Even a drink a day increases the risk of stroke, reveals a study

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Even mild-to-moderate consumption raises blood pressure and stroke risk, according to a large genetic study conducted in The Lancet, contradicting earlier claims that one or two glasses a day could have a protective effect.

British and Chinese researchers followed 500,000 Chinese for 10 years.

They say the results are relevant to all populations and are the best evidence to date about the direct effects of alcohol.

Experts said that people should limit their consumption of alcohol.

It's already known that excessive consumption of alcohol harms health and increases the risk of stroke – but some studies suggest that drinking small amounts can be good for one's health, while d & # 39; others indicate that there is no level of safe alcohol consumption.

What did the research find?

Researchers from the University of Oxford, Peking University and the Chinese Academy of Medical Sciences found that:

• one to two drinks a day increased the risk of stroke by 10-15%
• Four glasses a day increased the risk of having a stroke by 35%

For the purposes of their study, a drink was defined as:

• a small glass of wine
• a bottle of beer
• a single measure of wits

About 16 in every 100 men and 20 in every 100 women will have a stroke during their lifetime in the UK.

So if a group of 100 non-drinkers started to have a drink or two each day, there would be two more shots, a slight increase.

According to Professor David Spiegelhalter, of the University of Cambridge, this represents a 38% increase in the risk of total stroke for every half bottle of wine drunk daily.

He said: "The opposite effect of taking a statin is basically the opposite effect", namely medications prescribed by doctors to help lower cholesterol levels in the blood and prevent heart attacks and stroke.

The study also did not highlight any protective effect of mild or moderate alcohol consumption, ie, a reduction in the risk of stroke. cerebral.

The researchers explained that the effects of alcohol on the risk of heart attack were not obvious and that more data needed to be collected over the next few years.

"The claims that wine and beer have magical protective effects are not corroborated," said Professor Richard Peto, author of the study, Oxford University.

• How many cigarettes in a bottle of wine?

Why China?

East Asian countries are useful places to study the effects of alcohol.

Many people of Chinese descent have a combination of genes that prevents them from drinking alcohol. This causes an unpleasant reaction and makes them feel bad.

As a result, the consumption of alcohol varies enormously in China: one in three men do not drink and very few women.

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But by comparing the health effects of drinkers and non-drinkers based on their genetic profile, scientists claim to have been able to evaluate – with much more certainty than before – the direct effects of alcohol on the risk of stroke, regardless of any other factor.

Western populations do not have these genes, so it would be impossible to conduct a similar study here.

Most studies are observational, making it difficult to determine which factor causes which effect.

Dr. Iona Millwood, author of the study and senior epidemiologist at Oxford University, said, "Our genetic analyzes have helped us understand cause-and-effect relationships."

So what does this mean for me?

The researchers say their key message is that it is now clearly established that no protective effect of moderate alcohol on stroke.

This means that drinking small amounts of alcohol each day can increase the chances of a stroke.

This is reflected in the UK's current guidelines, which advocate a limit of 14 units of alcohol a week, with several days without alcohol to limit health risks.

What do the other experts say?

Dr. Stephen Burgess, from Cambridge University, said the study had certain limitations: it only concerned the Chinese population and focused primarily on the consumption of spirits and beer, not wine .

But he said the research reflected the culmination of many years of research on the impact of alcohol consumption.

"This strongly suggests that there is no cardiovascular benefit to drinking light alcohol and that the risk of stroke increases even with a moderate intake of alcohol." 39, light alcohol, "he said.

"The risk of stroke increases in proportion to the amount of alcohol consumed, so if people choose to drink, they should limit their consumption of alcohol."

Professor Kevin McConway, Emeritus Professor of Applied Statistics at the Open University, said the study did not answer all the questions.

"It certainly has advanced what we know about the role of alcohol in some diseases, but it can not be the last word," he said.

"The new study does not say exactly how alcohol increases the risk of stroke, but does not appear to increase the risk of myocardial infarction."

Professor David Spiegelhalter, Winton professor at the University of Cambridge for the public's understanding of risk, said the study was swaying him.

"I've always been reasonably confident that a moderate consumption of alcohol was protecting cardiovascular disease, but now I have some doubts," he said.