Bad news for those who like a drink – just a small glass of alcohol a day can cause an irregular heartbeat, research suggests.
The benefits of moderate alcohol consumption have been debated for a long time, with previous studies suggesting that an occasional glass of red improves heart health, while excess can have serious cardiovascular consequences.
To find out more, scientists at the University Heart and Vascular Center in Hamburg analyzed the alcohol intake of almost 108,000 people, who were followed for about 14 years.
The results suggest that consuming just one alcoholic drink per day increases the risk of atrial fibrillation by 16%, compared to total abstention.
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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 it is not clear why alcohol can trigger this, small amounts of wine, beer or spirits have been linked to episodes of irregular heartbeat.
“As far as we know, this is the largest study on alcohol consumption and the long-term incidence of atrial fibrillation in the community,” said the lead author, Professor Renate Schnabel.
“Previous studies have not been powerful enough to examine this issue, 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.
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“In our study, we can now demonstrate that even very low alcohol consumption can increase the risk of atrial fibrillation.
“These findings are important because regular consumption of alcohol, ‘a glass of wine a day’ to protect the heart, as is often recommended in the lay press, for example, should probably no longer be suggested without balancing the risks and possible benefits for all heart and blood vessel disease, including atrial fibrillation. “
Note: Moderate drinking increases the risk of atrial fibrillation
The scientists analyzed more than 107,800 people who participated in studies in Sweden, Norway, Finland, Denmark and Italy between 1982 and 2010.
Just over 100,000 of the participants, with an average age of 48 years, did not have atrial fibrillation at the beginning of the research.
In the following 14 years, more than 5,800 developed the disease.
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The results – published in the European Heart Journal – suggest that drinking a glass of alcohol a day increased the participants’ risk of atrial fibrillation by 16%, regardless of the type of drink they drank.
Drinking up to two alcoholic drinks a day increased the chance of atrial fibrillation by 28%, rising to 47% for those who consumed more than four, the results indicate.
The results were similar between male and female participants.
Scientists defined a drink as containing 12g of ethanol, the chemical compound in alcohol. This is equivalent to a small glass (120ml) of wine, small beer (330ml) or 40ml of spirits.
The scientists emphasized that the participants reported their own alcohol consumption, which may therefore be inaccurate.
Although atrial fibrillation often causes palpitations, it can also be asymptomatic, which can go undetected.
Nor did scientists take into account the effects of excessive alcohol consumption.
In an accompanying editorial, a team from McMaster University in Canada said that the Hamburg survey “makes an important contribution to our understanding of the relationship between alcohol intake and the AF incident. [atrial fibrillation], particularly in the lower spectrum of alcohol consumption.
“A significant relationship has been identified between alcohol and AF, and even small amounts of alcohol have been associated with an increased, albeit small, risk of incident AF.
“Along with a recent randomized study showing that a reduction in alcohol intake led to a reduction in the recurrence of AF, these data suggest that reducing alcohol consumption may be important for the prevention and control of AF.
“It is important to note that any reduction in alcohol consumption from low to moderate to prevent AF needs to be balanced with the potentially beneficial association that low amounts of alcohol can have with other cardiovascular outcomes.
“The net clinical benefit of consuming small amounts of alcohol requires further studies, ideally in randomized trials with adequate potency.”
They added: “Until then, each individual has to make their own better informed decision about whether consuming even one alcoholic drink a day is worthwhile and safe.”
Watch: Symptoms and treatments for atrial fibrillation