American Heart Association Says Up to 400 Milligrams of Caffeine Daily Is Generally Safe for Most Adults

The American Heart Association released a new scientific statement that up to 400 milligrams of caffeine per day is generally safe for most adults. Newsweek reported that this amount equals roughly three to five 8-ounce cups of caffeinated coffee. The statement links moderate caffeine consumption to lower rates of heart failure, coronary heart disease, and stroke among regular coffee drinkers.

Some randomized trials also showed reduced risk of atrial fibrillation in habitual coffee drinkers. Filtered coffee does not raise LDL cholesterol, while unfiltered varieties such as French press or boiled coffee contain cafestol that can increase LDL levels.

The AHA warned that energy drinks and energy shots can contain three to four times as much caffeine per ounce as regular coffee and may raise blood pressure or trigger irregular heart rhythms.

Caffeine reaches peak blood concentration within an hour, with effects varying by genetics, age, and prior use. Dr. Gregory M. Marcus, chair of the writing group and a professor of medicine at the University of California, San Francisco, told Newsweek that earlier advice had rested more on conventional wisdom than on science.

He noted that the first formal recommendation acknowledged that avoiding caffeine offers no benefit for patients with atrial fibrillation. Dr. Ethan Korngold, a cardiologist and Chief Medical Officer for Abbott’s Vascular business, told Newsweek that the findings challenge decades of caution from cardiologists.

He said the research shows caffeine in the right amounts and from the right sources may protect the heart. The AHA stated that more randomized controlled trials are needed to clarify effects across different people and non-coffee sources. Caffeine was not included in the organization’s 2026 Dietary Guidance for cardiovascular health.