New Study Shows 2 to 3 Cups of Coffee a Day Could Prevent Heart Disease by as Much as 48%

A new study recently revealed that drinking three cups of coffee a day is linked to a lower risk of heart disease, type 2 diabetes, or stroke. 

Published in The Journal of Clinical Endocrinology & Metabolism (JCEM) in mid-September, the research was conducted by co-lead author Chaofu Ke, an associate professor in the Department of Epidemiology and Biostatistics at Soochow University, in Suzhou, China, along with colleagues based in China and Sweden. Its findings join what is now a host of other data that indicates drinking coffee can be beneficial for cardiovascular health.

What diseases can drinking coffee prevent?

The new study from JCEM concluded that habitual, moderate coffee intake is associated with a lower likelihood of developing cardiometabolic multimorbidity (CM). CM is the presence of two or more cardiometabolic diseases, such as heart disease, type 2 diabetes, or stroke. Beyond this, the analysis also found that caffeine could impact the evolution of different stages of CM; more simply put, regularly drinking a few cups of coffee a day could help make people less likely to begin suffering from any cardiometabolic disease, and influence whether or not those with one cardiometabolic disease eventually incur CM.

How much coffee should you drink per day, according to this study?

The research looked at data from roughly 180,000 participants (none of whom had cardiometabolic diseases when the study started) from the UK Biobank, a large-scale, anonymous biomedical database. It compared people who drink less than 100 milligrams of caffeine per day with those who drink a moderate amount of caffeine, which the writers qualified as either three cups of coffee, or between 200–300 milligrams of caffeine per day.

For people who drink three cups of coffee a day, the risk of developing CM was reduced by a staggering 48.1%. And for those who consume between 200–300 milligrams of caffeine daily — which might include green and black tea — risk went down by 40.7%. According to the findings, individuals benefited when they drank roughly two to three cups of coffee on a daily basis.

How much weight should we give this research?

The scale and methodology of the study gives it weight, but it’s important to know that only a connection can be drawn from the results, not cause. 

Dr. Gregory Marcus, associate chief of cardiology for research and professor of medicine at the University of California, San Francisco — a source unconnected to the published research — told CNN that “It is important to emphasize that, while these data suggest a relationship between caffeine, tea, and coffee and a reduced risk of a combination of cardiovascular diseases, we need to be careful before we infer true causal effects.”

It’s also possible that one of the other chemical compounds in coffee or tea could be responsible for the positive results of the study. Tim Spector, MD, FRCP, FRSB, and scientific co-founder at ZOE explains that “…People often fixate on just one of the chemicals in coffee — caffeine — when there are hundreds of others. For instance, coffee contains a fair amount of fiber, an essential nutrient. This is important because most Americans don’t have enough fiber in their diets. 

“Other chemicals within the coffee may also support heart health via our gut microbes, namely polyphenols. These natural defense chemicals occur in many plants, particularly ones that have bitter tastes and dark colors, like coffee beans. Polyphenols are like rocket fuel for your gut microbes. As they feed on them, they produce other beneficial compounds that we believe may help explain coffee’s protective effects.”

In summary, the results of this study do add to the evidence that coffee drinkers have a reduced risk of heart disease, but more research needs to be done to identify the exact cause of this link.

Should you start drinking more coffee?

While these implications are reassuring for people who regularly drink coffee, as noted above it’s not proven that caffeine is the precise cause of the drink’s health benefits, so it doesn’t necessarily mean you should start increasing your caffeine consumption. 

There are, of course, dangers to drinking too much caffeine, and Dr. Joy Gelbman, a cardiologist at Weill Cornell Medicine, tells Food & Wine, “excessive caffeine can lead to elevated blood pressure, fast heart rate, and palpitations, so [it’s] best to emphasize moderation.”

Gelbman also emphasizes that you should “be mindful of what you add to your coffee or tea — taking your caffeine with cream and sugar is quite different from taking it black.”