A glass of wine a day could protect against a stroke
A large glass of wine a day could protect against the most common type of stroke, new research suggests.
The study of 20,000 adults found that up to three units of alcohol a day appeared to reduce the risk of an ischaemic stroke, where the blood supply is stopped due to a blood clot. These account for 85 per cent of all cases.
The research by the Karolinska Institutet and University of Cambridge found that heavier drinking – of any type of alcohol – increased the risks of all types of strokes.
Light drinking – classed as no more than one and a half units of alcohol per day, or a small glass of wine – was found to reduce the risk of ischaemic stroke by around 10 per cent.
Similar findings were found for moderate consumers, who were drinking up to twice as much.
However drinking more than this significantly increased the risk of all types of strokes, the study found.
And light to moderate alcohol intake did not protect against less common types of strokes – known as intracerebral haemorrhage and subarachnoid haemorrhage.
The study published in the journal BMC involved a systematic review of 25 studies, including data from the Cohort of Swedish Men and the Swedish Mammography Cohort, involving 21,000 stroke victims.
Lead author Associate Professor Dr Susanna Larsson at the Karolinska Institutet said: "Whether light-to-moderate alcohol consumption, generally defined as one to two drinks per day, is protective against cardiovascular disease remains a controversial topic.
"Alcohol consumption in moderation has been associated with increased high-density lipoprotein cholesterol, improved insulin sensitivity, and decreased levels of fibrinogen and inflammatory markers."
However, it also increases blood pressure, which raises stroke risks.
Prof Larsson believed the different associations between alcohol consumption and type of stroke may have to do with the effects alcohol has on the human body.
She explained: "Previous research has found an association between alcohol consumption and lower levels of fibrinogen – a protein in the body which helps the formation of blood clots.
"While this may explain the association between light to moderate alcohol consumption and lower ischaemic stroke risk, the adverse effect of alcohol consumption on blood pressure – a major risk factor for stroke – may increase the risk of haemorrhagic stroke and outweigh any potential benefit."