Light exposure during sleep impairs cardiometabolic function

https://www.pnas.org/doi/10.1073/pnas.2113290119

by sndean • 4 years ago

276 122 4 years ago

22c• 4 years ago

I wonder if enough overly bright device LEDs scattered around a room would hit 100 lux

This article refers to "moderate" (100 lx) light exposure - this amounts to an overhead light on in the room for the entire duration of sleep.

I would say an overhead light is a significant amount of light, but wonder how low the threshold is for sleep disruptions. Living in an urban environment, there's a non-negligible amount of ambient light that makes its way in. I don't use a set of blackout curtains, but I know several friends that say it makes a real difference.

scruple3• 4 years ago

I don't use a set of blackout curtains, but I know several friends that say it makes a real difference.

Maybe a year ago, I was planning on having a sleep study done. At some point in my 30s I stopped feeling like I was recovering when I slept. I decided, however, that there were some things that I could work on improving before having a sleep study.

Most of what I addressed falls under sleep hygiene: Blackout curtains, better sheets, better blanket/comforter, better pillows, a better mattress, a sleep mask, reducing noise. It took a while to sort all of this out. "Better" is also subjective.

I also slowly worked on getting to bed earlier. I used to get into bed around 11:30pm. Now I'm in bed between 9:30 and 10pm. I read a little bit and then sleep. I stopped having calories after ~7pm.

We have young children, too. 3 under 3. I sleep very well now. Despite the regular interruptions I actually feel like I am getting the highest quality sleep of my adult life right now.

The blackout curtains, though... The difference they made from one day to the next was immediately obvious. My wife and I both woke up feeling more refreshed, looked at each other and said, "Why did we wait so long to do this?"

aantix• 4 years ago

+1 for the blackout curtains. Easily 20% better sleep.

And our only source of light at night prior was a street light outside our bedroom window.

cj• 4 years ago

Blackout curtains are great for sleeping, but I have trouble waking up and getting out of bed when the room is still completely dark (when it’s light outside in the AM).

Recently bought some Hue smart lights to simulate sunrise with blackout curtains which is helping. Next up, motorized blinds that open at a scheduled time.

(#firstworldproblems)

whoisburbansky2• 4 years ago

Would you say the blackout curtains made a bigger difference than the sleep mask?

ijustwanttovote• 4 years ago

My wife was complaining about waking up in the middle of the night. I grabbed some black out curtains. She woke up the next day feeling better than she has for a long time.

Turns out there was a streetlight that would hit her in the face and was causing her to wake up. We didn't realize it until we got the blackout curtains.

exeldapp• 4 years ago

I don’t live in an area with a lot of light pollution but have black out curtains for full moons and that hour or two after sunrise before I’m awake and they have made a noticeable difference.

jbverschoor• 4 years ago

Pilots are only allowed to stay in hotels with 100% blackout curtains

moron4hire• 4 years ago

In searching to attempt to find corroboration for this factoid, literally the only things mentioning pilots and blackout curtains I could find were your own comment here and a random forum post from a pilot saying blackout curtains don't really work. Nothing about any requirement that pilots only be placed in hotel rooms with blackout curtains.

aucontraire• 4 years ago

Not true that there is any sort of official rule to this effect. I've slept in a lot of crew hotels that had only semi-decent curtains.

It is true that well-behaved airlines, who take an active interest in fatigue prevention, do try to book hotel rooms with blackout curtains and good sound proofing. This is however not a universal behaviour and not all destinations where layover is necessary have any hotels with these qualities.

Terry_Roll• 4 years ago

I don't use a set of blackout curtains, but I know several friends that say it makes a real difference.

Have blackout blinds on every window upstairs so thats its dark enough during summer mid day sun to sleep. They keep the heat out during the summer (to the point I dont need the air conditioning on albeit on the hottest days and the warmth in during the winter which contributes to energy saving, the only downside is the air gets stagnant in small buildings.

I believe a lot of German homes also have external blinds over their windows for similar reasons plus they offer a layer of security making it harder to break in, but then what do the Germans know?

100lux is quite bright, I have a lux meter and here in the UK 100-200lux is a really cloudy winters day level of brightness, where as a bright summertime day will exceed tens of thousands lux for comparison.

Its because light affects the release of melatonin black out blinds are fitted. Melatonin increases the release of stem cells and stem cells play their part in repairing the body, but like I say earlier, CO2 levels building up cause the body to be stimulated even during sleep so sleep is not as refreshing as it could be in small homes and almost all UK homes are small, but hey the CO2 helps contribute to an increase in GDP and thats all that counts!

Someone• 4 years ago

This article refers to "moderate" (100 lx) light exposure

I think that’s relative to daylight, which already is 1,000 lx under an overcast sky, 10,000 in full daylight, 100,000 in full sunlight.

bb123• 4 years ago

Pretty incredible how well our eyes can move between these completely different scales of brightness like its nothing.

lm28469• 4 years ago

Living in an urban environment, there's a non-negligible amount of ambient light that makes its way in. I don't use a set of blackout curtains, but I know several friends that say it makes a real difference.

God bless Europeans and their cutting edge roll shutter technology, I can sleep in total darkness despite the street lamp 10m away from my bedroom window. And ye[, it definitely makes a difference.

giantg2• 4 years ago

I even hate laptop/modem/smoke detector lights.

toomuchtodo2• 4 years ago

Eye mask. Try it, it is fantastic.

savant_penguin• 4 years ago

Could you suggest one? Maybe one that doesn't uncomfortably push your eyeballs in

jimmaswell• 4 years ago

Those never work or feel comfortable for me. I just throw a tshirt over my head, works great

jb19913• 4 years ago

I find that the pressure on my head over the course of a night, even with the fairly loose mask, is very uncomfortable and disrupts my sleep even more than the lights.

jimmux• 4 years ago

There was a time when it seemed like every new device had to have an always-on blue LED. Escaping blue light at night was an effort. These days small white LEDs are in fashion, which I find much more tolerable.

placatedmayhem• 4 years ago

A big of black gaffers tape takes care of that for me. Electrical tape in a pinch. If I use white gaffers tape, it significantly cuts the light but is still visible when I'm looking right at it.

ZYinMD2• 4 years ago

Hold my tower pc.

https://www.amazon.com/s?k=tower+pc+case

MrFoof• 4 years ago

You can buy some self-adhesive light attenuating film. They sell it in pre-cut shapes, in black (several strengths), white and silver. The name brand that started it all was, "LightDims".

I put them on... most things. Network gear LEDs. Power LEDs. All manner of things.

dylan6045• 4 years ago

Are you really trying to sleep in a room with that type of LEDs, or do you just really hate all things LED?

its_bbq• 4 years ago

Or just use a little electrical tape...

sliken• 4 years ago

Some duct tape (to block) or a sharpie (to decrease the brightness) does wonders.

lobocinza• 4 years ago

I have RGB memory that is really bright and light the whole room when lights are off. It was cheaper than a similar non-RGB when I purchased. Guess I will put same electric tape on it as I already did with everything else.

bladley• 4 years ago

Maybe related: Morning and Evening Blue-Enriched Light Exposure Alters Metabolic Function in Normal Weight Adults

https://pubmed.ncbi.nlm.nih.gov/27191727/

westurner• 4 years ago

Research on Blue light and sleep: https://justgetflux.com/research.html

https://en.wikipedia.org/wiki/Melanopsin :

Melanopsin photoreceptors are sensitive to a range of wavelengths and reach peak light absorption at blue light wavelengths around 480 nanometers.[30] Other wavelengths of light activate the melanopsin signaling system with decreasing efficiency as they move away from the optimum 480 nm. For example, shorter wavelengths around 445 nm (closer to violet in the visible spectrum) are half as effective for melanopsin photoreceptor stimulation as light at 480 nm.[30]

Under Melanopsin > infobox > "Biological process", e.g. "entrainment of circadian clock by photoperiod" and "regulation of circadian rhythm" are listed.

owenversteeg• 4 years ago

The research discusses 100 lux for one whole night, which is quite a lot (indoor levels range from 100 to 1000 lux, outdoors from 10k on a cloudy day to 120k with direct sunlight at noon.) Like others here, I’m curious about other strengths of light - I assume up to 0.1 lux is fine, as moonlight is typically 0.05-0.1 lux, but what about between 0.1 and 100 lux? And what about light exposure during part of the sleep cycle? There’s quite a lot of sleep research, much of it poor quality, so I’d be grateful for any specific study suggestions.

gehwartzen• 4 years ago

I noticed that on nights the full moon was shining though the regular curtains on my bedroom window I would get a horrible nights sleep. It wasn't fixed until I got blackout curtains.

erosenbe02• 4 years ago

One night? You could probably repeat this experiment with fart stench or any other obnoxious irregularity and find impairment of glucose tolerance at a decent p value.

I see the headlines now: "Fart stink during sleep impairs cardiometabolic function." So yeah, guess the wife is getting diabetes if I don't move to the dog house.

makeitdouble• 4 years ago

Joking (?) aside, cheapish air purifier are reasonably efficient to help for stinks and other air issues during sleep if they have a carbon filter (IKEA ones have the option for instance). Bonus point if they can auto-adjust power depending on the air status, but I don't think that's mandatory.

erosenbe02• 4 years ago

I agree -- our bedroom is small and benefits from even a simple filter! However, my point was to humurously criticize the study title for sounding too conclusive. The study is useful as a starting point but it is pretty well known in such literature that one-night of introducing variable X can yield results showing negative short-term perturbations. X can even be something generally regarded as positive such as first night on low-stress vacation, or even the first few times people share a room with a partner. Changing a routine increases vigilance (not sure of proper technical vernacular for that, but you get the idea).

amelius2• 4 years ago

One night?

https://www.nosleeplessnights.com/first-night-effect/

First Night Effect
When people spend a couple of nights in a specialist sleep clinic to check for sleep disorders, sleep experts have long known they can’t always rely on the first night’s data.

social_quotient• 4 years ago

I find these stickers helpful for a ton of little lights in the bedroom

LIGHT DIMS Black Out Edition - https://www.amazon.com/dp/B009WSN8PK/ref=cm_sw_r_cp_api_glt_...

dylan6045• 4 years ago

Grabs wheel, jerks hard left:

Oh my those are some fun images! The art on a lot of Amazon listings are just hillarious. Some are down right creepy. The 6th image for this listing has a very intersting bit of text on the screen in what I'm guessing a slide in a deck??? My favorites are the ones where the "product" is just photoshopped in with Escher level physics required to make it believable.

vatys• 4 years ago

Certainty

Elegance

Professionalism

Just Like You

ad404b8a372f2b9• 4 years ago

I use electrical tape to cover those and it's made a world of difference, it's crazy how many items have LEDs in them. Power strips, clocks, monitors, charger cables, my synth, ... My girlfriend thinks I'm nuts because I'll get up in the middle of the night to tape over previously undiscovered LEDs.

What do we need all these LEDs for?!

jcynix2• 4 years ago

I use electrical tape to cover those

Another easy solution is to add a layer of nail polish to dim leds.

hackerfromthefu• 4 years ago

Yeah and why isn't there a switch to keep them always off, on everything!

kingcharles2• 4 years ago

Ugh. When I was in jail I had to have a bright light shining on my face every night for five years. Cover the light and you went to the Hole.

tomcam• 4 years ago

Been there, done that, don’t want the T-shirt

rootw0rm2• 4 years ago

At one of the jails I was in the deps would put the dayroom TV on at full volume all night long when they were pissed at us. between that, no pillows, and 3:45 AM breakfast, sleep hygiene isn't terribly valued in county

kingcharles2• 4 years ago

Were we in the same jails?!

I think this shit is universal across county jails. Prisons get more litigation, but jails are hard to litigate in.

I fucking hate no pillows, 3AM breakfasts.

I sued and got the breakfasts legally changed to 6:30am. That got me another 10 days in the Hole.

vaylian• 4 years ago

The laws should be updated to include a right for dark sleep conditions, because we know now that this form of treatment is effectively physical harm.

rootw0rm2• 4 years ago

That would be nice. Proper nutrition would be great, too.

The Effects of Vitamin-Mineral Supplements on Serious Rule Violations in Correctional Facilities for Young Adult Male Inmates: A Randomized Controlled Trial

<https://journals.sagepub.com/doi/10.1177/0011128721989073>

bolangi• 4 years ago

Hope this discovery will influence hospital lighting policies.

Broken_Hippo• 4 years ago

Hospitals have slightly different constraints.

You - as a patient - often have time to sleep unlike in your daily life. And the hospital is often going to wake you up nonetheless: It is, generally, more important to take your vitals than it is to allow you uninterrupted sleep.

They also need to look out for safety. You have a bunch of patients who are feeling poorly. Some aren't quite sober due to pain medications. All in an unfamiliar setting. A bit of light makes it safer to move around at night if you should need to. Sure, a patient can control lights, but not everyone will be able to. In some areas, you are sharing a room, too.

All that said: For my last hospital stay, the room got as dark as I wanted at night - but I'm not sure that would have been the same during the summer (I can read outside at night during the summer).

vrc• 4 years ago

Hospitals are really there for downside mitigation and acute care, not necessarily for “recovery”. If you take that perspective, it makes a lot more sense why the lights, beeps, vital checks, loud talking in the hallway, etc all conspire to ruin your sleep. Ultimately, getting healthy enough to be discharged and getting back home is when/how you’ll fully heal.

Source: Spent a few nights in hospital a week ago and came home covered in bruises and sleep deprived —- but very alive and ready to recover!

Dove• 4 years ago

I always bring a sleep mask and ear plugs with me to the hospital. It confuses me that they don't hand them out! Sleep is essential for healing. I have often had nurses in hospitals tell me to sleep, but I've never had a nurse offer me ear plugs.

11235813213455• 4 years ago

Recently I started to only work in daylight times, I had to shift my sleep 3-4 hours sooner. The idea is to never need to use artificial lights, wouldn't work well in high latitudes winters though :))

isolli2• 4 years ago

It reminds me of this article [0], a very interesting read on "surviving" winter in Sweden (and Northern latitudes in general). It ends with how in summer things are flipped and everyone complains about how poorly they sleep.

[0] https://www.ft.com/content/180f3428-1923-11e9-b93e-f4351a53f...

soderfoo• 4 years ago

Before moving to Sweden,I was fully aware of short Scandinavian winter days. They're like the poster child for seasonal depression.

Nothing/no one prepared me for the sun rising at 3 am in May... It was quite an interesting first year.

isolli2• 4 years ago

Yes, the article resonated with me because I lived in Berlin for 4 years. When your child wakes up at 4 am and the sky is bright blue outside, it's impossible to put them back to bed!

rendall2• 4 years ago

Same, for Finland. The movie Midsommar really captures the mood of endless sunlight.

CamelRocketFish• 4 years ago

I’d be interested to know if this is because of light hitting the eyelids or light hitting any part of the body.

echelon• 4 years ago

I love studies like this. I know, I know. "It's just a study." But it means that people are having new thoughts about how the body responds to its environment and enters into chronic disease states.

Some of our "new ideas" about diseases are actually maybe not all that crazy [1].

Every time I see one of these potential connections, my brain jumps to generate new hypotheses for everything around it. I sometimes wish I was a PI looking into these things.

For instance, this article made me think that perhaps children being exposed to night lights upsets their metabolic behavior in early development enough to lead to long term neurotransmitter dysfunction and desensitization. ADHD. Just a hypothesis. Totally unsupported. Probably not a contributor. But I'd love to have access to journals and data and test these things.

In a different life...

[1] https://news.ycombinator.com/item?id=29882347

Tepix• 4 years ago

Are there similar studies that cover the effects of noise during sleep?

whiddershins• 4 years ago

I wonder if regular exposure means the body adapts.

These participants likely were acclimated to sleeping in a dark room.

Beltiras• 4 years ago

I live in the north part of the north hemisphere. It's bright outside the entire 24 hours for almost a month during summer. I use a sleep mask to combat it and the last 5 years I feel like I regained sleep during the summertime. Last year I purchased a Manta Sleep mask and they are next-level good. Total darkness and really easy on the face. I have no affiliation with the brand, just a really happy customer of theirs.

hobbescotch• 4 years ago

In the summer if I don’t sleep with my mask off I start to feel myself slowly unhinging. Sun being out at 2am while you’re trying to sleep can definitely make you feel out of it! Hard to find blackout curtains that work perfectly too.

layer8• 4 years ago

Easyblinds Blackout Blinds or Blackout EZ works well for me. (Basically, lightproof textile velcroed all around the window frame.)

rendall2• 4 years ago

Could this effect be explained otherwise by "disruption of normal sleeping environment"? Presumably all of these people are used to sleeping with dim lights. What would the effect be on subjects who were used to 100 lux light?

My intuitive sense is that light at night has some harmful effect. On the other hand, I live at a latitude where summer nights are very bright, and I and my fellow residents generally get used to it. Perhaps the effect diminishes?

Are there people with sleeping habits such that they would find darkness similarly disruptive?

ck2• 4 years ago

That's a pretty bold statement that nightlights are associated with obesity.

But there's a theory blue/white reduces melatonin output.

So, use red nightlights, apparently true red wavelengths don't affect sleep.

https://www.healthline.com/health/why-not-to-have-red-lights...

lizardactivist• 4 years ago

What worries me is that some of the research done on this suggests that even tiny amounts of light could have a noticable effect, like green and blue LEDs on common home electronics when it sits in standby or sleep mode.

Sxubas• 4 years ago

Is not the test population too small? (n=10) or is there any reason we can generalize this with such a small number?

MrYellowP• 4 years ago

Reminds me of how studies found out that, when sleeping with lights on, one gains weight.

amelius2• 4 years ago

Another thing to worry about during those situations where your sleep-environment is not optimal.

rryan• 4 years ago

N=20

Light exposure during sleep impairs cardiometabolic function

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