A new study finds that watching an excessive amount of TV may raise the risk of dying from a number of ailments, not only those already linked to the habit.

It's already known that people who watch too much television are more likely to develop heart disease and cancer, but the new study finds they are also at increased risk for liver disease, Parkinson's disease, and even Alzheimer's as well, according to Forbes.com.

A team of National Cancer Institute researchers conducted the study, in which participants were tracked for 14 years. They were queried about their daily habits, including diet, activity levels, and TV watching. The responses were then correlated with causes of death.

They found that people who watched three-to-four hours of TV a day had a 15 percent greater risk of dying overall. For each additional two hours of TV viewing time, mortality risk for a number of specific diseases rose considerably.

The study found that cancer mortality risk rose seven percent; for heart disease, it rose 23 percent; Alzheimer's, 12 percent; Parkinson's, 35 percent; chronic obstructive lung disease (COPD), 28 percent; flu/pneumonia, 24 percent; diabetes, 56 percent; liver disease, 33 percent; and suicide, 43 percent.

Of course, it isn't TV watching that kills people, it's what they are doing – or not doing – while staring at the tube that probably raises risk of death, the Forbes article noted.

Exercise partially reduced the association, but didn't totally eliminate it. Other studies have also found that exercise can't completely reverse the connection between sitting and mortality, which suggests that there's a difference between not exercising and excessive sitting, the study said.

The research appears in the American Journal of Preventative Medicine.