
Daily blue light shortens lifespan, causes brain neurodegeneration in Drosophila - minkeymaniac
https://www.nature.com/articles/s41514-019-0038-6
======
ramigb
If you are a human and not a fly here is what concerns you "... humans are
exposed to more blue-enriched LED illumination for most of the day, or even at
night due to shift work and light pollution in large cities.6 However, long-
term consequences of increased daily blue-light exposure across the human
lifespan are not known." saved you a clickbait.

~~~
mikorym
So this should be on the "in flies" Twitter. [1]

[1] [https://twitter.com/justsaysinmice](https://twitter.com/justsaysinmice)

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camgunz
I made a (what most people would consider terrible) vim color scheme that has
no blue light in it (it's like an old amber terminal). Initially I thought I
would hate it and switch back in a couple days/weeks, but I actually find it
very nice, and switching to anything w/ blue light or a "normal color scheme"
with blues and greens now weirdly feels like an assault. Feel free to give it
a whirl: [https://github.com/camgunz/amber](https://github.com/camgunz/amber)

~~~
hyperpallium
Installation instructions, for those with Drosophila-like memory (like me):

    
    
      $ md ~/.vim/colors
      $ cd ~/.vim/colors
      $ curl -LO https://github.com/camgunz/amber/raw/master/colors/amber.vim
      $ vim amber.vim
    

in vim

    
    
      :colorscheme amber
      :set background=light
      :set background=dark
    

I like the look of it, though the syntax highlighting isn't as distinguishing
as default (for java).

BTW: I code on a phone, and set the colour temperature to warm (at night; cold
during day).

~~~
iyrkki_odyss
What’s your setup?

~~~
hyperpallium
[http://termux.com](http://termux.com), tmux, vim, git, ecj, dx

aapt, apkbuilder, signer (for android apps)

bluetooth keyboard + ARM quad cortex-A53 1.3 GHz, 20 GFLOPS GPU, 1 GB RAM -
for 70's era unix tools, it is unbelievably powerful. Specs in the billions.

------
dang
All: we've compressed the title in order to make space for the fruit flies.
Now it is no longer baity.

This result is interesting in its own right, so hopefully the thread can
proceed to talking about other bits than baity titles and insects not being
mammals.

------
squarefoot
Insects aside, I realized there was something wrong about blue light much
before any articles appeared about its negative effects on our circadian
cycles. It was nearly 20 years back when I bought some of the then young blue
and white leds to make some experiments with them, and I quickly realized I
hated blue ones. No matter how I reduced the current through them, their light
made me feel uncomfortable and didn't like as well cold white ones because
they emit more blue light than warm white leds. I still have in a drawer those
10 leds I bought, none of them was ever used in any project. Unfortunately
lots of gadgets appeared in the early 2k and they all used blue leds which
were going to become the standard pretty much everywhere. It was then when I
realized how much and why I disliked that light: it made me nervous; I
couldn't stare at a blue led light, especially the bright ones, for some time
without feeling anxiety. Then one day I read about how blue light affects us
negatively and went "aha!". Now I mask or paint, or even swap where possible,
all blue leds those lazy designers keep sticking into gadgets and appliances.

------
manicdee
What intensity of light, for how long compared to sunlight?

Every time I hear these blue-light crusaders I am reminded of that “iPads are
bad for reading” so-called experiment where the iPads were fixed to the
desktop set at maximum brightness with a custom font chosen by the experiment
lead. Basically attempting to make life as uncomfortable for the subjects as
possible, then blaming all the negative effects on blue light emitted by the
iPad.

So short version: is this study meaningful in an way or does it shorten
lifespan by using extremely bright blue light for many hours longer than a
natural day/night cycle?

edit: they maintained similar photon flux density so the blue light would have
been extremely bright to compensate for being a single wavelength.

Edit2: the actually useful words in that linked paper are about two
paragraphs, the rest is baseless speculation. An effect was observed, with no
mechanism described, therefore extrapolation beyond the experimental
conditions is entirely in the realm of fan fiction and soap opera (ie: emotive
drama).

~~~
ip26
The study is worth reading. The light exposure was for 12 hours/day, they
showed steadily increasing mortality with increasing photon flux density of
blue, and they showed that white light exposure with blue filtered out (at the
same intensities) did not have the same effect.

~~~
manicdee
They also did not test increasing photon flux density of white/filtered light.
They only bothered controlling for PFD after introducing filtered light.

Sounds like experimental protocol was invented … on the fly.

~~~
ghostly_s
Also, white light with the blue filtered out is not an appropriate control
condition. What's to say the blue light flies didn't just deteriorate normally
and the artificially filtered white light had a positive health effect for the
control group?

------
mikorym
So to bring this a little bit back to biology (and away from the fact that the
article says little about humans) I would conjecture that the issue with blue
light may stem from Rayleigh scattering [1] of sunlight and the subsequent
phenomenon whereby the light that reaches us has a lot of the blue component
removed.

In the late afternoon, all the blue light get caught and even some of the red,
since the sun is now not just an atmosphere-length but an atmosphere length
plus a radius of the earth length from the observer and hence has more
distance to get scattered. This would mean we get orange-ish light.

Have biologists pointed this out?

[1]
[https://en.wikipedia.org/wiki/Rayleigh_scattering](https://en.wikipedia.org/wiki/Rayleigh_scattering)

~~~
baxtr
I always wondered: is there anyway to distinguish an evening from a morning
through the sort of light we see. So Image you see random pictures and don’t
know if it’s dawn or dusk. Can you see the difference?

~~~
goblin89
Interestingly enough, if you aren’t familiar with the location, there’s no
foolproof method to tell whether it’s morning or evening by light alone. There
may be cues, like if it’s a city then the properties of light could reflect
the denser pollution it has to penetrate in the evening, but that still
depends on location and time of year.

I sincerely thought I could tell mornings from evenings by light alone, until
I congratulated a friend on a great capture of evening light and he told me
the shot was taken in the morning. Did some research after that.

------
nikkwong
This is confusing to me, would love if someone helped elucidate the details.
My previous understanding was that bluelight is harmful because bluelight
visually interferes with the body's circadian rhythm by leading the body to
believe it's still daytime when it may not be.

This article says that "any bluelight is bad", is that incorrect? I don't
understand, isn't bluelight measured as light on the 450nm range of the
electromagnetic spectrum, whereas visual sunlight ranges from 400-700nm? So,
is the thesis that light at 450nm from the sun is only emitted when the sun is
highest in the sky, for a few hours a day, whereas bluelight from screens is
ever present—causing the circadian rhythm to go out of whack (?).

The article also states that blue light on any part of the body may cause
mitochondrial damage. I wonder if the most proactive biohackers would be
inclined to wear long-sleeves at non-peak hours to counter this problem. [0]

Maybe this is why Dave Asprey is seen always wearing his blue light blocking
glasses, even during daylight hours.

I am also not so inclined to dismiss this data because it only addresses fruit
flies. It seems natural to believe that the closer we get to following the
circadian cycles we evolved alongside with, the more likely our bodies are to
behave optimally. Sure, we may be more resilient to these types of stressors
than fruit flies, but, we already know that obeying circadian cycles is a key
component to achieving better health, and the work of this paper just seems to
push that idea a bit further than we may have originally been lead to believe.
It doesn't take much of a stretch of the imagination to guess about how these
factors could affect us.

[0]
[https://www.nature.com/articles/s41467-018-02934-5](https://www.nature.com/articles/s41467-018-02934-5)

------
nikolay
Blue Light FUD is an industry now. Although blue light exposure at night is
detrimental due to melatonin blocking, during the day, it's important - both
blue spectrum light and brightness. The fact that we spend most of the time
indoors during the day is one of the reason of the wide incidence of myopia
(shortsightness).

I warned LensCrafters that they may expect class action lawsuits as they call
blue light "harmful" and offer coating, which reduces blue light both during
the day and at night, which could be a trick to make people shortsighted to
sell them prescription eyeglasses later.

~~~
Meerax
I thought that myopia was more of a genetic inherited trait than related to
time spent indoors.

~~~
ScottBurson
> Multiple factors are involved in the development of myopia [18]. Both
> genetics and the environment play a role in the development and progression
> of myopia. Many epidemiological surveys have shown that excessive close-up
> work, a high level of education, and participation in fewer outdoor
> activities were important environmental risk factors for myopia [9,19–24].
> Genetic factors have been proven to play a significant role in the
> development of myopia, and several genes are associated with high myopia
> [18,25–30].

\--
[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6261017/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6261017/)

~~~
Meerax
Thanks! I'm myopic, have higher ed degrees, and work as a luthier specializing
in restoration work (excessive close up work for long hours). I knew it was
partly genetic looking at family history but had no idea that my everyday work
was compounding the problem.

------
JabavuAdams
To all the non-biology people saying essentially "meh, flies," we're not as
different from flies as you might think. Model organisms aren't just chosen
because they're easy to study. They're chosen because At the genetic,
molecular, and cellular level results actually transfer to us. This may not be
obvious if you haven't done advanced studies in biology.

~~~
acomjean
I’ve been working with a fly lab the last few years. They really do model
diseases and gene functions. There are tools to look up genes across species
and determine how close they are (othologs). Plus cheaper to study.

For example circadian rythmns were discovered in flies first:

[https://www.nobelprize.org/prizes/medicine/2017/press-
releas...](https://www.nobelprize.org/prizes/medicine/2017/press-release/)

Disease research also is done:

[https://dmm.biologists.org/content/9/3/235](https://dmm.biologists.org/content/9/3/235)

------
ginko
*in Drosophila

~~~
elvecinodeabajo
Big clickbait. I don't care about my LED screens damaging flies brains, my
fly-trap makes a very bigger damage.

------
lettergram
Their model animal is a fly (Drosophila). I can imagine that impacting the
claims significantly. Insects and mammals differ quite a lot.

I wouldn’t expect the same results in mammals (or any animals really).

~~~
Razengan
> _Insects and mammals differ quite a lot._

They can still be merged in teleportation accidents.

~~~
ironic_ali
Found Jeff Goldblum's account.

------
jszymborski
The report also states that flies living with blue LEDs with yellow filters
lived more-or-less as long as the flies grown in darkness.

That's rather comforting to me as most if not all LED fixtures have these.

~~~
jacob019
White LED light is produced by a narrowband blue LED chip (450-460nm) coated
with a wideband yellow phosphor (green-red). It's additive, the spectrum is
built up. Some of the blue light is converted by the phospor. You are most
certainly exposed to the blue light. Those flies were exposed to too much and
for too long. This study starts with the premise that blue light is harmful
and fails to demonstrate anything.

------
anonytrary
I _only_ use nightlight (~red tint) on all of my devices at all times and
people think I'm crazy. I can't even go back to normal -- it physically hurts
and everything just looks super blue.

Wanting to lower the energy of photons that are about to hit your face and get
focused into the back of your eye is completely reasonable. The only argument
against this practice is that the effects of LED screens is negligible, which
is apparently false according to this paper.

------
m463
On the other hand, a friend of mine who is a bio guy told me some wavelengths
of light turn on some wound healing mechanisms in our body.

I think it was 660 or 670 nm (red light)

~~~
newnewpdro
Is that with retina or wound exposure?

~~~
m463
wound. I found this article squirreled away:

[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4148276/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4148276/)

------
fallous
Is there some demonstrable decrease in longevity for sailors (absent the
obvious mortality risks of drowning)? It seems to me that if there was a
fundamental problem with humans dealing with long-term exposure to blue light,
admittedly reflected rather than directly emitted, it would show up in either
sailors or those that live along ocean coastlines.

Of course it's possible that reflected blue light has different effects.

~~~
ghostly_s
It took me a minute to figure out what you're getting at but I suppose you
mean "blue light" reflected from the blue surface of the ocean? The ocean
appears blue-ish because it absorbs the other colors, not because it is
emitting blue light. and the amount reflected is really rather paltry compared
to that being emitted from the sun, hence the dark color. I don't think this
change in frequency distribution is at all significant compared to LEDs, which
natively emit blue light and in common application use phosphors to
approximate white light while still largely being composed of the blue part of
the spectrum.

What this consternation overlooks is that LEDs that more faithfully replicate
the spectrum of a black body emitter do exist ("high CRI (Color Rendering
Index)" fixtures), they just aren't in common use because they are more
expensive. I'm not sure if anyone is working on a high CRI LCD.

------
kortex
Blue (and any high energy light) is known to facilitate radical formation,
redox and other electronic transitions, hence "ionizing radiation". It breaks
chemical bonds. Fruit flies are small enough to be translucent to visible
light. It is not unreasonable to think that blue photons wreak chemical havoc
in the bodies of small bugs, not unlike x-rays in mammals.

~~~
JabavuAdams
Blue light is not ionizing radiation. In fact, not even UV-C is ionizing. You
have to get shorter-wavelength than UV to ionize. UV is harmful because it has
enough energy to at least excite electrons to higher energy levels which can
lead to, I think, changes in bond rotations, but not outright ionization. UV
is clearly dangerous, but not because it ionizes.

I'm not sure how the transparency argument is relative. You seem to be
confusing energy, which depends on the frequency of individual photons with
intensity, which is the number of photons. Shine all the low-energy photons
you want, and you're just going to add heat, not create photo-products or
ionize.

~~~
kortex
I'm not confusing energy with intensity, but in a silly moment I got the word
"photoionization" with photodissociation/photolysis. Yes, you need hard UV to
actually eject an electron from its atom, but you need far far less energy to
break bonds and damage DNA. Photosynthesis is all about redox driven by blue
and red photons.

These are more than just bond rotations (with only slim exceptions, bond
rotations have the same energy state) from photostimulation. You can flip
cis/trans bonds (main mechanism of retinal), ring closing in vit D, and cause
all kinds of increased free radical activity [1]. In particular, blue light
interacting with certain chemophores, such as catechins, are relatively prone
to photoactivation [2].

Ever seen polycarbonate that's been around blue LED light sources (not
sunlight) for a very long time? It yellows. That's not "just adding heat",
that's chemical bonds breaking.

Transparent just means the entirety of the body can be bathed in light.

[1]
[https://www.ncbi.nlm.nih.gov/pubmed/15797866](https://www.ncbi.nlm.nih.gov/pubmed/15797866)

[2]
[https://www.ncbi.nlm.nih.gov/pubmed/29973539](https://www.ncbi.nlm.nih.gov/pubmed/29973539)

~~~
JabavuAdams
Thanks for the info! Apologies if I came across as patronizing.

EDIT> cis/trans retinal -- should have remembered that

~~~
kortex
No problem. At the time I was particularly sloppy with my terminology and that
didn't help discourse much.

~~~
JabavuAdams
Is there some way I can contact you? I'm curious to learn more about how you
know/learned chemistry. Contact details are in my profile. Thanks.

------
winrid
Highly recommend blue light blocking glasses. Helped my sleep quality a lot.

Was very surprised by how much light coming in from the city was keeping me
awake.

Taking melatonin worked for a while but I feel like it really messes with you.

------
foxes
Surely walking around outside exposes you to plenty of blue light. I think the
issue is when people stay up late working at the computer.

~~~
ip26
Note that the study involves exposing the flies for 12h a day, not all day
every day.

~~~
manicdee
At what intensity compared to sunlight or iPad screens?

------
ryanmercer
Glad I'm not a fly that lives less than 2 months!

------
awinter-py
e-ink laptop pls

~~~
ohlookabird
I recently got the Dasung Not-eReader and while it has its quirks it works
pretty well overall, especially as mini-screen for my laptop. It is fast
enough for me to work in vim without any ghosting. And it allows me to
actually do some work outside. But I agree, having an actual eInk laptop would
be fantastic.

------
philpem
Nice clickbait. Full title of the article:

> Daily blue-light exposure shortens lifespan and causes brain
> neurodegeneration in Drosophila

Drosophila are fruit flies. File under "interesting, but likely not applicable
to mammals".

EDIT: From front page to flagged in 32 minutes. That's impressive.

~~~
JabavuAdams
> Drosophila are fruit flies. File under "interesting, but likely not
> applicable to mammals".

Why assume this, without specific evidence? Drosophila are used as a model
organism partly because so many effects transfer. We all run on DNA, and our
cells all use protein and RNA machinery.

