Blue light is becoming increasingly prevalent in artificial illumination, raising concerns about its potential health hazard to humans. In a new study, scientists at Oregon State University investigated effects of chronic blue light on metabolic pathways in heads of mutant fruit flies (Drosophila melanogaster).
Yang et al. provide new insights into the mechanisms by which blue light interferes with vital metabolic pathways that are conserved between fly and human cells. Image credit: Pexels.
Blue light, which is characterized by high-energy short-wave light, has attracted interest as a potential health hazard to humans.
It is common in artificial lighting such as light-emitting diodes to which humans are increasingly exposed.
There is increasing evidence that blue light has the potential to damage human eyes contributing to diseases ranging from glaucoma to retinal degeneration and age-related maculopathy. However, little is known about the mechanisms of damage.
“Excessive exposure to blue light from everyday devices, such as TVs, laptops, and phones, may have detrimental effects on a wide range of cells in our body, from skin and fat cells, to sensory neurons,” said Oregon State University’s Professor Jadwiga Giebultowicz.
“We are the first to show that the levels of specific metabolites — chemicals that are essential for cells to function correctly — are altered in fruit flies exposed to blue light.”
“Our study suggests that avoidance of excessive blue light exposure may be a good anti-aging strategy.”
In earlier studies, Professor Giebultowicz and her colleagues found that fruit flies exposed to light ‘turn on’ stress protective genes, and that those kept in constant darkness lived longer.
To understand why high-energy blue light is responsible for accelerating aging in fruit flies, they compared the levels of metabolites in flies exposed to blue light for two weeks to those kept in complete darkness.
Blue light exposure caused significant differences in the levels of metabolites measured by the researchers in the cells of fly heads.
In particular, they found that the levels of the metabolite succinate were increased, but glutamate levels were lowered.
“Succinate is essential for producing the fuel for the function and growth of each cell,” Professor Giebultowicz said.
“High levels of succinate after exposure to blue light can be compared to gas being in the pump but not getting into the car.”
“Another troubling discovery was that molecules responsible for communication between neurons, such as glutamate, are at the lower level after blue light exposure.”
The changes recorded by the scientists suggest that the cells are operating at suboptimal level, and this may cause their premature death, and further, explain their previous findings that blue light accelerates aging.
“We used a fairly strong blue light on the flies — humans are exposed to less intense light, so cellular damage may be less dramatic,” Professor Giebultowicz noted.
“Our results suggest that future research involving human cells is needed to establish the extent to which human cells may show similar changes in metabolites involved in energy production in response to excessive exposure to blue light.”
The results appear in the journal Frontiers in Aging.
Jun Yang et al. Chronic blue light leads to accelerated aging in Drosophila by impairing energy metabolism and neurotransmitter levels. Front. Aging, published online August 31, 2022; doi: 10.3389/fragi.2022.983373