Just one large glass of wine a day can boost stroke risk for middle-aged by 33pc
Middle-aged drinkers who have just one large glass of wine a day increase their risk of stroke by a third, a study has suggested.
The study, which tracked more than 11,000 twins over 43 years, found that otherwise healthy people who drank at such levels had a higher risk of stroke than others with conditions such as diabetes and high blood pressure.
The results, published in the journal 'Stroke', showed drinkers in their 50s and 60s who had at least two alcoholic drinks a day - or one large glass of wine, or pint of strong lager - had a 34pc greater risk of stroke than those who consumed just under half the amount.
Under the current guidelines, it's recommended men should not regularly drink more than three or four units of alcohol a day, while for women it is two to three units a day.
A large glass of wine served in pubs is 250ml, or one third of a bottle.
With an alcohol content of 12pc, it is equivalent to three units of alcohol. Previous studies have shown that alcohol affects stroke risk - but this is the first to properly pinpoint differences with age.
The findings show that blood pressure and diabetes appear to take over as one of the main influences on having a stroke at around the age of 75.
However, Pavla Kadlecova, of St Anne's University Hospital in the Czech Republic, said: "We now have a clearer picture about these risk factors, how they change with age and how the influence of drinking alcohol shifts as we get older.
"For middle-aged adults, avoiding more than two drinks a day could be a way to prevent stroke in later productive age."
Researchers looked at results from the Swedish Twin Registry of same-sex twins who answered questionnaires in 1967-70, all of whom were under the age of 60 at the time.
Among identical pairs, siblings who had a stroke drank more than their siblings who had not had a stroke, suggesting that mid-life drinking raises stroke risks regardless of genetics and lifestyle.
Dr Shamim Quadir, research communications manager at the Stroke Association, said: "Alcohol is one of the world's leading causes of ill-health, and regularly drinking large amounts can significantly increase your risk of a stroke.
"Enjoying alcohol in moderation, taking regular exercise and eating a balanced diet are simple ways to reduce your stroke risk."
Last week a separate study by Harvard University in the US suggested that a small glass of wine a day could reduce the risk of heart failure by 20pc.
Experts said both studies suggest small quantities of alcohol could have a protective effect on the heart, but that larger amounts were risky.
(© Daily Telegraph, London)