Summary
Night shift work suppresses melatonin production through light-at-night exposure detected by ipRGCs, disrupting circadian rhythmicity and potentially increasing breast cancer risk, particularly with age. Lighting designers in healthcare and workplace settings should consider minimizing short-wavelength (blue) light exposure during night shifts to preserve melatonin secretion and reduce associated health risks.
Key Findings
- Night shift work is associated with increased breast cancer risk, with melatonin suppression by artificial light at night proposed as a key biological mechanism.
- ipRGCs containing melanopsin are the primary photoreceptors mediating circadian light input to the SCN, driving melatonin suppression.
- Age-related decline in melatonin production compounds the effects of night shift-induced suppression, potentially elevating cancer risk in older shift workers.
Categories
Shift Work & Staff Wellbeing: Examines how night shift work disrupts melatonin production and circadian rhythms, with implications for breast cancer risk.
Sleep & Circadian Health: Discusses circadian rhythm disruption, melatonin suppression by light at night, and SCN-mediated photoentrainment via ipRGCs.
The Science of Light: Covers ipRGC-mediated light sensing, SCN clock gene interactions, and the biological mechanisms linking light exposure to melatonin suppression.
Author(s)
A Engin, AB Engin
Publication Year
2015
Related Publications
Shift Work & Staff Wellbeing
- Off the clock: from circadian disruption to metabolic disease
- Endocrine regulation of circadian physiology
- Working against the biological clock: a review for the Occupational Physician
- Shiftwork and light at night negatively impact molecular and endocrine timekeeping in the female reproductive axis in humans and rodents
- Circadian Rhythms Disrupted by Light at Night and Mistimed Food Intake Alter Hormonal Rhythms and Metabolism
Sleep & Circadian Health
- Phototransduction by retinal ganglion cells that set the circadian clock
- The mammalian circadian timing system: organization and coordination of central and peripheral clocks
- The two‐process model of sleep regulation: a reappraisal
- Melanopsin is required for non-image-forming photic responses in blind mice
- Strange vision: ganglion cells as circadian photoreceptors
The Science of Light
- Phototransduction by retinal ganglion cells that set the circadian clock
- Color appearance models
- The mammalian circadian timing system: organization and coordination of central and peripheral clocks
- Diminished pupillary light reflex at high irradiances in melanopsin-knockout mice
- Melanopsin is required for non-image-forming photic responses in blind mice