Could coffee be good for your heart?

To create the scientific statement, AHA assembled a panel of experts to review decades of research on caffeine and cardiovascular disease. Although older guidelines on caffeine and heart health relied largely on lower-quality studies, the new panel integrated more recent clinical trials to better evaluate the potential impact of caffeine.

Overall, AHA found that consuming up to 400 mg of caffeine, or five eight-ounce cups of coffee, a day was generally considered safe for most adults. A moderate amount of caffeine consumption was also associated with a lower risk of several conditions, including heart failure, heart disease, stroke, atrial fibrillation, high blood pressure, and type 2 diabetes.  

Notably, these findings are based on black coffee without any added sugar, flavored syrups, and dairy products, which AHA noted can "substantially increase caloric intake and counteract potential health benefits associated with coffee itself." Unfiltered coffee, such as espresso or French press, also contains a component that was associated with higher levels of "bad" cholesterol.

AHA also cautioned that consuming higher levels of caffeine, especially from energy drinks, could increase the risk of high blood pressure, abnormal heart rhythms, and other cardiovascular issues. Compared to a regular cup of coffee, an energy drink may contain three to four times more caffeine. 

Coffee's other potential health benefits

In addition to potential cardiovascular benefits, research suggests that coffee can have a positive impact on several other aspects of health and well-being.

For example, a recent study published in Clinical Gastroenterology and Hepatology found that coffee drinking was associated with lower rates of liver disease, liver cancer, and liver-related death. Risk decreased with greater coffee consumption, with those drinking five or more cups a day seeing a 32% lower risk of cirrhosis, a 47% lower risk of liver cancer, and a 42% lower risk of liver-related death.

A separate study published in JAMA found that drinking a few cups of coffee or tea every day was associated with a reduced risk of dementia and better cognitive function over time. People who drank two to three cups of caffeinated coffee a day had an 18% lower risk of dementia compared to those who didn't drink coffee.

Drinking coffee regularly could also help boost longevity. In a study from Tufts University, researchers found that drinking up to three cups of coffee a day was associated with a lower risk of all-cause mortality. People who drank black coffee — or coffee with only "low" levels of sugar and saturated fat — had a 14% lower risk of all-cause mortality compared to those who didn't drink coffee at all.

Health experts have called for more research into coffee and caffeine to better understand their potential impact on health. Although coffee is the main source of caffeine for most people, tea, soda, and chocolate also all have caffeine. It's also not clear whether caffeine or another component in coffee like polyphenols is behind its health benefits.

"We have made tremendous progress in understanding the health effects of caffeine, but there is still a lot to learn," said Frank Hu, a professor of nutrition and epidemiology at the Harvard T. H. Chan School of Public Health and vice chair of AHA's scientific statement volunteer writing group.