Try it at home🕯

⭐️ Here's an experiment in rhythmicity you can try tonight.

Hi,

So what exactly does a circadian day look like? Well, in a circadian environment, activity can take place around the clock, just as in nature. This is a future goal for humanity. But it will take some shifts. For example, here's a building with regular night lighting:

And here's the same building after being fit with turtle-friendly lighting (see FWC guidelines for the specs):

While some may find the red "creepy", there is a biological reason we are seeing these changes taking place. Humans, animals, insects, plants, fungi, bacteria... we all receive information from the environment through many receptors. We all have processes that can only take place in darkness (like baby turtles finding their way to the moonlit ocean).

So when people ask where to start with improving their circadian rhythms, my answer is simple: reintroduce darkness.

Experiment for Circadian Nights

As a simple experiment, tonight at dinner, turn off all your overhead lights. Light a candle at the table. Watch your family relax. See what else you notice.

Keep the overhead lights off and continue dimming any other lights and lamps throughout the evening.

It takes about 3 hours for the body to transition from daytime to nighttime processes¹. Candlelight is the most time-proven manmade light that won't disturb circadian rhythms.

LED Sleep Lights

There are many LED sleep-light products that limit frequencies currently known to disrupt rhythms. I think they are worth trying, but also distrust them because, in science, we deal with known unkowns, but also unknown unknowns. For example, when we invented electric lights, we didn't recognize the nonvisual effects. So if you get pushback from your family on this, you can always respond that current lighting standards are all based on 50-year old science².

The Moon and Circadian Rhythms

There is another source of nighttime lighting that doesn't disturb circadan rhythms: the moon³. But as we all know, even behind blackout curtains the moon may still influence mood. So that is another good point to help bring your family onboard with circadian nightlights.

At bedtime, let the youngest blow out the candle (or let everyone blow it out together if there is contention). Now, everyone knows, and feels, it is time for bed.

Circadian Night-lights for the Bathroom

Here’s a bonus tip to go along with tonight's candle experiment. There is one area of the house that can wreck circadian rhythms and the effect of lighting the candle. That is the bathroom, especially in families with children where it gets used around the clock. As the pupils dilate through sunset, they should stay dilated until sunrise. If you leave regular light on in the bathroom, one simple potty break (or teeth-brushing session) can restart daytime processes at the cellular level. Putting sleep-lights (or safely using flame lights) in areas that get used around the clock (bathrooms, stairwells, etc) will protect your evening efforts.

How Circadian Nights Boost Mood

I hope this is helpful and that you enjoy a nice candlelit evening with your loved ones tonight! The goal with a circadian night is to differentiate it from the busy day. This means things get darker, cooler, and quieter⁴. They also get snugglier. We know from research into laboring women that darkness, melatonin and oxytocin are synergistic⁵. Snuggling up for bedtime cuddles is a natural way to amplify the healing effects of melatonin and get more restful sleep.

I look forward to hearing how this goes for you! In my own experiments I have seen things go from wild to mellow real quick when the electric lights go out and the flames come on. And my children always love it when it is time to light the candle.

Be safe!

That's all for today, but you can always review past posts at nikkofujita.substack.com/archive. There are links to the full-texts of the cited papers in the bottom of this post (click to access the PDFs). And I will send more research about the healing effects of darkness in my upcoming emails.

Best,

Nikko

P.S. Let me know if you have any questions, and please feel free to share your experiences in the comments. Also, in case you missed them, here are the last two posts I shared about darkness:

Darkness & Mental Health:

Save a life 🌟

Darkness & Fertility:

Rhythmicity from the start👶

1. Cain, S., McGlashan, E., Vidafar, P., et al. (2020). Evening home lighting adversely impacts the circadian system and sleep. Nature Research Scientific Reports, 10, 19110.

2. Alkhatatbeh, B., Asadi, S. (2021). Role of Architectural Design in Creating Circadian-Effective Interior Settings. Energies, 14, 6731.

3. Walker, W., Walton, J., DeVries, C, Nelson, R. (2020). Circadian rhythm disruption and mental health. Translational Psychiatry, 10:28.

4. Okamoto-Mizuno, K., Mizuno, K. (2012). Effects of thermal environment on sleep and circadian rhythm. Journal of Physiological Anthropology, 31:14.

5. Reiter, R., Tan, D., Korkmaz, A., et al. (2013). Melatonin and stable circadian rhythms optimize maternal, placental, and fetal physiology. Human Reproduction Update, 20:2, 293-307.