By MERRILL GOOZNER
The latest Journal of the American Medical Association has a meta-analysis of the limited number (8) of studies that looked at peoples’ television habits and their relationship to incidence of diabetes, heart disease and early death. According to Anders Grøntved of the University of Southern Denmark and Frank B. Hu of Harvard Medical School, two hours of television viewing per day resulted in a 20 percent increase in type 2 diabetes, a 15 percent increase in heart disease, and a 13 percent increase in all-cause mortality. All the findings were statistically significant. In absolute terms, for every 100,000 people who viewed TV for at least two hours a day, there were an additional 176 cases of type 2 diabetes, 38 cases of fatal cardiovascular disease, and 104 deaths of any type.
Is this really a smoking gun? Correlation is not causation. What else do we know about people who watch at least two hours of TV a day? Are they depressed? Are they bored? Is their sedentary lifestyle a product of some underlying condition, which may actually be the proximate cause of the diseased state?
As the authors note in their discussion:
Although the included studies attempted to control for various known risk factors, the possibility of residual or unmeasured confounding cannot be ruled out. . . Although all of the included studies excluded participants with chronic disease at baseline, it is still possible that reverse causality may contribute to some of the associations reported herein if participants with subclinical stages of disease become more sedentary.
Karen Goozner, a certified school counselor, recently surveyed the literature that associated violent childhood behavior with watching violence on TV. The literature suggested it was a co-factor, not a causative factor. she said. In other words, families with a history of violence – who believed physicial violence was an appropriate response to social or child-rearing problems and role-modeled that behavior for their children — tended to also watch violent television for entertainment. Did the TV do it? Or was it mom or dad?
Television can be blamed for many things. Bad writing. Bad acting. But let’s not blame the escape valve for the pressures of modern life and worklife that has driven western Europeans (3.5 hours a day average); Australians (4 hours a day average) and Americans (5 hours a day average) to seek refuge in the depressing, all-night escape of drinking in front of the tube.