This archived forum used to be called 'Peatarian' (in reference to Ray Peat).

Light therapy

Since there's a lot of talk on here about red/blue light recently and it has been kind of overlooked in the past, I thought I should start a thread about it.
Just starting to read up on it and could use some input.

I assume the natural sunlight we can find during the summer is something we can use as an orientation. We could try to emulate it during the winter and when we are exposed to mainly artificial light.

Color temperature of the sun throughout the day:

-Sunrise: 2500k
-Morning: 4000k
-Noon: 5500k
-Evening: 4000k
-Sunset: 2500k

Now getting as much natural sunlight as possible, getting up at sunrise and going to bed at sunset would be the best i guess. Not always possible though unfortunately.

Things we can do to emulate it:
Installing f.lux on your computer.
Yellow colored glasses during the evening, every time you look into a computer screen for extended periods of time and on cloudy days. Orange/red colored glasses after sunset. (circadian rhythm seems to be mainly dependent on light hitting the retina)
High watt halogen/incandescent around sunrise and sunset.

What about UV light?
Would occasional tanning beds during the winter be beneficial? (ideally at noon I assume)
Maybe one of those UV-bulbs for reptile terrariums?

What's your experience with light therapy and circadian rhythm in general?
What would you consider an ideal light regimen?
Some reliable sources for that topic for people who are just starting to read up on it?
asked Apr 4, 2015 by skally
edited Apr 4, 2015 by skally

3 Answers

Is there an app similar to f.lux available for Iphone? I read somewhere that you need to jailbreak your iPhone to be able to install f.lux on it...
answered Apr 4, 2015 by holl
No idea, sorry.
There are blue light filter films / foils you can put on your phone though if you can't find an app.
You don't want to get as much sunlight as possible or something similar, because sunlight contains UV (that are needed in moderation for vitamin D, but not too much for skin aging, free radicals, etc.) and blue light that is slightly toxic. The ideal is probably getting 15-30 (or more if your free fatty acids are low, use a safe sunscreen, etc.) minutes of direct sunlight on the skin, and then having as much as red and orange light, minimizing blue and UV, so incandescent bulbs are helpful.
answered Apr 5, 2015 by John Frusciante
By "as much as possible" I meant according to tolerance.
I would probably start to get a sunburn if I am in the midday sun during summer for more than 30mins. Someone with very dark skin might need more.

What do you think about uv lamps / tanning beds in the winter when people sometimes don't really see any sun for several weeks?
Yes, UV lamps in the winter are useful.
From Forever Fat Loss by Ari Whitten:

"1.  Deficiency in sunlight exposure during daylight hours. We need sunlight for numerous reasons, like making vitamin D (from the sun‚Äôs UV rays), stimulation of cellular energy production (largely from light in the red wavelengths), and melatonin suppression (from light in the blue wavelengths). Sunlight is bioactive! It affects numerous aspects of our physiology and is an essential requirement for health. The deficiency of red and UV wavelengths can result in deficient cellular energy production and the problems associated with low vitamin D, but as sleep and circadian rhythm are concerned, the big problem is blue light. Blue light is what the circadian clock is wired to respond to. Why? Because the only time an organism was exposed to light in the blue wavelengths (prior to the invention of electricity), was from the sun‚Äî particularly around midday. You know, like bright sun and the blue sky. If blue light photons were entering the eyeballs and feeding back into the brain, that meant that the sun was up and it was time to be awake. So what happens when you spend all day indoors (as many of us in the modern world do)? Well, we do not get enough of the stimulus that tells our brains ‚Äúthis is daytime, the time to be awake,‚Äù and melatonin (the hormone that should be suppressed during daylight hours) is not adequately suppressed."

Light is also necessary to improve blood glucose. It helps "sulfate" cholesterol which causes it to go in to cells where it belongs rather than staying in the bloodstream.  (not sure about this, I just started reading about it). When you get sun in the morning, it signals something in the pituitary gland which has an effect on hormones when you sleep at night. (According to Jack Kruse). It seems to have an appetite suppressing effect.

Morning sun contains red light which is anti inflammatory.  It's probably anti-aging, and if nothing else helps balance whatever blue light there is.  After noon blue light predominates which we already get too much of because of fake lighting, computers etc.  If you go outside after noon it's probably not a big deal, but it doesn't do anything to help beyond keeping you alert and awake, which you already are.  Blue light is aging and damages the skin and eyes (and probably every cell in your body), so there's reasons to avoid it.

If you can't get morning light, you could always buy a red bulb but I've read it has to be pressed on to the skin to make a difference.  You could buy something like the Light Stim or a DPL which can be pressed on to the eyes and entire face:

I avoided sun a lot the last ten- 15 years.  I have a lot of mid-life  health problems because of it.  I walked for years in the late afternoon thinking I was avoiding UV, but never felt better and couldn't figure out why.  I was so tired I couldn't get out bed a lot of days and became a zombie.  On good days now I wake up before the alarm at 5:30 and for a while this winter I slept through the night without getting up.  I only use food and a few supplements (selenium, zinc, b vitamins, aspirin, salt, coconut oil, calcium, progesterone cream)currently; I'm not on thyroid. I get 15 minutes- 2 hours of sunlight before noon daily.
answered Apr 6, 2015 by raintree
edited Apr 6, 2015 by raintree

I will try:
-red light in the morning during breakfast (and in the evening when I eat my dinner?)
-midday sun whenever possible (maybe one of those full spectrum 5500k reptile uv lamps around noon when I can't get any real sun. I could just put one on my desk)
-blue light blocking glasses in the evening / after sunset (especially when looking into computer screens)