Heavy coffee drinkers may think coffee is keeping them alive - maybe not.

Two thirds of us are regular coffee drinkers, and new research from the Mayo Clinic warns that drinking four or more cups a day could increase your risk of dying earlier.

Dr. Carl Levie was the lead researcher in the study.

We showed that higher coffee was associated with higher mortality, but that doesn't mean it was the coffee that caused it.

Dr. Levie says it may be heavy coffee drinkers are stressed out or lack proper sleep.

And remember, most large coffees at the take out place are already two cups worth, so you may be consuming more coffee than you realize.