According to a meta-analysis published in the American Heart Association’s journal Circulation, drinking one or more cups of caffeinated coffee daily may reduce the risk of heart failure.
 
The authors of the review incorporated clinical data from three trials, the Framingham Heart Study (FHS), the Cardiovascular Health Study (CHS), and the Atherosclerosis Risk in Communities (ARIC) study, and, using machine learning through the American Heart Association’s Precision Medicine Platform, examined the data of 21,000 clinical trial participants who were in studies that had at least 10 years of follow-up.
 
To analyze the outcomes of drinking caffeinated coffee, researchers categorized consumption as 0 cups per day, 1 cup per day, 2 cups per day, and >3 cups per day, with the coffee consumption self-reported across all three trials.
 
In all three studies, people who reported drinking one or more cups of coffee per day had an associated decreased long-term heart failure risk. The FHS and CHS studies observed a 5-12% decreased risk of heart failure per cup-per-day of coffee, compared with no coffee consumption, while the ARIC study showed that the heart failure rate did not change between 0 and 1 cup per day, but heart failure risk was reduced by 30% in people who drank at least two cups per day.
 
Interestingly, decaffeinated coffee actually significantly increased the risk of heart failure in the FHS, however, neither of the other trials established an increased risk tied to decaf coffee. Further investigation into the FHS found that caffeine consumption from any source appeared to be associated with decreased heart failure risk, and caffeine was at least part of the reason for the apparent benefit from drinking more coffee.
 
“While smoking, age, and high blood pressure are among the most well-known heart disease risk factors, unidentified risk factors for heart disease remain,” David P. Kao, MD, senior author of the study, said. “The association between caffeine and heart failure risk reduction was surprising. Coffee and caffeine are often considered by the general population to be ‘bad’ for the heart because people associate them with palpitations, high blood pressure, etc. The consistent relationship between increasing caffeine consumption and decreasing heart failure risk turns that assumption on its head.”
 
Still, Kao said that there is not enough clear evidence that coffee consumption decreases the risk with the same strength and certainty of more established methods, including smoking cessation, weight loss, and exercising.
 
“The risks and benefits of drinking coffee have been topics of ongoing scientific interest due to the popularity and frequency of consumption worldwide,” Linda Van Horn, PhD, RD, member of the American Heart Association’s Nutrition Committee, said. “Studies reporting associations with outcomes remain relatively limited due to inconsistencies in diet assessment and analytical methodologies, as well as inherent problems with self-reported dietary intake.”
 
AHA warned that federal dietary guidelines allow specifically for plain black coffee, and that popular coffee-based drinks are often high in calories, added sugar, and fat. Despite its benefits, caffeine can also be dangerous if consumed in excess, and it is recommended that children avoid caffeine.
 
The study did include some limitations, which may have impacted the results of the analysis. For example, drip, percolated, French press or espresso coffee types, origin of the coffee beans, and filtered or unfiltered coffee details were not specified. Unfiltered coffee typically contains a greater amount of cholesterol-raising phytochemicals called diterpenes than filtered coffee.