It has only been during the last 100 years that we have begun to see the pervasive use of artificial lighting in our homes and cities. Emerging research in the field of chronobiology suggests that exposure to certain wavelengths of light at certain times of the day may be disruptive to an organism’s circadian rhythm. In the long term, this can lead to poor sleep and disease in many individuals.1
You may have heard the term “circadian rhythm.” What exactly does it mean? The National Institute of General Medical Sciences defines the circadian rhythm as the “physical, mental and behavioral changes that follow a roughly 24-hour cycle, responding primarily to light and darkness in an organism's environment. They are found in most living things, including animals, plants and many tiny microbes.” 2
This cycle includes the body’s diurnal fluctuations in endocrine function, temperature regulation, metabolic activity, and much more.
The human circadian rhythm is mediated, at least in part, by a network of neurons in the hypothalamus of the brain called the suprachiasmatic nucleus or SCN. Light that enters the eye is converted to electrical signals, which are then sent to the SCN via the retino-hypothalamic tract.
Considered the body’s “master clock,” the SCN uses this information to synchronise the organism’s circadian rhythm. When the bright light of the morning sun enters the retina, wakefulness hormones like cortisol are released. When the sun sets and less light enters the retina, the sleep-inducing hormone melatonin is released by the pineal gland.
Excessive nighttime exposure to artificial light and blue light emitting devices such as smartphones, tablets, computers, and televisions will signal the SCN that it is daytime. The SCN then suppresses the pineal gland’s production of melatonin making it more difficult to fall asleep. This, in combination with a lack of daytime sun exposure, has led to widespread chronic circadian rhythm disruption across the globe.
One might ask, “So? What’s the big deal?” The big deal is that, aside from affecting your sleep, disruption of circadian biology has also been linked to chronic diseases such as obesity, diabetes, bipolar disorder, and seasonal affective disorder among much else. 3
During the day:
Every morning before breakfast, spend 5-15 minutes outside facing the sun. Even if it is cloudy outside, the strength of the light will still be strong enough to signal to your body that it is morning. This is even more effective if you are wearing as little clothing as possible and are barefoot on a conductive surface (such as sand, grass, soil, rock, concrete, brick, ceramic tile). If you work indoors and have to be at work before the sun rises, try to go outside for your lunch break and get as much sun exposure as possible. The midday sun has the most blue light and will send a strong signal to your body that it is day time. This is also when the sun’s rays can be most efficiently utilised to make vitamin D. The most powerful times of the day to set the circadian rhythm are sunrise, solar noon, and sunset. However, any daytime sun exposure is extremely beneficial. Favour indoor environments with natural lighting from windows. In fact, if at all feasible, experiment with working outside. You can take your laptop to a deck, patio, balcony, yard, park, stoop, porch, treehouse, or rooftop. Working outside also confers the benefits of fresh air and depth perception to reduce eye strain.
In the evening:
Begin to limit your blue light exposure at least 2 hours before bed. There are myriad methods of doing this. For your devices, there are screen protectors that are available for purchase but you can use apps like f.lux or Night Shift that work just as well. Another consideration is using red or amber light bulbs. Salt lamps are a great option, with the added benefit of looking really cool, one can’t help but feel a sense of calm in their presence. In general, it is probably best to favour lamps and avoid overhead lighting in the evening. Perhaps the easiest and most affordable option is the use of blue-blocker glasses. For optimal effect, it is wise to choose blue blockers that offer peripheral protection which most models do not offer. Admittedly not the most attractive, the UVEX blue blocker glasses have full peripheral coverage for the dedicated biohacker. The UVEX glasses were also reported to offer the most substantial reduction in blue light exposure by Consumer Reports. Although every surface of the body has the ability to detect light, the most sensitive is obviously the eyes. Wearing these glasses after sunset or at least 2 hours before bed will largely mitigate the negative effects of evening blue light exposure while still allowing you to go about your business. Blue blockers are not just to help you sleep. To learn more about blue blockers, and why you might even consider wearing them during the day, read part 2 of this series here (Link).
The circadian rhythm is the ebb and flow of an organism's biological processes. In humans, the strongest regulator of this rhythm is the wavelengths of light that the organism is exposed to. This occurs through the activity of the suprachiasmatic nucleus in the hypothalamus. In order to prevent circadian disruption, and the resulting associated disease, we can take proactive steps to expose ourselves to biologically adapted lighting environments. Even the smallest and simplest shifts, such as morning sun exposure or wearing blue blockers after dusk, can positively impact your circadian biology. Thus you may experience greater ease in falling asleep, deeper more restful sleep, and improved mood and attentiveness during the day.
Hack your light exposure to improve your sleep. With better sleep comes better health, and with better health you are more able to share your gifts with the world.
Brenton Levi: Brenton, a native born Texan, is a biohacking yoga and meditation instructor with a passion for spiritual exploration. With a degree in Environmental Philosophy and experience as an organic farmer, Brenton acknowledges the importance of connection in the human experience. This includes connection to the body, the breath, the Sun, the Earth, the seasons, and, most importantly, each other. Reconnecting on these levels can offer a deeper, more rich, and fulfilling experience of life. Through the research and implementation of both ancient and cutting edge techniques, Brenton aims to embody the potential inherent in humanity while inspiring others to do the same.