Published: January 19, 2010 in the NYTimes
A new study from Australia suggests that couch potatoes live shorter lives.
The study followed 8,800 adults ages 25 and older for six and a half years and found that each daily hour of television viewing was associated with an 18 percent increase in deaths from heart disease and an 11 percent increase in overall mortality.
Those who watched television four hours or more a day were 80 percent more likely to die of cardiovascular disease than those who watched two hours or less, and 46 percent more likely to die of any cause. And it did not matter whether they were overweight, according to the study, which appeared Jan. 11 in the online edition of Circulation: Journal of the American Heart Association.
Although it is possible that people who were already ill watched more television than those who were healthy, the researchers tried to rule that out by excluding subjects who already had heart disease and by adjusting for differences in risk factors like diet and smoking.
While the benefits of physical activity have been well studied, there is growing interest among researchers in assessing the effects of being sedentary.
“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,” said the study’s lead author, David Dunstan of the Baker IDI Heart and Diabetes Institute in Victoria, Australia. “Even if someone has a healthy body weight, sitting for long periods still has an unhealthy influence on blood sugar and blood fats.”