The theory that a small amount of alcohol might have been good for you may have finally been debunked. Previous studies have found that people who drink in moderation may be less likely to die early than those who stay away from booze altogether, and that men who drink four to seven units of alcohol per week may be more fertile.
Also, one or two drinks a day has previously been associated with a lower risk of stroke and heart attacks, but it was never clear whether the alcohol itself was improving the health or that non-drinkers had cardiovascular problems.
A major new study from the University of Oxford, published in The Lancet, found that the more we drink, the higher our blood pressure and the risk of stroke.
Researchers collaborated with teams at the Beijing University and the Chinese Academy of Medical Sciences, and analyzed results from 500,000 men and women in China. East Asia was chosen because there is a common genetic intolerance of alcohol in these populations, where people experience a red, flushed face because they lack an enzyme that breaks acetaldehyde.
As the effects are obvious and not related to other risk factors such as lifestyle and smoking, genetic variants could be used to study the causal effects of alcohol intake, researchers said.
Read more : There was no safe amount of alcohol, according to a new global report
The subjects were followed for 1
Those with reduced alcohol intake also had a low blood pressure and a reduced risk of a stroke. Overall, the researchers found that the risk of having an insult increases by 35% with every four alcoholic drinks per day, and there was no benefit to the health of moderate drinking.
"There is no protective effect of moderate alcohol intake against stroke. Even moderate alcohol consumption increases the chances of having a stroke," said Professor Zhengming Chen, co-author of the study. "The findings for a heart attack were less clear-cut, so we plan to collect more evidence."
The female participants in the study gained less than men, with just 2% drinking most weeks. This meant the researchers considered them a control group to help confirm that increased risk of an insult in men was caused by alcohol.
According to the results, alcohol could be the cause for 8% of all strokes from a blood clot and 16% of all strokes from brain bleeding in China.
The researchers expect the results to be applicable to other populations, including those without genetic intolerance to alcohol. This could be vital information for people in Europe, who have the highest alcohol consumption per person in the world.
"Stroke is a major cause of death and disability," said Professor Liming Li, another co-author from Peking University. "This large collaborative study has shown that stroke rates are increased by alcohol. This should help to inform individual choices and public health strategies."
This is not the first study to show how drinking alcohol, even casually, can have a huge negative impact on health. For example, last year's study found that drinking just one extra glass of wine or pint of beer over the recommended weekly limit could reduce your expectancy by 30 minutes.
A study published in 2017 found that even a moderate amount of alcohol is associated with changes in brain structure, leading to worsening brain function. And last August, a global study also published in the Lancet, found that no amount of alcohol is safe, and risks far outweigh any benefits.
"The policy of focusing on reducing alcohol consumption to the lowest levels will be important to improve health," said lead author Max Griswold of the University of Washington at the time.
"The widely viewed view of the health benefits of alcohol needs to be revised, especially as improved methods and analyzes continue to highlight how much alcohol contributes to global death and disability."