Adults who watch television for three hours or more each day may double their risk of premature death, compared with those who watch less, according to a new University of Navarra study published in the Journal of the American Heart Association.

"Television viewing is an important sedentary behavior and there is an increasing trend toward all sedentary behaviors," as highlighted by Professor Miguel A. Martinez-Gonzalez, lead author of research. "Our results are consistent with a series of previous programs of study in which time spent watching television was related to mortality. In our case, we have been able to prove that this adverse effect is present at equal exhibition to other mortality risk factors."

Researchers evaluated 13,284 young, initially healthy graduates (average age 37 years, 60% female) from the project Follow-up University of Navarra (SUN) to determine the association between three types of sedentary behaviors and risk of all-cause death. These behaviors were: television viewing time, computer time, and driving time. Participants were followed for a average of 8.2 years. The results were 97 deaths: 19 from cardiovascular causes, 46 from cancer and 32 from other causes.

The risk of death was twice as high for participants who watched three or more hours of television per day compared with those who were exposed to one hour or less, all other per diem expenses and lifestyle factors being equal. This risk was always evident after considering a wide range of other variables related to mortality....

There is no association with computer use and driving.

In contrast, the researchers found no association association between time spent using a computer or driving and the risk of premature death. The authors of research acknowledge that more programs of study are needed to confirm the effect of computer use and hours spent driving on mortality, and to determine the biological mechanisms that explain these associations.

"As the population ages, sedentary behaviors become more frequent, especially spending many hours a day watching television, and this represents an additional burden of sedentary behavior that increases many of the health problems associated with aging," stresses University of Navarra professor Martínez-González. "Our recommendations for adults are to increase their physical activity, avoid long sedentary periods and reduce exhibition to no more than one or two hours a day," he concludes.