Saturday, November 30, 2013

The Effect of Artificial Light on Sleep

      Insufficient sleep plagues many people in today’s non-stop world. Surprisingly, however, poor sleep is significantly due to the prevalence of artificial light—including computer screens, television, and cell phones—in our daily lives. Many people are attached to devices that emit artificial light. Consequently, this dependence on technology has an adverse effect on how well people sleep.
      One of the functions of the eye, other than sight, is the resetting of the circadian clock (Czeisler 2013). The circadian clock is the biochemical mechanism that regulates our sleep cycles. When we stare at a computer screen or constantly look at a phone throughout the day, sleep-promoting neurons are inhibited, as is the release of the sleep-inducing hormone melatonin (Czeisler 2013). Furthermore, artificial light stimulates the release of the neurotransmitter orexin, which causes one to feel aroused and awake (Czeisler 2013).
      I have noticed this effect of artificial light on my sleep cycles. During the school year, when I constantly use my computer and phone throughout the day, I routinely stay up until midnight or later without feeling very tired at all. In contrast, on a camping trip for example, I usually begin to feel sleepy an hour or so after the sun goes down. The main difference between my behavior in these two scenarios is that I don’t use any electronics while camping. One blogger, J.D. Moyer, explains and experiment in which he and his family went a month without artificial light—other than computers to do work. He says that other than not getting as much work done as usual, due to the darkness, he and his family slept much longer and felt much better as a result of this. In light of Czeisler’s explanation, these two observations about sleeping better without artificial light usage make sense. Without artificial light stimulating wakefulness and inhibiting the release of melatonin, our circadian clocks are on time and cause us to fall asleep and sleep longer.
      Though it would be nice to be able to sleep longer at night, some may argue that this is impossible by simply cutting out artificial light. Personally, I would not be able to fulfill all my obligations without using devices that submit me to artificial light. Admittedly, we could all probably reduce the amount of time we spend using computers and phones. I think many would agree that the result of longer, better sleep would be worth sacrificing time on electronic devices.

References:

Czeisler, Charles A. “Casting Light on Sleep Deficiency.” Nature. 497(S13).

Moyer, J.D. “Sleep Experiment: A Month With no Artificial Light.” Systems for Living

            Well. March 4, 2013. Blog.

5 comments:

  1. Matt, great post. Personally I try to be finished with work on my computer at least 30 minutes to an hour before bed. But being a student like yourself, it's not always possible. I have an app on my computer that changes the color of my screen to a soft yellow hue to help with the harsh fluorescent lights color. It seems to help me. I feel that all light are bad for sleep cycles, but are there wavelengths that affect the release of orexin or melatonin neurotransmitters? I know that yellow incandescent lights transmit more red (longer) wavelengths while fluorescent lights transmit blues (shorter) wavelengths. The article below by Sahin, shows that different wavelengths of light can alter mental alertness in humans. So I am wondering if we can change the colors of our electronic devices to help transition to better sleep.

    Sahin L, Figueiro MG. May 2013. Alerting effects of short-wavelength (blue) and long-wavelength (red) lights in the afternoon. Physiol Behav. 116-117:1-7. doi:10.1016/j.physbeh.2013.03.014. Epub 2013 Mar 25.

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  2. Matt,

    I enjoyed reading your post. I think it’s amazing how drastically light can affect our homeostasis. I know the majority of people today cannot get away from artificial light in their daily lives. Although a decrease in artificial light exposure or, as Billy mentioned, exposing yourself to less artificial light about an hour before going to sleep would definitely help to induce sleep naturally, it is easier said than done. Therefore, I researched some natural sleep remedies and found that taking tryptophan (a precursor to both melatonin and serotonin) supplements, melatonin supplements, and even tart cherry juice (which contains melatonin) an hour before bed can help to mimic the pineal gland release of melatonin and restore natural circadian rhythms (Tweed, 2012).

    I also came across a study that looked at the effects of a combination of melatonin, magnesium, and zinc in pear pulp on insomnia patients in a long-term care facility. The researchers claimed that the combination of magnesium and zinc were crucial to the endogenous synthesis of melatonin. The results from this study found that the patients who received the combined supplement treatment for eight weeks had better quality of sleep than the group who received a placebo for those eight weeks. Additionally, the participants in the treatment group reported to have less daytime sleepiness (assumed to be a result of better nighttime sleep) (Rondanelli et al., 2011).

    I think a study that further looked at the effectiveness of these supplements on participants with varied time exposure to artificial light would be interesting. I think it would be interesting to see if there is competition between neurotransmitter release of orexin and ingestion of melatonin. Does melatonin overcome the effects of orexin or is it simply a matter of reuptake and degradation of the orexin over time?


    References:
    Rondanelli, M., Opizzi, A., Monteferrario, F., Antoniello, N., Manni, R., & Klersy, C. (2011). The effect of melatonin, magnesium, and zinc on primary insomnia in long-term care facility residents in Italy: a double-blind, placebo-controlled clinical trial. Journal of The American Geriatrics Society, 59, 82-90. doi:10.1111/j.1532-5415.2010.03232.x

    Tweed, V. (2012). Basic remedies for…Sleep. Better Nutrition, 74(5), 8.

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  3. It seems like this alteration in circadian rhythms also has an effect on metabolism and leads to increased body weight. As another epidemic in our country, the effects of artificial light seem like they'd be a hotspot for research right now. One article I found seemed to think that artificial lights with low temperature colors positively affected sleep and melatonin levels (Wada et al. 2013).

    Fonken LK, Aubrecht TG, Melendez-Fernandez OH, Weil ZM, Nelson RJ. 2013 Aug. Dim light at night disrupts molecular circadian rhythms and increases body weight. J Biol Rhythms. 28(4):262-271.

    Wada K, Yata S, Akimitsu O, Krejci M, Noji T, Nakade M, Takeuchi H, Harada T. 2013 May. A tryptophan-rich breakfast and exposure to light with low color temperature at night improve sleep and salivary melatonin level in Japanese students.

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  4. Arg, Billy beat me to the punch.

    Great thoughts Billy. I too use a program (it is called f.lux and is a free download) that changes the hue of my computer to warmer colors when the sun goes down. I think it has really helped. There have been some cool experiments lately about resetting your circadian rhythm by camping. Check it out. http://www.the-scientist.com/?articles.view/articleNo/36888/title/Electric-Lights-Alter-Daily-Rhythms/

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  5. I recently had an appointment with my optometrist and we spent majority of the time discussing this exact topic! My optometrist is an admitted computer geek and has built a spectrometer that we used to examine the differences in UV light (from the sun), fluorescent bulbs, and the light emitted from a computer screen. It’s pretty startling to see and learn about the intense strain we put our eyes through when exposing them to these light sources, especially for the amount of time that we spend in front of a computer or phone screen. So now we are able to recognize not only the optical damage, but possible long term mental damage from lack of sleep and over excitation through these alerting effects these wavelengths have been producing. My eye doctor is also in the process of developing a sort of filter to put over screens or eye glass tints to help filter out some of these more harsh wavelengths, seemingly similar to what Billy mentioned in his comment.

    Kalina’s mention of different sleeping supplements to help counter this problem caught my attention as well, as I have often turned to melatonin supplements or similar products to help aid in my sleep. In relation to your question of neurotransmitter interaction or “competition” as a result of taking such supplements; I remember my organic chemistry professor mentioning how short the pharmaceutical half-life of melatonin has so that it may help you get to sleep, but shortly after depleting may not help with prolonging a restful sleep. So, I too am curious of how long then the NT (orexin) that Matt discussed would be active for, or would this too subside in its effects and allow for continued sleep. So is it okay to be on your computer until the moment your head hits the pillow as long as you counterbalance this with a few melatonin supplements?

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