Killing me softly with your TV screen

Researchers in Australia find that watching TV more than four hours a day increases risk of death from cardiovascular disease by 80 percent.

Elizabeth Armstrong Moore
Elizabeth Armstrong Moore is based in Portland, Oregon, and has written for Wired, The Christian Science Monitor, and public radio. Her semi-obscure hobbies include climbing, billiards, board games that take up a lot of space, and piano.
Elizabeth Armstrong Moore
2 min read
Researchers in Australia find that watching TV more than four hours a day increases risk of death from cardiovascular disease by 80 percent. stars alive/Flickr

The other day I wrote about devices such as Philips' DirectLife being valuable precisely because they remind us that even the most basic physical activity is good for our health. That was a sort of silver lining way to put it. Now, a harder truth.

New research out of Australia published this week in Circulation, the Journal of the American Heart Association, finds that every hour of TV watching--or being sedentary at all--increases one's risk of dying younger from cardiovascular disease (CD).

Researchers tracked the lifestyle habits of 8,800 adults, interviewing 3,846 men and 4,954 women age 25 and older, all of whom underwent testing to measure biomarkers such as cholesterol and blood sugar levels. Participants were enrolled from 1999 to 2000 and monitored through 2006. They were grouped into one of three categories: those who watched less than two hours a day; those who watched between two and four hours; and those who watched more than four.

The numbers show that those who watched more than four hours a day had an 80 percent increased risk of cardiovascular disease-related death than those who watched less than two hours a day. This increase in risk held in spite of how study participants fared on independent and common CD risk factors, including smoking, high blood pressure, high blood cholesterol, unhealthy diet, and high waist circumference.

The findings also suggest that any prolonged sedentary behavior, such as sitting at a desk and/or in front of a computer, may pose similar risks to one's health.

The human body is meant to be in motion, says lead author David Dunstan, who is also a professor and head of the Physical Activity Laboration in the Division of Metabolism and Obesity at the Baker IDI Heart and Diabetes Institute in Victoria, Australia:

Technological, social, and economic changes mean that people don't move their muscles as much as they used to; consequently the levels of energy expenditure as people go about their lives continue to shrink. For many people, on a daily basis they simply shift from one chair to another--from the chair in the car to the chair in the office to the chair in front of the television.

Average daily TV watching in Australia and the U.K. is three hours, and jumps to a whopping eight in the U.S., where two-thirds of all adults are overweight.

Still, Dunstan is not all doom and gloom, and insists that changing one's sedentary habits doesn't have to be hard: "In addition to doing regular exercise, avoid sitting for prolonged periods and keep in mind to 'move more, more often.' Too much sitting is bad for health."

Maybe companies like Google have it right: make it easier for your employees to be active, or you'll pay through the nose for their health insurance. Now, perhaps, employers should rethink how many 15-minute breaks to grant per day. And if you'll excuse me, I feel a strong urge to do some jumping jacks.