Does one drink a day increase the risk of stroke?

Does drinking alcohol increases the chance of a stroke

Does drinking alcohol increases the chance of a stroke

“Young adults who have just one drink a day could raise their risk of stroke by a fifth,” says a recent newspaper report. We look behind the headlines to give our verdict on the research.

Published 7 November 2022

Young adults who reported moderate or heavy drinking over time had a higher risk of haemorrhagic stroke than their peers who drank little during the same period, according to a recent study published in the journal Neurology.

Previous studies have shown that drinking alcohol can increase the risk of a stroke. But those studies haven’t given clear results on how this risk changes over time and how it affects younger adults.

What does this research tell us?

The research team in this study looked at the relationship between regularly drinking above the recommended alcohol limits and the risk of stroke in people aged 20-39. The researchers used the Korean National Health Insurance Database, which included information on whether the participants had a stroke, based on hospital records between 2009 and 2012.

The participants were asked about the number of days they drank alcohol per week and the number of drinks they had per session. They were assigned a score of one point for every year where they reported drinking more than 105g of alcohol per week on average. This equates to nearly 19 units of alcohol, e.g. eight pints of medium strength beer (4% alcohol), eight standard glasses of wine, or 19 single measures of spirits. (In the UK, it’s recommended that adults don’t regularly exceed 14 units per week.)

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The study adjusted for the participants’ age, sex, and income, as well as for factors associated with stroke, such as a history of heart and circulatory disease, high blood pressure, and diabetes, among others. The study included responses from more than 1.5 million participants. Men made up nearly three-quarters of the sample. Over 3,000 people had a stroke during the six-year study period. Among them, 1,773 people had an ischaemic stroke (the most common type, caused by a blockage cutting off the blood supply to the brain), and 1,535 people had a haemorrhagic stroke (caused by bleeding in or around the brain).

Moderate and heavy drinkers had a 19-23 per cent higher overall risk of stroke, compared to the participants that drank little. Alcohol appeared to increase the risk of haemorrhagic stroke more than ischaemic stroke. The risk of stroke increased over time in the participants that continued to drink.

The BHF verdict

This research suggests a link between moderate to heavy drinking and the risk of stroke in young adults. These findings are in line with previous studies that linked alcohol consumption to poor health outcomes. It is important to remember that this research shows a link and does not prove a cause -and -effect. Based on this research, we cannot say for certain that everybody drinking approximately 19 units of alcohol in a week over several years will have an increased risk of stroke. But it does add to a growing list of studies suggesting that drinking alcohol may lead to poor health outcomes, even in young adults.

More research is needed to understand how regular drinking may lead to a stroke and what other factors are involved.

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Generally, stroke risk rises as you get older, so the 20-39 age group which this study looked at are at a relatively low risk of stroke.

It is important to think about how much alcohol you drink, no matter how old you are.

Alcohol can raise your blood pressure and contribute to weight gain, increasing the risk of a stroke and heart attack, as well as that of type 2 diabetes. The recommended maximum weekly alcohol consumption limit in the UK is 14 units, spread evenly over three days or more.

How good was the research?

This study had some strengths, such as using a large sample, which means the findings are more reliable than those from smaller samples. It was based on information collected during annual health checks across the country, which means it represented people from different regions and backgrounds. It also used a database of insurance claims submitted by hospitals, which is a strong measure of stroke. The researchers made allowances for other factors known to increase the risk of stroke, such as age, sex, income, and high blood pressure, helping to separate the effects of alcohol intake.

This study also had some weaknesses. It was only based on young adults in Korea which means the findings may not apply to people from other countries, or other age groups. The amount of alcohol consumed was reported by the participants. People tend to forget how much they drink, so these estimates may be lower or higher than real volumes. The study only included people who’d had four consecutive health checks, so this group may not be completely representative. Finally, the study didn’t show strong effects for women, after adjusting for alcohol consumption limits. The study authors pointed out that the study sample included fewer women than men, and that the women experienced fewer strokes than men. More studies are needed to address these limitations and understand these effects in women.

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How good was the media coverage?

The study was picked up by The Daily Mail. Although the reporting was mostly accurate, the headline (“Just ONE wine or beer a day can raise your risk of a stroke by a FIFTH”) might leave readers to believe that any individual drink consumed in a day may result in this increase in risk, whereas the study looks at the effects of moderate to heavy drinking over several years. The Mail headline also gives the impression that nearly 19 units a week is low to moderate drinking, when in fact it is above the limits recommended in national guidelines.

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