Exposure to room light prior to bedtime suppresses melatonin levels, increases cancer
 

According to a recent study accepted for publication in The Endocrine Society's Journal of Clinical Endocrinology & Metabolism, exposure to electrical light between dusk and bedtime strongly suppresses melatonin levels and may impact physiologic processes regulated by melatonin signaling, such as sleepiness, thermoregulation, blood pressure and glucose homeostasis.

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