For some, bedtime is relaxing. The cares of the day fall away as you are lulled into the land of nod, where you rest and recharge before awaking fresh and ready to face the new day. For many others, this scenario is but a dream. Bedtime for them is a time of frustration marred by the inability to fall asleep or stay asleep.
Data now shows us that up to 35% of adults have brief symptoms of insomnia, 15-20% have short-term insomnia and around 10% have chronic insomnia [1].
Perhaps it wasn’t always so. The Hunter-Gatherer’s brain would have easily known when it was bedtime because the sun went down. This dimming light sent a message to the brain saying “It’s sleep-time soon. Start producing the hormone melatonin.”
We will never know how prevalent insomnia was then, but we do know that it is too prevalent now. There can be many factors contributing to this sleep disorder, which rarely presents without co-morbidities, but one theory points to something very simple: light.
Some experts are pointing the finger of blame at artificial lighting, especially late-night use of electronic devices. Why is this so? Dr. Daniel Siegel, professor of Psychiatry at UCLA, says “People are exposing their eyes to this stream of photons from these objects that basically tell your brain ‘Stay awake. It isn’t time for sleep yet.’ It tells your brain not to secrete melatonin [2].”
This is a problem, especially for those who stay up late on computers, or go to bed only to spend extensive time locked in the infinite scroll of social media. This stream of photons can suppress melatonin by up to 22% thus delaying the sleep-wake cycle [3].
How much light are we talking about here? Approximately 30 – 50 lux, or half the illumination of an ordinary room. Keep in mind that this light may be held only inches from your face [4].
Australian Researcher, Professor Shantha Rajaratnam, says “…the advent of electric lighting has significantly impacted upon sleep-wake patterns, but with the proliferation of electronic devices that emit light, we are expecting that these problems will increase [4].”
Interestingly, the blue light wave is thought to be the most disruptive. Such light can effectively reset the human circadian rhythm. This raises serious concerns. Dieter Kunz, of the Sleep Research and Clinical Chronobiology Research Group in Berlin said this:
“Maintaining synchronized circadian rhythms is important to health and well-being. A growing body of evidence suggests that a desynchronization of circadian rhythms may play a role in various tumoral diseases, diabetes, obesity and depression [5].”
Being that the average adult requires 7-9 hours sleep every night, it’s essential that we recognise the disruptive force that can be wielded by humble mobile phones and laptops.
So what do we do about it? Experts advise that we need to put space between our sleep zone and electronic devices. Suggestions vary as to how long this needs to be. Siegel advises that devices should be shut off at least one hour before bedtime. Rajaratnam believes this amount should be closer to two hours. Either way, the transition time is essential to sleep.
Pairing this electronic media block-out time with healthy sleep hygiene and routine can greatly boost your chances at attaining a good nights sleep. Good sleep and the absence of sleep disorders can then become part of a healthy lifestyle.
Facts About Sleep
- Sleep aids concentration, memory and cognitive function. Sleep insufficiency is therefore a public health concern as it can impact on alertness while driving motor vehicles, operating machinery and performing medical tasks (for example).
- Lack of sleep can have negative impacts on insulin and weight gain along with hypertension, depression and other chronic diseases [6].
- The brain uses sleep to wash away toxins that build up from a hard days thinking. “Cells in the brain, probably the glial cells which keep nerve cells alive, shrink during sleep. This increases the size of the interstitial space, the gaps between the brain tissue, allowing more fluid to be pumped in and wash the toxins away. (Dr. Maiken Nedergaard) [7].”
- Good sleep is therefore essential to general health and wellbeing, not just the ability to concentrate.
References
[1] Heffron, T (2014),”Insomnia Awareness: Facts and Stats,” Sleep Education, http://www.sleepeducation.com/news/2014/03/10/insomnia-awareness-day-facts-and-stats retrieved 1 May 2015
[2] Gmoser, J (2015), “This is what happens to your brain and body when you check your phone before bed,” Business Insider Australia, http://www.businessinsider.com.au/smartphone-impact-brain-body-sleep-2015-2 retrieved 1 May 2015
[3] Mulaney, R (2012) “Light from self-luminous tablet computers can affect evening melatonin, delaying sleep” www.news.rpi.edu/luwakkey/3074 retrieved 1 May 2015
[4] Rice, D (2013), “Artificial Light Leading to Increase in Sleep Disorders,” ABC News, http://mobile.abc.net.au/news/2013-07-01/artificial-light-leading-to-increase-in-sleep-disorders/4790448 retrieved 1 May 2015
[5] Holzman, D (2010), “What’s in a color? The unique human health effects of blue light,” National Institute of Environmental Health Science, 118(1):A22-A27 DOI: 10.1289/ehp.118-a22
[6]Institute of Medicine (2006), “Sleep Disorders and Sleep Deprivation: An Unmet Public Health Problem,” National Academies Press, Washington DC
[7] Gallagher, J (2013) “Sleep cleans the brain of toxins,” BBC News, www.bbc.com/news/health-24567412 retrieved 1 May 2015
