If you are anything like me, you spend hours a day doing homework,
studying or writing blogs on your computer. Modern day education relies on
things like laptops, tablets, and phones to help teach students. However,
recent research has linked blue light to accelerating aging phenotypes in drosophila
(flies). So what does this mean for
humans?
Research has established that blue light negatively effects the
human circadian rhythm. The human circadian rhythm is dependent on photoreceptors
that connect to the visual cortex and suprachiasmatic nucleus of the
hypothalamus (Gooley, et al., 2003). These photoreceptors are only activated by certain
wavelengths (wavelengths less than 550 nm), and blue light falls within this
category (Brainard, et al., 2001). Therefore, our circadian photoreceptors are
only disrupted or activated when exposed to certain wavelengths, showing why
blue light can be dangerous to a normal sleep cycle. Disruption in the normal
circadian rhythm has been suggested to play a role in various tumoral diseases,
obesity, depression, and diabetes (Holzman, 2010).
Knowing all this, the researchers at Oregon State University
conducted their research on drosophila knowing that blue light would at least cause
some changes in the behavior of the flies. They hypothesized that blue light
would affect expression of certain genes in the drosophila (Nash, et al., 2019).
Although there research did not prove or disprove this hypothesis, they did
find that the light was modifying the behavior of the flies in large ways. Drosophila
when given the choice avoided exposure to blue light. When experimentally
placed in blue light for long periods of time the lifespan of these flies shortened
drastically. This research is in its infancy but the primary researcher was not
afraid to hypothesize that it would quickly be related back to humans.
We all know that spending long days on our phones and computers
can be draining, but is this research enough to convince you to give up your
blue light emitting technology permanently? Do you think that the companies
responsible for creating laptops, tablets, TVs and phones should be held responsible
for the negative side effects now being experienced by their customers?
Citations:
Brainard, G.
C., Hanifin, J. P., Greeson, J. M., Byrne, B., Glickman, G., Gerner, E., &
Rollag, M. D. (2001). Action Spectrum for Melatonin Regulation in Humans:
Evidence for a Novel Circadian Photoreceptor. The Journal of Neuroscience, 21(16), 6405–6412. doi: 10.1523/jneurosci.21-16-06405.2001
Gooley, J. J.,
Lu, J., Fischer, D., & Saper, C. B. (2003). A Broad Role for Melanopsin in
Nonvisual Photoreception. The
Journal of Neuroscience, 23(18), 7093–7106. doi: 10.1523/jneurosci.23-18-07093.2003
Nash, T. R.,
Chow, E. S., Law, A. D., Fu, S. D., Fuszara, E., Bilska, A., … Giebultowicz, J.
M. (2019). Daily blue-light exposure shortens lifespan and causes brain
neurodegeneration in Drosophila. Npj
Aging and Mechanisms of Disease, 5(1). doi: 10.1038/s41514-019-0038-6
Holzman, D. C.
(2010). What’s in a Color? The Unique Human Health Effects of Blue Light. Environmental Health Perspectives, 118(1). doi: 10.1289/ehp.118-a22
Whitney,
ReplyDeleteAfter doing some research on my own and our conversation in person I have discovered that while blue light can have some negative and damaging effects on photoreceptors, it can also be used to treat circadian and sleep dysfunctions (Tonsini, Ferguson & Tsubota, 2016). Light-emitting diodes (LEDs) are found in most electronics, but studying the effect of exposure of blue light has been difficult due to the varying individual susceptibility to blue light damage. However, there is a link between blue light exposure and age-related macular degeneration (AMD) (Algvere, Marshall & Seregard, 2006). However, blue light in the range of 460-480 nm is effective at phase shifting the circadian clock than monochromatic light of 555 nm, as well as increasing alertness and cognitive functioning (Tonsini, Ferguson & Tsubota, 2016).
Given what I have found through my research and my own personal use of electronics, I am concerned about the amount of blue light that I am exposed to during my day. However, there are ways that I can limit my exposure. For example, I can limit my time on my computer or phone but an easier way to limit my blue light exposure is by using blue light blocking glasses. These glasses work by containing filters in the lenses that either blocks the blue light or absorbs the blue light. While this sounds like a great solution, the data supporting the effectiveness of the glasses is limited. Also, while I believe that companies should be held accountable for potential damage their products cause, it would be difficult to hold accountable every company that utilizes LEDs. I think is more reasonable to have these companies held raise awareness for the negative side effects of blue light.
References:
Algvere, P. V., Marshall, J., & Seregard, S. (2006). Age‐related maculopathy and the impact of blue light hazard. Acta Ophthalmologica Scandinavica, 84(1), 4-15.
Tosini, G., Ferguson, I., & Tsubota, K. (2016). Effects of blue light on the circadian system and eye physiology. Molecular vision, 22, 61.
After reading this post, I was most interested in how the disruption of the circadian rhythm might be linked to cancer. The suprachiasmatic nucleus is responsible for maintaining our biological clock, which is an evolutionary mechanism that is in place due to the Earth rotating every 24 hours. Since it is regulated by a person’s exposure to light, exposure to screens outside the hours of day will disturb this clock (Savvidis & Koutsilieris, 2012).
ReplyDeleteAll cells in our body, not just those in the suprachiasmatic nucleus, have proteins that control sleep/wake processes. Their functions, in addition to regulating when to fall asleep and wake up, include regulating aspects of blood pressure, digestion, and immune responses. They also contribute to DNA synthesis. If this is unregulated due to extended screen time, the hypothesis is that cancer can proliferate (Savvidis & Koutsilieris, 2012). A study conducted by the University of Connecticut Health Center using rats with implanted cancer cells showed a remarkable increase in growth in the tumor when exposed to constant blue light. This study provides convincing evidence that there is increased risk of cancer proliferation when exposed to high levels of screen time (Stevens, 2005).
Savvidis, C., & Koutsilieris, M. (2012). Circadian rhythm disruption in cancer biology. US National Library of Medicine National Institutes of Health. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3521792/
Stevens, R. G. (2005). Circadian disruption and breast cancer: from melatonin to clock genes.
US National Library of Medicine National Institutes of Health. Epidemiology, Vol 16, p 254-258 DOI: 10.1097/01.ede.0000152525.21924.54