People who consume wine and spirits even in moderation may increase their risk of developing the heart disorder, atrial fibrillation (AF), a new study indicates.

No such link between AF and the moderate consumption of beer was found.

AF causes irregular and rapid heartbeats, which can make the heart less efficient at pumping blood around the body. This can lead to palpitations, breathlessness, dizziness, angina and the development of blood clots.

Those affected are five times more likely to have a stroke and are at an increased risk of developing heart failure and dementia. Some 40,000 adults over the age of 50 have the condition in Ireland.

Swedish researchers looked at almost 80,000 adults aged between 45 and 83. The participants had filled out an extensive questionnaire about their food and alcohol consumption in 1997 and they were then monitored for up to 12 years.

Previous research had already found a link between high alcohol consumption - more than three drinks per day - and the risk of AF, and this study confirmed that link. But previous studies had not found any link with moderate alcohol consumption - defined as one to three drinks per day.

However, this study found that people who consumed moderate amounts of wine and spirits had an increased risk of developing AF.

In a further analysis of the findings, the researchers were able to estimate that the risk of AF increased by 8% with each additional drink consumed per day.

"While many studies have shown that light to moderate alcohol consumption can have beneficial outcomes on the heart, such as reducing ischaemic heart disease and stroke, it is important to balance these benefits against the potential risk of developing atrial fibrillation," noted Dr Susanna Larsson, of the Karolinska Institutet in Stockholm.

She pointed out that the researchers had ‘no explanation' as to why beer was not found to increase the risk of AF like wine and spirits had.

"It is likely that beer is consumed more regularly during the week, whereas wine and liquor is more often consumed during weekends only. Adverse effects of alcohol on AF risk may be less pronounced if alcohol consumption is spread out over the week compared with consumption of larger amounts of alcohol during a few days per week," she suggested.

Details of these findings are published in the Journal of the American College of Cardiology.