The common fruit fly, Drosophila melanogaster, was used in the study, which was published today in Nature Partner Journals Aging. Drosophila melanogaster is a valuable model organism because it shares cellular and developmental processes with humans and other animals.
As per new research from Oregon State University, the harmful effects of everyday, lifelong exposure to the blue light emitted by phones, computers, and household lighting get worse as people age.
A team lead by Jaga Giebultowicz, a scientist at the OSU College of Science who specialises in biological clocks, examined the survival rate of flies kept in darkness and then transferred to an environment of continual blue light from light-emitting diodes, or LEDs, at progressively older ages.
The study examined the impact of blue light on the mitochondria of the flies’ cells at the ages of two, 20, 40, and 60 days during the darkness to light transitions. Adenosine triphosphate, or ATP, is produced by mitochondria, which serve as the cell’s power plant and serve as a source of chemical energy.
In earlier studies, Giebultowicz demonstrated that continuous blue light exposure reduced the lifetime of flies, regardless of whether the light shone directly into their eyes.
“The novel aspect of this new study is showing that chronic exposure to blue light can impair energy-producing pathways even in cells that are not specialized in sensing light,” Giebultowicz said. “We determined that specific reactions in mitochondria were dramatically reduced by blue light, while other reactions were decreased by age independent of blue light. You can think of it as blue light exposure adding insult to injury in aging flies.”
Yujuan Song, Jun Yang, David Hendrix, and Matthew Robinson from the OSU College of Science, as well as Alexander Law and Doris Kretzschmar from Oregon Health & Science University, worked with Giebultowicz on the study, which was partially supported by the National Institutes of Health.
The circadian rhythm is a person’s 24-hour cycle of physiological activities, including brain wave activity, hormone synthesis, and cell regeneration, which play a significant role in eating and sleeping patterns. The experts highlight that natural light is essential for a person’s circadian rhythm.
But according to Giebultowicz, there is research that suggests that greater exposure to artificial light may be a risk factor for sleep and circadian problems. Humans are also exposed to growing levels of blue light due to the widespread use of LED lights and device screens, which emit a large proportion of blue light.
“This technology, LED lighting, even in most developed countries, has not been used long enough to know its effects across the human lifespan,” she said. “There are increasing concerns that extended exposure to artificial light, especially blue-enriched LED light, may be detrimental to human health. While the full effects of blue light exposure across the lifespan are not yet known in humans, accelerated aging observed in short-lived model organism should alert us to the potential of cellular damage by this stressor.”
The researchers believe there are a few things people may do to improve themselves in the meantime that don’t necessitate sitting for hours in the dark.
Amber lenses on your spectacles will block blue light and shield your retinas. Additionally, blue emissions can be blocked on phones, laptops, and other gadgets.
“Our previous work demonstrated that daily lifelong exposure to blue light, but not other visible wavelengths, has damaging effects on the brain, motor abilities and lifespan of the model organism,” Giebultowicz said. “Now we’re reporting that the damaging effects of blue light on the flies are strongly age dependent — the same length of exposure to the same intensity of light decreases lifespan and increases neurodegeneration more significantly in old flies than in young ones.”
In prior studies, it was shown that flies housed in daily cycles of 12 hours of light and 12 hours of darkness lived shorter lifetimes than flies kept in complete darkness or in light with the blue wavelengths filtered out.
The flies exposed to blue light had reduced movement, retinal cell and brain neuron damage, and lessened capacity to climb the walls of their enclosures, a typical activity. Even the eyeless mutant flies in the experiment showed signs of impairment, demonstrating that flies weren’t need to be able to see the light in order to be affected by it.