There is good news for coffee drinkers: Up to five cups of the brew a day are safe for most adults and may even have benefits for heart health, according to a new scientific statement by the American Heart Association.

Downing between about three to five 8-ounce cups of joe daily, or around 400 milligrams of caffeine, is linked to a lower risk of heart disease, heart failure, stroke and Type 2 diabetes, according to the AHA's statement, which was published Monday in the journal Circulation.

The research on coffee and caffeine has been very mixed, with some studies showing links to benefits and others showing health risks. So the new statement provides some much-needed clarity, said Dr. Eugenia Gianos, a cardiologist at Northwell Health in New York and chair of the American College of Cardiology's Prevention of Cardiovascular Disease Council, who wasn't involved in the statement.

"Not only is the lay public confused about this topic, but many clinicians out there don't know how to guide their patients," Gianos said, adding it is great that a drink so many people enjoy daily may even have benefits. "We could even be recommending soon that people have coffee. "

The statement's authors, which included researchers from the Harvard T.H. Chan School of Public Health, George Washington University and other institutions, analyzed dozens of studies looking at the impact of coffee and caffeine on heart health.

The scientific evidence for coffee's safety and health benefits has been building over time, said Dr. Gregory M. Marcus, a cardiologist and professor of medicine at the University of California, San Francisco, and the statement's lead author. Most of the studies the authors analyzed are observational and can't prove cause and effect. But there has been an increasing number of randomized, controlled trials -- a more scientifically rigorous method -- in recent years showing that coffee consumption can be beneficial for heart health, Marcus said.

Scientists are still trying to figure out why the caffeine in coffee may help the heart, Marcus said. People tend to exercise more on the days they have caffeinated coffee. Coffee acts as a diuretic and can lower blood pressure. Caffeine also blocks a substance that can cause atrial fibrillation, an arrhythmia that can lead to strokes.

Coffee contains other substances that seem to be beneficial for health, too, the statement's authors wrote, including polyphenols that may act as antioxidants and reduce inflammation. This could explain why in some studies, decaf coffee is also associated with lower risks of Type 2 diabetes and heart disease.

The scientific research suggests that the sweet spot for caffeinated coffee consumption is generally between two and four cups a day. That amount "may just be it's not so much that you get to toxic levels, but it's enough to have a biologic effect," Marcus said.

People can have a range of responses to the caffeine in coffee, which is influenced by genetics and consumption habits. "We all metabolize caffeine at different speeds," Marcus said.

The potential benefits of coffee, however, can be diluted or eliminated by the stuff many people add to it, the authors said, like sugar, syrups and creamers with a lot of saturated fat.

The AHA statement also looked at caffeine consumed in other ways, like energy drinks. The authors noted that energy drinks often contain much higher amounts of caffeine than coffee. Some research has found that consuming them can lead to health problems, including irregular heartbeats and high blood pressure. Marcus advises people to avoid those products.

Write to Andrea Petersen at andrea.petersen@wsj.com

(END) Dow Jones Newswires

July 20, 2026 05:00 ET (09:00 GMT)

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