Sitting for more than 30 minutes at a time linked to higher risk of cancer death, study finds
A new study suggests that prolonged sedentary behavior lasting over 30 minutes daily is associated with an increased risk of dying from cancer. Each additional hour of uninterrupted sitting raises the risk by 10%, but breaking up these periods with light activity can mitigate the danger.
Researchers who tracked over 90,000 people for a decade found that sitting or lying down while awake for more than 30 minutes at a stretch each day is linked to a higher risk of cancer death. The findings, published in PLOS Medicine, indicate that for every extra hour of prolonged inactivity per day, the risk increases by 10%.
However, the study also suggests that interrupting prolonged sedentary bouts with physical activity can help reduce the risk. Replacing one hour of sedentary time per day with light physical activities such as ironing or washing up was associated with a 12% lower risk of cancer death. Substituting 30 minutes of inactivity with moderate activity like walking at an average pace corresponded to an 8% lower risk. The risk was 22% lower when five minutes of inactivity was replaced with five minutes of vigorous activity daily.
Dr. Frederick Ho, lead author of the study at the University of Glasgow, highlighted that sitting for more than 30 minutes continuously is particularly harmful regarding cancer risk. He noted that even short walks can be protective. Current health guidelines emphasize moderate or vigorous exercise, but the findings suggest that light movement should not be overlooked.
The research analyzed data from wearable devices worn by over 91,000 UK Biobank participants followed for an average of 12 years. The authors acknowledge limitations, as the study is observational and cannot prove causation. Professor Kevin McConway, emeritus professor of applied statistics at the Open University, who was not involved in the research, commented that the findings are interesting but further studies are needed.
