Prolonged exposure, defined as daily use, to blue light (as would emanate from a smartphone or computer a screen) ,appears to have a measurable impact upon the ageing process. This occurs as the blue light wavelengths that are generated from light-emitting diodes damage cells in the brain and retinas.
The research, which has been undertaken at Oregon State University, is based on experiments using a model organism. At this stage the results cannot be fully extrapolated to humans; however, the findings as they currently stand raise questions and signal that additional study is required.
Blue light (visible light with wavelengths 400-450 nm) has been subject to many reviews into the impact on people. Most electronic screens produce blue light, with many white LEDs produced by pairing a blue LED with a lower-energy phosphor, thereby creating solid-state light (SSL).
For the research, Drosophila melanogaster (common fruit fly) was used as the model organism. This was due to the fly having similar cellular and developmental mechanisms to humans. The researchers looked at how flies responded to daily 12-hour exposures to blue light.
The flies exposed to daily cycles of 12 hours in light and 12 hours in darkness were found to have shorter lives when compared to flies kept in total darkness or where blue wavelengths were filtered out. Furthermore, those flies exposed to blue light had damage to retinal cells and brain neurons. There was also a deterioration with their locomotion.
Given that some of the flies in the study had not developed eyes (mutant strains), such flies were also affected. This led to the assessment that flies did not need to see the light in order to be harmed by it.
In terms of the reason, the researchers are of the view that the blue light is regulating certain genes. Lead researcher Jaga Giebultowicz emphasizes that natural light remains very important for the body’s circadian rhythm, which is the24-hour cycle of physiological processes affecting brain wave activity, hormone production and cell regeneration.
The research has been published in the journal npj Aging and Mechanisms of Disease. The research paper is titled “Daily blue-light exposure shortens lifespan and causes brain neurodegeneration in Drosophila.”
