Stroke and Nutrition

What is a Stroke?

A stroke is a condition that involves the blood supply to part of the brain being lost. There are three types of strokes:

• ischaemic, whereby the blood supply to part of the brain is cut off due to a blockage – this is typically a blood clot
• haemorrhagic, whereby the blood supply is lost due to bleeding around the brain, potentially caused by the rupture (bursting) of a blood vessel
• transient ischaemic attacks, known as mini-strokes, which are caused by temporary blockages, like fat

A stroke is considered a medical emergency because it can cause cells in the affected parts of the brain to die. Depending on where the stroke occurs and how severe it is, this can result in a loss of certain abilities, such as speech or movement, or, in the worst cases, death. Understanding the symptoms of a stroke is crucial to preserving function and ensuring that the person who is suffering a stroke is treated as quickly as possible to make the fullest possible recovery.

What are the symptoms of a stroke?

There are several symptoms to look out for to assess if somebody is having a stroke:¹

• face: this refers to droopiness on one side of the face, which may cause the sufferer to be unable to smile
• arms: this refers to the sufferer being unable to lift one of their arms, due to weakness or paralysis of the arm
• speech: this refers to the sufferer slurring their speech, being unable to understand what is said or being unable to respond

If these symptoms are observed in a person (especially in a person who is known to be at risk of suffering a stroke), it is best to call for an ambulance as this may be indicative of a stroke.

There may also be some additional symptoms, however these are less specific to a stroke:

• dizziness
• confusion
• problems with balance or co-ordination
• a very painful headache

Can food cause a stroke?

There are no foods that are directly linked to causing a stroke, however, having an unhealthy diet can increase the risk of having a stroke. Maintaining a healthy diet by consuming protein, getting enough fibre, and having the right balance of vitamins and minerals can be an important factor in decreasing stroke risk.

Which foods increase the risk of a stroke?

There are some food groups that are linked to an increased risk of stroke. These are:

• fats, particularly saturated fats – saturated fats can increase the amount of LDL (the ‘bad’ fat) in the body, and this can build up in the arteries, which increases the risk of a blockage occurring²
• salt – too much salt causes water to move into the blood, raising the blood pressure which can result in stroke
• consistently high sugar levels, which can cause damage to the blood vessels, increasing the chance of blockages and ruptures³
• processed foods, which have an increased amount of fats, salts, and sugars, which all increase the risk of stroke⁴

What nutrients help reduce the risk of a stroke?

A higher intake of fibre, fruits and vegetables, protein and vitamins and minerals can decrease the risk of a stroke. This is because these all provide the body with nutrients that decrease the risk of a stroke, or at least a severe one. There are some nutrients that have been found to be linked to preventing stroke or lowering the severity of one:

• antioxidants
• vitamins A, B, C and E
• calcium
• potassium

Antioxidants

Antioxidants are compounds that occur naturally. Their main purpose in the body is to neutralise harmful compounds that are produced because of normal processes, like metabolism, or because of abnormal processes, like cell death caused by stroke.

Antioxidants can prevent inflammation, which is one of the contributing factors to how severe a stroke will be. They also tackle oxidative stress, which is when there is a build-up of the harmful compounds caused by cell death. As a result, it has been observed that consumption of more antioxidants can result in a decreased risk of stroke.⁵

Vitamin A

Whilst it has not been directly associated to preventing stroke, vitamin A has antioxidant properties⁶ which, as previously mentioned, are important in decreasing the amount of damage that a stroke causes.

Vitamin B 

Vitamin B plays an important role in the body as it can decrease the amount of homocysteine in the blood.⁷

Homocysteine is an amino acid that is similar to another amino acid called cysteine. Whilst cysteine is used throughout the body in a variety of processes, homocysteine is often associated with an increased risk of cardiovascular issues, including blood clots (which can block arteries leading to strokes or heart attacks).^{8, 9}

Vitamin B can decrease the amount of homocysteine in the blood by helping to convert it to the more useful cysteine, thus ensuring a healthy intake of vitamin B can help prevent stroke.

Vitamin C

Vitamin C is important in helping to recycle antioxidants. Additionally, it may also help to neutralise the harmful compounds that can cause cellular damage.¹⁰ High blood pressure can increase the risk of having a stroke, but vitamin C is associated with decreasing blood pressure.¹⁰

Vitamin E

Vitamin E is another antioxidant; thus it neutralises harmful compounds. However, vitamin E also contributes to reduction of two other compounds in the body, prostaglandins and thromboxane. These cause blood clots and vitamin E can help lower the chances of this occurring.¹¹

Calcium

It is thought that calcium obtained through dairy products is able to decrease stroke risk by up to 22% in some subsections of the population.¹² This is because it may lower cholesterol and blood pressure and regulate insulin.

Potassium

Potassium helps to regulate blood pressure by maintaining water and electrolyte levels,¹⁰ which can help reduce the risk of a stroke.

When to contact a doctor

If you are at an increased risk of stroke due to diabetes, high blood pressure, high cholesterol or obesity, it is a good idea to contact your doctor to discuss ways to decrease your risk.

It is also important to contact emergency services if you believe somebody is having a stroke.

Conclusion

Strokes are life-threatening. However, understanding what symptoms to look out for and how we can take steps in our day-to-day life to decrease our risk will, hopefully, decrease the number of deaths caused by stroke.