We have all heard something about our "circadian rhythms" at one point in our lives or another but perhaps we don't really understand what they are and how important it is to have our circadian rhythms follow the natural 24 hour clock.
Circadian rhythm is our internal clock that follows the same 24 hour day light cycle found in nature. Our circadian rhythms tell our bodies when to eat, sleep, wake up, etc. They do this by releasing the appropriate hormones for each of these situations
that direct the body to do something. For example, cortisol is our "wake me up" hormone and is released in its highest concentrations between 6-8am and its release slowly wanes throughout the day until there is almost none present when it is time for us to get ready to fall asleep.
Our circadian rhythm evolved based on exposure to sunlight during the day and darkness during the night. A particular part of our brain called our suprachiasmatic nucleus (SCN) is responsible for setting these circadian rhythms. The SCN has connections to our eyes via the retina and optic nerves. Our retina is exposed to either light or darkness and conveys this message to our SCN. Our SCN takes this information and determines the appropriate hormones to release in response to these cues.
This should be a fairly simple process: see light = release hormones that keep us awake; see dark = release hormones that put us to sleep. Unfortunately, our lack of exposure to both natural light and natural darkness has thrown our circadian rhythms way out of whack and, as a result, our sleep/wake hormones are out of whack as well.
When discussing hormones, it is never good to hear the phrase "out of whack" since appropriate hormone release and hormone levels are needed for a balanced, healthy body. Anytime we start to release hormones when we shouldn't be or when we fail to release hormones when we should, we send mixed signals to the rest of the body and it can perform at its best. This creates a vicious cycle that can lead our bodies away from optimum health and towards disease.
In my clinical nutrition practice, I see this most commonly as cortisol being released at the wrong times throughout the day or as a failure to produce melatonin as the sun starts to set. When cortisol is elevated too high during the afternoon and evening hours, it can lead to an inability to quiet the mind and often manifests itself as a client telling me "I always start to feel tired around 8pm but then get my second wind and can't fall asleep until midnight or later." That "second wind" could very easily be an extra burst of cortisol that is being released when it shouldn't and is keeping you awake long past your body is ready for bed.
I also see circadian hormone imbalance in folks who fail to make melatonin as the sun is setting. In fact, that is the main signal to produce melatonin -- the setting sun. Our eyes see the day is winding down and tell the brain to send the signal to produce
melatonin so we can prepare for bed. However, in modern society, as the sun is starting to set, we feel this urge to turn on every light in the house to keep it bright. We also continue to expose our eyes to the blue light emitted from phones, tablets, computers and TV's even after the sun has set. Exposure to bright lights at night is the best way to convince your body it is still daytime, and thus, not produce any melatonin.
When we have the wrong cortisol release and the wrong melatonin release it can manifest itself in many ways including insomnia, an inability to wake up easily in the morning, weight gain around the midsection, fatigue in the mid afternoon, adrenal fatigue, thyroid dysfunction, and a sluggish metabolism among other health challenges.
RESETTING YOUR CIRCADIAN RHYTHM
The best way to reset your circadian rhythm is to allow yourself 1-2 weeks and do the following:
1. As the sun is setting, turn on no lights in your house. If you need extra lighting, use candles or very soft, low wattage lightbulbs on table lamps or night lights.
2. Avoid looking at screens, tablets, computers, cell phones or TVs after dark. Or, if you must look at them, do in only through a blue light filter (you can download these as apps or you can buy blue blocker sunglasses from Amazon and wear these as the sun goes down).
3. Honor your fatigue, even if it happens much earlier in the evening than you expected. Be prepared for your body to start fatiguing earlier in the night. When you feel your first signs of fatigue, be prepared and ready to go to bed.
4. If it feels too early to go to bed, or if you sometimes find it difficult to fall asleep, develop a simple bedtime routine: brush teeth, read a bit of a book, listen to a guided sleep meditation, etc.
5. When possible, wake up without an alarm clock.
6. At some point within the first 2 hours after sunrise, get outside and expose your eyes to the rising sun. This works especially well when doing this barefoot as the ion exchange with the Earth also helps set our circadian rhythm and grounds us. Exposure to light in the morning helps set our "wake hormone" cycle via photon capture in the tryptophan in our eyes. Try being outside for approximately 20 minutes or more if possible.
7. Throughout the day, get outside and allow your eyes to be in natural light instead of indoor light. Even on a cloudy day, the lighting outside is hundreds of times brighter than the office fluorescent lights.
Try these things for a couple of weeks and you should start to notice a big difference in your sleep-wake cycles corresponding more to Mother Nature. Your sleep-wake hormone release will start to rebalance itself and your body will be on the path toward better energy, deeper sleep and optimum health.