The dark side of artificial light

Abstract

Light is necessary for life, but increasing exposure to artificial light may be detrimental to human health. With prevalent use of light-emitting diodes (LEDs) in ambient lighting and electronic devices, humans are increasingly exposed to blue light that appears white due to addition of other colours. Excessive blue light can damage eyes, but it is not known whether daily LED exposure across lifespan may have other adverse health effects. A recent study in short-lived model organism Drosophila melanogaster revealed that cumulative, long-term exposure to blue light impacts brain function, accelerates the aging process and significantly shortens lifespan compared to flies maintained in constant darkness or in white light with blue wavelengths blocked. Increased mortality and brain neurodegeneration was also observed in flies with genetically ablated eyes, demonstrating damage to non-retinal cells. As molecular responses to light are similar in the cells of both fruit flies and humans, these studies suggest that lifelong daily blue light exposure may impair cellular health in humans.