June 15, 2011

Too Much TV Can Kill You

(Ivanhoe Newswire) "“ Watching television is the most common daily activity in many populations around the world. It's estimated that the average American watches about five hours of television a day. But that doesn't come without risk. A new study says watching television for 2-3 hours a day or more can be associated with a higher risk of type 2 diabetes, cardiovascular disease, and death.

The study included combining the results of several studies that analyzed the association between TV viewing and the frequency of type 2 diabetes, nonfatal or fatal cardiovascular disease and all-cause mortality. The researchers searched medical literature for relevant studies from 1970 to March 2011, and identified eight studies that met the criteria for the study.

The study authors, Anders Grontved, M.P.H., M.Sc., of the University of Southern Denmark, Odense, and Frank B. Hu, M.D., Ph.D., of the Harvard School of Public Health, found that per 2 hours of TV viewing time per day was associated with a 20 percent higher risk for type 2 diabetes; a 15 percent increased risk for cardiovascular disease; and a 13 percent higher risk for all-cause mortality.

"While the associations between time spent viewing TV and risk of type 2 diabetes and cardiovascular disease were linear, the risk of all-cause mortality appeared to increase with TV viewing duration of greater than 3 hours per day," the authors write.

Based on frequency rates in the United States, the researchers estimated that the absolute risk difference per 2 hours of TV viewing per day was 176 for type 2 diabetes, 38 for fatal cardiovascular disease, and 104 for all-cause mortality.

"It is biologically plausible that prolonged TV viewing is associated with type 2 diabetes, cardiovascular disease, and all-cause mortality. Numerous prospective studies have reported associations of TV viewing with biological risk factors for these outcomes including obesity, adverse lipid levels, and clustered cardiovascular risk; however, some studies did not report these associations. Future research should assess the association of prolonged daily use of new media devices on energy balance and chronic disease risk," the authors write.

SOURCE: JAMA, June 14, 2011.