Digestive system cancers (DSCs)—encompassing cancers of the digestive tract (mouth, throat, oesophagus, stomach, small intestine, colon and rectum) and accessory organs (pancreas, gallbladder and liver)—remain a major global health challenge, accounting for roughly 30% of cancer diagnoses and 40% of cancer-related deaths in 2024. While obesity, smoking, excessive alcohol intake, and poor diet are established risk factors, physical activity has emerged as a potentially modifiable factor that may reduce DSC risk through mechanisms such as improved insulin sensitivity, reduced inflammation, and enhanced gastrointestinal motility.
A new study published in JAMA Oncology has provided some of the most comprehensive evidence to date linking long-term physical activity patterns with reduced risk and mortality from these cancers. Researchers analysed data from 231,067 participants in three large US cohorts—the Health Professionals Follow-Up Study (HPFS) and the Nurses’ Health Studies I and II (NHS/NHSII)—with up to 32 years of follow-up. The study assessed both total leisure-time physical activity and consistency in meeting recommended guidelines over time.
Study Results
Over three decades of follow-up (median age 43 [IQR, 36–55] years), 6,538 incident DSCs and 3,791 DSC deaths were documented. Higher physical activity levels were significantly associated with lower risk and mortality:
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Overall DSC risk: ≥45 vs <3 MET-hours/week, hazard ratio (HR) 0.83 (95% CI, 0.74–0.93; P < .001 for trend)
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DSC mortality: HR 0.72 (95% CI, 0.62–0.83; P < .001 for trend)
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Digestive tract cancers: HR 0.85 (95% CI, 0.75–0.97)
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Digestive accessory organ cancers: HR 0.73 (95% CI, 0.58–0.92)
Traditional dose-response analysis suggested the greatest risk reduction occurred at around 50 MET-hours/week. However, when long-term consistency was taken into account, those who consistently achieved guideline-level moderate activity (median 16.9 [IQR, 13.6–20.5] MET-hours/week) over 30 years had a substantial reduction in DSC risk (HR 0.83; 95% CI, 0.75–0.90). Performing much higher amounts of exercise (median 38.5 [IQR, 28.5–53.8] MET-hours/week) did not offer additional benefit (HR 0.87; 95% CI, 0.81–0.93).
Consistent, Moderate Activity is Key
“In this cohort study, higher physical activity levels were associated with lower DSC risk and mortality for both digestive tract and digestive accessory organs,” the authors wrote. “Consistently achieving the recommended level (≥7.5MET-hours/week) might be a more effective strategy for lowering DSC risk than achieving high levels.”
The protective associations were independent of BMI and persisted across age, sex, and dietary subgroups, suggesting benefits beyond weight control. The authors propose that sustained physical activity may influence insulin and lipid metabolism, systemic inflammation, and immune function—all key pathways in digestive tract carcinogenesis.
Clinical Implications
These findings underscore the importance of encouraging patients to adopt sustainable, long-term exercise habits rather than focusing on intensity alone. Regular, moderate activity—equivalent to about five hours of brisk walking or two hours of running per week—appears sufficient to confer optimal protective effects.
Paper: Zhang, Y., et al. Consistent Adherence to Physical Activity Guidelines and Digestive System Cancer Risk and Mortality. JAMA Oncology. 30 October 2025. Access online here.
