New Study Shows Coffee—Even 25 Cups a Day of It—Isn’t Bad for Your Heart

Researchers from Queen Mary University of London have found that coffee consumption does not stiffen arteries

coffee heart health.jpg
Pongsak Tawansaeng/EyeEm/Getty Images

Coffee lovers often find a dark little cloud of doubt dogging their morning pour—coffee is so good and so life-affirming, they think, there’s no way that drinking the stuff can be good for their bodies. In particular, people have worried that imbibing several daily doses of caffeine could be hurting their arteries and hearts. A new study from the U.K., however, indicates that a little Java—or even a lot, up to 25 cups worth—does not appear to have an impact on arteries.

Researchers from Queen Mary University of London, funded in part by the British Heart Foundation, looked at the artery health and coffee consumption patterns of more than 8,412 people. Each participant was categorized into one of three groups: those who drank less than one cup per day, those who had one to three cups and those who drank four to 25 cups each day. Anyone who drank more than 25 cups per day was excluded from the study, likely because they were too jittery to examine. The participants all underwent MRI scans of their hearts and infrared pulse wave tests, which examines arterial stiffness.

Previous studies seemed to indicate that drinking coffee was associated with stiffening arteries, a condition which causes stress on the heart and can lead to an increased risk for heart attacks and strokes. However, after correcting for other factors like smoking, alcohol consumption, height, weight, diet, gender, ethnicity and blood pressure, the researchers found that coffee consumption did not appear to impact artery health. The research was presented today at the British Cardiovascular Society Conference.

“What we found was that drinking more than three cups of coffee a day did not significantly increase the stiffness of blood vessels compared to people who drink one cup or less a day,” Kenneth Fung, who led the data analysis for the study, tells Amy Woodyatt at CNN. “The main message for people to take away from this is that coffee can be enjoyed as part of a healthy lifestyle, and coffee lovers can be reassured by this result in terms of blood vessel stiffness outcomes.”

While the new research doesn’t finally determine whether drinking coffee is a net healthy or net unhealthy habit, it does help untangle this one cardiovascular worry. “There are several conflicting studies saying different things about coffee, and it can be difficult to filter what we should believe and what we shouldn’t,” Metin Avkiran, associate medical director at the British Heart Foundation, says in a press release. “This research will hopefully put some of the media reports in perspective, as it rules out one of the potential detrimental effects of coffee on our arteries.”

Elio Riboli, chair in Cancer Epidemiology and Prevention at the School of Public Health, Imperial College London, who has studied coffee’s impact on mortality, tells Kashmira Gander at Newsweek this latest study jibes with his findings. “It brings good news for coffee drinkers, and a further scientific element in support of our previous findings that coffee, far from being ‘bad for health’ is on the contrary beneficial.”

But is drinking 25 cups per day beneficial? The study researchers won’t go that far—while it does not appear to promote arterial stiffness, Fung says they would like to analyze the health of heavy coffee drinkers in order to suggest an upper limit on consumption.

In fact, another study released just last month suggests that, over the long term, six cups of coffee per day is the upper limit. Imbibing caffeine levels beyond that, researchers from the University of South Australia found, began to increase blood pressure levels, leading to a spike in the potential for cardiovascular disease.

That’s not likely to be the last word on the health effects of coffee. David DiSalvo at Forbes reports that in recent years studies have found that drinking coffee was associated with lower mortality, healthier livers, protection against diabetes and dementia as well as improved memory. It’s also associated with negative affects like worsening heartburn, increased sugar cravings, anxiety and insomnia.

In general, Vivian Manning-Schaffel at NBC News reports that researchers believe that caffeine consumption is associated with living longer, while antioxidants in coffee might account for other health benefits associated with the brew.

Still, scientists are poring over the details to figure out how it all works.

Get the latest stories in your inbox every weekday.