For decades, researchers have been investigating whether coffee drinking is bad for our health. Overwhelmingly, the answer is no.

A wealth of scientific studies suggest that drinking coffee can help people live long lives. Perhaps the best evidence for this comes from two giant studies: one of more than 400,000 people in the US and another of more than 500,000 Europeans. Both studies found that regular coffee drinkers were less likely to die from any cause than people who don't sip a daily cup of joe.

Other research has even suggested that drinking somewhere in the neighborhood of four cups of coffee per day may be the best dose for aging hearts.

But coffee is not the perfect drink.

"For some people it is unhelpful, because it makes them jittery, and they get addicted to it, and they get headaches if they don't drink a lot of it," Robbins said. "And I think our society is a little high-strung sometimes."