Legend has it that coffee was discovered by a goat herder around 850 AD in what is now Ethiopia. It soon spread around the globe and is currently consumed by billions of people every day. But as the drink gained in popularity, it also gained a bad rap. From claims that coffee led to illegal sex in the 1500s, or that it caused impotence in the 1600s, to the more recent belief that it stunted your growth, history has not been kind to coffee.
In recent years, rumors have been replaced by scores of scientific studies. But reading through the research can be dizzying, as you’ll often come across a conclusion that directly opposes another you just read. In fact, it’s unlikely that any single study would yield enough evidence to convince us about the health effects of coffee one way or another. So some scientists instead focus on compiling these disparate findings into mega-studies called meta-analyses. Eventually, the meta-analyses became so numerous that scientists started aggregating those into what are known as umbrella reviews to see if they could glean any general wisdom about coffee’s effects.
Two umbrella reviews were published last year (here and here), and their findings flew in the face of centuries of coffee gossip. The verdict was that coffee drinking is linked to lowered risk of myriad diseases like type 2 diabetes, heart disease, a few types of cancer, liver disease, Parkinson’s, Alzheimer’s and depression—not too shabby. Above all, coffee drinkers were less likely to die early from any cause. And with the possible exception of drinking it while pregnant, there were no negative effects to speak of.
“The key message is that with the evidence that we have up to date, we can say that coffee can be part of a healthy diet,” says nutritional epidemiologist Giuseppe Grosse at the University of Catania in Italy and lead author of one of the umbrella reviews.
