Science Research | Prolonged exposure to blue light might accelerate aging

Long-term exposure to blue light can catalyze the ageing process, at least in small fruit flies.

Is Blue Light Bad For You, blue lamps
Is Blue Light Bad For You

The conclusion that blue light exposure might shorten lifespan and cause brain neurodegeneration, was made by scientists from the University of Oregon.

The study was published in the journal of Aging and Mechanisms of Disease.
Blue-light exposure leads to neurodegeneration in small fruit flies

The excess of artificial light in people's lives causes concern among scientists. In particular, the effects of prolonged exposure to blue light emitted, for example, from LEDs in household appliances such screens of smartphones, monitors and TVs, are poorly understood.

It is known that blue light negatively affects sleep patterns and can damage the retina, but so far little is known about other possible negative effects.

Fruit Drosophila became the model organism for the experiment to learn about other possible effects - the fly's mechanisms of cell development and transformation are very similar to human ones. 

At first, researchers compared the life expectancy of 2 groups of Drosophila; the first group was maintained in complete darkness for the entire time, the second group was maintained in daily cycles of 12 hours of exposure to artificial white light and 12 hours of darkness. 

As it turned out, darkness increased the median life expectancy of Drosophila by 42 percent. In those insects that were exposed to artificial light, the aging process accelerated.

When the flies were exposed to blue LED, the effect became even more pronounced - their median lifespan was half lower than that of the group maintained in darkness.

For the experiment, white-eyed flies were used - these flies are prone to be temporarily blinded by bright light because they lack the protection provided by the brown pigment. 

The wild species of Drosophila turned out to be more resistant to artificial light, but their median lifespan decreased by 10% after exposure to white light and by 30% after a prolonged exposure to blue LED.

Impairment of the musculoskeletal system, retinal degeneration, neurodegenerative processes in the brain, and damage to mitochondria in the muscles were observed in flies exposed to artificial light. 

Older flies were more prone to these processes. Flies with impaired phototransduction - process through which photons, elementary particles of light, are converted into electrical signals in the process of vision - were less impacted by artificial light. This led scientists to the idea that it may partly contribute to the harmful effects of blue light.

Natural lighting, the authors explain, is crucial for the circadian rhythms of the body; a 24 -hour cycle of physiological processes, such as the activity of brain waves, the production of hormones and cell regeneration, which directly affect nutrition and sleep.

The negative effect of blue light also affects vertebrates - for example, experiments on rats show that continuous exposure to blue light leads to a significant decrease in the number of dopaminergic neurons. 

Recent data, the researchers note, demonstrate how important it is to further study the effects of artificial lighting and blue light on the body.

“There is evidence that excess artificial light is a risk factor for sleep disorders and circadian rhythms," says biology professor Jadwiga M. Giebultowicz, one of the authors of the work.