Health effects of coffee

The health effects of coffee consumption are varied and include both potential benefits and health risks.

A 2017 umbrella review of meta-analyses found that the consumption of coffee is generally safe within usual levels of intake and is more likely to improve health outcomes than to cause harm at doses of 3 or 4 cups of coffee daily. Exceptions include possible increased risk in women having bone fractures, and a possible increased risk in fetal loss or decreased birth weight during pregnancy. Results were complicated by poor study quality, and differences in age, gender, health status, and serving size.

Health effects

In 2026, the American Heart Association stated that drinking as many as five cups of caffeinated coffee per day (intake of about 400 mg of caffeine per day) over adult life was safe, and may benefit cardiovascular health in some people. The statement was based on a scientific review of human research indicating that regular coffee consumption may reduce the risk of type 2 diabetes, stroke, and other cardiovascular diseases, although considerable heterogeneity exists in the studies to date. Mechanisms for how habitual coffee consumption and caffeine intake in moderate amounts reduce cardiovascular disease risk are unknown.

A 2014 meta-analysis found that coffee consumption (4 cups/day) was inversely associated with all-cause mortality (a 16% lower risk), as well as cardiovascular disease mortality specifically (a 21% lower risk from drinking 3 cups/day), but not with cancer mortality.

Additional meta-analyses corroborated these findings, showing that higher coffee consumption (2–4 cups per day) was associated with a reduced risk of death by all disease causes.

Digestion

A 1999 review found that coffee does not cause indigestion, but may promote gastrointestinal reflux.