People in their 20s and 30s who drink moderate to heavy amounts of alcohol may be more likely to suffer a stroke than those who drink low or no amounts, according to new research.

A team from Seoul National University analyzed records from a Korean national database for young adults who had four annual health exams and were asked about their alcohol consumption.

Those who drank 105g or more of alcohol per week were considered moderate or heavy drinkers.

This is the equivalent of nearly six pints of medium-strength beer, eight small glasses of wine or around nine large shots of spirits – roughly one drink a day.

Out of the 1.5 million participants, a total of 3,153 had a stroke during the study period of six years.

Analysis revealed those who were moderate to heavy drinkers for two or more years were around 20 per cent more likely to have a stroke than people who drank less or nothing at all.

As the number of years of moderate to heavy drinking increased, so did the risk of stroke.

People with two years of moderate to heavy drinking had a 19 per cent increased risk, people with three years had a 22 per cent increased risk and people with four years had a 23 per cent increased risk.

The association was mainly due to an increased risk of haemorrhagic stroke – or stroke caused by bleeding in the brain.

These results were after researchers accounted for other factors that could affect the risk of stroke, such as high blood pressure, smoking and body mass index.

The UK charity Stroke report that one in five people who have strokes are now under the age of 55.

Study author Eue-Keun Choi said: ‘The rate of stroke among young adults has been increasing over the last few decades, and stroke in young adults causes death and serious disability.

‘Since more than 90 per cent of the burden of stroke overall can be attributed to potentially modifiable risk factors, including alcohol consumption, and since stroke in young adults severely impacts both the individual and society by limiting their activities during their most productive years, reducing alcohol consumption should be emphasized in young adults with heavy drinking habits as part of any strategy to prevent stroke.’

Writing in the journal Neurology, the researchers said there are several possible mechanisms that could explain the link between alcohol and stroke.

Drinking lots of alcohol can lead hypertension – high blood pressure – which in turn can be a major risk factor for stroke.

Alcohol can also increase the chances of atrial fibrillation, which can cause an irregular heart rate and in turn increase the risk of a stroke.

The researchers said their study was limited by only including Korean people, meaning the risk may not transfer to other races and ethnicities.

Participants also filled out questionnaires and may have forgotten how much alcohol they drank.

In the UK, it is recommended that adults should not regularly drink more than 14 units of alcohol per week.