Heart group says up to five daily coffees may be safe for most adults
An American Heart Association statement links black coffee to some heart benefits, while warning about heavy coffee use and energy drinks.
By Sofia Marchetti · World Affairs Correspondent
3 min read
The American Heart Association says most adults can safely drink as many as five cups of caffeinated coffee a day, equal to about 400 milligrams of caffeine. The finding matters for millions of regular coffee drinkers because the group also tied certain intake levels to lower risks of several cardiovascular problems.
The guidance comes from a scientific statement published in the AHA journal Circulation. The association said the potential benefits were linked to caffeinated coffee consumed black, without added sugar, flavorings or other fillers.
Gregory Marcus, who chaired the statement’s writing group and is associate chief of cardiology for research at UC San Francisco Health, said up to five cups a day is safe and does not raise cardiovascular risk when the coffee is black.
Where the benefits appeared
According to the American Heart Association statement, drinking two to four cups of caffeinated coffee a day was associated with a lower risk of heart disease, heart failure and stroke. The review also found that regular black coffee drinking was linked over time to a lower risk of type 2 diabetes, even though caffeinated coffee may reduce insulin sensitivity in the short term.
The findings were more complicated for blood pressure. The researchers said people with healthy blood pressure who drank one to three cups a day had a higher associated risk of developing high blood pressure. Drinking more than three cups a day, however, was linked to a lower risk.
The AHA statement also set a caution line. It said drinking more than four cups of caffeinated coffee a day may increase the risk of heart failure, even as it described up to five cups, or about 400 milligrams of caffeine, as safe for most adults.
That means the most favorable range in the review was not the smallest amount of coffee. The association’s summary pointed to two to four cups a day as the range connected with lower risks for several cardiovascular outcomes, while emphasizing that preparation matters.
Tea and energy drinks
The AHA statement also addressed other caffeinated drinks. It said tea has been associated with reduced risks of atrial fibrillation, heart failure and stroke, similar to caffeinated coffee.
Energy drinks drew a sharper warning. The researchers said those products can contain 40 to 69 milligrams of caffeine per fluid ounce, making them three to four times more concentrated than a regular cup of coffee.
At those higher caffeine concentrations, the review linked intake to cardiovascular harm, including higher risks of high blood pressure and irregular heart rhythm. The AHA said those concerns applied even to groups usually viewed as lower risk, including healthy adults under 30.
The statement does not extend coffee’s possible heart benefits to sweetened specialty drinks. The AHA’s findings were tied to black coffee, so drinks with milk, sugar, sweeteners or flavorings were not presented as carrying the same associations.
This story draws on original reporting from Fortune.