Light at Night (03-08-17)

Bedrosian and Nelson studied how being exposed to light at night influences wellbeing and mood.  They share that “Many systems are under circadian control, including sleep–wake behavior, hormone secretion, cellular function and gene expression. Circadian disruption by nighttime light perturbs those processes and is associated with increasing incidence of certain cancers, metabolic dysfunction and mood disorders. . . . Converging evidence suggests that circadian disruption alters the function of brain regions involved in emotion and mood regulation.”  Light at night seems to negatively affect mood throughout the day.  Ways to reduce circadian system disruption by artificial nighttime light mentioned by Bedrosian and Nelson include “‘Smart’ homes and ‘smart’ lighting fixtures [that] use precise LEDs to adjust the wavelength of light depending on the time of day. . . . New street light designs are being introduced to focus the light toward the street and avoid upward light leakage. And heavy black out curtains impermeable to light are being adopted for bedroom use.”

T. Bedrosian and R. Nelson.  2017.  “Timing of Light Exposure Affects Mood and Brain Circuits.”  Translational Psychiatry, vol. 7,