How does Circadian Rhythm affect Melatonin?
Circadian rhythm, or the 24-hour sleep wake cycle, is the foundation upon which optimal health is built. The relationship with light and dark orchestrates every aspect of our biology, specifically conducted by the hormone melatonin. Melatonin functions to tell us what time of the day it is; it helps us fall asleep in the evening, also ensuring that we stay asleep over the course of the night. The “darkness hormone” is produced and secreted by the pineal gland, a small pinecone-shaped gland about the size of a grain of rice, located in the very center of the brain.
Light serves as the external cue to coordinate the production and secretion of melatonin by the pineal gland. When photons enter the eye, the photoreceptors in the retina, especially melanopsin, convert this light information into electrical signals that then travel through the optic nerve to the superchiasmatic nucleus (SCN) of the hypothalamus. The SCN is the body’s biological clock or “master clock”. When stimulated by light, it inhibits the pineal gland’s production and secretion of melatonin, promoting a waking state. In the absence of light stimuli, the inhibitory action of the SCN is turned off, and the pineal gland begins to produce and secrete melatonin.
Melatonin initially peaks at the light/dark transition, thus inducing sleep onset. Then at 1-2 AM, there is another larger melatonin pulse which helps maintain sleep duration. If using sleep trackers like Oura or Whoop, one will see heart rate initially drop after sleep onset, indicating the first melatonin peak, and then reach an overnight low in relation to the second pulse. Overnight heart rate should form a trough-like pattern; falling gradually until early morning, and then gradually rising until waking. This indicates melatonin is functioning properly and that the body is getting into a deep parasympathetic state necessary for overnight regeneration and recovery.
When we are aligned with the natural light environment ie. no artificial light after dark, melatonin functions as it is supposed to. However, when we are exposed to artificial light at night (ALAN), or even bright light after sunset, melatonin function becomes disrupted. When this happens, the body is tricked into thinking it’s mid-day and melatonin secretion is delayed and total production reduced. As a result, one may experience difficulty falling asleep or staying asleep for the duration of the night, something known as circadian rhythm sleep disruption.
As sleep quality becomes compromised, health begins to deteriorate. Less regenerative growth hormone is secreted overnight due to decreased deep sleep cycles. Hormonal issues arise as melatonin is responsible for signaling the rise and fall of other hormones, like cortisol, thyroid, estrogen, testosterone. Oxidative stress also increases as melatonin functions as one of the body’s primary antioxidants. This dual purpose of melatonin is most important in the brain where it’s conveniently produced at the highest concentrations due to the increased oxygen demands of neural activity. From there, it is then transported via the cerebral spinal fluid throughout the rest of the body to serve the same purpose; reducing free radicals, or reactive oxygen species (ROS), produced as a byproduct of cellular respiration. It helps keep inflammation at healthy levels, ensuring that mitochondrial DNA transcription occurs without issue, thus preventing genetic mutations which lead to a disease state.
The rate of degenerative disease has increased exponentially since the introduction of electric lighting (among other things), all due to the disturbance of the master molecule, melatonin. When studying the disease process, one comes to understand that all disease results from the same fundamental problems— impaired melatonin being one of the most prominent root causes. Low melatonin, and the compromised pineal gland function associated with it, correlates with every disease. Cancer, Alzheimer’s, MS etc. is not the issue, low melatonin is.
Other than moving off-grid and becoming a total Luddite, what can be done about this? “Blue-blocking” glasses can be worn after sunset to mitigate the extent to which blue light wavelengths enter the retina, thus protecting melatonin status. A darker red or amber lens color will provide better results than lighter orange, pink or yellow options. Glasses take some getting used to, and can become somewhat of a hassle in the long run, so another option is replacing regular household lightbulbs with red lightbulbs— the closer to the 660nm wavelength, the better, as this deep red light does not impact melatonin. I personally like the 660nm “corncob” bulbs sold by Gembared. However, as mentioned, even bright light can alter the circadian rhythm. The full moon provides about one lux of ambient light, which is enough to have an effect. Most red lights that are shaded will fall under this one lux threshold, though the five foot vicinity around the fixture will exceed this level unless it is thoroughly filtered.
In addition to good light hygiene, one must practice good sleep hygiene. Eliminate regular caffeine consumption. No eating within two hours of bed. Sleep in a completely dark room, using an eye mask or black-out shades to eliminate all light sources. Keep the room cool. Sleep naked so the body can more easily regulate temperature. Turn off your cell phone or put it on airplane mode, and unplug the Wi-fi router as non-native electromagnetic frequencies (nnEMFs) can induce oxidative stress and alter melatonin function. Also extremely important: go outside in the morning and see sunrise with bare eyes– no glasses or contacts as they block much of the infrared spectrum. This practice sets the daily circadian rhythm and is especially important when transitioning time zones in order to mitigate jet lag and restore a normal sleeping pattern as quickly as possible.
Lastly, utilize the CLRLY product line in conjunction with healthy circadian practices. The Liver Detox Protocol is designed to reduce oxidative stress and increase T3 production which will help decalcify the pineal gland and increase melatonin levels. Excess oxidative stress, along with the use of fluoride in public water supplies and dental applications, leads to a build-up of calcium in the pineal gland and results in loss of function and reduced melatonin levels over time. As T3 climbs, calcium ATPase pump activity increases and promotes normal cytoplasmic calcium levels, which will improve mitochondrial function and regeneration of the pineal gland. Shilajit can additionally be used to break down fluoride as well as chelate other heavy metals from the body, further reducing oxidative stress. Finally, CLRLY cannabinoids promote parasympathetic activity and can improve sleep quality as well as serving an additional anti inflammatory role.
Many people turn to melatonin supplementation for sleep issues, but it’s not advised. The 5-10+ milligram doses found at most pharmacies are far greater amounts of the hormone than the pineal gland normally secretes, and over time, can affect endogenous production and timing of release. Additionally, even though melatonin supplements can help one fall asleep, they often lead to sleep disruption later in the night. In emergency sleep situations such as jet lag or chronic insomnia, less than one milligram can be dosed right before bed; this is closer to normal endogenous levels and will come with fewer negative side effects.
“What if I’m a shift worker who sleeps during the day?” I used to work 12-hour night shifts when I worked in the oil field, and developed my own health issues during this time period. It is impossible to stay healthy when going against the body’s most basic evolutionary programming; inevitably, it will catch up. As someone who has learned through experience that success and the ability to design better life circumstances directly correlates to health, I recommend finding a new job.
The ultimate solution to restoring a healthy circadian rhythm is to respect the darkness and simply not use any artificial light after sunset. This is a lot to ask of many, but for those focused on maximizing the human experience, I believe it is essential. Melatonin function has more far-reaching implications outside of regulating the daily circadian rhythm. The rise and fall of the hormone in relation to the monthly lunar cycle, and on a yearly basis in relation to the solar cycle, govern what are called infradian rhythms. These are the longer term biological cycles, largely unstudied, that impact things like fertility, breeding, migration, development and aging. Melatonin plugs us into instinct, allowing us to intuitively understand what we need and when we need it just as it does for the rest of the animal kingdom. If we protect its function, we are not only able to maintain our health, but are more able to more fully and directly experience life in organic form.