The researchers observed an inverse association for coffee drinking with mortality, including among participants who reported drinking at least one cup per day, up to eight or more cups per day.
The study looked at patterns in an existing dataset, so it's hard to say whether coffee is responsible for a longer life or if it is just associated with one. Most of the subjects (154,000) drank two to three cups per day and 10,000 of them drank at least eight cups every day!
It does however provide further evidence that coffee drinking can be part of a healthy diet and offers reassurance to coffee drinkers.
Overall, coffee drinkers were about 10 to 15 per cent less likely to die than abstainers during a decade of follow-up.
The researchers found longevity benefits linked with almost every level and type of coffee consumption.
Researchers arrived at this conclusion after assessing the health of 500,000 people who took part in a study based in the United Kingdom.
"But here's a situation where there was always some feeling of, 'Oh, can't be - I enjoy it too much, it can't be good for me.' And now we're finding out that it's good".
Lead author Dr Erikka Loftfield, a cancer epidemiologist, said the results applied to all types of coffee including ground, instant and decaffeinated. And it also doesn't matter what version of the "coffee gene" people have.
But, "drinking coffee is not a miracle in a cup, and is unlikely to prevent the consequences of an unhealthy lifestyle, such as the typical Western diet or smoking tobacco", Heller noted. But those who drank the most coffee were less likely to die, the findings showed.
It might reduce inflammation in the body, improve how insulin gets used, it might help liver function and it might benefit the linings of the blood vessels. But the new study suggests even higher amounts of coffee could be beneficial.
Dr. Robin Poole, a specialty registrar in public health at the University of Southampton who did not work on the study, told Newsweek the research is significant as it includes a very large sample of people from the general population, and data both on coffee consumption and genetics.
Researchers accessed genetic data for 403,816 of the 498,134 study participants to create 2 genetic "caffeine metabolism" scores (CMSG) by "adding the number of alleles of single base changes, or single nucleotide polymorphisms (SNPs), previously associated with blood caffeine metabolite levels, and the map near genes with plausible roles in caffeine metabolism".