Alaina Shreves of the University of Oxford and colleagues from the UK and US conducted a prospective study and found that overall physical activity, including low-intensity exercise and regular walking, is associated with a dose-dependent reduction in cancer risk. The study used data from over 85,000 participants (median age 63) from the UK Biobank repository, who wore accelerometers for a week as part of the study. Machine learning algorithms were used to calculate their overall physical activity, sedentary behavior, and low- and moderate/high-intensity activity. Cases of 13 common cancers were monitored over an average of 5.8 years. Statistical analysis of the data was performed using Cox proportional hazards models, adjusting for demographics, general health, and lifestyle. The results were published in the British Journal of Sports Medicine.
Participants in the highest quintile of physical activity (more than 34.3 microgravity units) were found to have a 26 percent lower risk of developing cancer compared to those in the lowest quintile (less than 21.6 microgravity units). Low-intensity activity was associated with a six percent lower risk, while moderate/vigorous intensity activity was associated with a 13 percent lower risk. Daily step count was inversely correlated with cancer risk in a dose-dependent manner, reaching a plateau at around 9,000 steps per day. No significant association with walking intensity was found.
