- Chronic exposure to blue light can damage energy-producing pathways.
- The effect of blue light on the mitochondria of fly cells worsened as they aged.
- The full effects of exposure to blue light over a lifetime are not yet known to humans, but the rapid aging observed in flies is concerning.
Natural light is important for a person’s circadian rhythm, which affects processes such as brain wave activity, hormone production and cell regeneration. But with the advancement of technology, people are exposed to more and more light in the blue spectrum from LED lights and device displays, such as computer screens or cell phones. Recent evidence suggests 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 enough to know its effects on human life,” said Jaga Giebultowicz, a researcher at Oregon State University who studied of biological clocks. “While the full effects of lifetime exposure to blue light are unknown in humans, the rapid aging observed in short-lived model organisms should alert us to the potential damage to cells of this stressor.”
In previous work, Giebultowicz showed that daily lifetime exposure to blue light, but not other visible wavelengths, has detrimental effects on the brain, motor ability and lifespan of Drosophila melanogaster is a species of flowering plantthe common fruit fly.
Now, in a new study published in ageGiebultowicz and his team showed that the harmful effects of blue light on flies are strong 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.
The new study examined the survival rate of flies that were kept in the dark and then moved with increasing age to an environment of constant blue light from LEDs. The dark to light transitions occurred at the age of 2, 20, 40 and 60 days, and the study included the effect of blue light on the mitochondria of the fly cells.
The researchers determined that the specific reactions of mitochondria are dramatically reduced by blue light, while other reactions are reduced with age-independent blue light.
“You can think of this exposure to blue light as adding insult to injury in aging flies,” Giebultowicz said.
Data provided by Oregon State University.