Sleep is probably the most obviously important part of health. We all know what it feels like to lack sleep - groggy, sluggish, brain-dead….and we hopefully all know what it feels like to be well-rested and wake up with energy and clarity. We spend ⅓ of our life sleeping, which allows the body to heal and regenerate. Today, our society is chronically sleep-deprived, as evidenced by the coffee shops on every corner. Good sleep is foundational for good health - it is a must!
I took my sleep for granted until my wife and I had twins (3 years ago). Now I treat it like gold!
Light exposure affecting sleep is a great example of what might be called a “Paleo”, or “Ancestral” health principle that is backed by a vast amount of modern scientific research. This is the way your body was designed! If you think back to even just a few generations ago, most of our ancestors’ day would have been spent outside working, farming, hunting, gathering, under bright sunlight and blue skies, even in the winter. At night the sun sets and darkness sets in, and until recently there was no light pollution from cities, no street lights, car lights, electricity, and especially no LED devices. This goes hand-in-hand with several other ancient health principles that I strongly believe in - your body was designed to eat real food (not fake, processed food) and it was designed to be moving (not sitting).
If you violate the body’s design you violate your ability to be healthy!
Your sleep is regulated by what is called your Circadian Rhythm. Circadian rhythm is the natural hormonal rhythm of your 24-hour wake/sleep cycle, during which certain hormones rise and fall consistently each day. The most familiar examples of this natural rhythm are the hormones cortisol and melatonin. Cortisol, which is produced by the adrenal glands, is your body’s main stress hormone. A healthy cortisol rhythm rises upon waking up in the morning and should gradually decrease throughout the day. Many people are familiar with the terms Adrenal Fatigue or Adrenal Exhaustion (more properly termed HPA Axis Dysfunction) which is an abnormal or blunted adrenal hormone rhythm. This rhythm is controlled by clock genes in your body along with your sleep/wake cycle and melatonin production. Melatonin is your body’s primary sleep hormone, and it rises at night to induce sleep and is suppressed during the day while you are awake. In order to fall asleep and stay asleep, you need to do everything in your power to protect your melatonin production.
This internal clock system is ‘programmed’ by your exposure to light during the day and darkness at night. Your body is designed to be exposed to bright sunlight during the day and darkness at night. Today’s modern, technological, device-driven society violates this natural design. Think about our culture - today we spend most of our day inside under artificial fluorescent (or worse now - LED) lights, we check our phones 100’s of times per day, we use our computers all day and night, and at night we watch TV. This violates the body’s design and alters the natural circadian rhythm.
What is crucial to be aware of is that your circadian rhythm doesn’t just determine your sleep, wakefulness, energy or fatigue levels on a regular basis, but it is connected to most important functions of your body - including hormone secretion, immune system function, metabolism, cellular function, and gene expression. When this disruption happens regularly, no matter what age, it can have drastic negative health effects.
For this reason, altered circadian rhythm is associated with most of our modern diseases, including diabetes, cardiovascular risks, obesity, mood disorders, diseases of metabolism and energy, and even cancer. In this podcast episode we take a dive into some of the science behind this, but as always the goal is to leave listeners with easy-to-implement action steps that can make a huge difference in your life.
3 DAILY ACTION STEPS
1 - Get Daytime Sunlight
“Canadian and US population-based surveys substantiate people nowadays spend very little time, on average 12%, outdoors, with half of this amount spent inside vehicles, and the rest, 88%, indoors. (Klepeis et al., 2001; Leech et al., 1996; Matz et al., 2014)”
Daytime sunlight is incredibly important to setting the proper circadian rhythm. You want your brain to know when it is daytime! Your eyes detect sunlight through your retina, and certain specific wavelengths set your internal clock through the Suprachiasmatic Nucleus (SCN) of the Hypothalamus. The hypothalamus then communicates through the Paraventricular Nucleus and sympathetic nervous system with the Pineal Gland to synthesize and release melatonin. The hypothalamus also acts, together with the pituitary, as the control tower to control the release and balance of the stress hormones from the adrenal glands, thyroid hormones, and reproductive hormones. Melatonin is synthesized from the building block Tryptophan, and uses very similar pathways to the synthesis of serotonin, your “happiness” neurotransmitter. These pathways are intimately connected and are one of the reasons why someone could get Seasonal Affective Disorder (S.A.D.) from lack of sunshine in the winter time.
It’s really important to not spend your entire day indoors. You (and your kids) need to get outside - not behind a window, not behind sunglasses, but to get light exposure directly into your eyes, and the earlier in the day the better. This is step #1 to controlling your light exposure! In the podcast episode I mention ways that I have implemented more into my regular routine.
2 - Block Artificial Blue Light
Blue light wavelengths (440-500 nm) are of a particular concern because of their ability to suppress melatonin synthesis (blue light = daytime = no need for melatonin). Blue light is not all bad - we need the blue wavelengths of sunlight to set the clock in the daytime - but sunlight has a full spectrum of light wavelengths and in our society we have an imbalance of blue wavelengths as compared to all the others, and we need a balanced spectrum. In fact, prolonged exposure to blue light has been shown to damage mitochondrial DNA and increase free radical production in the retina. Think about our life today - fluorescent or LED lights, bright computer screens, cell phones all day long, TVs, etc etc. Blue light is the #1 source of non-native EMF (electromagnetic frequencies), which are an incredible danger to our health.
Blue light wavelengths are most dangerous at night, because they signal to your brain that it is daytime. IT IS INCREDIBLY IMPORTANT TO BLOCK BLUE LIGHT AT NIGHT! Artificial light at night (ALAN) is heavily associated with concerns including diabetes, cardiovascular events, and breast and prostate cancers. Incandescent bulbs are much more balanced than LED or fluorescent bulbs, and my wife and I use amber-colored bulbs for our lamps at our house as bedtime approaches.
In the podcast episode we dive deeper into the science of blue light, but here are 3 great resources to take control of this huge concern to your health.
F.lux - this is a free software you can install onto your computer and shift the temperature of the screen from blue light dominant to warmer wavelengths. Click the link to install.
NightShift - this feature is available on Apple products like iPhones and iPads. You can turn the temperature all the way to the warmest setting, or you can set an automatic timer to turn on NightShift at night and off in the morning.
Blue blocker glasses - These can be purchased for under $15 on Amazon . I personally wear a more professional pair during the day when I am indoors at my clinic that have a clear frame and look like normal glasses. At night I wear a dorkier pair of orange Uvex glasses while watching tv or looking at my phone.
3 - Black-Out the Night
In this episode we talk about a particular study that showed that a small amount of blue light could suppress melatonin - even through the eyelids! I also discuss how children are much more susceptible (200%) to this than adults. For our 3 year-old twin girls we are very careful about their light exposure leading up to bedtime, we have the amber-colored light bulbs in our lamps, we have two sets of curtains on the window to block out as much light as possible, we even cover the small LED lights on top of their air filter in their room.
I also discuss in the podcast the most significant change for me personally - using a black-out sleep mask. Listen to the episode to hear about my experience! Sleep masks can be purchased for under $10 on Amazon here. This has been the most significant thing I have ever done for my sleep! I use one from Nikken (www.Nikkenmania.com) that has magnets to influence the magnetic field in the brain and induce a good night’s sleep.