Coffee refill? Go for it, says American Heart Association, with note of caution.

Health

Coffee refill? Go for it, says American Heart Association, with note of caution.

Co-author of new guidance explains how many cups a day are safe — possibly even good for you — and why energy drinks are different

Anna Lamb

Harvard Staff Writer

July 29, 2026

3 min read

Good news for java enthusiasts: Earlier this month the American Heart Association released a statement endorsing up to five cups of caffeinated coffee a day as safe for the average adult. In fact, the statement adds, drinking more coffee may be good for you.

“I don’t think we are there yet in terms of recommending people who don’t drink coffee initiate coffee-drinking as a preventive strategy,” said Frank Hu, the Fredrick J. Stare Professor of Nutrition and Epidemiology at Harvard’s T.H. Chan School of Public Health. Hu is a co-author of the statement.

“For people who are already drinking coffee, I think the data is very reassuring that two to five cups per day is not just safe, it may be healthful in terms of lower risk of certain chronic diseases.”

Using large cohort data from studies like the Nurses’ Health Study and Health Professionals Follow-Up Study, AHA researchers looked at behavior over decades and found no long-term negative impacts on blood pressure and heart rhythms associated with the overconsumption of caffeine in the participants who limited their coffee intake to the two-to-five-cup range.

Frank Hu.
Harvard file photo.

And, according to the statement, drinking up to five eight-ounce cups of caffeinated coffee was linked to a lower risk of developing Type 2 diabetes, heart disease, heart failure, and stroke. There are a few hypotheses behind these benefits, Hu said, but ultimately more research is needed to determine the exact mechanisms at work.

“Coffee contains not just caffeine, but numerous bioactive compounds like polyphenols, which may have health benefits,” Hu said. “Studies have shown that the metabolism of the…