A new coffee mortality study shows that drinking more than four cups of coffee per day, especially for those under 55 years old, could cause early and premature death.

A new study published in Mayo Clinic Proceedings revealed that drinking 28 cups of coffee or more a week - four cups or more per day - can increase a person's chances of dying by 21 percent, Medical Daily reported, according to Fox News.  

Men under the age of 55 drinking this amount of coffee have their chances of prematurely dying of any cause increased to 56 percent.  For women, the increase was twofold, Fox News notes.

"On the basis of these findings, it seems appropriate to suggest that younger people avoid heavy coffee consumption," the authors of the study wrote.

According to the National Coffee Drinking Study from the National Coffee Association, 83 percent of American adults consume coffee every day, Fox News reports.On average, coffee drinkers consume just over three cups a day, The Christian Post notes.

However, Forbes reports that many earlier studies have found that heavy coffee consumption is linked to reduced mortality.

"There continues to be considerable debate about the health effects of caffeine, and coffee specifically, with some reports suggesting toxicity and some even suggesting beneficial effects," study co-author Dr. Carl Lavie, a cardiology researcher at the Ochsner Medical Center in New Orleans, said in a statement.

Forbes reports that one recent study in The New England Journal of Medicine suggested that drinking up to six cups per day is actually linked to reduced mortality from all causes - 10% for men and 15% for women. The results were true whether the people drank caffeinated coffee or decaf. The high levels of antioxidants in coffee may explain its connection to enhanced health and longer lifespan, Forbes writes.

The authors of that study said: "Our results provide reassurance with respect to the concern that coffee drinking might adversely affect health."