We all know that sitting is the new smoking — it raises the risk of disability, diabetes, heart disease and cancer, not to mention obesity.
And research also shows that even if you hit the gym or the jogging path every day, sitting is bad for you.
A new study puts some precise numbers on the different types of cancer that might be associated with too much sitting around can do. For every two hours spent sitting in front of the computer or television, the average person raises his or her risk of colon cancer by 8 percent, of endometrial cancer by 10 percent and of lung cancer by 6 percent.
“The primary finding from our meta-analysis is that prolonged TV viewing and time spent in other sedentary pursuits is associated with increased risks of colon and endometrial cancer,” Daniela Schmid and Dr. Michael Leitzmann of the University of Regensburg in Germany wrote in their report, published in the Journal of the National Cancer Institute.
They did what’s called a meta- analysis, trolling through data gathered in 43 observational studies that covered 4 million people, including 68,936 diagnosed with various cancers.
The report found no link between amount of time spent sitting and other types of cancer, including prostate cancer, breast cancer and non-Hodgkin lymphoma.
Dr. Graham Colditz, an expert on cancer prevention at Washington University in St. Louis, says the data is strong enough to say that sitting actually causes colon and endometrial cancer. Yet hardly anyone is doing anything to help Americans move around more.
Colditz says the office is one place to start. “For example, given that working adults can spend eight or more hours a day at work, the worksite is an ideal and key setting to reduce sedentary time through worksite policies or changes to the physical work environment,” Colditz wrote in a commentary.
It’s still not clear what it is about sitting that raises cancer risk. “Prolonged sitting time lowers energy expenditure and displaces time spent in light physical activities, which consequently leads to weight gain over time,” Schmid and Leitzmann wrote. “Moreover, TV viewing is accompanied by increased consumption of unhealthy foods, such as sugar-sweetened beverages, sweets, and fast food,” they added.
It could be as simple as obesity, which itself is a major cause of cancer. Or it could be more complicated.
Either way, health experts agree there’s no downside to sitting less and exercising more.