Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.
RUNNING HEAD: UNDERSTANDING THE EFFECTS OF LIGHT REGARDING MELATONIN 
Understanding the Effects of Light Regarding Melaton...
RUNNING HEAD: UNDERSTANDING THE EFFECTS OF LIGHT REGARDING MELATONIN 2 
Table of Contents 
 Title Page (pg 1) 
 Table of...
RUNNING HEAD: UNDERSTANDING THE EFFECTS OF LIGHT REGARDING MELATONIN 3 
Abstract 
Melatonin is a sleep-inducing hormone th...
RUNNING HEAD: UNDERSTANDING THE EFFECTS OF LIGHT REGARDING MELATONIN 4 
Introduction 
For more than 120 years, artificial ...
RUNNING HEAD: UNDERSTANDING THE EFFECTS OF LIGHT REGARDING MELATONIN 5 
night too (instead of increasing it). Which explai...
RUNNING HEAD: UNDERSTANDING THE EFFECTS OF LIGHT REGARDING MELATONIN 6 
Method 
The materials utilized were a dime-simeter...
RUNNING HEAD: UNDERSTANDING THE EFFECTS OF LIGHT REGARDING MELATONIN 7 
melatonin was inhibited. After a one hour exposure...
RUNNING HEAD: UNDERSTANDING THE EFFECTS OF LIGHT REGARDING MELATONIN 8 
Discussion 
Figueiro (2012) concluded that even if...
RUNNING HEAD: UNDERSTANDING THE EFFECTS OF LIGHT REGARDING MELATONIN 9 
References 
 Bernstein, M., & Kallabis, R. (n.d.)...
RUNNING HEAD: UNDERSTANDING THE EFFECTS OF LIGHT REGARDING MELATONIN 10 
 Beil, L. (2011, July 4). In Eyes, a Clock Calib...
RUNNING HEAD: UNDERSTANDING THE EFFECTS OF LIGHT REGARDING MELATONIN 11 
 Light suppresses melatonin secretion in humans;...
RUNNING HEAD: UNDERSTANDING THE EFFECTS OF LIGHT REGARDING MELATONIN 12 
Tables 
Figure i- Comparison between relative sle...
RUNNING HEAD: UNDERSTANDING THE EFFECTS OF LIGHT REGARDING MELATONIN 13 
Figure ii- Supports RESULTS section of experiment...
RUNNING HEAD: UNDERSTANDING THE EFFECTS OF LIGHT REGARDING MELATONIN 14 
Figure iii-How the Circadian Rhythm Functions
RUNNING HEAD: UNDERSTANDING THE EFFECTS OF LIGHT REGARDING MELATONIN 15 
Figure iv-No glasses, blue melatonin supressing g...
Upcoming SlideShare
Loading in …5
×

First draftresearchpaperorfinal

Research Paper Final

Related Books

Free with a 30 day trial from Scribd

See all
  • Be the first to comment

First draftresearchpaperorfinal

  1. 1. RUNNING HEAD: UNDERSTANDING THE EFFECTS OF LIGHT REGARDING MELATONIN Understanding the Effects of Light Regarding Melatonin Daniela I. Lin Everglades High School
  2. 2. RUNNING HEAD: UNDERSTANDING THE EFFECTS OF LIGHT REGARDING MELATONIN 2 Table of Contents  Title Page (pg 1)  Table of Contents (pg 2)  Abstract (pg 3)  Introduction (pg 4-5)  Method (includes participants, materials, apparatus, and procedure) (pg6-7)  Results (pg 7)  Discussion (pg 8)  References (pg 9-11)  Tables/Figures (pg 12-15)
  3. 3. RUNNING HEAD: UNDERSTANDING THE EFFECTS OF LIGHT REGARDING MELATONIN 3 Abstract Melatonin is a sleep-inducing hormone that’s produced by the brain’s pineal gland it’s normally suppressed only by daylight. Nowadays though, artificial daylight in our modern technology has been found to mimic natural light confusing the brain into decreasing melatonin even at night too! Studies conducted have shown that before (Fonken, L., & Nelson, R., 2011) artificial light present in devices had been emitting mostly red wavelengths but now it has replaced with “bluish bulbs” to increase energy efficiency. Through studies (utilizing precise dime-semeters and specialized googles) conducted by Figueiro, M., Plitnick, B., Rea, M., & Wood, B. (2012), we can see that after 2 hours there is a significant repression of melatonin. Keywords: Melatonin, Blue Light, self-luminous devices, Circadian Rhythm, Artificial light
  4. 4. RUNNING HEAD: UNDERSTANDING THE EFFECTS OF LIGHT REGARDING MELATONIN 4 Introduction For more than 120 years, artificial light has been emitting mostly red wavelengths (for example incandescent light bulbs). The problem now states Fonken, L., & Nelson, R. (2011) is that the artificial light sources we use today are increasingly “becoming blue” or utilizing short blue wavelengths. He estimates that 1.6 billion new computers, phones, and cellphones were sold last year alone. These newer technologies were replaced with even “bluer bulbs” for increase energy efficiency. In 1958, Woodland Hastings and Beatrice Sweeney (2010, January 1) tested the ability of different wavelengths. They found that “the greatest power to reset the organism’s daily meter lay in the blues.” Now studies show that light acts on the body on two pathways (the primary optic tract and the retinohypothalamic tract). The primary optic tract is known to control over visual effects and visual reflexes. While the retinohypothalamic tract controls the circadian, endocrine, and neurobehavioral functions. Thus making the retinohypothalamic tract more sensitive to blue light exposure(energy wavelength of about 459-485 nm). Blue’s power to “reset” circadian rhythms is not because of the color but because of the fact that it more easily penetrates into the surface of oceans and photoreceptors than other visible wavelengths(such as red=incandescent bulbs). Scientists believe that the color balance of the sky might have helped preserve blue light’s reset role throughout history. Electronic devices with overly brightened blue emitting displays can cause great suppression of the hormone melatonin. Melatonin is a sleep-inducing hormone that is produced by the brain’s pineal gland. Normally, daylight activates light sensitive retinal proteins that control our biological clock by triggering signals to the brain’s suprachiasmatic nucleus (SCN). As a result, the SCN causes the pineal gland to decrease its production of melatonin. However, as a result of artificial light in self-luminous tablets mimicking the daylight the brain gets “confused” and decreases melatonin production during the
  5. 5. RUNNING HEAD: UNDERSTANDING THE EFFECTS OF LIGHT REGARDING MELATONIN 5 night too (instead of increasing it). Which explains why people nowadays are going to sleep later (especially teenagers). Suppression of melatonin at night (by light) results in circadian disruption (our human biological clock) which can lead to higher chances of obtaining diabetes, obesity, breast cancer, and other diseases. To produce white lights electronic devices must emit at short wavelengths which is especially disrupts our circadian rhythm. The 2011 “Sleep in America” poll released by the National Sleep Foundation (NSF) has found that 43% of Americans between the ages of 13-64 said that they rarely/never get a good night’s sleep during school weeks. More than half state that they have experienced some sort of sleep problem often/every night (like snoring, waking at night, and feeling unrefreshed in the morning). Overall, 95% of Americans surveyed admitted to using devices that emitted short wavelengths before bedtime. These following results show potential positive correlation of artificial light and melatonin suppression (which leads to inability to sleep). According to Michael Gradisar, PhD, Flinders University (2011, March 7), baby boomers (46-64 years old), generation X'ers (30-45 year olds), generation Y'ers (19-29 year olds), and generation Z'ers (13-18 year olds) all report very different technological preferences (hence very different sleep patterns/schedules). Roughly 55% of generation Z'ers and 47% of generation Y'ers say that they surf the Internet every night/ almost every night within the hour before their bedtime. About 18% of generation Z'ers and 20% of generation Y’ers state that they are awakened by a text message, phone call, or email after having gone to sleep(they state that this happens a few times a week). As a result, generation Z’ers and generation Y’ers report more of an average sleepiness than the baby boomers and generation X’ers. Meaning that suppression of melatonin affects teenagers the most and thus it’s of utmost importance to restrict usage of modern technology.
  6. 6. RUNNING HEAD: UNDERSTANDING THE EFFECTS OF LIGHT REGARDING MELATONIN 6 Method The materials utilized were a dime-simeter which is a small and inexpensive “data logging device” that can record light and activity levels over many days. It can be worn as a badge, collar, hat, near the eye, or etc. the size is comparable to a dime (hence the name). Also special glasses that absorbed or blocked artificial Light, compact fluorescent light bulbs with differing color frequencies, and self-luminous devices (more specifically an IPAD Air) accompanied it. To ensure valid test results the participants chosen were around average age of the 18.9. Individuals that possessed major health problems such as heart disease, diabetes, and high blood pressure or were taking over the counter medication were excluded from the experiment. “Atypical people” that were predisposed to rising earlier or later were also filtered out of the experiment through a questionnaire. All of this made sure that melatonin production was made at the relatively same time in all subjects (they approximated from 11:00 pm-1:00 am). In order to test their theories, they gathered 13 individuals who utilized self-luminous tablets to perform daily tasks (read, play games, watch movies, and etc.) The 13 participants were divided into three groups (control group, extra melatonin suppression group, and no melatonin suppression group). The first group was given a pair of clear goggles with blue light (470—nm). This was the group with “extra melatonin suppression” because blue light is known to be a strong melatonin suppressor. The second group used orange tinted glasses that filtered out short-wavelengths of radiation emitted by the tablets (the “no melatonin suppression group”). The third and final group was the control group who wore nothing and used the tablets like any other regular person. All three groups had their tablet set at the brightest possible setting. A dime-simeter was worn close to the corners of the eye by each subject to accurately record each person’s light exposure results. The research team hypothesized that the amount of time exposed and the distance between the screen and the eye impacted how much
  7. 7. RUNNING HEAD: UNDERSTANDING THE EFFECTS OF LIGHT REGARDING MELATONIN 7 melatonin was inhibited. After a one hour exposure, the controlled group’s melatonin was repressed by about 7%, the group with the blue goggles was about 48%, and the group with the tinted orange goggles was not applicable (because it was used as a dark control in other words if measured it would be none b/c their goggles were made to filter out all the light). Although melatonin levels were still rising they rose lower than a normal person’s would if surrounded by pitch darkness. A two hour exposure showed a significant amount of blockage (of the production of melatonin). The controlled group’s melatonin was repressed by 23%, the blue goggles group was about 66%, and the orange tinted glasses group was still not applicable. Results For the tablet with blue LEDs condition, suppression values were significantly different than zero at 00:00 (t(10) ¼ 15.0, p < 0.001) and at 01:00 (t(11) ¼ 16.1,p < 0.001). For the tablet-only condition, suppression was not significantly different than zero after 1 hour exposure (t(10) ¼ 1.80, p ¼ 0.103) to the tablet, but was significantly greater than zero after 2 hour of exposure (t(11) ¼ 3.39,p ¼ 0.006). According to the studies(shown below in figures pg 13)of Figueiro, M., Plitnick, B., Rea, M., & Wood, B. (2012), the calculated mean SEM (standard error of the means) CS values after 1 hour exposures were 0.46 plus or minus 0.0013 for the tablet with blue LEDs condition and 0.03 plus or minus 0.0066 for the tablet-only condition.
  8. 8. RUNNING HEAD: UNDERSTANDING THE EFFECTS OF LIGHT REGARDING MELATONIN 8 Discussion Figueiro (2012) concluded that even if melatonin suppression is not significant (for example after an hour) you are still susceptible to an increased risk of diseases such as obesity (lack of sleep makes the brain irritable and seek comfort= food). She and her team also figured that the type of task being performed also impacts how much light is delivered to the cornea. This was proven by the team’s dimesimeter measurements, which showed that the brightness levels varied approximately 5 lux per activity (diff brightness levels= diff levels of repression). The team concluded exposure to compact fluorescent lamps at 6500k suppressed melatonin the most. As a result of blocking melatonin (hormone that induces sleep) the most, people in the 6500k setting reacted with faster reaction times because they were more alert than others. They also concluded that commercially available fluorescent light bulbs with different color temperatures not only increasingly affect the circadian rhythm (a human’s 24 hour biological clock) but also cognition or cognitive performances (because of lack of sleep). She hopes that through these studies corporations and institutions can develop more “circadian-friendly” electronic devices. These devices would decrease and increase contrast levels based on the time of the day (able to “tell” the time even through bad weather conditions). Until then, she states that the best thing for people to do is limit the amount used/time spent using electronic devices, dimming the screen as much as you can, and not utilizing them at all before bedtime to lessen melatonin suppression.
  9. 9. RUNNING HEAD: UNDERSTANDING THE EFFECTS OF LIGHT REGARDING MELATONIN 9 References  Bernstein, M., & Kallabis, R. (n.d.). Healthy Body Healthy Planet: Issues in Artificial Lighting. Retrieved September 21, 2014.  Duffy, J., & Czeisler, C. (2010). Effect of Light on Human Circadian Physiology. Retrieved September 21, 2014, from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2717723/  Figueiro, M., Plitnick, B., Rea, M., & Wood, B. (2012). Light level and duration of exposure determine the impact of self-luminous tablets on melatonin suppression. Applied Ergonomics, 44(2), 1-4. Retrieved September 21, 2014, from http://www.gwern.net/docs/melatonin/2012-wood.pdf  Fonken, L., & Nelson, R. (2011). Illuminating the deleterious effects of light at night. <i>F1000 Medicine Reports,</i> <i>3</i>(18). Retrieved September 21, 2014, from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3169904/  Rensselaer Polytechnic Institute (RPI). (2012, August 27). Light from self-luminous tablet computers can affect evening melatonin, delaying sleep. ScienceDaily. Retr ieved September 22, 2014 from www.sciencedaily.com/releases/2012/08/120827094211.htm  Annual Sleep in America Poll Exploring Connections with Communications Technology Use and Sl eep. (2011, March 7). Retrieved October 1, 2014, from http://sleepfoundation.org/media-center/press-release/ annual -sleep-america-poll-exploring-connections-communications-technology-use-/page/0,1/
  10. 10. RUNNING HEAD: UNDERSTANDING THE EFFECTS OF LIGHT REGARDING MELATONIN 10  Beil, L. (2011, July 4). In Eyes, a Clock Calibrated by Wavelengths of Light. <i>The New York Times</i>. Retrieved October 1, 2014, from http://www.nytimes.com/2011/07/05/health/05light.html?_r=3&pagewanted=all&  Chellappa, S., Steiner, R., Blattner, P., Oelhafen, P., Gotz, T., & Cajochen, C. (2011). Non-Visual Effects of Light on Melatonin, Alertness and Cognitive Performance: Can Blue-Enriched Light Keep Us Alert? <i>Non- Visual Effects of Light on Melatonin, Alertness and Cognitive Performance: Can Blue-Enriched Light Keep Us Alert?,</i> <i>6</i>(1), 1-11. Retrieved October 1, 2014, from http://www.plosone.org/article/fetchObject.action?uri=info:doi/10.1371/journal.pone.0016429&represe ntation=PDF  What’s in a color? The Unique Human Health Effects of Blue Light. (2010, January 1). <i>What’s in a Color? The Unique Human Health Effects of Blue Light</i>, A23-A27.  Kresser, C. (n.d.). How artificial light is wrecking your sleep, and what to do about it. Retrieved October 27, 2014, from http://chriskresser.com/how-artificial-light-is-wrecking-your-sleep-and-what-to-do-about-it  Blue light has a dark side. (2012, May 1). Retrieved October 27, 2014, from http://www.health.harvard.edu/newsletters/harvard_health_letter/2012/may/blue-light-has-a-dark-side/
  11. 11. RUNNING HEAD: UNDERSTANDING THE EFFECTS OF LIGHT REGARDING MELATONIN 11  Light suppresses melatonin secretion in humans;AJ Lewy, TA Wehr, FK Goodwin, DA Newsome, and SP Markey Science 12 December 1980: 210 (4475), 1267-1269. [DOI:10.1126/science.7434030]  Magri, F. et al. Changes in Endocrine Circadian Rhythms as Markers of Physiological and Pathological Brain Aging. Chronobiology International. 1997 July; volume 14, issue 4, pp. 386-396.  Stoschitzky K, Sakotnik A, Lercher P, Zweiker R, Maier R, Liebmann P, Lindner W. Influence of beta - blockers on melatonin release. European Journal of Clinical Pharmacology. 1999. April. Vol. 55. Issue 2. pp.111-115.  Kalpakcioglu B. and Senel K. The Role of Melatonin in Rheumatic Diseases. Infectious Disorders Drug Targets. 2009, August. Vol. 9. Issue 4. pp. 453-456.
  12. 12. RUNNING HEAD: UNDERSTANDING THE EFFECTS OF LIGHT REGARDING MELATONIN 12 Tables Figure i- Comparison between relative sleepiness/wellbeing in regards to frequency of light exposed to
  13. 13. RUNNING HEAD: UNDERSTANDING THE EFFECTS OF LIGHT REGARDING MELATONIN 13 Figure ii- Supports RESULTS section of experiment (shows overall values)
  14. 14. RUNNING HEAD: UNDERSTANDING THE EFFECTS OF LIGHT REGARDING MELATONIN 14 Figure iii-How the Circadian Rhythm Functions
  15. 15. RUNNING HEAD: UNDERSTANDING THE EFFECTS OF LIGHT REGARDING MELATONIN 15 Figure iv-No glasses, blue melatonin supressing glasses, and orange light supressing glasses used in experiment

    Be the first to comment

    Login to see the comments

  • vpyuuki

    Dec. 5, 2014

Research Paper Final

Views

Total views

367

On Slideshare

0

From embeds

0

Number of embeds

2

Actions

Downloads

3

Shares

0

Comments

0

Likes

1

×