You may not remember your grade-school Life Science days when you first learned about circadian rhythm, so I’ll give you a little crash course; no need to strain your brain going that far back. Plus, if you’re like me, you were hardly paying attention anyway.
Often referred to as the “body clock,” the circadian rhythm is a cycle that tells our bodies when to sleep, rise, eat—regulating many physiological processes. This internal body clock is affected by environmental cues, like sunlight and temperature.
When we were cavemen (and women), and up until only a little over 100 years ago, we just had the light of the sun and flames as light sources. This was optimal to our DNA. Like most every aspect of this modern life, our DNA hasn’t progressed at the same rate as technology. When we “buck our systems” with processed foods, sedentary lifestyle, social isolation, artificial light, etc., our health suffers. We can see this in wild animals living near suburban areas where they are exposed to artificial lights at night; their eating, migrating, reproduction, and immune functions are disrupted.
One of the most obvious effects of nighttime lighting is sleep disruption. During dark nights, melatonin levels rise to promote sleepiness and regulate sleep phases throughout the night. Exposure to light at night strongly suppresses melatonin, which interferes with sleep timing and sleep quality. By now, I don’t think I need to remind you of how important sleep is to the body and brain.
Blue light is the most stimulating to the photo receptors in our eyes that tell our brains it’s daytime. Many big cities are opting for more energy efficient LED (blue) lighting in public areas. That’s bad news for LED city dwellers, according to this study of 19,000 residents who self-reported less quality and quantity of sleep, as well as more daytime sleepiness.
Too much exposure to night-time light, especially blue light has been linked to:
We still have to LIVE in this modern world, so what do we do about it?
- Get up and out into the sunshine early to tell your brain GOOD MORNING!
- Setting your phone/devices to “nightshift” mode
- Wearing blue blocking glasses starting around 3 hours before bedtime
- Black-out curtains in the bedroom if you are exposed to city lights
- No TV and screen time an hour before bed
Getting out into the bright sunshine in the morning and again at “high noon” if you can (a quick walk outside in the middle of your day is good for more reasons than just this one) gives the photo receptors in your eyes something very bright to compare to artificial night-time light, in essence, making you more resistant to light at night.
While artificially extending the day has it’s many benefits, our health does pay a price for it. Thankfully, we are learning more and more about what it does to us and ways to combat it. Apple already came out with the “nightshift” feature where it shifts your screens toward the orange tones. Smart home lighting features are being designed where their colors shift with the sun as well. This is all great news, because we certainly aren’t going back to the Little House on the Prairie days. Although, I think I would love it if we did.