Yeah, yeah, yeah, we get it already: A sedentary lifestyle will send you to an early grave. You have to be more active if you want to live a long and healthy life. Now, a new study published in the Journal of the National Cancer Institute has hammered home that point once again. “Prolonged TV viewing and time spent in other sedentary pursuits is associated with increased risks of certain types of cancer,” wrote the authors in their conclusion. In particular, they highlight colon, endometrial, and lung cancers. OK, got it. Scary news delivered. Could you move a little? You’re blocking the TV.
Some of the very same scientists who keep telling us not to eat sugar and to stop binge drinking have found a new way to torment us; they've begun to investigate the downside of a sedentary lifestyle. In fact, any number of recent studies have linked too much sitting around to obesity, diabetes, and even all-cause mortality. For these reasons, the American Cancer Society as well as other organizations have begun to change their guidelines and now recommend you limit the hours you spend sitting, lying down, watching TV, and taking part in other forms of screen-based entertainment.
Now a team of researchers from University of Regensburg, Germany, have conducted a new and quite thorough investigation of sedentary lifestyles. The team combed through 43 observational studies, including analysis of over four million people and 68,936 cancer cases. Next, they broke down sedentary behavior into three categories — TV viewing time, occupational sitting, and total sitting time — and compared the highest levels of sedentary time with the lowest and calculated relative risks for many different types of cancer. What did they find?
The amount of increased risk with each two-hour increase in sitting time amounted to eight percent for colon cancer, 10 percent for endometrial cancer, and six percent for lung cancer. TV viewing time showed the strongest relationship with colon and endometrial cancer. The news gets worse. Physical activity did not seem to produce a positive counter-balancing effect; so even if you exercise regularly, too much time spent sitting may still be detrimental to your health.
There was one small patch of brightness in the study, though. The researchers found no increased risk associated with sedentary behavior and cancers of the breast, rectum, ovaries, prostate, stomach, esophagus, testes, renal cell, and non-Hodgkin lymphoma. However, the bleak results of this study will still make you think twice before you pick up the remote or log onto your favorite shows. Another bit of fun ruined!
Source: Schmid D, Leitzmann MF. Television Viewing and Time Spent Sedentary in Relation to Cancer Risk: A Meta-analysis. Journal of the National Cancer Institute. 2014.