A new study just released by the Journal of the American Medical Association has pointed to a link between television viewing and the risk of type 2 diabetes, cardiovascular disease and all-cause mortality — causing a rash of news reports claiming that television will kill you.
Alright folks, say it with me now. Correlation is not causation.
This information comes from a meta-analysis of eight studies: four of which reported on type 2 diabetes, four on cardiovascular disease, and three on all-cause mortality.
For every two hours of TV viewing per day, your chances of diabetes increased by 20%; for cardiovascular disease it was 15%; and a 13% increase in all-causes mortality. Sure, that may sound steep, but once you look at the actual numbers, it's not a huge leap. Write the researchers:
The estimated absolute risk differences per every 2 hours of TV viewing per day were 176 cases of type 2 diabetes per 100 000 individuals per year, 38 cases of fatal cardiovascular disease per 100 000 individuals per year, and 104 deaths for all-cause mortality per 100 000 individuals per year.
That's right, less than two people more in a thousand.
Now, we're not going to say that spending 12 hours a day in front of your computer as a freelance blogger is healthy, but this confluence of correlation and causation does nothing to get to the root of the problem. Being too sedentary is universally acknowledged as a bad thing, but watching TV won't give you diabetes. There's diet, exercise, genetics, lifestyle, and a whole bunch of other things to take into account too, not just staring at a screen all day.