Does coffee lower the risk of premature death?

Coffee likely lowers your chance of dying early. A large review of 201 meta-analyses¹ found roughly 17% lower odds of death at three to four cups per day compared with no coffee. A meta-analysis of nearly 3.9 million participants² confirms this. Drinking more than 3.5 cups per day does not appear to offer any additional benefit beyond that.

What you put in your coffee matters considerably. In a cohort study of 46,222 adults³, a protective effect was only visible with black coffee or coffee containing little sugar and saturated fat. Coffee with large amounts of cream and sugar showed no demonstrable benefit.

For people with type 2 diabetes the signals are particularly encouraging. A Harvard cohort study of more than 15,000 diabetes patients with a mean follow-up of 18.5 years⁴ found a 26% lower chance of death at high versus low coffee consumption. A broad review in Geroscience⁵ confirms that the benefits are most pronounced at moderate consumption.

All of this research is observational. Randomised trials are largely absent^1,6,5. People who drink a lot of coffee may also live more healthily in other ways. Moreover, indications of a causal relationship are convincing only for type 2 diabetes and chronic kidney disease, not for mortality in general⁵.

There are risks as well. Coffee is associated with an increased risk of lung cancer, even after correcting for smoking⁷. In women there is a link with a higher rate of bone fractures¹. During pregnancy, moderation is advisable: high consumption was associated with a 31% greater chance of low birth weight and a 46% greater chance of pregnancy loss¹. For healthy, non-pregnant adults, up to 400 mg of caffeine per day, roughly one to four cups, is considered safe, although drug interactions may play a role⁶.