

Stroke is the umbrella term for a clot or bleed in the brain and the condition is the nation's third biggest killer, and the leading cause of severe disability, affecting around 150,000 Britons a year - which equates to one person every five minutes.

While the majority of those affected are older, a quarter are under 65 - like the 53-year-old BBC broadcaster Andrew Marr, who is currently recovering from a stroke he suffered in January. Marr was fit and a keen runner, proving there's no cast-iron guarantee of avoiding the condition.

However, a healthy lifestyle certainly goes a long way towards reducing the risk of suffering a stroke. And that's not all - a new Swedish study suggests that drinking at least four daily cups of black tea is associated with a reduction in stroke risk of more than a fifth.

Over the past few years the Swedish researchers, from the Karolinska Institute in Stockholm, have also found that drinking two or more coffees a day is associated with up to a 17% reduction in stroke risk, and eating a moderate amount of chocolate a week (slightly more than one bar) could be linked with men having a 17% reduction in their stroke risk.

The research team, which carried out a population study involving nearly 75,000 men and women, believes the effect may be connected to compounds called flavonoids in tea, coffee and chocolate. Flavonoids, which are found in higher concentrations in fruit and vegetables, are thought to have antioxidant, anti-clotting and anti-inflammatory properties.

Dr Susanna Larsson, lead author of the Swedish studies, says: "We've found that consumption of flavonoid-rich foods, including chocolate, tea, fruits (especially apples or pears) and vegetables is associated with a reduced risk of stroke.

"Furthermore, we've observed an association between fish consumption and reduced stroke risk, and an association with increased stroke risk for the consumption of red and processed meat."

But Dr Clare Walton, research communications officer at the Stroke Association, says the Swedish study is "fairly weak", although she thinks there is a link between tea and reduced stroke risk as there has been previous "stronger" research.

"The link between these foods and drinks is antioxidants, and of course you can get the highest intake of antioxidants from fruit and vegetables. They have a much greater link to reducing stroke risk than things like chocolate and tea," she points out.

Stroke consultant Dr Ajay Bhalla, from Guy's and St Thomas' and King's College Hospitals, London, stresses that the studies only show an association, not cause and effect.

"You can only speculate on the cause - they don't tell us that we should be drinking at least four cups of tea a day or gorging on chocolate - that's the wrong message."

What is a stroke?

Strokes, often referred to as 'brain attacks', occur when the brain is starved. This happens because there's either a blood clot (ischaemic stroke) or bleed (haemorrhagic stroke) in the brain.

The Stroke Association says around 80% of all strokes are caused by clots, often linked to a build-up of fat in the arteries which can lead to clots travelling to the brain.

However, in younger people, around half are caused by bleeds, as there has been less time for fatty deposits to build up.

Bleeds can be caused by high blood pressure, or malformations in blood vessels in the brain which may have been present since birth. A weak point in the vessel may burst if there's a surge in blood pressure.

"Haemorrhagic strokes are almost always more severe," explains Walton, "and about 50% of them are fatal."

Risk factors Anyone of any age can have a stroke - even children. While most occur in the elderly, every year more than 20,000 Britons under 65 have a stroke.

Although men have a higher risk, women are one and a half times as likely to die from the condition.

Risk factors include genes, age, diet, the amount of alcohol you drink, smoking, lack of fitness, and some other medical conditions.

High blood pressure contributes to 50% of strokes, and the Stroke Association recommends that people have their blood pressure checked regularly.

Eating a healthy diet, including plenty of fruit and vegetables, and reducing saturated fat and salt intake (salt is a major factor in high blood pressure), will also help reduce stroke risk.

Obesity is another major factor, and diabetes, which can be linked to being overweight, may also lead to a higher risk.

An irregular heartbeat (atrial fibrillation) can lead to blood clots forming in the heart and travelling to the brain. People with atrial fibrillation are five times more likely to have a stroke, but medication can treat the condition.

Dr Bhalla stresses: "Risk factors are applicable to young and old, but their influence is less strong in a younger person."

Sudden onset Stroke symptoms occur very suddenly, and vary widely depending on where in the brain the clot or bleed is, and its severity.

A person may become numb, weak or paralysed on one side of the body, or they may slur their speech and find it difficult to find words or understand speech.

Some lose their sight or have blurred vision, and others become confused or unsteady.

Certain types of stroke are more common, explains Walton, as they occur in the two middle cerebral arteries which are the main arteries to the brain.

"Most strokes happen because those arteries get blocked by a blood clot," she says, pointing out that such strokes are why the Stroke Association publicises the FAST message, which describes common symptoms.

"Most strokes have either facial weakness, arm weakness down one side, and problems with speech, because the two middle cerebral arteries feed those areas of the brain," she says.

"If different blood vessels get blocked, you'll get slightly different symptoms."

Think fast The Stroke Association recommends people familiarise themselves with the FAST Test for common stroke symptoms. If a person fails any one of the tests, get emergency help immediately.

:: Facial weakness: Can the person smile? Has their mouth or eye drooped?

:: Arm weakness: Can the person raise both arms?

:: Speech problems: Can the person speak clearly and understand what you say?

:: Time to call 999.

Recovery The Stroke Association says around one in five people who have a stroke die within 60 days. A third make a significant recovery within a month, but most stroke survivors will have long-term problems and it may take a year or longer for them to make the best possible recovery.

Speed of treatment is essential, and Walton stresses that if a patient gets to hospital within three hours of the sudden onset of symptoms, they're much more likely to make a good recovery, as it's within those first hours that anti-clotting medication is effective.

Dr Bhalla says the prognosis after a stroke is driven by a number of factors including age, the size and type of stroke, its location, speed of treatment and quality of rehabilitation.

"The patients that do really well are those that get to hospital very quickly, get to a specialised unit and have good rehabilitation and support long-term," he says.

:: For more information about strokes, visit www.stroke.org.uk, or call the Stroke Association on 0303 3033 100