You read my last article on sleep right?
Well did you read it in bed?
And how did you sleep?
The reason i'm asking is we are going to have a look at whether (or not) your electronic devices are having a detrimental affect on your sleep.
We work with many people, each with varying goals, some want to lose weight, some want to climb a mountain, some want to gain muscle or achieve the best body they have ever had and some simply want to get on track to a healthier life.
Whatever the goal is, one of the main ingredients that is needed to achieve it, or become closer to doing so, is sleep.
Because of how highly we rate sleep it is something we always try to address at Paramount Fitness, Nottingham, as we know that getting adequate sleep enables our members to function optimally and essentially hit their goals. Poor sleep can be seriously detrimental to this process and our health in general, so it is in our interest to always be on the look out for new research in this area.
New research suggests that sleep and the brain are quite unique compared to the rest of the body. The research suggests that sleep is when waste products that accumulate throughout the day are cleared - unlike the rest of the body that clears waste products consistently via our lymphatic system.
However, seeing as there just isn't the room available in the brain for the extra pipe work (Our brains have ingeniously used our blood vessels as a transportation method to move waste products which are needing to be cleared).
And it seems that the longer we stay awake the more waste products we accumulate, to the detriment of brain function.
Here's a link to a great TED talk that explains it in more detail; http://www.ted.com/talks/jeff_iliff_one_more_reason_to_get_a_good_night_s_sleep
Poor sleep is linked to a myriad of health problems and we seem to be sleeping much less than we use to, but its not just the lack of hours but also the quality of our sleep which has suffered.
Here's a few reasons why we think its worth looking at sleep in another light (no pun intended! well, maybe).
Effects of Sleep Deprivation;
- Disfunctional appetite - which can contribute to weight gain.
- Decrease in cognitive function.
- Decreased power output.
- Increased risk of heart disease and stroke.
- Linked to glucose metabolism and type 2 diabetes.
- Strongly linked to depression.
- Decreased immune function; sleep less than 7 hours and you're almost three times more likely to develop a cold.
- Sleep affects the body’s inflammatory responses. Poor sleep is strongly linked to inflammatory bowel diseases and can increase the risk of disease recurrence.
So how can our simple devices that we are so attached to be contributing to lack of or poor quality sleep?
Well it seems to come down to how these devices are illuminated and the effect that has on a very important little hormone we know as melatonin.
Our devices, like iPhones, tablets and laptops etc emit light of a blue wavelength, which effectively seems to trigger our brains into thinking that it is daytime, and it's this artificial lighting from things like our phones and tablets at night that could be one course of sleep disturbance.
Numerous studies suggest that blue light in the evening disrupts the brain’s natural sleep-wake cycles, which are crucial for optimal function of the body.
The pattern of waking during the day when it is light and sleeping at night when it is dark is a natural part of human life. Only recently have scientists begun to study and understand how daylight and darkness are interrelated with the sleep and waking cycle we go through.
Exposure to light or darkness is obviously a key factor in how human sleep is regulated and has been for eons. Its only recently that anything other than the sun and fire illuminated the darkness.
The human retina in the eye is connected by nerves to an area of the brain known as the hypothalamus, when the retina is exposed to light it stimulates and sends a signal to an area of the hypothalamus called the suprachiasmatic nucleus (SCN) which then sends more signals to other areas of the brain that regulate hormones that amongst other things stimulate sleepiness or wakefulness, and one of the key hormones involved in this cycle is melatonin.
Most of the studies on the effect of blue light point to the disruption of this very important hormone.
So, what is melatonin?
Melatonin is a hormone produced by the pineal gland in the brain, it also helps regulate other hormones and is made from the Amino acids you eat in your diet. It's a key component in regulating the body's internal clock known as your circadian rhythm.
The circadian rhythm is our body's internal 24-hour clock that plays a critical role in regulating the cycles of when we fall asleep and when we wake up.
Exposure to the normal day/night cycle keeps us on our 24 hour cycle through daily resetting, or it switches to a new cycle and resets when we move across new time zones. However, when the normal signals of light and dark are altered or disrupted, the circadian rhythm is also disrupted and is allowed to run free and has been found to average about 24.25 hours. If you're a Night Owl, your cycles typically run slightly longer, and if you are a weird morning person, your cycle may be a little short of 24 hours.
As the day draws to a close, around 8 or 9pm when it begins to get dark, the intensity of light decreases and as a result the production rises and melatonin levels in the blood shoot up. Melatonin will continue to rise and blood levels elevated all through the night until around 3AM when new light signals levels to fall back.
However melatonin levels are not thought to be a good way to predict the quality or amount of sleep someone will get.
So although melatonin is not specifically a "sleep hormone" it seems to be a key part in regulating our rhythms and cycles, and acts as a signal to our body that it is dark in a biological sense at least.
One study by Charles A. Czeisler Et al found a relationship between the intensity of the light we are exposed to and the levels in which melatonin was suppressed or decreased. "Humans seem to require light of considerably higher intensity for melatonin suppression than do other mammals"
The studies used various levels of light to measure the effects on melatonin.
Measured in Lux (lx)
"The lux (symbol: lx) is the SI unit of illuminance and luminous emittance, measuring luminous flux per unit area"
As stated, it seems humans require light of a higher intensity to suppress melatonin.
This is where our tablets and other light emitting devices come in. A team of scientists from the Rensselaer Polytechnic Institute in New York suggest exposure to the light from self-luminous displays, like our tablets and iPhones could be connected to sleep disorders due to the fact that these devices emit light close to the peak sensitivity of melatonin suppression in humans.
It seems exposing our retina to bright lights in the evening, or also too little light during the daylight hours, can disrupt this melatonin release cycle.
It's not just light emitting devices either, it is also lack of or too much exposure from a disrupted pattern that appears to have an effect also, from things like jet lag or working shifts, that limit, over expose or change the usual light/dark exposure.
During the study they found that 2 hours of exposure to the light from an iPad before bedtime suppressed the body's melatonin levels by around 23%, which is a significant difference.
So if artificial light is suppressing our production of melatonin at the right times and is having a detrimental effect on sleep, are there any steps we can take to combat the effects?
Fortunately other than wearing amber coloured glasses at night, there are some pretty simple things you can do immediately to combat the disrupting effects of suppressed melatonin and its possible effects on sleep.
5 ways to continue your gadgetry and still arrive at slumber;
1. F.lux - this little app is something you can install onto your laptop that automatically adjusts the colour and brightness of your computer screen based on the timezone you are in, when it begins to get dark outside, the screen blocks blue light from your screen and shifts to the red end of the spectrum
2. Stop using your gadgets at least 1-2 hours before bed and turn the lights down to a dimmer setting. Seeing as we begin to produce melatonin about 2 hours before bed there's no need to throw them down a well and hide in the dark as soon as you get in from work. But try to put them down a couple of hours before your usual bedtime to allow the production of melatonin.
3. Turn the brightness down. If you're going to read before bed, but your choice of book is electronic, simply go into settings and turn the brightness down, or better still invert the colors, that way you can read in the faintest of light.
4. Read a real (old school) paper book and keep the TV out the bedroom. Fiction works best.
5. Afternoon walk outside. The simplest and most positive one of the lot. Simply aim to get outside more during the day to increase the amount of natural blue light you expose yourself to alongside that of vitamin D as well. Don't worry, we need blue light. It seems to only become detrimental to us with too much exposure at night, and the higher our exposure during daylight hours the less of an impact blue light has at nighttime.
If you found this blog post helpful, please share it with your friends using the tabs below.
- Cos S, Sanchez-Barcelo EJ. Melatonin and mamary pathological growth. Frontiers Neuroendo. 2000;21:133-170.
- Brown GM, Pandi-Perumal SR, Trakht I, Cardinali DP. Melatonin and its relevance to jet lag.Travel Med Infect Dis. 2009 Mar;7(2):69-81. Review
- Herxheimer A, Petrie KJ. Melatonin for preventing and treating jet lag. Cocharane Database Syst Rev. 2001;(1):CD001520
- Kim MK, Park EA, Kim HJ, et al. Does supplementation of in-vitro culture medium with melatonin improve IVF outcome in PCOS? Reprod Biomed Online. 2013; 26(1):22-9.
- Kunz D, Mahlberg R. A two-part, double-blind, placebo-controlled trial of exogenous melatonin in REM sleep behaviour disorder. J Sleep Res. 2010;19(4):591-6. doi: 10.1111/j.1365-2869.2010.00848.x