Let's talk about indoor lighting

>> because I am very concerned about the

amount of short wavelength light that

people are exposed to nowadays,

especially kids.

>> This is an issue on the same level as

asbestos.

>> This is a public health issue and it's

big. And I think it's one of the reasons

why I'm really happy to come here and

talk because it's time to talk. When we

use LEDs,

the light found in LEDs, when we use

them, certainly when we use them on the

retiny looking at mice, we can watch the

mitochondria

gently go downhill. They're far less

responsive. They their membrane

potentials are coming down. The

mitochondria are not breathing very

well. Can watch that in real time.

>> Welcome to the Huberman Lab podcast,

where we discuss science and

science-based tools for everyday life.

I'm Andrew Huberman and I'm a professor

of neurobiology and opthalmology at

Stanford School of Medicine. My guest

today is Dr. Glenn Jeffrey, a professor

of neuroscience at University College

London. In today's episode, we discuss

how you can use light, in particular

red, near infrared, and infrared light

to improve your health. And no, not just

by getting sunlight, although we do talk

about sunlight. Dr. Dr. Jeffrey's lab

has discovered that certain wavelengths

or colors of light can be used to

improve your skin, your eyesight, even

your blood sugar regulation and

metabolism. Dr. Jeffrey explains how

light is absorbed by the water in your

mitochondria, the energy producing

organels within your cells to allow them

to function better by producing more

ATP. He also explains how longwavelength

light, things like red light, can be

protective against mitochondrial damage

caused by excessive exposure to things

like LED bulbs and screens, which of

course we are all exposed to pretty much

all day long nowadays. And simple,

inexpensive, and even zerocost ways that

you can get longwavelength light

exposure. And again, not just by getting

more sunlight. He explains that

longwavelength light can actually pass

into and through your entire body and

that it scatters when inside you. Now,

that might sound scary, but it's

actually a great thing for your health

because that's how long wavelength light

can improve the health of all your

organs by entering your body and

supporting your mitochondria. Believe it

or not, certain wavelengths of light can

actually pass through your skull into

your brain and help promote brain

health. During today's episode, we also

discuss new findings that correlate the

amount of sunlight you're exposed to

with longevity. Those are very

surprising findings, but they're

important. Also, why everyone needs some

UV light exposure. And we discuss

whether it's important to close your

eyes when using red light devices or in

red light saunas and how best to apply

red light and things like infrared light

in order to drive maximum health

benefits. Today you're going to learn

from one of the greats in neuroscience

as to how to use light to improve the

health and longevity of any and every

tissue in your body and the mechanisms

for how that works. Before we begin, I'd

like to emphasize that this podcast is

separate from my teaching and research

roles at Stanford. It is however part of

my desire and effort to bring zero cost

to consumer information about science

and science related tools to the general

public. In keeping with that theme,

today's episode does include sponsors.

And now for my discussion with Dr. Glenn

Jeffrey. Dr. Glenn Jeffrey, welcome.

>> Thank you. Thank you very much.

>> We go way back. Later I'll tell a little

bit of the story and why it is truly

unforeseen that we'd be sitting here

talking about what we're talking about.

But it's great to see you again and I'm

super excited about the work you've been

doing over the last few years because

it's completely transformed the way that

I think about light and health, light

and mitochondria. And frankly, every

environment I go into now, indoor or

outdoor, I think about how that lighting

environment is impacting my cellular

health, maybe even my longevity. So, if

you would be willing, could you explain

for people a little bit about light as,

let's say, the visible spectrum, the

stuff that we can see and the stuff

that's kind of outside what we can see

as a framework for how that stuff

impacts our cells. Because I think

without that understanding, it's going

to be a little bit mysterious how it is

that lights of particular colors,

wavelengths as we call them, could

impact our mitochondria the way they do.

But with just a little bit of

understanding about light, I think uh

people will get a lot more out of our

conversation.

>> Yeah, sure. We think about light purely

in terms of the light we see and that's

that's perfectly natural. And the light

we see runs from deep blue, violet out

to pretty deep red, deep bicycle light.

Um, and that's what we see. That's what

we're aware of. The trouble is that

actually there's a lot more of it than

that. The sun kicks out a vast amount of

light that we don't see. So, let's say

the visual range is just grab the

numbers, which is say 400 to 700. That's

that's our spectrum.

>> Nanometers.

>> Yeah. Nanometers.

>> And there we're talking about the

wavelength, how bumpy those wavelengths

of light are.

>> Sunlight extends out almost to 3,000

nanometers. Just think about it. Big big

range. And then that's in the infrared.

And on the other end, the bits that we

don't see, the deep deep blues and the

violets, that goes down deeply to about

300 nmters. Now, this is a continuum. We

parcel it up because there's bits we see

and there's bits we don't see. You can

think about it as a continuous

wavelength. And the wavelength gets

longer and longer and longer as we go

out into the deep red. So short

wavelength lights, the ones just below

blue, they're very very high frequency.

They carry quite a kick. And that's why

when you're sitting in the sun and you

get sunburnt, it's mainly because of

those ultraviolet short wavelengths that

are present and then you go beyond our

visual range beyond 700 and the

wavelengths become very very long and

they carry a certain kind of energy but

they don't carry the kick. So the

important point to think of is when you

go out in sunlight, you see all these

colors, blues, greens, reds, but there's

so much out there that you don't see.

And we thought probably you didn't need

to be aware of, but nearly all animals

basically see this visual range that we

have. Red, orange, yellow, green, blue,

indigo, violet, right? We can separate

those out by shining light through a

prism. I think the cover of the Pink

Floyd

>> Pink Side of the Moon album. Um, and

that's separating out the different

wavelengths. Um, you say that the short

wavelengths have a kick. Uh, I want to

talk a little bit about what that kick

is. Uh, we distinguish between ionizing

and nonionizing radiation. And I think

for a lot of people, they hear the word

radiation and they think radioactive and

they think that all radiation is bad or

dangerous. But in fact, light energy is

radiating, right? So, it's radiation

energy. But at the short wavelengths

below UV,

>> they are ionizing radiation. And maybe

we could just explain what that means,

how that actually changes our cells

because if we get too much of that, it

indeed can alter our DNA.

>> I think the important point to think

about is not only what the wavelengths

are, but also how body responds to those

wavelengths. So let let's bounce back a

little bit to for instance the sunburn.

Um we're getting sunburnt because the

body is blocking those wavelengths.

those wavelengths cannot penetrate very

far. So when you're out on the on a hot

sunny day and part of your body goes

pink, it's going pink because it's

blocking those wavelengths. So the

energy is not being distributed

throughout the body. The energy is

hitting the skin and you're getting an

inflammatory response to it. Now,

interestingly,

we block those from our eye because our

lens and our cornea also blocks those

short wavelengths. So that's part of the

reason why we don't see them. Um but

it's also the reason why for instance

people get snow blindness because it's

just sunburn on the cornea and the lens.

It's recoverable from but it's very

painful

>> and with age some people who get a lot

of sun exposure will get cataract.

>> Yes. Yeah.

>> Which is a kind of a um the lens becomes

more opaque.

>> It does. And I've heard that described

as being the lens being cooked. Um, but

in actual fact, you know, I used to run

uh the eye bank at Morfield's Eye

Hospital, Eyes for Research, and you can

actually open a patient's eyes up when

they're dead. And you can look at the

color of the lens, and you can get a

rough idea of how old that person was.

>> So, one of the one of the surgical

procedures that, you know, medics love

is um to replace a cataract. take an

older person um they've got this thick

brownish lens and pop it out and put a

clear lens in and the instant response

in 90% of them is wow in the patients.

Yeah. These are live patients.

>> They're live patients. It's done under a

local anesthetic in in older patients.

They just go wow isn't that amazing?

Suddenly they're getting a lot more

light in their eye.

>> Because the lens was brown it blocked a

lot of the blu wavelengths and so they

go everything is very bright.

everything's very sparkly. Um, and it it

was it was quite a dramatic response.

But the interesting thing is two days

later they said, "Yeah, it's gone."

>> And and the brain kind of reapts

that visual input from from the retina.

Um, but going back over the literature

of replacing cataracts, it's quite

interesting. It tells you actually, you

know, quite a lot. Now when we put those

plastic lenses in, we have UV blockers

in them so that the amount of so you

don't actually get a lot of short

wavelengths coming through. Um but there

was certainly the response in the

earlier days when we didn't have UV

blockers of people saying, "God, that's

sparkly. That's really sparkly."

>> Yeah. The the sparkliness being those

short wavelengths um like think of off

the top of water on a really sunny day.

So, I think the takeaway for me is that

we should all be protecting our skin

against too much UV and other short

wavelengths and we should probably

protect our eyes against too much

ultraviolet exposure over time. We know

that you don't want the mutations of the

skin that um or the the uh clouding of

the of the lens. I mean, you pointed out

you can replace the lens, but um you

know, I think at the same time, we need

UV, right? I mean, vitamin D production

is uh requires UV exposure. Um, do we

know how what that how that works, what

that pathway is?

>> Yeah, we've got a fairly good idea, but

I want to just take you back a step if I

may. There's some really fantastic work

coming out at the moment where a few

dermatologists are re-evaluating the

issue of sunlight on the human body. And

the leader of that is um is a character

called Richard Weller um from Edinburgh.

and he's going back over all the data

and Richard's coming out and saying, you

know, um all cause mortality is lower in

people that get a lot of sunlight and

his argument is that the only thing

you've got to avoid is sun burn.

>> You know, the mutations of DNA are

occurring really when you've got very

very high levels, not when you've got

relatively low levels. And Richard's

work has been terribly interesting

because he's dug out all the little

corners, all the little things that you

think about three days later. He's dug

out all those little corners. And you

know, things like uh aboriges in

Australia don't get skin cancer. You

know, um white people there probably are

in the wrong place given their

evolutionary stage. But

>> yeah, high levels of skin cancer in

Australia,

>> in the Caucasian population,

>> but maybe they're getting too much sun

exposure too fast. The UV index is very

high down there. I will say you can I

mean you got you feel it quote unquote.

That's interesting. I hosted a uh a derm

oncologist on this podcast Teao Dr. Teao

Solommani. So he's a dermatologist who's

also an on dermcology. So skin cancer is

his one of his specialties. And he um

surprised me when he told us that um

indeed sunburn can lead to skin cancers.

Too many sunburns can lead to skin

cancers. But that the most deadly skin

cancers, the most deadly melanomas are

not associated with sun exposure.

>> Those can occur independent of sun

exposure and they often occur on parts

of the body that get very little sun

exposure. Like the melanomas will show

up. I think Bob Marley died from uh

eventually from one that that started on

his between his toes or something or on

the bottom of the foot. There's a lot to

unpack about the relationship between

light and skin cancers. And I'm I'm

going to chase down the literature trail

of this uh Weller guy.

>> Oh, Richard Weller is a Richard Weller

is very interesting. He's he says I

think he said he hasn't got any

dermatological friends anymore.

>> Probably not.

>> But he also pointed out that um if skin

cancer was directly related with

sunlight, then we should find in skin

cancer patients, you know, very high

levels of vitamin D. In actual fact,

they've got relatively low levels of

vitamin D. So, as you say, that story

needs to be unpacked. And what's

happened, I think, in the dermatological

literature is that we've followed a

pattern. Yeah. We've followed an

assumption and it's gone a very long way

down the line and then it's taken a

little bit of a rogue to come out and

say, "Hang on, we need to take a step

back here." And I think Richard Weller

is leading that. And um um we we

obviously both have an interest in

daylight uh but his interest in daylight

tends to be focused a little bit more on

those blue short wavelengths whereas I'm

at the other end of the spectrum but uh

I think he's a mover and a shaker.

>> Great. Well, I'm excited to see where

that literature leads and I I'm glad

that somebody's, you know, parsing, as

you said, all the corners of it because

I think we've been fed um a story that,

>> you know, excessive sunlight leads to

skin cancer. And the data on all reduced

all cause mortality um in people that

get a lot of sunlight. I I saw a study

out of Sweden looks very very solid, but

more data is needed clearly. Yeah. So,

>> I think that that story um there was a

story out of Sweden. There was also a

story out of the University of East

Anglia and um we're talking big numbers,

you know, we're talking very big numbers

on that. So it could have a lot of

points that we don't quite understand

yet, but I think the solid thrust of it

and the interesting thrust of it for me

is that that all caused mortality

flagships up on that are cardiovascular

disease and cancers. It's not the

obvious ones that we'd be thinking

about. So yeah, let's use the term

unpacking. That one definitely needs

unpacking. But from a public health

perspective, that's an important area.

>> Well, I'm certainly a fan of people

getting sunlight both in their eyes and

on their skin. Although not to the point

of burning, obviously.

>> Yeah.

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see the episode description. Today's

episode is also brought to us by JWVE.

JWV makes medical grade red light and

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to get up to $600 off. So, let's talk

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and other aspects of cellular function

and maybe use that as a segue into the

longer wavelengths.

>> Yeah, sure. that area is expanding

enormously. Um, and it's expanding

enormously in lots of little pockets and

the pockets aren't weren't always

talking to one another very well. Um,

the first person that came along and

said, "Look, longer wavelengths are

really positively affecting

mitochondrial function

um was a lady called Tina Karu in Russia

and who was very largely ignored. Um, I

don't I think she's still alive. I would

love to buy her a glass of champagne if

only because she started it off. She

kick kickstarted it off. But she was

very much of the opinion that

mitochondria absorb long waves of light.

Parts of the mitochondria absorb it. And

one of my studies um to try and pin this

down was to take a whole load of

mitochondria, put them in a test tube,

put a spectrometer on them and a light

and say, "What are these guys

absorbing?" Well, I found the point

where they were absorbing the damaging

blue light, but I could not find the

red. I could not find it. There was a

lot of stomping around in the lab. You

know, who's made a mistake? You know,

everyone parceling the brain blame on.

But it changed. It changed because

what absorbs long wavelength light?

Well, a most obvious one is water. The

sea is blue because the long wavelengths

are absorbed. So someone came along and

said is it about water? Is it about

water in mitochondria that's doing this?

Now when we make mitochondria make

energy they make energy called ATP and

you make your body weight in that every

day. It's a vast process and you make it

as a wheel turns round. Mitochondria

have these little wheels these pumps

that spin around but they spin around in

water. Nano water. And apparently I'm

not a physicist. Nano water is viscous.

So one idea I think which we have to

take quite seriously is that the

viscosity of water is changing as a

consequence of long wavelength light

that penetrates deeply in the body.

There is an increase in the spin rate of

the motor that produces ATP and it gains

momentum. Now that is absolutely fine. I

can I can stick with that one. I think

that one makes considerable degree of

sense and it gets us over a problem.

Mitochondria themselves are not

absorbing long wavelength light.

>> It's the water that they're surrounded

by.

>> It's it's their environment. Okay. So I

think in the end when you talk about the

function of anything we tend to focus on

that thing and we don't talk too much

about where is it, what is it, what's it

surrounded by and how does it influence

it. So the first reaction I think is

that the motor starts to go around a

little faster. But then something else

happens which is really interesting

which is we start to make more of these

chains that make energy. So let's say

mitochondria has got a is a chain. It's

a series of things and electrons are

passed along that chain um to produce

energy. Well when we give long

wavelength light we find the proteins in

those chains we find a lot more of them.

So my analogy is that giving red light

gets the train to run down the track

faster. That's true, but then something

detects the speed of that train and

says, "Lay down more tracks. We need

more tracks."

>> So we're finding a lot more protein

there um that is associated with passing

that electron down the pathway to make

energy.

>> Interesting. So it sounds as if

longwavelength light via water is

actually changing the structure of

mitochondria and its function as well.

Yeah, I I think I I think I would say

it's it's improving the function and

it's influencing the the mito more

mitochondrial proteins to be

synthesized. So we've got an immediate

effect and we've got a longer term

effect as well. Well, one thing we know

about mitochondria is that they started

off as independent bits of biology and

then the ukareotic cells which we have,

you know, essentially took those in

>> and they became fundamentally part of

the the cell and it's passed on through

the genome. So, the idea was that

mitochondria were separate from our

cells at one point or from cells and

were were essentially um co-opted by our

cells or hijacked our cells, we don't

know which. And then now they be because

they share a genome, mitochondrial DNA

and and genomic DNA, um they're passed

along. And it makes perfect sense to me

as to why that if they're really of

bacterial origin, which we think they

are, that they would be absorbing or

through the water, they would be

absorbing long wavelength light because

they evolved in water. I think it's

worth us just uh mentioning uh this

business of absorption versus reflection

in terms of colors. I think people might

find this interesting that uh you said

you know the ocean appears blue because

it's absorbing all the red all the long

wavelength light and it's reflecting

back the short wavelength blue light.

>> Yeah. Yeah.

>> Red stuff does the exact opposite. Like

when we see a red apple it's doing the

exact opposite. It's reflecting the red

light back towards us. The long

wavelength light. I think most people

probably don't realize that. And then we

talk about you know white containing all

the wavelengths

>> and black absorbing all the wavelengths

right? That's that's the the notion. So

it's it's it's interesting um to think

about light as either being absorbed or

reflected back and makes perfect sense

to me why the mitochondria would absorb

the red light. But of course I'm saying

that under already hearing the the just

so story. So it makes sense once you

hear it.

>> It makes sense when once you hear it and

and why the hell did we not think about

that five years ago? We know we were

scientists make really big mistakes in

the pathways that they follow and you

know they don't talk about their

mistakes but their mistakes are every

bit as important as their their great

results. Why didn't we think about

water? Because our minds were trapped in

a certain pathway going down a certain

alleyway. And so whatever you think

about the water hypothesis, the key

point is that improvements in function

as a consequence of exposure

to longer wavelengths light correlate

tightly with what water absorbs. Right?

So okay, that's a big one. That that's a

big one that is there. We know that's

true. You can pull it apart and find

there things called water holes where

there are places where water absorbs a

bit more than it does in other places.

But fundamentally

the absorption of long wavelength light

fits water.

So much of your work focuses on how long

wavelength light can enhance the

function of cells that are not on the

surface of the body. They're not on the

skin. They're in the eyes. And um and

now we'll get to these data soon, but uh

you publish data that longwavelength

light can penetrate very deeply and even

through the body.

>> Mhm.

>> Even when people are wearing a t-shirt,

like all the way through the body and

impact mitochondria all along the way.

>> So maybe we should just talk about

longwavelength light and how it can

penetrate through the skin. You

mentioned that UV is is essentially

blocked by the skin. So if I step

outside for instance on a nice sunny

morning or even a partially overcast

morning but some long wavelength light

is coming through

is it passing all the way through my

body and impacting the water and

mitochondria of every cell along the

way? How is it scattering? I mean how

how deep does this stuff go?

>> Okay, so let's stand you out. Let's

let's let's let's strip you off and

stand you out in sunlight, you know,

12:00 in July.

The vast majority of longwavelength

light is being absorbed in the body. So

what we assume is that it has a very

very high scattering ratio. So the vast

majority of that long wavelength light

is going to hit inside your it's going

to get through into your body and it's

going to bounce around.

>> So it's going to literally go through

the skin.

>> It goes through the skin. And let's

let's take the simple experiment. The

simple experiment was you strip people

off and you stand them in front of

sunlight and you put a radiometer on

their back.

>> Tell us what a radiometer radiometer

measures the amount of energy coming

through. Okay. And then we put a

radiometer on we put a a spectrometer on

your back as well which tells us the

wavelength. So what we get from that the

reading we get from that is that a few%

a few% is coming out the back. Now, we

shouldn't concentrate on that. What we

should concentrate on is what happens to

the rest because it's not bouncing back

from the surface of the skin. Very

little bounces back. It's being

absorbed.

>> Amazing. Which is amazing.

>> Well, it's very interesting.

>> It makes sense based on the physics of

it, but but it's amazing, right? That

the long wavelength light is actually

penetrating our skin, bouncing around in

our internal organs, and some's getting

out the other side. I think that's going

to surprise a number of people. In any

conversation like this, we need to talk

about silos, people coming from

different angles at a problem. And I

have the advantage of uh Bob Fosbury

working with me. Bob was um lead for

analyzing atmospheres on exoplanets with

the European Space Agency. He had a lot

to do with the European use of Hubble

and a lot of his spectrometers are up on

the James Webb telescope. Now, there are

super advantages for having someone from

another silo to come in, but there also

really annoying issues as well. So, I

said, "Bob, I really want to measure

whether light goes through the body."

And he said, "We all know that. Forget

it. It's a waste of time, you know." And

I said, "You think you know it based on

principles of physics. I don't know it."

And actually, I don't think you know

something until it's published and

everybody knows it and can talk about

it. So, yeah, Bob came along and said,

"Yeah, it has to long wavelength." has

to go through. Um and um but it needed

demonstrating. Now the other thing that

I Bob did pick up on this and did start

to get a lot more interested in it

because then he went through his

wardrobe and he took different layers of

clothing from his wardrobe and put long

wavelength lights behind them. So what

goes through clothing? And the amazing

thing is long wavelength light goes

through clothing.

>> It goes through clothing.

>> It goes through

>> any clothing.

>> Well, if you want to wear rubber, I

think not. But if you want to wear um

your standard t-shirt, I think I think

he used six layers t-shirt.

>> And does color matter? Like I'm wearing

a black shirt right now.

>> Makes no difference whatsoever. And the

other thing we do not know, and this is

terribly important, there's lots of we

don't knows here, is this long

wavelength light bounces around all over

the place. So we have got some long

wavelength light sources. And I think

I'm shining this long wavelength light

there, right? And then when I put my

instrumentation up, it's all over the

place

>> inside the body.

>> Inside the body, inside the room, it's

going every I can't control it. Not

unless I start putting

materials like aluminium foil to block

it. So when we think about long

wavelength, its advantages, you know, we

talk about, you know, using this device

or that device. What we also need to

think about is uh okay, you've got a

small device with a small beam of light

going here.

It's bouncing all around the room. It's

coming in from a different angle in

different parts of your body,

>> but certainly most concentrated in terms

of energy at at the at the point source,

>> but you cannot assume that the point

source is the only source of that long

wavelength light if you're in a confined

confined space. Well, let's um use that

as an opportunity to talk about a

related study and then we'll circle back

to the the uh let's call it the the

light passing through the body study. Um

because the study I'm about to mention I

think is going to be so interesting to

people um and a little bit shocking

>> and very very cool because it's

actionable. uh which is you did a study

showing that

even if you illuminate just a small

portion of the skin with long wavelength

light, it changes the blood glucose

response, literally blood sugar response

is altered by shining red light on the

skin.

>> And for years there were these, let's

call them um uh corners of the internet

that would say things like, "Oh, you

know, when you eat out of it, it has a

different effect on your body than when

you eat indoors." But there are too many

variables there, right? Because when you

eat out ofdoors, typically it's at a

picnic and then you have greenery and

there's socializing and no one's going

to fund a proper study to look at, you

know, to parse every variable in a

picnic versus an indoor cafeteria and

and it's not worth the taxpayer dollars,

frankly. You did the right study, which

was to shine light on what was it, the

back.

>> It was on a small area of the back.

Yeah. And and I must make it very clear

first of all, the person whose idea this

was was my my colleague Mike Pner. And

um and Mike's thought processes were

very very clear. We were on a long drive

to do some research well out of London

and that's a great time for cuz it's the

the journey starts at 5 in the morning

that it's a great time for gossip. It's

a great time for wild ideas for streams

of consciousness which sometimes are

very important in science. And it was

Mike who said to me, you know, if we

make mitochondria work harder, then they

need glucose and they need oxygen. So,

pause while Glenn, who's driving, kind

of has to catch up on this idea. I'm

generally about a mile behind him

intellectually. And I went, "Yeah,

yeah." So, he said, "Well, let's not

make idiots with ourselves. Let's do it

with bumblebees."

Right? So our first experiment was to to

increase of course why not the the why

>> first experiment was on bumblebees

because it didn't involve people. Um it

was simple to do and all we did was we

starve bumblebees overnight. Gave them a

standard blood glucose test. So you know

lot

>> sounds a lot harder than working on

humans.

>> No it's not. You just give them a little

bit of glucose cuz they haven't and they

go and their blood glucose goes up.

you've gave them red light or blue

light. We give them red light and their

blood glucose does not go up as much. We

give them blue light and their blood

glucose goes very high.

>> So, they're using more of the energy.

>> Yeah. So,

>> in the red light condition,

>> in the red light condition, in the blue

light condition, we're slowing their

mitochondria down and so the uh there is

more glucose flowing around. I should

say that sampling the blood in a bee is

a little bit difficult, but um you

basically pull off one of the antenna

and you squeeze a bee and you get a

little piece of

>> Well, the bee lover,

but you know, we went to the chemist and

we bought just the standard blood

glucose test that you can get for a few

dollars.

>> We got a result. Therefore, it's worth

moving forward. Therefore, we got the

ethical permission. Therefore, we did

the exper I can't do the experiment on

blue light. I regard that as unethical.

But really, yeah,

>> we're under blue light all day. I'm

absolutely convinced that being under

blue light or short wavelength shifted

light all day is altering blood glucose

in ways that are detrimental. But in any

case, before I rant about that, what

what happened in humans?

>> So, in the humans, we did a standard

blood glucose tolerance test, which is

horrible. So, you get people to starve

overnight. They come in, they drink this

big sort of cup of vile glucose. So, we

really pump up the glucose in their body

and then we prick their fingers at

regular intervals and sample their blood

and see how their blood glucose level

changes. And your blood glucose level

will peak in about 40 to 60 minutes.

It's hard getting subjects for this one.

Um, we also put a tube up their nose so

we could detect how much oxygen they

were consuming. You're calling on

friends. I mean, I even dragged my son

in as a as a subject for that one. The

result when we gave people a burst of

red light beforehand

to stimulate their mitochondria was

super clear. It wasn't ambiguous. The

blood glucose levels went up, but they

didn't peak anywhere near as seriously

as they did without the red light. Now,

I'm told that the level of your blood

glucose is not necessarily a massive

issue for concern. What is an issue for

concern is it spiking how much it spikes

and the reduction in the spike was of

the order of it was just over 20% if I

remember correctly.

>> Where was the light shown on the body?

>> It was shown on the back and it covered

I forget what the percentage of the body

area was. I did this calculation four or

five times because it was ridiculously

small. So we were stimulating a very

limited area of the body but we got a

systemic response. There was no way that

the mitochondria in that little patch of

skin was having that effect. But it fits

into a wider notion that all these

mitochondria

act as a community. Now we now know that

that's coming all from different

corners. They act they do things

together. It takes them a little time to

have a conversation about it, but they

act together. And if we're doing

something which was over one to two

hours, that's that's long enough for

them to hold that conversation. I'd love

to know more about that. Do you recall

whether the subjects could feel heat

from the infrared light?

>> Okay. So, they're not they're not

feeling heat. So, that removes also a

potential placebo effect of some sort.

>> Do you recall just roughly uh what the

area of illumination was? Was it you

>> it's in the publication. Let's go like

this.

>> Okay. So, for those just listening,

maybe like a 4x6 rectangle.

>> Four 4x6 rectangle makes sense.

>> 4x6 in. Yeah. For the all those metric

system folks out there, we're on common

ground here given you're from the UK.

We're not unique in finding this. It's

just that other people are finding

things with red light that are sitting

behind different walls. So John

Metrofanes

in you did most of his research in in

Australia, he induces Parkinson's

disease in primates, which you can do

pretty much overnight with a drug and

and then he was giving red light to

different parts of the body. Now

Parkinson's disease originates from a

very small nucleus deep in the brain

stem. Um but he was reducing the

symptoms of Parkinson's disease in these

primates very significantly with lights

that were being shown on the abdomen. So

any one of these you take in insul insul

isolation and there are many of these

studies and you go yeah maybe yeah

>> what does he think it was doing? I mean

it's clearly it's not rescuing the

dopamine neurons that degenerate in

Parkinson's but maybe it's rescuing

components of the pathway. it could be

rescuing components of the pathway. Um,

I think that we know that red light and

we we we're using that term very

loosely. Perhaps we shouldn't. We know

that long wavelength light reduces the

magnitude of cell death in the body.

Cell death is very often initiated

apoptosis by mitochondria. When

mitochondria get fed up and that I see

them as batteries when the charge on the

battery goes down low enough they put

their hand up and they say time to die

>> and I think they actually present a

molecular eat me signal.

>> Yes.

>> Which is interesting like you know when

we talk about cells dying that we think

about it as a um you know sort of they

they go from a shout to a whimper and

then they get cleaned up like they they

just they die but they actually um they

solicit for their own death with this

eat me signal. Yeah. they'll get

optionized you know for the people that

you know think about the immune system

optinization there similar things so if

I understand correctly he induced an

insult to these dopamine neurons and

then he used red light shined on the

abdomen to offset some of the

degeneration that would have occurred

>> yeah okay now that that again fits into

the wider spectrum of other research

that's not put together so that was John

and John has been a big leader in uh red

light dementia and Parkinson's disease.

Um, and a lot of it in primate models,

which is which means it's it's got some

it's got a lot of validity to it.

>> Yeah, they're similar to us to them.

>> Yeah. Another experiment we did was over

life you will lose a third of your rod

photo receptors in your retina.

>> Maybe just explain for people what the

rod system is.

>> Okay. The rod system is the majority of

your photo receptors are rods. They tend

they're the receptors that you use when

you're dark adapted. Um, which a lot of

us aren't really much these days. So,

we've got our cones which deal with

color and deal with bright light. Then,

as we turn the lights down, we start to

use our rods. So, loads and loads of

rods, relatively few cones.

>> What I usually tell students is this is

like you in the old days when everyone

didn't have a smartphone near their bed.

You wake up in the middle of the night

and you need to use the restroom. You

you can navigate to the restroom. You

might flick the light on in the

restroom. I don't recommend doing that.

It'll quash your melatonin unless it's a

red light. Or you go out on a hike and

you don't bring what we call a

flashlight, Glenn. You guys call a

torch. But as you come back, your your

eyes start to adapt. It's it's getting

dark. You can still see the outline of

the trail. There's not starlight yet,

but you you're able to, as you say, dark

adapt and you can see enough of what you

need to see. You're using your rod

system.

>> Yeah. The key thing here is rods are me

very very numerous. Cones are not. So,

so what what happens then for instance

if we take a aging animals and we just

expose them to red light every day we

give them a burst of red light and then

we count the number of rods they've got

when they reach old age and the result

is super clear. We have reduced the pace

of cell death in the retina. Okay. So

red light is affecting mitochondria.

Mitochondria have the ability to signal

cell death. And we're drawing back the

probability of that cell dying. Now, we

did that mice. We did it on a lot of

mice. It was a killer of an experiment

to keep animals going forever. And then

I forced one of my graduate students

basically to go 1 2 3 4 and count photo

receptor out the segments. She was a

hero. Um so we can use red light to

reduce the pace of cell death. So I am

not too surprised that John Metrofanis

would have reduced the pace of cell

death in the substantia Niagara that

nucleus that gives rise to uh

Parkinson's disease. Um I'm seeing that

coming out of loads of different labs

things that are all consistent with that

kind of story. The other thing that I

think you can you can start to address

is

if you've got bad mitochondria say very

loose term if you've got bad

mitochondria as you do have in uh

Parkinson's disease you know they're bad

they're not functioning very well on

their way to death are they influencing

other parts of your body you know

Parkinson's patients you think well okay

they're all going to have movement

disorders but actually a lot of

Parkinson's patients have a lot of other

things that are going on in them And

we're minded to think that as good

information can be passed to

mitochondria and can be shared in that

community, so can bad information.

>> You know, if you really upset

mitochondria in one place, then other

things are changing in different places.

So the big takeaway here, and it's not

controversial to say, I've heard lots of

people saying it, and I didn't say it

originally, is that they're a community.

You can't deal with them in isolation.

>> Even across cells in different areas of

the body, they're a community.

>> They are a community.

>> Probably by secretreting certain things

that support each other. Um maybe I've

heard some evidence that mitochondria

can actually be released from cells.

>> Oh yeah.

>> Um

>> different although not entirely

different than neurotransmitters are

released between cells and communi

communicate between cells. very

interesting when one thinks about

mitochondria of uh having maybe

bacterial origin again that our cells

co-opted or they co-opted us. We don't

know the again the direction there. Um I

have a question about how far long

wavelength light can penetrate and

through what tissues. I realized that in

the studies we've been talking about

it's long wavelength light exposure to

the back lowering the blood glucose

response

>> or to the abdomen offsetting some of the

degeneration uh as it relates to this

Parkinson's model.

>> If I were to take a long wavelength

light and put it close to my head would

it penetrate the skull?

>> Oh definitely. If you look at um if you

if you look at a longwave light source

and again this is published Bob Fosbury

did this he put his hand on one come

straight through his hand but the

interesting thing is you can't see the

bones it's passing through the bone so

that led me to go into grabbing a few

skulls and yeah it's it's really not

affected that much by bone and I was

talking to some aiology guys at uh in

Cambridge who wanted to use red light

and they were they were taking I think

heads or something and and looking at

them and they were shining red light in

the eye and they say we can see it in

the ear that's not I can see it and vice

versa. So there are things that red

light does not will not doesn't go

through. So it is absorbed by

deoxxygenated blood. So you get

fantastic pictures of your veins in your

hand um or in your head. But the most

obvious thing that you think is that

long wavelength light would be blocked

by something thick like a skull. The

answer is no.

>> So going back to our example of the

ocean appearing blue

>> because of blue light getting reflected

back and red light getting absorbed. I

think this is very important to kind

double click on in people's minds

because people will see an image for

instance and I'll put a link to it in

the from this recent publication of

yours of red light and and other excuse

me long wavelength light not just red

light um being shown on a hand and

indeed you don't see the bones and you

see the vasculature this deoxxygenated

blood

>> when people see a structure under a

particular wavelength of light

the kind of reflex is to assume assume

that those structures are the ones that

are um uh using the the the light, but

in fact it's just the ex exact it's the

stuff you don't see right that it's

passing through. And I think I think for

a lot of people that's just kind of

counterintuitive. So they'll see an

image of of the the veins during that

deoxxygenated blood and they'll say,

"Oh, you know, red light is is impacting

the veins, right?" But but the

interesting thing is that it's passing

through all that is interesting on in

itself but it's passing through all

these other structures and to me the

idea that when I go out on a sunny day

because the sun includes long wavelength

light or were I to be near a long

wavelength light emmitting device

>> that it's actually getting into the deep

brain tissue through the skull for I

think for most people it's just not

intuitive to think about light passing

through things that are solid in that

way.

>> Yes. And and I have exa I had exactly

the same problem. I had exactly the same

problem. Um if you you put a radiometer

and a spectrometer to measure the energy

and the wavelength on one side of

someone's head and a light source on the

other side of someone's head, you you

get a clear result. Now, interestingly,

as a it's not a sideline, it's actually

a very important issue. Um a a

biomedical engineer Ilas Takanides at

UCL has used this because he works on

some of his work is on neonates that

have had stroke and he takes the neonate

and actually does exactly that

experiment. He passes red light

wavelengths of light through the side of

the neonate's head and records them

coming out the other side. and he can

use that as a metric of how well the

mitochondria are functioning in that

damaged brain. And the readouts that he

gets are readouts that are indicative of

the potential survival of that neonate.

Wow.

>> Now, I think there are lots of wows

here. First of all, he's got his work

into a major London teaching and

research hospital. He's got it into

kids. And we've acknowledged that this

is not dangerous, right? He's gone

through loads of ethics committees. The

long wavelength light red and out

towards infrared and near infrared is

nonionizing. Yeah.

>> Right. It's not altering the DNA of the

cells. It's it's contributing to the

healthy function of the mitochondria.

Forgive me for interrupting. No, I think

because when people hear about light

passing through a baby's head,

>> Yeah.

>> in order to make that kid healthier, I

mean it's spectacular. I love that this

is being done at at such a fine

institution and so carefully. But the

reason it's safe is because that's long

wavelength light. Were this to be short

wavelength light, we have no idea what

it would be doing. I mean, babies have

very thin skulls. UV would be who knows.

X-ray certainly you would never ever

ever want to do this. So, yeah, I think

it's important that people really

remember what we're talking about

passing through. Okay. And and I think

that it's a very important point because

I have gone through so many ethics

committees to shine long wavelength

light to do various things including on

people that are they've got problems. So

they've got they've got sight problems,

their patients. We've actually also done

it with children. Um, and we've got

through ethics committees really with

very very little comment because on many

of the ethics committees there are

physicists and they understand the

issue.

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Let's talk about the two uh sort of

bookends of uh age. You just mentioned

uh babies and we'll return to uh babies,

children, and youth. Uh let's talk about

some of the work you've done on retinal

aging and using longwavelength light.

I'm being very careful with my language

here because if I say red, people think

you have to see it, but there's red,

near infrared, nir it's typically shown

as IR, infrared light. And I think we we

batch those when we say long wavelength

light. It's going what 650 nmters would

be red out to I guess is as far as 900

nmters or so.

>> And and yeah, and then beyond 900 is

infrared. So we've got we've got the

near infrared and we've got the

infrared. Now you're right, we've got to

start kind of we've got to start

defining these terms a little bit more

clearly. But I think for nearly all of

the research we're talking about, we're

talking about where vision stops, which

is around 700, and we're talking about

the near infrared, which is for

practical purposes is going up to around

900. Um, but you know, I I I remember

doing an experiment with um with UV

once, and it was an experiment, bizarre

experiment, trying to work out if a

reindeer could see

UV light. Do they?

>> Uh yeah, they do actually. But then, you

know, while we were doing the

experiment, I I was beginning to say,

look, I I'm not believing any of this

data because I can see this flashing

now. And as was pointed out to me, you

will see wavelengths of light, you know,

that you shouldn't see if you just turn

the energy up,

>> right? So, if I put you in a room with

UV and I pump loads of energy into that

UV, you'll see things that you

shouldn't. And likewise with uh the

reds, you shouldn't really see much

above 700. I can get you to see at 150

if I just turn turn the energy up a bit.

And you see these little red glows.

>> Yeah, this explains a lot of people's

ideas about whether or not they've seen

ghosts, but that's a different that's a

different podcast, ghosts in UFOs. But

an interesting discussion for another

time. But um and I can't help but

mention that, okay, maybe we'll return

to this later, but Glenn has worked on a

variety of species uh as have I over the

years. So maybe at the end we'll do a

quick catalog of uh the species that

we've worked on over the years. So I'm

not surprised to learn that you worked

on rain reindeers given the other

species you've worked on. But returning

to um the human

you published some papers over the last

uh you know five six years or so looking

at how when the eyes specifically are

exposed to long wavelength light it can

do excellent things for preserving

vision or offsetting some uh loss of

visual function. Could you detail those

experiments for us? So let's take two

pieces of information first. So one of

the main theories of aging is the

mitochondrial theory of aging.

Mitochondria regulate the pace of aging.

So if you can regulate mitochondrial

health, you can regulate aging. That's

relatively clear. So that's that's the

first thing. And then the second thing

to remember is that there's more

mitochondria in your retina than there

is in any other part of your body. Your

retina has got the highest metabolic

rate in the body, ages fast, and my

argument always is it's the sports car.

Bangs out of the garage, you know, but

after after so many thousand miles, you

got to service it otherwise it falls

apart. So, there was a very strong

argument for trying to manipulate

mitochondria in the retina, which is

great for me because I'm a retinal

person. I'm a visual person, so I had

the tools to do it. So the first

experiment we did which was I very

gratifying was to actually measure

people's ability to see colors. Now, we

used a rather sophisticated test first

of all, and that was we'd put on a a

very high resol resolution monitor, say

the letter T in blue, and then we'd add

loads and loads of visual noise to it in

the background or or we'd have a an F in

red, visual noise, and then we found the

threshold at which they could see that

letter and happily identify it. So, we

found out what their visual ability was

for colors. We then gave them a burst of

red light

to improve their mitochondria in cells

that are very mitochondrial dependent.

And we then brought them back and we

found the threshold had changed. The

threshold had improved in every one of

those subjects by one.

>> They could see something they couldn't

see before.

>> See before

>> by one. I think it's hard. Uh what what

scale is it on? Like some of these tests

like this is like the Triton test. Well,

so we tested Tritan and Proan.

>> So, this is nerd speak for the different

visual tests. Um, most people are

familiar with the Snellen chart. When

you go to get your driver's license, you

have to read the letters of different

sizes. Very different. This is measuring

the just noticeable difference between

you can see something, you can't see

something. When you say there was an

improvement of but one, could you frame

that in real world context for for

people who are not thinking about visual

psychophysics?

>> Okay. It's very simple. Of all the

people we've tested, we've got an

improvement and there's very large

numbers of them except one subject.

>> Ah, you're saying but one. I thought you

meant that was the numerical size of the

the effect.

>> If you look over the population, the

size of the effect is around 20%. It's

very substantial. Okay. But the our

ability to improve visual function

varies enormously between individuals.

You said but one. This is a UK uh US uh

moment. No, but don't apologize. I

should apologize. Um okay. An

improvement of 20% improvement in

threshold. So people are seeing better

than they did prior. Could you explain

what they did for them for the

intervention? How how many times a week,

a day? How long are they shining red

light in their eyes? What's the excuse

me, long wavelength light? What what's

the nature of that light? Maybe even

tell us how far away from it they are.

>> Okay. So in our first experiments we

used 670 nanometers right which is a

deepish red light. The only reason we

used that is because all the studies

before us doing different things had

used 670. Consequently there was a

database. So that's why we did it and we

did it with a little torch that we put

in front of somebody

>> flashlight. That's trans I'll translate

for the flashlight. Not a torch with

fire near the eye.

>> No definitely not. Um and um we did that

for 3 minutes and originally we did that

every day for an hour.

>> I open not not very little difference

because the long wavelength light passes

through the lid without it being

affected very much. So I said to people,

whatever you're comfortable with, you're

doing me a favor. You're being a subject

in my experiment. I'm not paying you for

it. You want to keep your eyes closed,

you keep your eyes closed. And those

people all had an improvement in their

color vision. Now we then titrated that

down. So instead of doing it every day

for so many days, we just did it for one

day and 3 minutes of that light one day

and we brought them back. I think it was

an hour later

that it all improved.

>> How stable was the effect? I mean, did

they have to only do one treatment ever?

>> No. Oh, I wish that was the case. In all

of those people, and I'd have to say we

did it, we we've done similar

experiments on flies, on mice, on

humans. It's 5 days.

>> It lasts 5 days.

>> 5 days. It's a solid 5day effect. So,

something very fundamental that is

conserved across evolution

is playing a role here. Five. And I have

to say that to a first approximation,

anything I find in a fly, I find in a

mouse. Anything I find in a mouse, I

find in a human. I can't find a a big

disjuncture between those those things.

So, it lasted it lasted five days. And

the real big point to take on board is

it's a switch. There's not a dose

response curve here. It is a you put

enough energy in at a certain wavelength

of light and it goes bang and click and

then 5 days later goes chunk and stops.

I have a lot of questions about these

studies. So, um I'm going to try and be

as precise about them. I know what's on

people's minds. If people are going to

get in front of a long wavelength light

emmitting device,

do you think it's critical that it be

670 nmters or could it be 650 out to

800? I mean, how how narrow band does

the does the light actually have to be

in terms of wavelength? pretty much

anything works to a rather similar

extent at 670 going upwards. When you go

below 670 towards 650 the effects tend

to be somewhat reduced. If this is

happening uh very quickly you said an

hour later the vision is better

thresholds have changed and it lasts 5

days.

Do you think we can get this same effect

from sunlight given that sunlight

contains these long wavelengths of light

or is it that the the sunlight isn't of

sufficient energy for most people? I

mean

with this what you call torch I call

flashlight light source you know you the

way you described it and showed it with

your hand for those listening is you

know fairly close to the eye maybe you

know eyelids closed or maybe open if

people can tolerate that and you're

shining that light in their eyes for a

couple of minutes.

How different is it than stepping

outside on a really bright day closing

my eyes if I look in the direction of

the sun because that's pleasant or just

walking in the sunlight and getting long

wavelength exposure. I'm a big big fan

of natural sunlight because you've

evolved life's evolved for billions of

years under sunlight, right? It's only

recently changed. I don't know that cut

off point, but there's an enormous

difference between the light produced by

a flashlight and sunlight. Sunlight is

an enormous broad spectrum

>> and that flashlight is just a little

window of light that happens also to be

present in sunlight. Now, I think the

two situations are probably

incomparable,

>> right? And and I'm not going to spend

whatever is left of my career hunting

that down.

>> We know and I I think this is the global

concept I've got, which is that we can

do much with single wavelengths of long

wavelength light, right? Like a a

flashlight which is 850 or 610. We can

do a lot, but we can never do the same

as you can get from sunlight. But you

can't do those tight controlled

experiments with sunlight that I can do

much more easily with specific

wavelengths.

>> Yeah. And you're in the UK, so you'd

have a lot of days to do experiments at

all. I'm just kidding. Well, I must say,

you know, often times when I tell people

to get sunlight in their eyes in the

morning to set their circadian rhythm.

I'm like a, you know, I'm like a

repeating record with that and I will be

till the day day I die. People will say

there's no sunlight where I live. And I

remind them that even on a very overcast

day, there's a lot of photon energy

coming through, but the long wavelength

light is cut is cut off. Um, so they're

still getting a lot of photons. I mean,

compare how bright it is at 9:00 a.m. uh

versus midnight the night before their

sun is that they can't see the outline

of the sun as an object is what they're

referring to.

>> I I think the important point there is

that long wavelength light gets

scattered by water. It gets absorbed and

scattered by water. So on a winter's day

we've got a cloud and that cloud has got

contains water. There will be an

attenuation of the longer wavelength

light. It won't be vast but there will

be an attenuation but more it will start

coming at you in different angles. So

when you when you're walking on a sunny

day and you're walking down the road,

sun's in front of you, you feel warm in

your chest when you've got clothes on

and it's a longer wavelength light doing

it because it's relatively focused. on

that winter's day, you're still getting

a lot of long wavelength light, but it's

coming at you in a lot of different

angles and it's slightly attenuated. So,

my argument, which is the new mantra of

the of the lab to some extent, is get a

dog, right? Get a dog because you'll

have to go out in you'll have to go out

in daylight two or three times a day.

>> You'll get no argument from me. You

you're uh you're making me very happy.

Uh Glenn, uh I I love dogs. listeners of

this podcast will know I absolutely love

dogs and my last dog it was an English

bulldog half English bulldog half

mastiff. So the next one will also be an

English bulldog. Uh couple more

questions because I know people are

curious about longwavelength light

emmitting devices for their eyes and and

other tissues. Um

you mentioned that one subject did not

respond and if I'm not mistaken these

effects at least on the eyes I don't

know about the other effects on blood

sugar etc but on the eyes and visual

function seem to be gated by age right

if I recall people younger than 40 um

you you saw less of a of an effect

>> overall statistically we saw less of an

effect you know some people.

My youngest son responded very very

strongly and at the time I think he was

about I think he was about 25. So you

have to look at a population level to

get that but okay look this all makes

sense. Mitochondrial theory of aging

means that if we imp we we should have

more room to improve mitochondria in the

elderly than the young. But we all age

at different rates. One of the biggest

problems about doing experiments on

humans as opposed to mice is we all do

radically different things. Some take

exercise, some have very good diets,

some have poor diets. And mice sitting

in our animal house eating the same

food. They're very, very similar to one

another. Everything is the same. So, we

have to accept that noise. But generally

when your mitochondria are in a poor

state which is consistent with aging,

yes, we've got more room to lift them up

and improve their function. What was the

time of day so-called circadian effect

uh of this?

>> Very clear. Again, same in flies, mice,

and humans. Your biggest effect is

always in the morning and it's always

generally just before perceived sunrise

up until about 11:00.

So, and it's very very clear, but let's

look at the backdrop to this. Your

mitochondria, they're not doing the same

thing all the time. So, if we we we did

this experiment 24 hours looking at

mitochondria. And if you look at what

mitochondria are doing over 24 hours,

it's shifting sh. not the same even over

a 3-hour period. It's shifting and so

the the proteins that we have in

different parts of mitochondria are

changing in concentration radically.

It's it's a very very active area. So if

you're doing area if you're doing

research on mitochondria and you're not

taking account of time a day, you may

have a problem. So but the mornings are

very very special. Um in the morning

there are lots of things changing in

your body. Your hormone levels are very,

very different. Your blood sugars tend

to be picking up. You've been asleep. A

predator may have been watching you. You

need to wake up and you need to be ready

on the road. You can't be like a lizard

that's got to wait for the sun to rise

and to get themselves into into a

position where you can get your body

temperature up. So, the morning is very

important. You're making more ATP, this

this petrol that mitochondria make in

the morning than at any other time. Now

I can improve function across a wide

range of issues in the morning. I can't

do it very easily in the afternoon. And

I think this comes from a very myopic

point of view which is we think about

mitochondria as purely as things that

make energy. They do lots of other

things and and my interpretation is that

in the afternoon well the standard lab

joke is they're doing the ironing.

They're doing other things that as

organels they need to do.

>> They are over a period of a day they're

making contact with other organels in

the cell particularly something called

the endopplasmic reticulum. They're

junctioning with that. We've got such a

limited view of what they do. I was

surprised to find that a mitochondria at

9:00 in the morning was not a

mitochondria at 4:00 in the afternoon.

that poses some very serious problems

about the interpretation of our data if

people are doing things at different

times of day.

>> So if somebody wants to improve their

vision with long wavelength light

exposure um maybe we can just give them

a a rough contour of what this would

look like uh long wavelength of 670 and

greater um emitting

flashlight torch um at a comfortable

distance from the eye. So it could be,

you know, 3 in, 6 in, a foot, depending

on how bright it is. But if I were going

to run the experiment, I'd probably want

to bring it about as close as people

felt like they wanted to close their

eyes, but then move it back just a

little bit, just below the threshold of

kind of I don't want to say discomfort,

but where it's just too bright. And then

you're saying it doesn't matter if their

eyelids are closed or open. You give it

3 minutes, 5 minutes of exposure once

every 5 days or so. And is that going to

be sufficient?

>> There is the difference between

something that has an effect

>> and then the efficiency of that effect.

So if you take a 670 nanometer

light source and you do exactly that,

you will have an effect. Mhm.

>> Now, as we're going forward, we're

finding certainly we're finding the

energy at which you give that wavelength

is dropping and dropping and dropping

and still effective. So, you don't need

a very bright light.

>> No, no, you don't. So, we were the

original uh experiments they used watts.

They measured it in watts, not lux. flux

is not very meaningful to this situation

because it's it that's adjusted for the

human eye. We want to know what was the

energy that the cell experienced.

>> So people started off at say 40 mwatts

per cime squared and I looked at that I

thought criy

>> that's bright

>> that's bright

>> that's very bright

>> big after effect.

>> Yeah that's going to make someone wse

>> it is. So then we got ourselves down to

what we do in the lab now generally

which is around eight which is very

comfortable has the same effect.

>> Mhm.

>> But then we had someone in the lab do an

experiment um and we had the flashlights

that had batteries in them. She got a

lovely effect and we found out the

batteries have been run down and she was

getting an effect close at 1 mill per cm

squared. That is low.

>> That's dim red light.

>> That is low. Okay. So, sounds like one

can use dim to moderately bright red

light that's comfortable. Um, I say red,

but I mean long wavelength light that's

comfortable and likely get the effect.

Um,

>> sounds like

>> the effect can occur at any age, but

it's going to be more pronounced in

people that have experienced some loss

of vision because of age, which

everybody does.

>> Yes. You've also looked at this in the

context of macular degeneration which is

a very common form of blinding and

especially in people as they get older.

Uh what were the results in terms of

rescuing vision in people with macular

degeneration?

>> Okay. So macular degeneration is when

you could put it crudely that the center

of your retina that you you're using for

reading um degenerates and it's part of

an you could say it's part of an aging

process. If I get you all to live to 50,

uh say if I get you all to live to 100

years, probably 20% of you will have

macular degeneration. It remember the

retina as a sports car. It burns out. So

um I had a I had a very significant

failure in a clinical trial because we

took a whole group of patients um who

had macular degeneration. We treated

them with red light and we treated their

part more women have macular

degeneration than men. We took their

husbands as the control subjects. Um and

to a first approximation we got

absolutely no effect whatsoever.

Uh this is kind of a point where you

know people people working with Glenn

are getting getting losing enthusiasm.

Um but lo and behold their husbands

their vision they didn't have macular

degeneration but their vision was

improving enormously particularly the

way in which they could deal with

darkness. So we we we stomped around

over this something was wrong and we

found that when we looked back at it we

found that the subjects that we were

dealing with the patients their disease

had reached a certain point. It had gone

beyond a certain point. Now when that

study was replicated by someone who

thought about it a bit more than me, an

opthalmologist called Ben Burton in the

UK, he got a great result. He started to

get a really good result. And when you

talk to people about red light and I

talk to people, I talk to Parkinson

societies, I talk to various groups and

I talk to the researchers and it there

is one thing that's very clear is that

red light can impact on aging. It can

impact on disease. But it can't do it if

that disease has really got its teeth

into you.

>> Right? So where we need to get into

situations is early on in disease. So we

we thought very much about one point

about rheumatism um you know rheumatoid

arthritis.

>> Yeah. Very common autoimmune condition.

>> Yeah. And um we had absolutely zero