Health down the 'tube'

Watching television is a habitual part of most people's lives, a route of escapism from the world at large, even a way to spend time with family before or after meals. It's an activity that sends people to their couches in droves, and now, as a new study shows, it may also be responsible for an increased risk of type 2 diabetes, cardiovascular disease and premature death.

The study comes from the Harvard School of Public Health and shows that individuals who watch 2-3 hours of television or more per day are more likely to develop heart conditions and diabetes as a result. Considering that television watching is the most commonly reported daily activity apart from working and sleeping, and that most Americans watch five hours of it per day on average, this information is of particular importance.

Anders Grøntved and Frank B. Hu, M.D., both of Harvard, conducted a meta-analysis by looking at and assessing published studies from 1970 to 2011 that linked TV watching with type 2 diabetes, cardiovascular disease and premature death. They noted that two hours of TV watching per day increased the likelihood of type 2 diabetes and cardiovascular disease, while three hours or more increased premature death.

These numbers are perhaps a direct result of the obesity association that goes hand-in-hand with increased TV watching. Individuals who stay indoors to watch TV are less likely to exercise and more likely to eat unhealthily.

Increased TV watching is a prominent issue not just in adults, but in children as well, as it hinders their participation in physical activity and establishes an unhealthy lifestyle from the onset.

However, the authors say that it's the sedentary lifestyle that leads to the health risks, not the television watching itself.

"Associations of sedentary behaviors analogous to TV viewing with type 2 diabetes, fatal or nonfatal cardiovascular disease and all-cause mortality have been reported in cohort studies," the authors write. "Additional research quantifying the mediating influence of diet and physical in activity is warranted."

Grøntved and Hu also note that it's important to monitor other activities that contribute to a less active lifestyle, such as Internet use.

"Future research should assess the association of prolonged daily use of new media devices on energy balance and chronic disease risk," Hu says.