Drinking 3 cups of coffee a day is linked to a longer lifespan, according to a huge new study

• A study analyzing 450,000 people found a link between drinking 2-3 cups of coffee and living longer.
• People who drank coffee — even decaf — had a lower likelihood of death compared to non-drinkers.

Drinking two to three cups of coffee a day may be linked to living longer, according to a new study.

Researchers analyzed data from 450,000 people in the UK Biobank, who were observed for about 12.5 years.

They found ground coffee drinkers were 27% less likely to die early compared to non-coffee drinkers. Instant and decaf drinkers had a 11% and 14% lower likelihood of early death, respectively.

People who drank two to three cups of coffee — no matter the type — were also less likely to develop cardiovascular disease. People who drank caffeinated coffee had a slightly lower likelihood of developing heart arrhythmias (irregular heartbeats).

"Our findings indicate that drinking modest amounts of coffee of all types should not be discouraged but can be enjoyed as a heart healthy behaviour," the study's lead author, Peter Kistler, of the Baker Heart and Diabetes Research Institute in Australia, said in a release.

Plenty of research finds coffee is good for you

The new study, published in the European Journal of Preventive Cardiology, builds on existing research into coffee's effect on longevity. A paper published in The Journal of Nutrition last year found that Italians who drank three to four cups of espresso daily had lower risks of all-cause mortality over an eight year period compared to coffee abstainers.

The health benefits may remain even after adding a little sugar: UK residents who drank unsweetened to slightly-sweetened coffee were up to 31% less likely to die compared to their coffee-less peers, according to a recent study that tracked 171,000 people for seven years.

The link between decaf coffee and longevity may benefit people with caffeine sensitivity, or who want to limit their coffee intake to the recommended four cups a day.

Coffee studies have limitations

But many studies on coffee and lifespan don't establish a direct link. Studies observing behavior over a period of time cannot determine causality, because other factors like the environment or behavior could contribute to the outcome.

Research studying coffee in a clinical trial, where researchers can carefully monitor and control participants' environments, is limited to outdated and small-sample studies.