If you’re like most Americans, you probably spend at least some portion of your day in front of the TV. After work and sleep, watching TV is our most common everyday activity — the average American watches five hours daily. But that habit could be deadly, according to recent research.
Dr. Frank Hu of the Harvard School of Public Health and his colleagues report in the Journal of the American Medical Association that too much TV time was associated with increases in the risk of developing type 2 diabetes and heart problems and the risk of death from any cause.
While it’s not surprising that being a couch potato isn’t exactly good for your health, Hu’s team quantified for the first time how much the passive act of TV watching contributed to conditions like diabetes and heart disease, as well as to premature death. For every two hours of TV watching, the researchers found, the risk of type 2 diabetes increased by 20% over 8.5 years of follow-up, the risk of heart disease rose by 15% over a decade, and the odds of dying from any cause increased 13% during a seven year follow-up.
Hu’s study, which analyzed data from eight large studies conducted since the 1970s, didn’t explicitly say why TV time was associated with poor health, but the potential connections are no mystery. “Excessive TV watching is related to decreased physical activity, increased consumption of health foods, and increased caloric intake,” says Hu.
That is, every hour you spend on the couch is another hour you’re not exercising. And TV watching tends to promote other unhealthy activities like snacking on junk food (the constant commercials for pizza and beer don’t help) and eating fewer fresh fruits and veggies. All of these are known risk factors for diabetes and heart disease, conditions that can contribute to early death.
The data from the previous studies on TV watching and health weren’t refined enough to determine whether the same negative health effects occurred in people who watched a lot of TV and also exercised, but Hu says, by and large, TV viewing and physical activity are mutually exclusive. “Most studies show that people who watch a lot of TV tend to exercise less,” he says.
That means it’s important for doctors to start asking their patients not only about how physically active they are, but about how much time they spend in front of the TV. “Now we know that excessive TV watching may do more damage than other types of sedentary behaviors,” says Hu. “So it’s a good idea to ask how much time people spend in front of the TV and for doctors to give advice not only about exercise but about how to reduce TV watching.”
That may be easier said than done, given Americans’ seeming obsession with TV. Many people, especially kids, don’t just limit themselves to the television set; they’re also watching on their mobile devices and computers. That makes TV a hard habit to break, but one that may ultimately save lives.