TV Watching May Shorten Your Life

Every hour spent watching TV each day may increase your risk of an early death from cardiovascular disease by as much as 18%, Australian researchers say. What's on the television is not the problem; it's the time spent sitting while watching. The report was released online in Circulation.

"This research provides another clear link between too much sitting and death from disease," says lead researcher Dr. David Dunstan, head of the Physical Activity Laboratory at the Baker IDI Heart and Diabetes Institute in Victoria.

"The findings have serious implications for Americans and Australians when you consider that aside from sleeping, watching television is the behavior that occupies activity of four hours viewing a day," he adds.

The good news is research has shown that moving the muscles frequently throughout the day is one of the most effective ways of managing weight and protecting against disease, Dunstan adds.

"We tend to underestimate the value of incidental, nonsweaty activity throughout the day when we are either not sleeping or exercising—the more you move, the greater the benefits for health," he notes.

Dunstan points out that while obesity can add to these problems, even normal-weight people can have increases in blood sugar and cholesterol if they sit too much.

For the study, Dunstan's team collected data on the lifestyles of 8,800 healthy men and women aged 25 and older. In addition to lifestyle habits, the researchers tested participants' cholesterol and blood sugar levels. Over more than six years of follow-up, 284 people died. Among these deaths, 87 were due to cardiovascular disease and 125 from cancer.

The participants were grouped into three TV-watching categories: those who watched less than two hours a day, those who watched two to four hours a day, and those who watched more than four hours a day.

The researchers found that every hour of daily TV watching increased the risk of dying from any cause by 11%. For cardiovascular diseases the increased risk was 18%, and for cancer it was 9%. Compared with those who watched less than two hours per day, those who watched TV for more than four hours each day had an 80% increased risk of dying early from cardiovascular disease and a 46% increased risk of dying from any cause.

The association between TV watching and death remained even when the researchers took into account risk factors for cardiovascular disease such as smoking, high blood pressure, high cholesterol, unhealthy diet, excessive weight, and exercise.

"What we are now starting to understand is that the risks associated with sedentary behavior are not necessarily offset by doing more exercise," Dunstan said.

"In other words, irrespective of how much exercise you do, if you sit watching television for four hours on a daily basis you still have a substantially increased risk of early death from all causes and a much greater risk of cardiovascular disease," he said.

— Source: Brigham and Women's Hospital