A new study has shed light on the dangers of prolonged periods of inactivity, revealing a clear link between sitting for more than 30 minutes at a time and an increased risk of dying from cancer. Researchers tracked over 90,000 people for more than a decade, finding that continuous sedentary behaviour is associated with a higher risk of cancer mortality.
The study's findings, published in the peer-reviewed journal PLoS Medicine, indicate that sitting or lying down for extended periods can have serious consequences. For every additional hour of uninterrupted sitting while awake, the risk of cancer death rose by 10%, according to the research led by Dr Frederick Ho from the University of Glasgow. He stresses that even light movement should not be overlooked, and that breaking up sitting time with simple activities like a short walk could offer significant protection.
By analysing data from wearable devices worn by over 91,000 UK Biobank participants, researchers discovered that replacing sedentary periods with physical activity can help reduce various cancer risks. For example, substituting one hour of daily inactivity with light physical activity, such as ironing or washing up, was associated with a 12% lower risk of cancer death. Additionally, replacing just five minutes of inactivity with five minutes of vigorous physical activity was linked to a substantial 22% reduction in risk.
These findings build on existing research that has long linked prolonged sitting to increased risks of cardiovascular disease and certain cancers. The University of Glasgow team aimed to understand whether the pattern of sedentary time accumulation also influences health outcomes, and their results suggest it does. This adds a new layer of understanding to how our daily habits impact long-term health.
While the study provides compelling insights, its observational nature means that it establishes an association rather than direct causation. As such, further research is necessary to solidify these conclusions. Professor Kevin McConway, an emeritus professor of applied statistics at the Open University, who was not involved in the research, described the findings as interesting but noted that more research would be beneficial.