Lask of natural light said to disrupt circadian rhythms…
Circadian rhythms are the physical and mental changes in the body responding to the cycle of light and darkness which regulate sleep/wake cycles, hormone releases, and body temperature. The study suggests the circadian rhythm could be disrupted due to a lack of natural lighting in combination with increased artificial lighting.
Melatonin release, which affects the sleep cycle, is influenced by the circadian rhythm. Healthy sleep cycles have been linked to lower risks of diabetes, depression, obesity, and some types of cancer.
The researchers write, “The question is the extent to which circadian disruption compromises human health, and can account for a portion of the modern pandemics of breast and prostate cancers, obesity, diabetes and depression. As societies modernize (i.e. electrify) these conditions increase in prevalence. There are a number of promising leads on putative mechanisms, and epidemiological findings supporting an aetiologic role for electric lighting in disease causation. These include melatonin suppression, circadian gene expression, and connection of circadian rhythmicity to metabolism in part affected by haem iron intake and distribution.”
By improving lighting, for example, dimmer lights in the evening and avoiding tablets and smartphones, we might reduce these physiological effects.
Electric light, particularly at night, disrupts human circadian rhythmicity: is that a problem? Richard G. Stevens. The Royal Society Philosophical Transactions B, March 16, 2015. DOI: 10.1098/rstb.2014.0120