Overview
- The AHA published a scientific statement in the journal Circulation that finds up to 400 milligrams of caffeine per day is not linked to higher cardiovascular risk for most healthy adults.
- The statement translates 400 mg roughly to three to five eight‑ounce cups of brewed coffee but stresses cup size and brew strength vary by region and preparation.
- Most evidence the AHA reviewed is observational, meaning studies show associations such as lower rates of coronary disease, heart failure, stroke and type 2 diabetes but do not prove causation.
- The review highlights that unfiltered coffee contains cafestol, which can raise LDL cholesterol, that sugary creams and syrups reduce any benefit, and that concentrated products like energy drinks and shots carry higher risks for blood pressure and arrhythmias.
- Researchers note variable individual responses driven by genetics, age, medications and health conditions, report mixed randomized‑trial findings on heart rhythm, and call for more trials comparing caffeine sources and preparations.