Part 1: Sleeping Beauty
Our human physiology evolved with the sun, making us diurnal creatures. This means we are most active during the day and we are resting at night. While not all of us can adhere to a schedule as such, these tools are useful for all people on all types of circadian rhythms. I hope you find some useful takeaways from this 2 part series to help optimize your much needed beauty rest.
There is a lot of discussion about the importance of sleep these days, and rightfully so. The importance of sleep cannot be understated. Well, maybe it can, but it definitely shouldn’t be!
I say it can be understated because all too often in modern society we end up sacrificing sleep in the name of some sort of productivity. Or maybe we’re binge watching a TV show, a book series, social media scrolling, etc. Whatever it may be that keeps you from your ever important beauty slumber, the effects of both poor quality and low quantity sleep are somewhat frightening. Some of these effects include, but are not limited to, an increased risk of hypertension, diabetes, obesity, depression and cardiovascular disease. Brain repair and memory consolidation also occurs during sleep, particularly during the REM cycle of sleep.
With all of that in mind, today I want to talk about tools we can leverage in our quest for a better night's sleep. I will go through some of the science behind light and its relationship to sleep from the lens of human’s natural sleep-wake cycles in our ancestral hunter gatherer setting and how it is different in our modern world, and I’ll end with tips and tools you can use to increase your quality and potentially quantity of sleep.
So, let’s talk about light. Light is the source of all life, the force that keeps us going, the beautiful reminder in the morning that tells us it’s time to usher in a new day. Something truly fascinating is how the human eye takes in light in the morning: in the sensory neurons in the inferior (bottom) part of the retina, because we evolved in an environment where morning sunlight was coming from above. These neurons take in blue light, which exists between 380 to 500 nanometers in wavelength (an important fact we’ll revisit later), and send a signal to your body that it is morning, creating a hormonal cascade that indicates to your circadian rhythm that the day is at its beginning. Based on sleep studies we have done on our hunter gatherer counterparts (https://www.eurekalert.org/news-releases/603386), we have determined they sleep less than we would have thought: an average of 6.5 hours per night, with seldom daytime naps, and the most light exposure they receive is in the early morning. This early morning sunshine light is light waves between 460 and 484 nanometers (blue light), and it creates an initial large wave of cortisol (yes, the nebulous stress hormone!), which is actually not as nebulous as it has been made out to be. It is instrumental in signaling your initial energy wave for the day, helping usher you out of bed and into your day, setting your circadian clock.
As your day continues, cortisol levels begin to decline, and melatonin levels begin to rise, ultimately leading to the feeling of sleepiness after the sun has fallen from the sky and the moon has taken its place. In our ancestral environment, prior to our friend Thomas Edison and his brilliant light bulb moment, we would be relegated to the use of fire to maintain our visibility, and our hunter gatherer ancestors would be exposed to this fire light (amber light waves) prior to drifting off to sleep about 2-3 hours after the sun has gone down, depending on the season. The flames of fire emit amber light waves, which are closer to infrared light waves, hovering around the mid to high 500’s in nanometers on the light spectrum. This change in nanometers helps melatonin levels continue to rise as cortisol levels decline, ushering your beautiful diurnal physiology into its much needed beauty sleep.
In the modern world, however, we have created an environment where the use of fire is no longer necessary after the sun goes down. We have LED’s, screens, and fluorescent lights which all emit light waves in the blue light spectrum, creating confusion amongst our physiology in terms of when and how much melatonin to release, in conjunction with keeping our cortisol levels elevated, all of which is less than conducive with an easy transition into our beauty slumber. With this in mind, here are some tips to maximize light exposure in your transition to sleep in the evening:
If possible, avoid looking at screens at least an hour before bed time. Your eyes are more sensitive to blue light at night than in the morning.
Make use of amber lighting if possible. Many companies offer very affordable LED bulbs that only emit amber light wavelengths, so you can enjoy the benefits of amber light without the potential of burning your house down. Keep these at floor level if possible, again because of the evolutionary adaptation of your eyes taking in light in the inferior (bottom) portion of your retina
Black-out curtains are a fantastic option for places with light pollution from outdoors (especially in your bedroom)
If screens at night are at some point a necessity, you can also use blue blocking glasses, or at the very least keep the screen below the level of your eyes if possible (remember, your retina evolved to take in blue light from above)
Hopefully you can integrate some of these tools into your sleep hygiene routine to help improve your quality (and maybe quantity)! Stay tuned for Part 2: Caffeine and Sleep! Teaser: It’s not all the good news you are hoping for, but there is still good news!
