Hi,
Here's an amazing fact: sensitivity to evening light can have a 50-fold variation among individuals! Where do you think you fit on the spectrum of light-sensitivity?
Homes also vary in their evening brightness. Is your home on the dimmer or brighter side of evening?
As you can see in the above chart, the regular use of indoor lighting has the effect of “extending sunset." This light range happens to be one with especially high variation in individual sensitivity as measured by predicted melatonin suppression.
Evening Light and Melatonin Suppression
The most sensitive people experience significant melatonin suppression in 100% of normal homes. The least sensitive people experience melatonin suppression only in the brighter-than-average homes.
But what are the deeper takeaways of this information? An unfortunate finding is that energy-efficient lighting is the currently the most disruptive. But the good news is that doesn't have to be so. If you have dimmable lights or the option for warm tones, use them! Switching from energy-centric to human-centric light could be the key to wellness recovery for many.
Light and Chronotherapies
How is this so? Perform a web search of any illness plus chronotherapies to find cutting edge info. These are hopeful new approaches that doctors and therapists are beginning to use. Chronotherapies apply knowledge about circadian rhythms to medication timing and concurrent lifestyle choices.
The Need for Educators in Circadian Environmental Design Choices
But even if you aren't a doctor, you can still be a leader in your family and your community. In the words of Cain, McGlashan, Vidafar et al:
Humans have a unique degree of control over the light environment. However, we ofen make poor health choices with our lighting due to low awareness of the powerful non-visual efects of light... This suggests a need for broader education regarding the sleep and health impacts of light, as well as more accessible biologically conscious lighting solutions.
Read the review here: Evening light adversely impacts the circadian system and sleep (2020).
That's all for today, but you can always review past posts at nikkofujita.substack.com/archive. I will send more info about ways we can make our homes feel more natural in my upcoming emails.
Best,
Nikko
P.S. The effects of unsuppressed melatonin are amazing. In case you missed it, here is the last post I wrote about it: