Blood pressure and stroke risk rise steadily the more alcohol people drink, and previous claims that one or two drinks a day might protect against stroke are likely incorrect, according to the results of a major genetic study.

Oxford University and Chinese researchers used the facts that many Chinese people have genetic variants that make them alcohol intolerant, and that men, but few women, drink alcohol in China, to do a genetic study they say has implications for everyone, regardless of ethnicity.

The research using data from a 160,000-strong cohort of adults from 10 Chinese regions found that people who drink moderately — consuming 10-20 grams of alcohol a day — raise their risk of stroke by 10-15%.

For heavy drinkers, consuming four or more drinks a day, blood pressure rises significantly and the risk of stroke increases by around 35%, the study found.