3+ hour TV watching may increase cardiac mortality risk

Young adults who watched three or more hours of television a day increased their risk of death from cardiovascular disease or cancer twofold, according to a study published online June 25 in the Journal of the American Heart Association.

The study utilized the Seguimiento Universidad de Navarra (SUN) cohort to determine the effects of certain sedentary habits on mortality. The participants were graduates of Spanish universities with a mean age of 37 years. Researchers looked at driving time, computer use and television watching time to determine connections, if any, to mortality risk.

Nineteen out of the 13,284 participants died from a cardiovascular-related event. Forty-six deaths were attributable to cancer and 32 deaths were related to neither cardiovascular disease nor cancer.

Incident rate ratios for death in those individuals watching three or more hours of television a day were 2.04 and increased 1.4 for each additional two hours watched. In contrast, using a computer or driving mortality risks were reported to be 1.1 and 0.94 respectively. Each additional two hours a day on the computer added 0.96 to risk, while driving added 1.14. All sedentary behavior together had an increased incident rate ratio of 1.17 for each additional two hours.

Lead author Miguel Martinez-Gonzalez, MD, PhD, MPH, of the Department of Public Health at the University of Navarra in Pamplona, Spain, stated in a press release, “Television viewing is a major sedentary behavior and there is an increasing trend toward all types of sedentary behaviors. Our findings are consistent with a range of previous studies where time spent watching television was linked to mortality.”

The research team cautioned that the growth in sedentary lifestyle will show an increase in mortality from cardiovascular disease, cancer and other related conditions as the population ages. They suggested improving activity level early will help reduce risks later in life and noted that further studies would need to confirm the effects of computer use and driving time on mortality, disease risks and biological mechanisms.