Three to five cups of coffee per day have been consistently associated with less cardiovascular disease and lower mortality in observational research. Causality has not been proven, unfiltered coffee raises LDL cholesterol, and pregnant women should limit their intake.
Moderate coffee consumption, roughly 3 to 4 cups per day, has been consistently associated with a lower risk of cardiovascular disease in large observational studies. Specifically, this amounts to around 15% lower odds of developing cardiovascular disease and around 19% lower odds of dying from it, compared with drinking no coffee at all (PMID 29167102, 32706535, 40806142, 40626862, 38963648). Overall mortality is also roughly 17% lower in moderate coffee drinkers. Both caffeinated and decaffeinated coffee show this favourable association.
It is important to stress that these are associations from observational research, not proven causality. People who drink a lot of coffee may also lead healthier lives in other respects. Mendelian randomisation studies, a method better suited to investigating causality, do support a causal protective effect for conditions such as type 2 diabetes and chronic kidney disease, but are less convincing for other cardiovascular outcomes (PMID 32706535, 40806142).
The picture regarding blood pressure is nuanced. A cup of coffee can briefly and mildly raise blood pressure, but regular coffee drinking does not demonstrably lead to chronically elevated blood pressure, even at intakes of up to 600 mg of caffeine per day (PMID 40626862, 38963648, 28756014). The evidence on heart rhythm disorders is mixed: the risk of most rhythm problems does not appear to be increased, but coffee can acutely raise the frequency of so-called ventricular extrasystoles (harmless extra heartbeats). The effect on atrial fibrillation remains unclear (PMID 40626862, 38963648, 28756014).
There are also clear drawbacks and risks to take into account. Unfiltered coffee, such as that made in a cafetiere or by boiling, raises LDL cholesterol (the 'bad' cholesterol), which is unfavourable for cardiovascular health. Filtered coffee has little to no such effect (PMID 40626862). Excessive consumption can cause anxiety and sleep problems, and at extremely high doses there is a risk of poisoning (PMID 26074744, 40806142, 28756014). Women who consume large amounts also face an increased risk of bone fractures (PMID 29167102).
A specific at-risk group is pregnant women. High coffee consumption during pregnancy is associated with a 31% greater chance of low birth weight, up to a 22% greater chance of preterm birth, and a 46% greater chance of pregnancy loss. Guidelines advise pregnant women to limit their caffeine intake to a maximum of 200 mg per day, which corresponds to 1 to 2 cups (PMID 29167102, 40806142). The most favourable association for overall health is found at 1 to 5 cups per day; both drinking no coffee and drinking extremely large amounts appear to be less beneficial.
The claims are based on multiple large observational studies and meta-analyses (PMID 29167102, 32706535, 40806142, 40626862, 38963648, 28756014, 26074744). Randomised controlled trials with hard cardiovascular endpoints are largely absent, which limits causal interpretation.