A new study has revealed that walking for just five hours a week could significantly lower your risk of developing or dying from deadly digestive system cancers — including bowel, liver, and pancreatic cancer.
Published in JAMA Oncology, the groundbreaking research from Harvard T.H. Chan School of Public Health found that maintaining a moderate level of physical activity, such as walking or other heart-pumping exercises for about 17 hours weekly, can dramatically reduce cancer risks — but only if sustained over 30 years.
In 2024 alone, cancers of the digestive system — such as those affecting the mouth, throat, esophagus, stomach, bowel, pancreas, gallbladder, and liver — accounted for 40% of all cancer-related deaths worldwide. While unhealthy habits like smoking, excessive drinking, and lack of exercise are well-known risk factors, this study provides new insight into how much and how long consistent exercise is needed for cancer prevention.
Researchers tracked 231,067 cancer-free adults aged 40 to 75 for around 32 years across three major U.S. studies. Participants regularly reported their activity levels, including walking, jogging, swimming, cycling, tennis, or even stair climbing.
Over the course of the study, 6,358 digestive cancer cases and 3,791 deaths were recorded. Results showed that individuals who consistently stayed active over the decades had a markedly lower risk of developing or dying from digestive cancers.
The team emphasized that while around 50 hours of exercise a week offers the most benefit, even moderate, regular activity — such as walking five hours weekly — can make a significant difference. The key, researchers say, is not intensity, but long-term consistency.

