“Because coffee can quicken heart rate, some people worry that drinking it could trigger or worsen certain heart issues. This is where general medical advice to stop drinking coffee may come from. But our data suggest that daily coffee intake shouldn’t be discouraged, but rather included as a part of a healthy diet for people with and without heart disease," said researcher Dr. Peter M. Kistler.
"We found coffee drinking had either a neutral effect – meaning that it did no harm – or was associated with benefits to heart health.”
Heart health benefits
For the first part of the study, the researchers analyzed 10 years' worth of data from over 382,000 people enrolled in the U.K. Biobank. Participants answered questions about how much coffee they drank on a daily basis, and the researchers compared that with their incidence of heart disease, including heart attack and stroke, arrhythmias, and coronary artery disease. None of the participants had a history of heart disease when the study began.
The study showed that regularly drinking two to three cups of coffee per day was linked to a lower risk of heart disease. Participants who fell into this group were 10% to 15% less likely to develop heart failure, coronary heart disease, heart disease-related death, or arrhythmia. Additionally, one cup of coffee per day was linked with a lower risk of stroke.
In a second study, the researchers analyzed data from nearly 35,000 people who had a history of heart disease to understand how coffee affected their health outcomes. Their work showed that drinking coffee didn’t worsen heart problems, and participants had a lower mortality risk when they drank two to three cups per day.
Experts say there are many ways that coffee can promote better heart health. They point out that the compounds found in coffee may work to reduce inflammation, boost metabolism, improve insulin sensitivity, and reduce oxidative stress.
“There is a whole range of mechanisms through which coffee may reduce mortality and have these favorable effects on cardiovascular disease,” Kistler said. “Coffee drinkers should feel reassured that they can continue to enjoy coffee even if they have heart disease. Coffee is the most common cognitive enhancer – it wakes you up, makes you mentally sharper, and it’s a very important component of many people’s daily lives.”