A new observational study suggests a simple way to lower cancer death risk: regularly break up long periods of sitting.
Researchers from the University of Glasgow tracked over 91,000 participants in the UK using wrist-worn activity monitors for seven days. They then followed their health outcomes for about 12 years.
The study defined prolonged sedentary behavior as any uninterrupted sitting session lasting at least 30 minutes. Each additional hour per day of this prolonged sitting was associated with a 10% higher risk of cancer death.
Conversely, replacing just one hour of sitting with light activity was linked to a 12% lower risk. Swapping 30 minutes for moderate activity showed an 8% reduction, and replacing just five minutes with vigorous activity was associated with a 22% lower risk.
"This study adds to growing evidence that prolonged sedentary behavior is an independent health risk," said Dr. Georgia Spear, chief of breast imaging at Northwestern Medicine. "Breaking up sitting with regular movement may provide measurable health benefits."
Light activity includes walking at a low speed or doing household chores like ironing or washing dishes. The researchers caution the study cannot prove causality and that the monitored period may not capture the full context of sedentary habits.
Experts recommend standing and moving every 30 to 60 minutes, taking short walking breaks, and incorporating light activity throughout the day as part of a broader cancer prevention strategy.