All the participants in the study were given MRI heart scans and infrared pulse wave tests. Researchers corrected for factors such as age, gender, ethnicity, smoking status, weight, blood pressure, diet and how much alcohol a person drinks.
“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 at Queen Mary University of London, told 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.”
Although some participants in the study drank 25 cups a day, the average intake among the highest coffee consumption group was five cups a day.
“We’re not telling people to drink 25 cups a day per se. If anything, if you drink within recommended guidelines, then we don’t expect to see an increase in arterial stiffness compared with those who drink one cup or less a day,” he added.
The research also showed that moderate and heavy coffee drinkers were most likely to be male, smoke and consume alcohol regularly.
Professor Metin Avkiran, associate medical director at the British Heart Foundation, said in a press release: “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. 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.”