A new study has found that the harmful effects of daily, lifelong exposure to blue light emitted by phones, computers and household appliances worsen with age.
Scientists from Oregon State University studied the ruminant fruit fly, an important model organism because of the cellular and developmental mechanisms it shares with other animals and humans.
Jaga Gibolovich, a researcher in the Ohio State University College of Science who studies biological clocks, led the study to examine how often flies survive in the dark and then gradually transition to an environment of continuous blue light from light-emitting diodes, or LEDs.
The transitions from dark to light occurred at 2 days, 20, 40 and 60 days, and the study included the effect of blue light on mitochondria in flies cells, according to the media.
Mitochondria serve as the cell’s power plant, generating adenosine triphosphate (or ATP), a source of chemical energy.
In previous research, Giboltovich showed that prolonged exposure to blue light affects the longevity of flies, regardless of whether it shines directly into their eyes.
“The novel aspect of this new study shows that chronic exposure to blue light can impair energy production pathways even in cells that are not specialized in light sensing,” Giboltovic revealed. We determined that certain reactions in mitochondria were significantly decreased by blue light, while others decreased by age regardless of blue light. You can think of it as exposure to blue light adding harm to ageing flies.”
Scientists note that natural light is essential to a person’s circadian rhythm, a 24-hour cycle of physiological processes such as brain wave activity, hormone production and cell renewal, which are important factors in eating and sleeping patterns.
There is evidence to suggest that increased exposure to artificial light is a risk factor for sleep and circadian rhythms, Gibeltovic said.
With the mainstream use of LED lighting and device displays, humans are exposed to increasing amounts of light in the blue spectrum because commonly used LEDs emit a high percentage of blue light.
She continued: “This technology, LED lighting, even in most developed countries, has not been used long enough to know its effect on human life. There are growing concerns that extended exposure to artificial light, especially blue-enriched LED light, may be harmful to human health. While the full effects of blue light exposure across the lifespan are not yet known in humans, accelerated ageing has been observed in a short time in the model organism, alerting us to the potential for cellular damage due to this stress.”
Meanwhile, the scientists said there are some steps people can take to help themselves, including glasses with amber lenses that will filter blue light and protect the retina. Phones, laptops and other devices can be set to block blue light emissions.
“Our previous work has shown that daily, lifelong exposure to blue light, but not to other visible wavelengths, has adverse effects on the brain, motor abilities and typical lifespan of the organism,” Gibeltovic explained. We now report that the harmful effects of blue light on flies are strongly age-dependent – the same length of exposure to the same intensity of light reduces lifespan and increases neurodegeneration more significantly in older flies than in younger ones.”
In previous research, flies exposed to daily cycles of 12 hours in light and 12 hours in darkness had shorter lives compared to flies kept in complete darkness or flies kept in light with blue wavelengths filtered.
Flies exposed to blue light showed damage to retinal cells and brain cells and impaired movement, and the flies’ ability to climb the walls of the enclosures in which they were placed was diminished, a behaviour usually common.
