Having just one or two alcoholic drinks a night significantly increases the risk of suffering a stroke in later life, a major study has shown.
Experts from Oxford University said their study of 500,000 people finally dispels the 'myth' that light drinking protects health.
They found that one or two drinks a day increased the risk of suffering a stroke in the next ten years by 10 to 15 per cent, and four drinks a day by 35 per cent.
For years many experts have argued that consuming alcohol moderately has a protective effect - pointing to studies which showed the odd glass of wine or pint of beer reduced the risk of heart attacks and strokes.
But critics argue those studies were flawed - because they included alcoholics who have become tee-total or people who did not drink because of other health problems.
Experts from Oxford University said their study of 500,000 people finally dispells the 'myth' that light drinking protects health
So the evidence seemed to suggest that light drinkers were at lower risk than those who drank nothing at all.
The new study, published in the Lancet medical journal, got around this problem by using a genetic study of people in China.
A third of people in China carry a genetic quirk that means they cannot tolerate drink.
Their genes mean they do not have the ability to clear away a toxic byproduct of alcohol - causing them to become nauseous and flushed after even a small volume of drink.
The researchers tested the genes of people in ten parts of China - and then tracked their drinking.
Those who did not drink because of their genetic mutation were judged to be a reliable marker of zero alcohol consumption, because they simply could not tolerate the drink.
The other two-thirds of the participants who did not suffer from the same genetic quirk were able to drink freely - and the men on average drank four drinks a day and were at a far higher risk of suffering high blood pressure and strokes.
Beer before wine and you'll feel fine, is how the tactical tippler thinks - but the old adage appears to be a myth.
In a less than surprising revelation, researchers last month found hangovers are just as bad, regardless of what order you drink your drinks.
Scientists gave alcoholic drinks to 90 volunteers in different combinations in a laboratory experiment on two separate nights.
Some were asked to drink two and a half pints of Carlsberg, followed by four large glasses of white wine. A second group started with wine before beer.
Researchers had to control the drunk participants, who were singing and dancing, with a megaphone. They were sent to bed in the lab at 1am.
Participants were asked about their hangover the following day and gave a score on a so-called Acute Hangover Scale.
The findings, led by a team at Cambridge University, indicated that no matter how you order your drinks, if you drink too much you are still likely to be ill.
Dr Kai Hensel, one of the researchers, said: 'The vomiting rate was a little higher than I'd have thought. But they enjoyed it.'
Chinese women drank very little, regardless of their genetic make-up.
But researcher Professor Sir Richard Peto, co-director of the Clinical Trial Service Unit at Oxford University, said he was confident the findings were applicable to British men and women alike.