dr.K's tiips

Sleep Insufficiency and the Blue Light

May 6 2014 by Dr. Kaminski

Sleep is a mysterious activity that most don’t consider an activity at all. It is essential to life – several days of total sleep deprivation can result in death – but most of us do not encounter people who died from sleep deprivation. We do encounter every day, perhaps while looking at the mirror, people who are chronically sleep deprived. Our cavalier attitude to sleep, as if optional, is truly inexplicable, if we consider its centrality to our quality of life.

Most of us have become so “adjusted” to chronic sleep deprivation, it almost seems “normal”.

You may be aware that you are groggy, but the serious disruption to your memory, concentration and attention – the consequences of chronic sleep deprivation- might be imperceptible to you. Chronic sleep insufficiency also induces stress biomarkers, interferes with weight and hormonal regulation, and results in irritability, anxiety and depression. Those are all heavy-duty issues. In fact, we are so sensitive to lack of sleep that even a reduction of one and a half hour, for only one night, has been demonstrated to decrease our cognitive effectiveness by 30 percent.

You may treat quality of life essentials, i.e., exercise and good nutrition, as optional but we all must sleep. No one ever succeeded a voluntary sleep deprivation. It is impossible. But why can we not sleep more efficiently? Why do we have to sleep so many hours? We have totally revolutionized the waking hours, inventing one timesaver after the other, thereby making two thirds of our life increasingly efficient. Why can the other third not be revolutionized? Why can we not enjoy condensed sleep of 2 instead of 7 hours a day?

We still know little about the subjective experience of sleep. We can observe the dreaming person, but much like the experience of death, no one has ever been able to give a first hand account.

Curtailing sleep makes the same sense as curtailing the intake of water. Sleep cannot be rationed and needs to be played out in a complex repetitive and mysterious ritual: The sleep cycle, the REM vs. Non REM sleep, deep sleep and light one, dreams and amnesia. Much like the steepest depth of the oceans and the far reaches of galaxies, we have but recently become slightly acquainted with the mystery of sleep. What do we know for sure? We know that sleep is essential to our life. We know that on the average adults need to sleep at least 7 hours per day. We know that sleep is tightly regulated by our circadian rhythm. We are also familiar with the notion of Sleep Architecture – the rhythmic five phases of sleep that we usually pass through: stages 1, 2, 3, 4, and REM (rapid eye movement) sleep. Whether we sleep too little by choice or due to a sleep disorder, most of us make the same mistakes when retiring to sleep. The essentials of sleep hygiene are widely known and often reviewed. For a refresher, here are two links to sites that I find to be clear and helpful: The University of Maryland Sleep Center, and the Cleveland Clinic Sleep Disorder Center

But the environment of our sleep, even if carefully and attentively controlled, is secondary to the effects of our circadian rhythm on the quality of sleep. The circadian rhythm in turn, is dependent almost exclusively on the degree of light (or darkness) that gets into our eyes. And it is no wonder: One of the most reliably recurring phenomena on planet earth is the gradual daily alteration from darkness the brightness as the nights alternate eternally with days. Our biological clock (and that of many animals and plants) has evolved to correspond to changes of light in 24 hours cycles. The hormone melatonin, secreted from the pineal gland in the brain in response to the diminishing light of dusk, is essential for our ability to sleep. As the light grows dimmer the melatonin level increases and it signals to the brain that it is time to sleep. The alternating states of sleep and wakefulness are fundamental to the rhythm of all our biological activities: The efficient and tightly choreographed dance of life.

This harmonious adaptation to life on earth has been seriously interrupted by the advent of modern technology. Almost every aspect of technological innovation is aimed at overcoming the traditional relationship between our biology and the environment. While modern technology has made our lives easier in many ways, it has been advancing at a pace that exceeds our evolutionary adaptation. This growing discrepancy between our natural rhythms and the expansion of our abilities through modern technology, presents a survival challenge to all of us. Much like the struggle to preserve our planets natural environmental rhythm, we must pay attention to our personal one. In a way, our ancient biological clock is groaning under the strain of keeping up with technological advancement.

Nowhere is it more obvious and immediate as with the regulation of sleep. Until the introduction of artificial lighting, the sun was the major source of light, and humans spent their evenings in relative darkness. Now, as soon as day light dims, we are deluged by artificial light. Daylight is artificially extended to no end and even when we retire to bed we continue to be surrounded by numerous light emitting fixtures: No wonder then, our pineal gland is utterly confused. When should the melatonin surge occur? Where is the once dependable transition from day to dusk to night? We all understand that our environment is sensitive to our technology and we need to be “more green”, but when it comes to sleep we need to be “less blue”. Less blue? I mean this literally. We must cue our pineal gland to secrete melatonin on time, without the darkness it has come to depend on. Two important aspects are the ingestion of melatonin capsules and elimination of blue light at night. The melatonin boost is simple. All research now points to the fact that very low dose of melatonin (the body need as little as 0.2mg to signal it is night) taken at around 9pm can have profound effect on the quality of our sleep. Some people may need more – but not much more than 0.2 mg – the drug stores are still selling 3 and 6mg capsules which is actually counterproductive as it floods the brain with a large surge of melatonin. The putative rewards of daily melatonin intake are numerous and a great body of research already exists and widely accessible on the WEB. For me it is one of the three supplements I take daily (the other ones being trans – Resveratrol and Vitamin D3). I suggest you read about it and consider taking it.

Blue light presents a different problem. Blue wavelengths—which are beneficial during daylight hours because they boost attention, reaction times, and mood—seem to be the most disruptive at night. While light of any kind can suppress the secretion of melatonin, blue light does so more powerfully.The environmental push for more efficient light emitting fixtures is replacing the energy wasteful incandescent light bulbs with the very efficient fluorescent and LED bulbs. But they also tend to produce more blue light. This is a curious point (albeit increasingly common) where the personal benefit is at odds with the planetary one. Green Vs. Blue! Obviously the way to solve it is not by sacrificing the environment but by modifying our personal one. On a large scale, coating fluorescent and LED bulbs with blue wave length filter, would be a universal solution whose time has not come yet but is sure to be requested the more we are aware of the real and serious problem to our health.

But until then what can we personally do to limit the effect of artificial light on our Melatonin production? One way, as mentioned above, is to take melatonin supplement to try and overcome the melatonin suppression and the absence of melatonin surge.

Eliminating blue light after dusk is not simple. The best way is to stop the light, as it is about to get into the eyes. We should remember that in order for melatonin to be secreted the light has to come through the eyes. Each wavelength visible to us excites a different group of neurons according to its relative intensity. (Indeed blind people have complex difficulty with their circadian rhythm and in a way live in a perpetual “jet lag” which has only recently been identified.)   Eyeglasses that block blue light (typically the lens have yellowish brown tint) are very helpful. In a way, they are to blue light what sunshades are to day light. It is a bit awkward, and most people would be reluctant to wear it outdoors – who knows, perhaps one day it would become fashionable? Wearing the shades at home works quite well and from my experience it is not as cumbersome as I had assumed. Another way, which has other advantages, is to eliminate screen lights from the bedroom. Computers, phones, Ipads and TV sets, emit blue light (to say nothing of how disruptive to sleep the content is). Software and apps that filter blue light from gadgets are increasingly available. Also filters that physically block the glare can be applied to your gadgets. Needless to say, part of good sleep hygiene is leaving the phones and other handhelds, computers and television outside the bedroom.

Of course not all people are casual about their sleep. You may suffer from insomnia and other sleep disorders and would have loved to sleep longer but can’t. What should you do if despite a good evaluation and correction of your sleep hygiene, elimination of medical conditions that can cause insomnia, and taking care of your anxiety and stress, you still cannot fall asleep or stay asleep for the entire night? This is when pharmacological sleep aids should be considered; there are certain conditions, at certain times in life, which merit sleep medications. Prescribing sleep medication entails many considerations, including the type of insomnia, the gender and age of the patient, possible interactions with other medications or diet, and underlying health issues. Considering prescribed sleeping pills, what kind and for how long, merits a separate write up. However, the most salient and irrefutable fact regarding sleeping medications is that they cannot circumvent the issues noted above more than vitamin supplements are a good substitute for eating fruits and vegetables. It is at best a paltry imitation of good sleep and cannot replace the attention to our biological rhythm and the centrality of melatonin and light to its equilibrium. Simply put, swallowing a sleeping pill cannot cheat the brain into considering it a “goodnight sleep”. The disruption caused by sleeping aids to the sleep architecture, invariably renders them a temporary solution, one that cannot be a replacement for “natural” sleep. It is my strong recommendation that you discuss with your physician the option of taking low dose melatonin and evaluate all aspects of your sleep hygiene.

I understand that most do not want to waste their life sleeping. Yet given that the quantity and quality of sleep is essential to your ability to function during the waking hours, and has enormous consequences to your health and wellbeing throughout life, you would not want to waste your daily restoration (literally!!) on second rate, poor quality and insufficient sleep.

 

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