Increasing consumption to above that amount was not associated with harm, but the beneficial effects were less pronounced.
Coffee was also considered to be linked with a decreased risk of several cancers including endometrial, skin, prostate and liver cancer and also of diabetes mellitus type 2, gout and gallstones as per the researchers.
Again, as majority of the whole research pool was based on observation, the team was unable to determine cause-and-effect relationships, so while the aforementioned benefits are great on paper, it's not certain that they're, in fact, the result of drinking coffee.
"Coffee drinking appears safe within usual patterns of consumption", the researchers concluded in their study, published in the British Medical Journal on November 22.
In July, there were two studies that suggested drinking coffee leads to a longer life.
The scientists, led by Robin Poole from the University of Southampton in the United Kingdom, learned that people who drank coffee were 17% less likely to die early during the study period from any cause, 19% less likely to die of heart disease and 18% less likely to develop cancer, compared to people who did not drink coffee.
Finally, there seemed to be beneficial associations between coffee consumption and Parkinson's disease, depression and Alzheimer's disease.
There was less evidence for the effects of drinking decaffeinated coffee, but it had similar benefits, they said. Fear not, drinking more than this isn't a bad thing- those who drank seven still appeared to benefit, enjoying a 10 per cent reduced chance.
"Coffee is one of the most commonly consumed beverages worldwide", researchers wrote.
A meta-analysis of 40 cohort studies showed a lower incidence of cancer for high versus low coffee consumption (relative risk 0.82, 95% CI 0.74 to 0.89), any versus no consumption (RR 0.87, 95% CI 0.82-0.92), and one additional cup per day (RR 0.97, 95% CI 0.96-0.98), they reported.
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Experts believe naturally-occurring compounds found in coffee boost wellbeing, by improving liver function and bolstering the immune system.
Dr Marc Gunter, of the International Agency for Research on Cancer, said: "We are not at the stage of recommending people to drink more or less coffee".
Listen up, coffee addicts: A new search says that drinking three to four cups of coffee per day might be good for you.
The authors conclude that coffee drinking "seems safe within usual patterns of consumption, except during pregnancy and in women at increased risk of fracture".
Dr Oyinlola Oyebode, Associate Professor at the University of Warwick, said: "The main conclusions are moderate coffee consumption is not just safe, but more likely to be associated with benefits to health in the majority of adults".