Watching too much TV raises death risk

A new study suggests that it does not matter how long you engage in physical activity  or exercise, sitting too long in your leisure time could increase the risk of death from all causes, particularly cardiovascular deaths.

The study led by Dr. Alpa Patel, an epidemiologist with the American Cancer Society and colleagues showed that both men and women who sit for a longer time daily were at a higher risk of dying from all causes.

The study published online July 22 in the American Journal of Epidemiology is not a trial and the findings do not mean that if an individual who reduces his leisure time spent sitting would definitely cut his risk of death.

The findings are similar to what Australian researchers reported recently.

Dunstan D.W. and colleagues from Baker IDI Heart and Diabetes Institute reported a study in the Jan 2010 issue of Circulation saying that the time spent watching TV, which is the predominant leisure-time sedentary behaviour, was associated with risk of all-cause and cardiovascular deaths.

The researchers followed 8800 adults aged 25 or older participating in the Australian Diabetes, Obesity, Lifestyle Study for on average 6.6 years during which 284 deaths from cardiovascular events and 125 deaths from cancer were recorded.

After adjusting for age, gender, waist circumference and exercise, the researchers found each one-hour increment in television viewing time per day were associated with an 11 percent increased risk for all-cause mortality, an 18 percent increased risk for cardiovascular death and a 9 percent increased risk for cancer death. 

Compared to those who spent fewer than 2 hours per day watching TV, those who spent anywhere between 2 and 4 hours or more than 4 hours a day were at 13 percent or 46 percent increased risk for all-cause death respectively.  The increase in the cardiovascular death was 18 and 80 percent respectively.

But the researchers found no significant association between watching Tv and risk for both cancer death and non-CVD or noncancer death.

By David Liu