Drinking three to four cups of coffee daily, without sugar or cream

Making coffee at home costs just one or two yuan per day. It takes only a few minutes to brew each cup, so it doesn’t take much time at all.

One review combined results from 201 separate studies. All of these original studies simply recorded outcomes without grouping participants. The overall finding was that drinking 3–4 cups of coffee daily lowered mortality risk by 17% compared to non‑drinkers (relative risk 0.83, 95% CI 0.79–0.88; this is a reliable range).

Poole R, Kennedy OJ, Roderick P, et al. (2017). Coffee consumption and health: umbrella review of meta-analyses of multiple health outcomes. BMJ, 359, j5024. https://doi.org/10.1136/bmj.j5024

There is some debate here: the authors note that almost all evidence comes from observational tracking studies and state that “reliable randomized controlled trials are needed to confirm a causal relationship.” In other words, participants must be randomly assigned to groups for a true cause‑and‑effect conclusion. For this benefit to apply, coffee should be consumed black; adding sugar or cream cancels out these advantages. This recommendation does not apply to pregnant women or people with arrhythmia, anxiety, or insomnia.