The researchers identified the half a million participants through the United Kingdom biobank, an initiative to enroll approximately 9.2 million people, with long-term follow-up, and create a large database of individual, genetic sequencing to further understand the role of DNA on disease and treatment.
Among the most striking findings in the study: It didn't matter whether you drank caffeinated or decaffeinated coffee, and it didn't matter whether you drank instant or brewed coffee. Nearly one-third of those in the study drank two or three cups of coffee daily, and 10,000 hardcore types guzzled at least eight cups daily.
"Our study provides further evidence that coffee drinking can be part of a healthy diet and offers reassurance to coffee drinkers", Loftfield said.
This adds to a significant body of research indicating that coffee is connected to a long list of health benefits. The combined data showed that those who consumed a moderate amount of coffee, about three to five cups a day, were at the lowest risk for problems.
Feel free to pour yourself a cup of coffee before reading this - even if you've already had some today. There have been however some studies that show that regular coffee intake may not be good for health.
"It's hard to believe that something we enjoy so much could be good for us".
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.
Alice Lichenstein, a Tufts University nutrition researcher not linked to the study agrees, saying coffee has had negative health connotations which partially come from early literature suggesting coffee is not healthy for people.
This study also looked at another question scientists have been asking: how genetics affects coffee consumption. These polymorphisms were responsible for persons being slow metabolizers of caffeine. So the next time someone says they're trying to limit their coffee consumption, you can tell them not to worry about it.
That means, for example, if you're adding 500 calories of cream and sugar to a coffee beverage the size of a Big Gulp, you might want to keep an eye on that.