Alcohol and stroke
If you drink alcohol you have probably wondered whether it is doing you any long term harm. This factsheet describes the link between drinking alcohol and stroke and explains how "binge" drinking puts men and women at an increased risk of stroke. It outlines ways you can become aware of, and cut down on, the amount you drink. Limiting your drinking really can reduce the likelihood of having a stroke.Studies have consistently shown that a little wine or beer each day can protect against heart disease. However, the evidence is less clear about alcohol and stroke.
The initial research on the health benefits of alcohol came from studies published in the mid-1990s. This showed that people who drank moderate amounts of alcohol – one or two units per day – had a lower risk of dying from heart disease than those who drank heavily or didn’t drink at all. Drinking 10 or more units a day clearly increased an individual’s risk of heart disease. At first it seemed to be red wine that was protective, but it slowly became clear that small amounts of all types of alcohol appear to be good for the heart. The benefits of small amounts of alcohol against heart disease have only been demonstrated in men who are over 40 and women after the menopause, but it is generally thought that a unit or two a day probably protects adults of all ages.
Effect on stroke
The picture is more complicated with stroke. Nearly nine out of 10 strokes are ischaemic – caused by blood clots blocking arteries. As with heart attacks, small amounts of alcohol seem to help protect against this type of stroke.The remaining percentage of strokes are haemorrhagic – bleeding caused by burst blood vessels in or around the brain. Alcohol does not protect against haemorrhagic strokes and even relatively small amounts of alcohol – two or three units per day – can double or treble the risk of having a haemorrhagic stroke.
Recent research has also shown that heavy drinking increases the risk of all types of stroke. A large Scottish study, which followed nearly 6,000 men over a period of 20 years, found that those who drank five or more units per day were twice as likely to die from a stroke compared with those who didn’t drink.
How alcohol works
Alcohol is known to thin the blood and thus may reduce the risk of clots forming in blood vessels – the cause of ischaemic strokes. However, this blood thinning action may have an adverse effect on people at risk of haemorrhagic strokes and increase the chances of a bleed.Alcohol may also affect the way that cholesterol is carried in the bloodstream, reducing the risk of fatty deposits building up in blood vessel walls. This may also reduce the risk of ischaemic strokes. In larger amounts, however, alcohol increases blood pressure, the main risk factor for stroke. It also leads to a rise in homocysteine levels read more
