Researchers at Baylor College of Medicine in the United States have explored a potential link between disrupted daily rhythms and the risk of liver cancer, pointing to a connection with jet lag. The findings appeared in the Journal of Hepatology.
The study used two groups of laboratory mice that had previously received human liver cell transplants. One group followed a natural day–night cycle, while the other experienced a deliberately altered sleep–wake schedule designed to mimic the effects of crossing multiple time zones, such as a flight from San Francisco to London. The researchers carefully compared outcomes between the two groups to understand how circadian disruption might influence liver health.
Compared with the mice living in harmony with their natural biorhythms, the jet-lagged animals showed shorter lifespans and a greater tendency to develop liver cirrhosis, a chronic condition in which healthy liver tissue is gradually replaced by fibrous tissue. In addition, jaundice and liver tumors appeared more frequently in the jet-lag group. These observations suggest that misalignment of internal clocks could be linked to several adverse liver outcomes in this animal model.
On the molecular level, the pathways that drive cancer progression in these mice bore similarities to those seen in humans. When the researchers restored normal circadian rhythms, tumor growth slowed and metastasis was reduced, indicating that timing signals may influence the tempo of cancer progression in the liver.
The scientists are careful to note that the study does not prove jet lag directly causes cancer in people. Rather, the data could inform the development of prevention strategies and targeted therapies for liver cancer associated with disrupted circadian biology. This work adds to a growing body of evidence that the timing system in the body can shape cancer risk and how it advances. (Baylor College of Medicine; Journal of Hepatology)
These results underscore the potential importance of maintaining regular sleep patterns for liver health and overall cancer risk management. More research in humans will be needed to translate these findings into clinical practice and public health guidance. (Baylor College of Medicine; Journal of Hepatology)