess pounds is advisable.

• Medical conditions: some conditions such as high blood pressure, high cholesterol, diabetes and atrial fibrillation are linked to an increased risk of stroke, but managing them and keeping them under control with the help of your doctor may help reduce that risk.

• Drinking: consuming too much alcohol can lead to high blood pressure and atrial fibrillation, both of which are linked to a higher risk of stroke. Try to stick to the recommended guidelines for safe drinking, which include having no more than 14 units of alcohol each week while spreading your drinking over three days or more if you regularly drink that much.

Having as healthy a lifestyle as possible is arguably one of the best ways to prevent a stroke, especially as being healthy may help reduce your risk of developing conditions that can lead to a stroke in the first place, such as high blood pressure and diabetes.

This means eating a healthy, balanced diet with at least five portions of a variety of fruit and vegetables every day and a limited amount of fatty, processed and salty foods. Keeping moderately physically active is also important – try to aim for 30 minutes of activity every day (or at least on five days out of the week), or 150 minutes a week in total. Walking, cycling, gardening and swimming are ideal ways to stay active, but there are lots of other things you can do – the key is to find something you enjoy and stay as active as you can in general (in other words, try to reduce the amount of time you spend sitting down). Staying active can also help you to reduce your stress levels – which is useful, since feeling stressed all the time has been linked with both stroke and heart attacks (x).

Natural support for stroke prevention

As well as having as healthy a lifestyle as possible, taking certain nutritional supplements may help support your wellbeing and have an impact on some of the risk factors that may lead to strokes. Some of the supplements you could consider include the following:

High-strength fish oils: There’s plenty of evidence that fish rich in omega-3 fatty acids may help reduce your risk of stroke as well as heart disease, with studies showing eating fish may help reduce the risk of ischaemic but not haemorrhagic stroke (xi). Researchers don’t always agree, however, and a well-publicised review has suggested there’s little to no effect of omega-3 fats on cardiovascular health, including stroke (xii). Despite these findings, eating fish is considered an important part of a healthy diet, and the NHS recommends eating at least two portions of fish a week, one of which should be oily fish (xiii).

If you don’t like eating fish, however, this is where good-quality, high-strength supplements can come in handy. Even vegetarians and vegans can benefit from healthy omega-3 fatty acids thanks to the latest supplements that source omega-3s from algae, rather than fish.

Vitamin C: Vitamin C – which is found in a wide range of fruit and vegetables – has been linked with a reduced risk for stroke. For instance, studies published in the Journal of the American Heart Association have found having high blood levels of vitamin C might significantly reduce your risk of stroke – one suggests the risk could be up to 70 per cent lower (xiv). Another study suggests low vitamin C levels is linked with an increased risk of stroke, especially in men who are overweight and have high blood pressure (xv). A small-scale study carried out by French researchers has also found having low blood levels of vitamin C could increase your risk for haemorrhagic stroke (xvi).

According to the NHS, good sources of vitamin C include citrus fruit such as oranges, peppers, strawberries, blackcurrants, broccoli, Brussels sprouts and potatoes (xvii). However, while it’s found in many foods, some cooking and storing practices can destroy vitamin C, which explains why many nutrition practitioners recommend taking it in supplement form.

Vitamin K2: There’s little vitamin K2 in typical Western diets, particularly for those who eat a lot of processed foods. But some experts believe this nutrient may help prevent calcium deposits forming in blood vessel walls – called arterial calcification – and prevent arterial stiffening (xviii).

Vitamin K2 is found in foods such as hard and soft cheeses, egg yolks, curd cheeses, chicken and goose liver, but you can also find it in nutritional supplements.

Vitamin D: One of the potential complications of stroke is that your bone mineral density can become weaker – this is called altered calcium homeostasis. Indeed scientists believe this might explain why there’s an increase in fractures in people who’ve had a stroke. Some also believe having a low vitamin D level may be a risk factor for stroke (xix). Others suggest there’s evidence that vitamin D has neuroprotective effects as well as anti-clotting capabilities (xx).

Currently the UK Department of Health suggests that everyone should consider taking a daily vitamin D supplement during the autumn and winter, since it’s difficult to get enough from sunlight at these times of the year and food sources are few and far between. If you don’t go outdoors very often, if you have dark skin or lighter skin that you usually cover up when you do go out, the government even advises that you consider taking a supplement year round (xxi).

The recommended form of vitamin D is vitamin D3 or cholecalciferol, as it’s the natural form of vitamin D your body makes when it’s exposed to sunlight. Vitamin D3 supplements are available in tablet form, and now you can get them in veggie-friendly drops too. However most vitamin D3 supplements are made from the fat of lamb’s wool, which means they’re unsuitable for vegans. The good news is that vegan vitamin D3 supplements sourced from lichen are now more widely available.

L-arginine: This amino acid may help with stroke prevention as it changes into nitric oxide in the body. Nitric oxide helps to relax and widen blood vessels – a process called vasodilation –which may help protect against stroke. One study has even found that taking l-arginine within 30 minutes of having a stroke decreases the frequency and severity of stroke-like episodes (xxii). You can find L-arginine in most foods that are rich in protein, such as fish, red meat, poultry, soya, beans and dairy products. It’s also available in supplement form.

Astaxanthin: A naturally occurring antioxidant sourced from a freshwater algae called Haematococcus pluvialis, astaxanthin is the red pigment in the algae that gives the fish and seafood that eat it their red/pink colour. There is evidence that astaxanthin may be beneficial for brain health (see our article on nutrition for the brain for more details). Experts have also found it may help with cholesterol management (xxiii), which may also be useful, especially if your cholesterol is too high.

Researchers have also studied astaxanthin’s effects on stroke, particularly on protecting against damage to the brain after a stroke. However these studies are animal-based, which means their results may not be replicated in humans.

You can get more astaxanthin in your diet by eating fish and shellfish such as salmon, lobster, red snapper, shrimp, rainbow trout, crawfish and crab. However it’s difficult to get the amount of astaxanthin used in clinical trials through diet alone (studies have used doses from 4 - 16mg of astaxanthin a day, but a serving of wild salmon provides less than 4mg of the compound). Taking a good-quality supplement would help you achieve these therapeutic doses more easily – plus it’s ideal if you don’t like eating fish or seafood.

Coenzyme Q10: This vitamin-like antioxidant substance is produced by the body as well as found in a variety of foods such as liver, kidneys, chicken, red meat, sardines, mackerel, broccoli, asparagus, whole grains, spinach and cauliflower. It’s often recommended for heart health, and an analysis of 12 clinical trials suggests it may help reduce high blood pressure, which is associated with stroke (xxiv).

CoQ10 is widely available in supplement form too. However if you’re interested in CoQ10 for its stroke prevention benefits you may want to consider a formulation that provides CoQ10 combined with omega-3 fatty acids.

Turmeric: The curry spice turmeric contains an active ingredient called curcumin, which may be beneficial for the brain (see our article on nutrition for the brain for more details). Some studies have also found curcumin may help protect against stroke and reduce against the damage a stroke can cause in the brain – however, again, these are all animal-based studies, which means they don’t necessarily apply to humans.

There’s lots more to discover about issues that affect the brain in the cognitive health section of our health library.

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Disclaimer: The information presented by Nature's Best is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. Self-treatment is not recommended for life-threatening conditions that require medical treatment under a doctor's care. For many of the conditions discussed, treatment with prescription or over the counter medication is also available. Consult your doctor, practitioner, and/or pharmacist for any health problem and before using any supplements or before making any changes in prescribed medications.

 

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