Flies under blue light. Credit: Oregon State University College of Science
Key Points:
- Chronic exposure to blue light can impair energy-producing pathways.
- Blue light’s effect on the mitochondria of flies’ cells worsened the older they got.
- The full effects of blue light exposure across the lifespan are not yet known in humans, but the accelerated aging observed in flies is concerning.
Natural light is crucial for a person’s circadian rhythm, which impacts processes such as brain wave activity, hormone production and cell regeneration. But as technology has advanced, humans have become subjected to increasing amounts of light in the blue spectrum from LED lighting and device displays, like a computer screen or cell phone. Recent evidence has suggested that increased exposure to artificial light is a risk factor for sleep and circadian disorders.
“LED lighting, even in most developed countries, has not been used long enough to know its effects across the human lifespan,” said Jaga Giebultowicz, a researcher at Oregon State University who studies biological clocks. “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.”
In previous work, Giebultowicz demonstrated that daily lifelong exposure to blue light, but not other visible wavelengths, has damaging effects on the brain, motor abilities and lifespan in Drosophila melanogaster, the common fruit fly.
Now, in a new study published in Aging, Giebultowicz and her team have shown that the damaging effects of blue light on 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 young ones.
The new study examined the survival rate of flies kept in darkness and then moved at progressively older ages to an environment of constant blue light from LEDs. The darkness-to-light transitions occurred at the ages of 2, 20, 40 and 60 days, and the study involved blue light’s effect on the mitochondria of the flies’ cells.
The researchers 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,” said Giebultowicz.
Data provided by Oregon State University.