The jury’s been out for a while on whether or not caffeine is good for the body and its health. It’s been implicated in everything from preventing Alzheimer’s disease to maintaining liver health, and slowing down the maturing process of adolescents to increasing the risk of heartbeat problems. Adding to its purported benefits, and seemingly defying conventional wisdom, a new meta-analysis finds that drinking caffeinated drinks, such as coffee, could lower a person’s risk of atrial fibrillation.  

The meta-analysis, which was conducted by researchers at Fu Wai Hospital in Beijing, found that participants who drank caffeinated beverages decreased their risk of atrial fibrillation in a dose-dependent manner. For every increase of 300 milligrams of caffeine they drank each day, their risk of atrial fibrillation decreased by six percent. The findings were published online in the Canadian Journal of Cardiology. “It is unlikely that caffeine consumption causes or contributes to atrial fibrillation. Habitual caffeine consumption may reduce atrial fibrillation risk,” they concluded.

Considering that 90 percent of the people in the world use caffeine in some way or another, the findings offer at least some respite to those who often wonder if the excessive caffeine they’re drinking will cause their hearts to become overstimulated. Atrial fibrillation is characterized by an irregular and often rapid heart rate, often causing blood to circulate poorly throughout the body, according to Mayo Clinic. It’s occurs when the heart’s two upper chambers beat at a pace that’s uncoordinated with that of the lower chambers. Symptoms of the condition include palpitations, shortness of breath, and weakness.

The researchers came to this conclusion after looking at six prospective cohort studies involving over 220,000 participants. Of the studies, three were conducted in the U.S., two in Sweden, and one in Denmark. Three of them also looked exclusively at caffeine’s effect on atrial fibrillation through coffee consumption, while the other three looked at coffee as well as tea, cola, cocoa, and chocolate, MedPage Today reported.

Besides atrial fibrillation, the researchers also found that caffeine consumption might have been associated with a reduced risk of hepatic fibrosis, a malformation of the bile ducts and blood vessels in the portal system between the liver and the gastrointestinal tract. A finding that resonates with previous studies that have also found caffeine consumption improved liver health — one finding that just three cups of coffee a day could lower liver cancer risk by 50 percent. Because of these findings, the researchers also speculated that caffeine had the same effect on the heart. “Though there are few studies evaluating the anti-fibrosis effect of caffeine on the heart,” they wrote, according to MedPage Today, “it is possible that caffeine also prevents cardiac fibrosis.”

Source: Cheng M, Hu Z, Lu X, et al. Caffeine intake and atrial fibrillation incidence: Dose response Meta-analysis of prospective cohort studies. Canadian Journal of Cardiology. 2013.