Prolonged Sitting Linked to Increased Cancer Mortality Risk, Study Finds

A new study published in PLOS Medicine reveals that prolonged uninterrupted sitting is associated with a higher risk of death from cancer. Conducted by researchers at the University of Glasgow, the study tracked 91,292 participants from the UK Biobank who wore activity monitors for one week and were followed for a median of 12.38 years. The analysis showed that each additional hour of continuous sitting per day increased the risk of cancer mortality by approximately 9%. Furthermore, extended sitting was linked to a greater likelihood of developing various cancers, including colorectal, liver, kidney, pancreatic, breast, ovarian, and thyroid cancers, many of which are associated with obesity and type 2 diabetes.

The researchers emphasized that frequent interruptions of sitting with light physical activity, such as short walks or standing tasks, significantly lowered cancer risk across most measures. Replacing one hour of prolonged sitting with light activity correlated with a 12% reduction in cancer mortality risk. The study suggests that brief breaks during sedentary periods may improve blood sugar and lipid regulation and boost metabolism, which are negatively affected by extended inactivity.

However, the authors caution that the observational nature of the study does not prove a direct causal link between sitting and cancer. Additionally, since participants only wore activity monitors for one week, it is unclear if this accurately reflects their long-term habits. Despite these limitations, the researchers conclude that meeting weekly physical activity goals alone may not be sufficient if much of the day is spent sitting continuously. Incorporating short movement breaks throughout the day could be a simple and effective strategy to enhance health and reduce cancer risk.