Research
Hormonal
Shift work, particularly night shift work involving exposure to light at night, is associated with an increased risk of breast cancer.
Women who work night shifts have a higher risk of breast cancer, likely because artificial light at night suppresses melatonin. If you work nights, minimizing light exposure during work hours and ensuring total darkness during daytime sleep may help mitigate this risk.
ModerateSupportsMEDIUM confidence
Several studies, including the Nurses’ Health Study, report increased risk of cancer among shift workers including breast cancer... The mechanism proposed in these studies is increased exposure to light at night, resulting in reduced levels of endogenous melatonin.
Why this rating
Based on large observational studies (Nurses' Health Study) and supported by mechanistic hypotheses, but the paper notes a need for further prospective exposure measures.
Source
Circadian misalignment and health
Kelly Glazer Baron et al. · International Review of Psychiatry · 2014
DOI 10.3109/09540261.2014.911149
narrative_reviewCited 617×
Read the paper DOI resolved against Crossref · corpus check 2026-06-10
More from this paper
- Circadian misalignment causes dysregulation of appetite-regulating hormones (specifically decreased leptin) and impaired glucose metabolism, independent of sleep duration.Good
- Circadian misalignment, specifically evening chronotype and social jet lag, is associated with increased risk for obesity, type II diabetes, and cardiovascular disease in humans.Moderate
Related findings · Hormonal
- Initial treatment for type 2 diabetes should be a combination of metformin and either an SGLT-2 inhibitor or a GLP-1 receptor agonist to achieve cardiorenal protection, rather than monotherapy or older agents like sulfonylureas.Strong
- For patients with specific monogenic obesity syndromes (leptin deficiency, POMC/PCSK1/LEPR mutations), targeted pharmacotherapy (recombinant leptin or setmelanotide) is highly effective and should be prioritized, unlike in polygenic obesity.Strong
- Continued weekly administration of 2.4 mg subcutaneous semaglutide prevents weight regain and promotes further weight loss in adults with overweight or obesity, whereas switching to placebo results in significant weight regain.Strong
This is one finding among thousands. Every one is graded and traced to its source, so you can see what the evidence actually supports. Browse the research →