Perhaps you're reading this with your phone in one hand and a cup of coffee in the other, or while heading out from work to meet a colleague for work. If that's the case, we have some very good news -- although, perhaps with a small caveat.

Over the past few years, a series of studies have come out showing that drinking coffee--in fact, drinking a lot of coffee--has significant health benefits. In fact, some suggested there could be big benefits in drinking copious amounts.

The big unanswered question, however, has been whether there's any amount of coffee that's actually "too much." Now, a brand new study that examined 347,077 coffee drinkers, seems to have found an answer: the precise number of cups of coffee at which at which health problems might begin to show up, and could even outweigh the benefits.

Let's not hide the ball, By synthesizing several of these of the earlier "positive" studies with the new one out of the University of South Australia that suggests an upper limit, we can come up with the perfect number: Five cups of coffee per day.

Here's the background, the new study, and why when it comes to coffee, five is a magic number.

First, drink more coffee

First, the benefits. Study after study after study suggests real benefits to drinking coffee from a health perspective. As a coffee fiend myself, I've followed several of them over the years, including:

A study in which researchers funded by the American Heart Association and the University of Colorado School of Medicine found that risk of heart failure or stroke went down 8 percent for each additional cup of coffee per day.

A British study of 498,123 people found that the ones who habitually drank coffee were between 10 and 15 percent less likely to die during any 10 year period than non-coffee drinkers.

A Stanford University study that tracked 100 people over several years, and found that coffee drinkers tended to live longer than non-coffee drinkers. Here, the theory--just a theory, but still -- was that increased caffeine consumption might counteract the "fundamental inflammatory mechanism associated with human aging."

A Spanish study found that drinking four cups of coffee per day led to a 64 percent lower risk of dying among study participants compared to non-coffee drinkers.

If you read through all of those studies, you come away with the idea that drinking as many as four cups of coffee per day could have some significant health benefits.

But if four is good, then how about five? And if five is good, why not 10?

But then, stop at five

While I consider myself a pretty serious coffee drinker, the truth is I would rarely go past three cups in a day: one or two with breakfast, and perhaps one in the afternoon.

According to this new study out of South Australia, however, I've got some room to go before hitting the danger area. The problem, once you reach it, is the point at which the increased stimulation can lead to heart disease.

"In order to maintain a healthy heart and a healthy blood pressure, people must limit their coffees to fewer than six cups a day -- based on our data six was the tipping point where caffeine started to negatively affect cardiovascular risk," said Professor Elina Hyppönen of the Australian Centre for Precision Health, one of the study's authors.

Specifically, once you reach six cups of coffee per day, the risk of heart disease increases by 22 percent according to the study.