Excess TV may cut life short

Sitting in front of a television set for hour after hour day after day may raise the risk of death from heart disease and other causes - even in people who do not weigh too much.

Researchers tracked lifestyle habits of 3,846 men and 4,954 women in Australia divided into three groups: those who watched TV less than two hours per day, those who watched between two and four hours, and those who watched more than four hours.

The negative health effects were seen in the heavy TV watchers regardless of other heart disease risk factors, including smoking, high blood pressure, high blood cholesterol, bad diet and lack of exercise. Only a relatively small number of participants (284 people) died during the study including 87 from heart disease and 125 from cancer. People with pre-existing heart disease and some others were excluded from the study.

Compared with adults who watched less than two hours of TV a day, those who watched more than four hours had a 46 percent higher risk of death from all causes and an 80 percent higher risk of cardiovascular death during the six-year study period. Each hour spent sitting in front of the TV per day raised a person's risk of death from cardiovascular disease by 18 percent and the risk of cancer death by 9 percent. The study focused on watching television. But the findings suggest that sitting anywhere for extended periods of time - at a desk or in front of a computer - may pose a health risk.

The high risk was seen in obese people in the study as well as those with a healthy weight because prolonged periods of sitting have an unhealthy influence on blood sugar and blood fat levels. A lot of the normal activities of daily living that involved standing up and moving the muscles in the body have been converted to sitting. 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.