Watching hours of TV daily could shorten your life

An employee watches a program inside an appliance store selling second-hand television in Manila July 4, 2008.

SYDNEY (Reuters) - Couch potatoes, beware. Sitting in front of the television for hours daily could shorten your life, according to an Australian study.

Researchers from the Baker IDI Heart and Diabetes Institute in the state of Victoria tracked the lifestyle habits of 8,800 adults and found that each hour spent in front of the TV daily increased the risk of dying earlier from cardiovascular disease.

The study, published in "Circulation: Journal of the American Heart Association," found every hour in front of the TV was associated with an 11 percent increased risk of death from all causes, a 9 percent higher risk of cancer death, and an 18 percent increased risk of cardiovascular disease (CVD) related death.

"Compared with people who watched less than two hours of television daily, those who watched more than four hours a day had a 46 percent higher risk of death from all causes and an 80 percent increased risk for CVD-related death," the researchers said in a statement.

The researchers said this association held regardless of other independent and common cardiovascular disease risk factors, including smoking, high blood pressure, high blood cholesterol, unhealthy diet, excessive waist circumference, and leisure-time exercises.

Researcher David Dunstan said the study focused specifically on television watching but the findings suggest that any prolonged sedentary behavior, such as sitting at a desk or in front of a computer, may pose a health risk.

"The human body was designed to move, not sit for extended periods of time," said Dunstan, head of the institute's physical activity laboratory in the division of metabolism and obesity.

"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."

Dunstan said the findings applied not only to individuals who were overweight and obese, but also those of a healthy weight.

"Even if someone has a healthy body weight, sitting for long periods of time still has an unhealthy influence on their blood sugar and blood fats," he said.

"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."

The researchers interviewed 3,846 men and 4,954 women aged 25 and older who underwent oral glucose-tolerance tests and provided blood samples so researchers could measure biomarkers such as cholesterol and blood sugar levels.

Participants were enrolled from 1999 and followed through 2006 and reported their television-viewing habits.

(Reporting by Belinda Goldsmith, Editing by Miral Fahmy)