Up to 5 cups of coffee per day may potentially lower heart disease risk, doctors say
Drinking up to five cups of coffee a day, or up to 400 milligrams of caffeine, is safe for most adults, and research suggests regular coffee consumption may be linked to a lower risk of stroke, diabetes, and heart failure, according to a new scientific statement from the American Heart Association.
The official report, published Monday in the journal Circulation, clarifies years of conflicting advice regarding caffeine and the heart.
"Coffee is potentially linked to lower risks of type 2 diabetes, stroke, and heart failure, though its relationship with blood pressure is complex and data isn't entirely consistent across the board," said Dr. Jennifer Miao, a board-certified cardiologist and fellow with the ABC News Medical Unit.
For decades, doctors advised people with heart issues to avoid stimulants. However, this comprehensive review marks a major shift by distinguishing between natural coffee beans and synthetic caffeine.
While older guidelines relied heavily on lower quality studies, the AHA panel integrated recent clinical trials showing that even for patients who have had a procedure to address an irregular heart rhythm, daily coffee can cut the risk of the condition returning by 39%. Habitual coffee consumption was also associated with a 20% to 30% lower risk of developing Type 2 diabetes.
The AHA warns that your daily brewing method drastically impacts these potential health benefits, however. These heart healthy links apply strictly to paper filtered or instant coffee. Unfiltered options, including a French press, espresso, or Turkish coffee, retain a natural compound called cafestol.
Cafestol raises low-density lipoprotein, or LDL, the "bad" cholesterol that can clog arteries over time.
Crucially, these positive heart associations do not translate to highly concentrated synthetic caffeine products like energy drinks, shots or pills.
The AHA notes that high caffeine energy drinks are consistently linked to cardiovascular harm. These products are associated with sudden spikes in blood pressure and acute episodes of irregular heart rhythms, even in healthy adults.
"The AHA distinguishes between coffee and energy drinks, which can pose significant cardiovascular harm," Miao said. "In large amounts, energy drinks can trigger life-threatening heart rhythm issues and even cardiac arrest."
Finally, your ideal caffeine limit is heavily influenced by your genetics. Inherited variations in a liver enzyme gene called CYP1A2 dictate how fast your body metabolizes stimulants.
While some people can easily clear 400 milligrams of caffeine, which is about three to five 8-ounce cups of coffee, others may experience sleep disruption and blood pressure spikes with far less caffeine.
Doctors still caution that anyone with an underlying heart problem or existing risks of developing heart disease or stroke should talk to their doctor about what amount of coffee or caffeine may be safe for them to consume.
"Consume caffeine in moderation, not solely for potential health benefits," Miao advised. "Everyone's sensitivity is different, so if you have any underlying conditions or concerns, please talk to your doctor."
Dr. Yonathan Daniel is an internal medicine resident physician at NYU Langone Health and a member of the ABC News Medical Unit
