In November 2018 researchers from the USA, China and the Republic of Korea assessed the effect of sedentary behaviour, primarily time watching television, on risk of young-onset colorectal cancer in 89,278 women, aged 25-42 years at the start of the study. During the 1 262 540 person-years of follow-up a total of 118 young-onset diagnoses of colorectal cancer were made. Results showed that sedentary TV viewing time was significantly associated with increased risk of young-onset colorectal cancer. This association was observed in individuals with no family history of colorectal cancer and was more pronounced for rectal cancer.
Nguyen LH et al. Sedentary Behaviors, TV Viewing Time, and Risk of Young-Onset Colorectal Cancer. JNCI Cancer Spectr. 2018 Nov;2(4):pky073