While there’s been conflicting evidence around the health benefits of coffee in the past, researchers wrote in the BMJ that a cup of Joe is “more likely to benefit health than to harm it”.
That said, they warned that pregnant women and those at risk of fracture (such as postmenopausal women) are excluded from the findings. Among these groups, they said coffee could be harmful.
For the study, researchers analysed evidence from over 200 studies and found that drinking three to four cups of coffee a day was associated with a lower risk of early death and getting heart disease compared with drinking none at all.
Coffee was also associated with a lower risk of several cancers, including prostate, endometrial, skin and liver cancer, as well as type 2 diabetes, gallstones and gout.
The greatest benefit was seen for liver conditions, such as cirrhosis of the liver.
There also seemed to be beneficial associations between coffee consumption and Parkinson’s disease, depression and Alzheimer’s disease.
Researchers warned that drinking coffee could be bad for pregnant women and added that it was also linked to a very small increased risk of fracture in women.
The studies used mainly observational data, providing lower quality evidence, so no firm conclusions could be drawn about cause and effect, but the findings do back up other recent reviews and studies of coffee intake.
As such, researchers said that, excluding pregnancy and women at risk of fracture, “coffee drinking appears safe within usual patterns of consumption”.
There was less evidence for the effects of drinking decaffeinated coffee but it had similar benefits for a number of outcomes.
In a linked editorial, Eliseo Guallar at the Johns Hopkins Bloomberg School of Public Health, said although we can be reassured that coffee intake is generally safe, doctors should not recommend drinking coffee to prevent disease - and people should not start drinking coffee for health reasons.
As this study shows, some people may be at higher risk of adverse effects, he said, and there is “substantial uncertainty” about the effects of higher levels of intake.
Finally, coffee is often consumed with products rich in refined sugars and unhealthy fats, “and these may independently contribute to adverse health outcomes,” he added.
However he concluded that even with these caveats, “moderate coffee consumption seems remarkably safe, and it can be incorporated as part of a healthy diet by most of the adult population”.