Frontiers: Poor Sleep May Increase the Risk of Breast Cancer by 30%
19:15 16 October, 2026Sleep disturbances are associated with an increased risk of breast cancer. Women with the least healthy sleep habits were 30% more likely to develop the disease than those with the healthiest sleep patterns. This is the conclusion reached by Chinese researchers who analyzed data from more than 220,000 people. The study was published in the journal Frontiers in Endocrinology.
Researchers examined data from 220,089 participants in the UK Biobank project, whose health was monitored for an average of 11.6 years. During this period, 8,459 participants were diagnosed with breast cancer.
The scientists assessed sleep quality using five indicators and assigned participants scores ranging from zero to five. Higher scores indicated healthier sleep patterns. A comparison of the groups at opposite ends of the scale showed that those with the least healthy sleep habits had a 30% higher risk of developing the disease.
To investigate the biological processes that might explain this association, the researchers also examined 251 blood-based metabolic markers. According to the authors’ calculations, changes in some of these metabolic indicators could account for approximately 13.5% of the observed association between sleep patterns and breast cancer risk.
The association persisted even after the researchers accounted for genetic predisposition to the disease. However, the study was observational and does not prove that sleep disturbances directly cause breast cancer. The findings also do not mean that improving sleep alone can prevent the disease.