Drinking five cups of coffee or more a day may have limited to no effect on arteries, a new study suggests.
Researchers at the Queen Mary University of London garnered international media attention for the release of the study, which looked at arterial stiffness following daily consumption of coffee. Results showed found no evidence exists that drinking more than three cups of coffee a day affected the arteries.
Kenneth Fung, the lead author and doctoral candidate at Queen Mary, pointed out that, though, that the study is still in early stages and had limitations.
Fung and coauthors looked at nearly 18,000 participants who participated in an imaging study, which required them to self-report their coffee consumption habits. Researchers grouped them into three categories based on if they drink one cup or less, one to three cups or more than three a day.
The amount of coffee consumed daily by those in the three or more cups a day varied, although the average was five cups, according to the results. Two participants self-reported that they drank 25 cups a day, but that was an outlier, Fung said.
When Fung looked at arterial stiffness of each of the participants, he found no statistical difference between the three groups, he said. The main takeaway of the study is in the context of a healthy lifestyle, four to five cups of coffee is likely ok for the arteries, he said.
The study had multiple limitations, Fung said. The participants all self-reported coffee intake, which meant that it was unclear what size each person considered a cup. Participants also did not report if they drank caffeinated or decaffeinated coffee.
The research is still in early stages, he said, and Fung and coauthors plan to continue to conduct more research with the goal of submitting a manuscript to an academic journal for publication. One area of further study is breaking people down into smaller groups, so that there is less of a range between five cups of coffee and 25.
Fung is a coffee drinker himself, although he would fall in the one to three cups of coffee group. His own habits led him to pursue the study, he said, because he wanted to know what effects coffee might have on his heart.