Speculation over whether high coffee consumption increases the risk of the most common kind of irregular heartbeat - atrial fibrillation - can now end, according to new research published in the journal BMC Medicine , which found no evidence this is the case.
Previous research has suggested high coffee consumption may increase the risk of AF. However, a new study - the largest study of its kind, involving nearly 250,000 people - found no evidence an association between the two.
All studies were conducted in either Sweden or the US.
The first part of the study was made up of 76,475 men and women, who, in 1997, reported how many cups of coffee they had each day. This was followed up for 12 years.
The median daily coffee consumption was three cups.
Consumption of coffee has increased considerably over the last few decades, from approximately 3.5 million tonnes globally in the 1970s to 7 million tonnes today, making studies of this kind all the more important.
The second part of the study was a follow-up meta-analysis that included four other prospective studies, bringing the study population total to 248,910 people.
While 10,406 cases of AF were diagnosed, the research team found that coffee consumption was not associated with AF incidence, even in more extreme levels of coffee consumption.
Men may be more sensitive to high coffee consumption than women
The gender-specific analysis found that, while coffee consumption was associated with a nonsignificant increased risk of AF in men, there was a nonsignificant decreased risk of AF in women.
As such, the research team wonder if men could be more sensitive to high coffee consumption than women, though they note further research is required.
Lead author Susanna Larsson, from the Karolinska Institutet in Sweden, says:
"We find no evidence that high consumption of coffee increases the risk of atrial fibrillation. This is important because it shows that people who like coffee can safely continue to consume it, at least in moderation, without the risk of developing this condition."
The researchers note, however, that their study does not suggest high coffee consumption is not linked to other forms of irregular heartbeat, noting that some patients with AF at study baseline reported reducing their coffee intake because it triggered arrhythmia.
A Knowledge Center article from Medical News Today looks at the some of the health benefits and risks of drinking coffee.
Written by Jonathan Vernon