Bad news for those who enjoy a tipple – just one small glass of alcohol a day may cause an irregular heartbeat, research suggests.
The benefits of moderate alcohol consumption have long been debated, with past studies suggesting an occasional glass of red boosts heart health, while too much can have serious cardiovascular consequences.
To learn more, scientists from the University Heart and Vascular Center in Hamburg analysed the alcohol intake of nearly 108,000 people, who were followed for around 14 years.
Results suggest consuming just one alcoholic drink a day raises the risk of atrial fibrillation by 16%, compared to abstaining altogether.
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Atrial fibrillation is defined as an irregular and often abnormally fast heart rate, an uncomfortable condition that can lead to strokes in severe cases.
Although unclear why alcohol may trigger this, small amounts of wine, beer or spirits have been linked to irregular heartbeat episodes.
“To our knowledge, this is the largest study on alcohol consumption and long-term incidence of atrial fibrillation in the community,” said lead author Professor Renate Schnabel.
“Previous studies have not had enough power to examine this question, although they have been able to show a relationship between alcohol intake and other heart and blood vessel problems, such as heart attack and heart failure.
“In our study, we can now demonstrate even very low regular alcohol consumption may increase the risk of atrial fibrillation.
“These findings are important as the regular consumption of alcohol, the ‘one glass of wine a day’ to protect the heart, as is often recommended for instance in the lay press, should probably no longer be suggested without balancing risks and possible benefits for all heart and blood vessel diseases, including atrial fibrillation.”
Watch: Moderate drinking increases atrial fibrillation risk
The scientists analysed more than 107,800 people who took part in studies in Sweden, Norway, Finland, Denmark and Italy between 1982 and 2010.
Just over 100,000 of the participants, who had an average age of 48, did not have atrial fibrillation at the start of the research.
Over the next 14 years, more than 5,800 developed the condition.
Results – published in the European Heart Journal – suggest consuming one glass of alcohol a day raised the participants’ risk of atrial fibrillation by 16%, irrespective of the type of drink they indulged in.
Having up to two alcoholic drinks a day increased the odds of atrial fibrillation by 28%, rising to 47% for those who consumed more than four, the results imply.
The findings were similar between the male and female participants.
The scientists defined one drink as containing 12g of ethanol, the chemical compound in alcohol. This is equivalent to a small (120ml) glass of wine, small beer (330ml) or 40ml of spirits.
The scientists stressed the participants reported their own alcohol consumption, which may therefore be inaccurate.
While atrial fibrillation often causes palpitations, it can also be asymptomatic, which may go unnoticed.
The scientists also did not take into account the effects of binge drinking.
In an accompanying editorial, a team from McMaster University in Canada said the Hamburg research “makes an important contribution to our understanding of the relationship between alcohol intake and incident AF [atrial fibrillation], in particular at the lower spectrum of alcohol consumption.
“A significant relationship between alcohol and AF was identified, and even small quantities of alcohol were associated with an increased, albeit small, risk of incident AF.
“Together with a recent randomised trial showing a reduction in alcohol intake led to a reduction in AF recurrence, these data suggest that lowering alcohol consumption may be important for both prevention and management of AF.
“Importantly, any reduction in low-to-moderate alcohol consumption to potentially prevent AF needs to be balanced with the potentially beneficial association low amounts of alcohol may have with respect to other cardiovascular outcomes.
“The net clinical benefit of consuming low amounts of alcohol requires further study, ideally in adequately powered randomised trials.”
They added: “Until then, each individual has to make its own best educated decision as to whether consuming up to one alcoholic drink per day is worthwhile and safe.”
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