Monday January 18, 2010

New Study Reveals TV Viewing Associated with Premature Death

By Thaddeus M. Baklinski

MELBOURNE, Australia, January 18, 2010 ( – Australian researchers at the Baker IDI Heart and Diabetes Institute have found that mortality rates from all causes and especially from cardiovascular disease are significantly higher with increased television viewing time in adults.

The research team led by Dr. David Dunstan examined the associations of prolonged television viewing time with all-cause, cardiovascular disease (CVD), cancer, and non-CVD/noncancer mortality in Australian adults.

The study found that each hour spent in front of the television daily was associated with an 18 per cent increased risk of cardiovascular disease (CVD) related death, an 11 per cent increased risk of death from all causes, and 9 per cent increased risk of cancer death.

The study tracked 8,800 people over six years and found that, relative to those watching less than 2 hours of television per day, there was a 46% increased risk of all-cause and an 80% increased risk of CVD mortality in those watching 4 hours or more of television per day.

The report indicates that these statistics were independent of traditional risk factors such as smoking, blood pressure, cholesterol, and diet, as well as leisure-time exercise and waist circumference.

The problem the researchers identified, even among people who exercised regularly, was the prolonged periods of time spent sitting still.

“It’s the incidental moving around, walking around, standing up and utilizing muscles that (doesn’t happen) when we’re plunked on a couch in front of a television,” Dr. Dunstan explained in a recorded interview on the Baker IDI website.

“The absence of movement can slow down our metabolic processes,” he said. “When we’re sitting down or even lying on the couch, we’re burning the equivalent of the energy we burn when we’re sleeping.”

The study, published in the American Heart Association journal Circulation, focused on TV watching primarily because it is the predominant leisure-time sedentary behavior in many countries.

“Recent time-use surveys from Australia, the Unites States, and the United Kingdom indicate that, aside from sleeping, watching television is the behavior that occupies the most time in the domestic setting,” the report states.

A recent survey by the Nielsen Co. found that North Americans averaged 151 hours of TV viewing a month — more than five hours a day.

Dr. Dunstan suggests in the conclusion to the report that reducing time spent watching television (and possibly other prolonged sedentary behaviors, such as time spent in front of a computer), along with an increase in appropriate moderate- to vigorous-intensity exercise may be of benefit in preventing cardiovascular disease and premature death.

“The implication of these findings is that an extraordinary amount of sitting can undo the good effects that we know are a benefit when we get regular exercise,” Dr. Dunstan said.

The full text of the research report is available here.