Episode Transcript
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William Davis, MD (00:06):
Over the past
decade, most of us have
converted our home lighting tolight-emitting diode or LED
bulbs, as they save asignificant amount of energy,
requiring 75-90% less energythan older incandescent lights.
Personally, I convert the 50 orso light bulbs in my house to
(00:26):
nearly all LEDs.
Most current LEDs emit, ofcourse, visible light, but they
also emit a significant amountof blue light and very little
red and infrared, in contrast toold-fashioned incandescent
bulbs that emit some blue and alot of red and infrared.
Remember when you had to changean incandescent bulbs that emit
some blue and a lot of red andinfrared.
(00:46):
Remember when you had to changean incandescent bulb when it
died?
If you tried to unscrew it, itwould burn your hand because the
bulb was extremely hot.
That's the effect of red andinfrared that generates heat.
Change an LED bulb and you cando so immediately, as the bulb
is cool, even after dying justmoments earlier.
(01:07):
This is due to the absence ofsignificant amounts of red and
infrared.
While well intended to saveenergy, it is now becoming clear
that the wholesale conversionto blue-emitting LED lighting
has been exerting adverse healtheffects, especially visual has
been exerting adverse healtheffects, especially visual.
So let's begin talking aboutthe role of light, specifically
(01:27):
blue wavelengths, in thisepisode of the Defiant Health
podcast, then about the role ofred and infrared.
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So, as I mentioned in theopening comments, as a society
(02:15):
we've converted our lightingover to the LED blue emitting
light bulbs, and it was done forgood purpose.
It was done to conserve energy.
So federal regulations fromCongress and the Department of
Energy has essentially done awaywith incandescent bulbs, or
most forms of incandescent bulbs, and we replaced them with LEDs
.
So it's not uncommon to haveLEDs at work in stores in your
(02:37):
home in the form of light bulbs.
As well as TV screens, computerscreens, tablets, smartphones
they are all LED, so we arewildly overexposed to this LED.
You know what this reminds me of.
This reminds me of the reducersaturated fat and cholesterol
blunder created bymisinterpretations of science,
(02:59):
us dietary guidelines.
It took us 40 to 50 years torecognize what a huge mistake
this was.
It took the elimination orreduction in saturated fat in
total fat and increase in theintake of carbohydrates,
specifically grain forms ofcarbohydrates as well as sugars,
and the unrestrainedproliferation of processed and
(03:21):
ultra-processed foods to show usjust how destructive this has
been.
Of course, in the world of dietit's caused epidemic, a
nationwide, now a worldwideepidemic of overweight and
obesity, type 2 diabetes andnumerous other health
consequences.
I think there's a parallel hereto this wholesale conversion,
(03:42):
the replacement of incandescentbulbs with LED bulbs, and we're
only starting to see it now,many years after this initiative
was introduced.
Now, blue is not all bad.
Blue light is not all bad.
Let's review the light spectrumjust for a moment because it
helps to understand.
So at the far short wavelengthat the left, on most charts of
(04:03):
wavelength of light, you'll seethat blue is just after
ultraviolet.
Ultraviolet, of course, is thestuff you can't see that
activates vitamin D in the skin.
Then to the right, in a higherwavelength, is blue, and then we
have visible light.
Visible light is actually avery narrow part of the
electromagnetic spectrum.
And at the right we have red,visible, followed by infrared.
(04:27):
Infrared-like ultravioletcannot be seen.
You can feel it as heat, butyou cannot see it.
But red and infrared haveunique effects and that's the
flip side of all this.
Part of the problem is our wildoverexposure to blue and lack
of red.
We'll talk about that and we'lltalk about this even further in
(04:48):
a future episode of this DefineHealth podcast.
Now, blue is not all bad.
It has some positive aspects.
It increases alertness, arousal, it improves cognitive function
and, in some people, can reducemigraine headaches, though in
other people it actuallyactivates.
So it's unclear why thatdiscrepancy, but it does have
brain effects that can bepositive if you're exposed in
(05:12):
the morning or midday and, ofcourse, if you're exposed most
in the midday.
That's when you maximallyactivate vitamin d in the skin,
with exposure to the uvb form ofradiation just a little shorter
wavelength than blue.
So blue actually has positiveaspects and that's actually why
I converted my desk lamp someyears ago to blue LED, because
(05:35):
we were told that it increasedalertness and cognitive function
.
So I took my desk lamp, forinstance, and replaced the two
incandescent bulbs with two LEDbulbs.
Well, personally, I started tonotice after a couple of years
that my vision was deteriorating, so much so that if I worked at
night, I could barely see thescreen.
I could barely read the text ona screen and images.
(05:57):
If I watched a video, forinstance, it was fuzzy, I had a
hard time and it was worse atnight.
Now, why would that be?
So I converted back to twoincandescent bulbs.
So incandescent bulbs, the oldfashioned bulbs, are richer in
red and infrared.
They do have some blue, ofcourse.
They have visible light, butthey are enriched in the red and
(06:20):
infrared part of the spectrum,while the LED lights are visible
light with lots of blue andvery little red.
So I converted my desk lampback to two incandescent bulbs.
Lo and behold, my visionnormalized within 48 hours.
Now, one person's experiencesuch as mine is not proof of
anything, but it is consistentwith what we're seeing and
(06:43):
hearing and reading andexperiencing nationwide, that is
, a deterioration in visualacuity, with overexposure to
blue, particularly later in theday.
So what does excessive exposureto blue do, especially if it's
done afternoon?
So after about 4 pm blue startsto become a toxic factor and
(07:05):
not a beneficial factor.
So among the effects ofexcessive exposure to blue
includes a reduction in visualacuity Not just in me, but it's
been shown in other people thatoverexposure to blue,
particularly in the afternoonand evening, reduces your visual
acuity and that reduction invisual acuity over time can
become permanent.
(07:25):
It's not.
It may be temporary at thebeginning, but over months and
years it becomes permanent.
Part of that reason is damageto the retina.
There are light-sensitive cellsin the retina that is, the
light-sensitive portion of youreyes called retinal ganglion
cells, and this has beenassociated with glaucoma,
development of glaucoma andother eye conditions.
(07:46):
So exposure to blue later inthe day has been associated with
retinal damage.
It's also been associated withthe development of cataracts.
Recall that cataracts are thedevelopment of opacities in your
lenses, in the lenses of youreyes, and as you have greater
opacities in your lenses, thisis cataracts and you can't see
(08:06):
after a while.
Light has a hard timepenetrating the opaque cataracts
.
So there's an interestingexperiment in which lenses were
taken out of the eyes of pigsand exposed to blue light, red
light, and examined to seewhether they continue to
transmit light or not.
Now the pig lenses exposed toblue light developed opacities
(08:28):
consistent with cataracts within24 hours of continuous blue
light exposure, suggesting thatthere's a time dependence, and
it only took in these lensesthat were taken out of the pigs,
of course, exposed to bluelight.
It didn't take that long forblue overexposure to develop
cataracts.
And you know what I believe?
I'm seeing this around me.
(08:49):
I'm seeing people in their 40sand 50s.
Cataracts were typically aproblem of people in their 60s,
70s and onwards.
I'm seeing people in their 40sand 50s now having to undergo
cataract extraction or cataractremoval surgery because their
lenses are opaque and they can'tsee.
And so I think this is aphenomenon being played out
(09:10):
because of our overexposure toall the blue wavelength in our
lighting and our devices.
Exposure to blue light alsoreduced the release of melatonin
from the pineal gland.
Recall that melatonin is thehormone of a circadian rhythm
from the pineal gland.
Recall that melatonin is thehormone of the circadian rhythm.
It's a thing that surges laterin the day and evening to
(09:32):
facilitate sleep.
So this is the reason why youhear this kind of advice.
So avoid LED screens later inthe day, because they reduce
release of melatonin and causesleeplessness.
That's a real phenomenon.
So blue light exposure later inthe day disrupts sleep and
disrupts your circadian rhythm.
Now more recent evidence alsosuggests that the effects of
(09:53):
blue light go beyond the eyesand the components of the eyes,
like the retina and lenses andit.
Organs of your body don'trespond to insulin and your
pancreas thereby overcompensatesby producing huge amounts of
(10:19):
insulin.
It's not uncommon to produce10-fold more, 30-fold more,
100-fold more insulin, whichleads to weight gain, especially
abdominal visceral fat.
It leads to all theconsequences of insulin
resistance that includeimpairment of cognition,
alzheimer's disease, coronarydisease, heart disease, type 2
(10:40):
diabetes, hypertension, dementia.
So an increase in insulinresistance is very important,
even a modest increase, becausethis effect induced by blue
light is over and above thatinduced by bad diet, lack of
vitamin D, lack of magnesium,sibo and endotoxemia.
If you don't know what thatmeans, please see my prior
(11:01):
episodes of this podcast or myblog, williamdavesmdcom, or, of
course, my books, such as theSuper Gut Book, where I talk
about how the bowel microbiome,through dysbiosis, sibo, small
intestinal bacterial overgrowthand endotoxemia, adds to insulin
resistance.
Where here we have yet anotherfactor adding to this very
(11:24):
ubiquitous process that leads toso many diseases insulin
resistance in this case,exposure, overexposure, blue
light, especially later in theday.
Now there's also evidence totell us that exposure to blue
light reduces tone in the vagusnerve, vagal tone and heart rate
variability.
Recall that the nervous systemis divided into two the
(11:47):
autonomic nervous system, thatis the nervous system that
controls internal body functionsthat you're unaware of.
So in other words, if you eatsomething let's say you eat an
omelet you don't have to thankgoodness, tell your esophagus
and stomach to begin thedigestive process.
You don't have to tell yourpancreas to release pancreatic
enzymes.
You don't have to tell yourstomach to propel that chewed,
(12:08):
partially digested food into theduodenum.
All this happens, of course,beneath consciousness.
This is all conducted by theautonomic or automatic, you can
say nervous system, and a lot ofthat's controlled by the
sympathetic and theparasympathetic nervous system,
the two main components of thatautonomic nervous system.
The sympathetic nervous systemis the gas pedal on your
(12:31):
physiology.
It's the part of your nervoussystem responsible for fight or
flight, excitement, arousal,getting out of danger, getting
out of the way of danger.
The parasympathetic system isthe brake on your nervous system
.
It's the thing that'sassociated with relaxation,
quiet meditation.
So if we have exposure to bluelight later in the day, it
(12:52):
reduces these phenomena, as sois with the parasympathetic
system, and it pushes you closerto anxiety, experiencing
nervousness, phenomena relatedto excessive sympathetic tone,
like hypertension, and there mayeven be more serious
consequences.
This has not been well charted,but we know, for instance, that
(13:13):
people with reduced heart ratevariability also have greater
cardiovascular mortality.
So does blue light exposureincrease cardiovascular
mortality?
That has not yet been shown,but there is the potential by
this effect that blue light canreduce heart rate variability.
That may lead to these moreserious complications.
(13:34):
Now there's also evidence totell us that overexposure to
blue increases the risk formacular degeneration.
Of course this is the processthat many older people
experience.
That is the most common causefor blindness.
So there's deterioration visionbecause of this.
There is the expansion ofsomething called drusen.
This is the material thataccumulates in the retina.
(13:57):
That leads to loss of vision,in macular degeneration, and
blue light seems to stimulatethe deterioration of retinal
health and the accumulation ofdrusen.
There's also evidence thatexposure to blue light,
particularly later in the day,can accelerate the phenomenon of
skin aging, breakdown of thedermal layer of skin.
Recall that blue is right nextto ultraviolet, so it shares
(14:20):
some of the features ofultraviolet light.
Now, those two frequenciesultraviolet and blue, as I
mentioned, do provide benefits,but here overexposure can lead
to an acceleration of skin aging.
Both blue and ultravioletOver-exposure to blue can
accelerate cognitive decline.
It's a slow, progressiveprocess, but over-exposure to
(14:42):
blue can actually have negativeeffects on the brain that can
lead to decline in cognitivefunction.
Now we'll be talking in futureabout the benefits of red to
counteract some of those effectsof the blue.
So just reducing your exposureto blue is insufficient.
We've got to talk about alsorestoring or increasing your
exposure to red, especially ifyou live in a climate where it's
(15:03):
not possible to get sunlightall the time, because if you
live where I do or a place likeI do, where it's cold and it's
gloomy and dark much of the year, right now I haven't seen the
sun more than three days in thelast month.
So exposure to red helps inaddition to reducing your
exposure to blue.
And then there are adverseeffects on the mitochondria.
(15:25):
The mitochondria are the littleorganelles, they say, in your
body's cells, such as those inyour brain, in your retina, that
are the energy generators, andthey're very fragile.
They depend on light.
Mitochondria are thedescendants of bacteria from
billions of years ago thatlarger cells incorporate into
(15:46):
their bodies, and these thingsbecame little organelles, energy
producing organelles.
They produce a form of energycalled ATP, and it's the
currency of energy production.
It's the thing that gives youthe drive, the movement ability
to contract muscle, to walk, torun, to swim.
So an adverse effect onmitochondria can lead to low
(16:06):
energy and dysfunction of organs.
Well, overexposure to blueincreases the production of
something called a reactiveoxygen species, and all that
means is these areoxygen-containing compounds.
That means these areoxygen-containing compounds like
hydrogen peroxide that aredamaging to DNA, rna, proteins
(16:28):
and other structures andcompounds in the cells of the
body, and it damages themitochondria.
Now, these reactive oxygenspecies are counteracted by
exposure of the mitochondria tored and infrared, and so that's
why I say there's two sides ofthis coin overexposure to blue,
lack of red, infrared, but forour current conversation, it's
the overexposure to blue thatincreases the reactive oxygen
(16:50):
species.
That must be counteracted byexposure to red and infrared.
But once again, this is anargument in favor of reducing
your late-day exposure to theblue way-length of light.
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So how can we remedy thissituation of overexposure to
blue light that has consequencesthat include reduced visual
acuity, damage to your lenses ofyour eyes, damage to the retina
and long-term consequences suchas increased risk for macular
degeneration, the increase ininsulin resistance reduction,
(20:51):
vagal tone and heart ratevariability and perhaps even
cognitive decline, deteriorationof skin health and adverse
effects on mitochondrialgeneration of energy and
mitochondrial health.
Well, let's start by reducingyour exposure to LEDs by
thinking about replacingselected LED lights with
old-fashioned incandescentlights.
(21:12):
Now, I'm not suggesting youchange all your lighting in your
house back to incandescent,because that's energy
inefficient and there are somereal benefits societally to
converting to lower energy LEDs.
It may save a lot of money, itmay reduce the carbon footprint
of human life, but you may dowhat I did, that is, just
exchange the LEDs withincandescent bulbs in areas you
(21:35):
frequent.
For me it's my desk where Iwork a lot, or maybe for you
it's a chair where you like tosit and read, the places where
you frequently are exposed tolight.
Think about replacing LEDs withincandescent, recognize that
fluorescent lighting is nobetter.
Most people don't have a lot offluorescent lights in their
home, but they have a lot atwork.
That's a problem.
(21:55):
So if there's some way torestore some incandescent
exposure rich in red lightreduced in blue so maybe you
have your own desk lamp that hasan incandescent bulb at your
desk at work.
Another thing to consider isblue blocking glasses,
particularly later in the day,especially after 4 pm.
There's two forms that I'maware of.
There's clear blue blockingglass and you can test them by
(22:18):
shining them, by holding them upto light, and you should see
blue reflected in the lens.
That is, it's blocking blue.
The clear lenses are prettygood at blocking blue.
It's the yellow or orangelenses, however, that are even
better at blocking most bluewavelengths.
So think about wearing themwhen you're overexposed to blue.
Whether it's at your desk or atyour computer with an LED
(22:40):
screen, or looking at yoursmartphone late in the evening
or your tablet.
Blue blocking glasses canminimize or reduce your exposure
to blue, especially importantlater in the day Because,
remember, exposure to blue turnsoff your brain's production of
melatonin and can disrupt yoursleep pattern, disrupt the
circadian rhythm.
(23:00):
So getting rid of blue later inthe day can allow your pineal
gland to produce melatonin andthereby reassume the normal
circadian rhythm.
Now, as I mentioned, the flipside of this argument is to not
only reduce our exposure to blue, but to also increase our
exposure to red and infrared,particularly if you live in a
(23:22):
climate where you can't getsunlight.
Now I remind everybody that wereally can't do much better in
the red infrared frequency thangetting sunlight.
So if you live in Hawaii orFlorida or Arizona or other very
sunny climate, you probablydon't need to worry too much
about red exposure and infraredexposure, because you get
natural red.
You can't do better thannatural red.
(23:43):
But if you're living in aclimate like I do or live a life
like I do, where you live a lotof your time indoors, the sun
is too weak, it's covered byclouds, it's too cold For me in
the last few days it's been zeroor below zero.
You can't really go outside.
Even though red infraredpenetrates clothing, the
intensity of the radiation is solow.
(24:04):
Recall that red infraredexperience is heat.
If it's really cold, you're notgetting that heat.
So we'll talk more in futureabout the benefits and the hype,
the over-hyping, of exposure tored and infrared.
It is important, but it hasbeen the subject of a lot of
profiteering by manufacturers ofdevices, so we'll talk about
all the aspects of red andinfrared.
(24:24):
In the meantime, think aboutreducing your exposure to LED
blue from all the differentsources to take advantage of all
the benefits of reducingoverexposure to blue and, in
future, re-exposure to redinfrared.
Now, if you learned somethingfrom this episode of the Defiant
Health Podcast, I invite you tosubscribe through your favorite
(24:44):
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Post a review, post a commentand join this movement of
self-empowerment in health.
Thanks for listening.