American Heart Association says up to five cups of black coffee a day may lower heart disease risk
A new American Heart Association statement finds that consuming up to 400 mg of caffeine daily – roughly five 8-ounce cups of black coffee – is safe for most adults and may be linked to reduced risk of cardiovascular disease and type-2 diabetes.
The American Heart Association released a scientific statement indicating that up to 400 milligrams of caffeine per day, equivalent to about five 8-ounce cups of black coffee, is generally safe for most healthy adults and may be associated with lower incidence of heart disease, stroke, heart failure and type-2 diabetes. The conclusions were published Monday in the journal Circulation.
The review highlighted that the potential benefits are most consistently observed with plain black coffee, whereas adding sugar, flavored syrups or heavy cream may diminish the positive effects.
"For most healthy adults, up to about 400 milligrams of caffeine a day, which is roughly five cups of black coffee, appears safe," said Lauren Manaker, a registered dietitian based in South Carolina, who was not involved in the research.
"How you take your coffee makes a real difference. The benefits show up most clearly with plain black coffee. Once you start piling on sugar, flavored syrups and cream, you may be trading away some of the good you were hoping to get."
The association cautioned against equating coffee with energy drinks, noting that the latter often contain three to four times more caffeine and additional stimulants, which have been linked to higher blood pressure and irregular heart rhythms.
"Coffee and energy drinks are not the same thing, and we shouldn't treat them that way," Manaker added, urging people to steer clear of high-caffeine energy products.
Researchers also emphasized that individual responses to caffeine vary based on age, medications, genetics and metabolic rate, and that no universal caffeine limit applies.
"There's no one-size-fits-all caffeine limit. Your age, your medications, your genetics and how quickly your body clears caffeine all shape how you respond," Manaker said.
The statement notes that most evidence comes from observational studies, and further research is needed to confirm the findings.