Prolonged sitting, watching TV may increase colorectal cancer risk

The new link between young-onset colorectal cancer -- diagnosed before age 50 -- and extended time spent sitting adds further weight to studies raising caution about being sedentary.

By Tauren Dyson

Feb. 5 (UPI) -- Sitting and watching TV for an extended time can increase the colorectal cancer risk for younger adults, a new study says.

Women under age 50 who sat and watched television for more than two hours at a time per day had a 70 percent higher risk of developing the deadly cancer, according to a study published this month in JNCI Cancer Spectrum. Women who sat for more than one hour per day also had an increased risk of 12 percent.


These results were true regardless of how much the women exercised or what their body mass index measured. They also held true for women without a family history of colorectal cancer.

"This study may help identify those at high risk and who might benefit more from early screening," Yin Cao, an assistant professor of surgery at Washington University School of Medicine and a study co-senior author, said in a news release.

Colorectal cancer is more aggressive in young people and often spotted in later stages than in older patients. The researchers say the connection between sitting while watching television and cancer is more closely associated to rectal cancer than colon cancer.


One previous study linked too much sitting to women having a 10 percent higher risk of developing myeloma, ovarian cancer, and invasive breast cancer.

Another study linked sitting for a prolonged period to having an increased risk of death due to 14 illnesses for both men and women.

This current study is one of the first to associate specific sedentary behavioral patterns with young-onset colorectal cancer risk.

"The fact that these results were independent of BMI and physical activity suggests that being sedentary may be an altogether distinct risk factor for young-onset colorectal cancer."

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