Coffee consumption and health: umbrella review of meta-analyses of multiple health outcomes

Umbrella review of 201 meta-analyses of observational research and 17 of interventional research notes coffee seems generally safe within usual levels of intake, with largest risk reduction for various health outcomes at 3-4 cups a day, and more likely to benefit health than harm

The researcher acknowledge that robust RCTs are needed to understand whether the observed associations are causal.

 

An editorial notes that as the evidence is so robust and consistent across studies and health outcomes, people can be reassured that drinking coffee is generally safe, although some caveats apply:

 

• Some population subgroups may be at higher risk of adverse effects; several harmful associations between coffee and pregnancy related outcomes, including higher risks of low birth weight, pregnancy loss, and first and second trimester preterm birth were identified; also coffee was associated with an increased risk of fracture in women.

 

• For many endpoints, the lowest risk of disease is associated with drinking three to five cups of coffee a day. Higher intake may reduce or reverse the potential benefit, and there is substantial uncertainty, both in individual studies and in meta-analyses, about the effects of higher levels of intake.

 

• Coffee is often consumed with products rich in refined sugars and unhealthy fats, and these may independently contribute to adverse health outcomes.