A University of Glasgow study has revealed that sitting or lying down for more than 30 minutes at a time each day is linked to a higher risk of dying from cancer. The research, published in PLOS Medicine, analyzed data from over 91,000 UK Biobank participants who wore wearable devices and were monitored for an average of 12 years.
Key Findings on Sedentary Behaviour
The study found that every additional hour of uninterrupted inactivity per day was associated with a 10% greater risk of cancer death. Extended periods of sedentary behaviour, such as sitting or reclining while awake, have long been linked to cardiovascular disease and certain cancers, but this research provides new insights into how the accumulation of sedentary time affects cancer mortality.
How to Reduce the Risk
Researchers discovered that replacing sedentary habits with physical activity could cut the risk by over 20%. Specifically, swapping one hour of sedentary time with light physical activity daily—such as gentle walking or routine housework—lowered the risk of cancer death by 12%. Substituting 30 minutes of inactivity with moderate physical activity, like walking at a normal pace, reduced the risk by 8%. Most notably, replacing five minutes of inactivity with five minutes of intense physical activity each day was linked to a 22% lower risk of cancer death.
Dr Frederick Ho, lead author of the study, said: "What our data shows is that sitting for more than 30 minutes at a time is particularly linked to a higher risk of cancer. The good news is that breaking up your sitting time with something as simple as a short walk could be protective." He added: "Current health guidelines focus heavily on moderate or vigorous exercise, but our findings show that light movement shouldn't be ignored. Moving forward, clinical trials will help us move beyond blanket advice and develop personalised strategies for breaking up sitting time."
Implications for Public Health
The study, titled "Accelerometry-measured prolonged and interrupted sedentary behaviour and cancer incidence and mortality: A cohort study of 91,292 UK Biobank participants," underscores the importance of interrupting prolonged sitting with even light activity. The findings suggest that simple changes, such as taking short walks or doing household chores, can significantly reduce cancer death risk.
