Night-Shift Work and Gastrointestinal Cancer Risk in Nurses: Review
Summary
This narrative review looked at research on whether working night shifts increases the risk of gastrointestinal (GI) cancers, such as colorectal and stomach cancer, in nurses. The review highlights that long-term night-shift work can disrupt circadian rhythms, lower melatonin (a hormone that helps regulate sleep and has protective effects against cancer), and increase obesity and insulin resistance — all of which may raise cancer risk. Evidence is strongest for colorectal cancer, especially after 15 or more years of rotating night shifts, while results for stomach cancer are less consistent.
Why It Matters For Night Shift Workers and Night Owls
For night-shift nurses, the review points out that cancer risk may build gradually through years of disrupted schedules. It emphasizes that how shifts are structured — like rotating patterns and recovery time — could play a role in lowering this risk. The findings also underline the importance of long-term health monitoring and lifestyle support for night-shift workers, since the connection between schedules and cancer may take decades to appear.
Notes
Recent thematic review on GI cancers in nurses.