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Dr. Glen Jeffery on Huberman Lab: Why LEDs harm mitochondria

Red and near-infrared wavelengths restore ATP in aging mitochondria; brief morning exposure blunts sugar spikes and slows vision decline with age.

Andrew HubermanhostDr. Glen Jefferyguest
Dec 1, 20252h 14mWatch on YouTube ↗

EVERY SPOKEN WORD

  1. 0:00 – 3:12

    Glen Jeffery

    1. AH

      Let's talk about indoor lighting-

    2. GJ

      Mm-hmm.

    3. AH

      ... because I am very concerned about the amount of short wavelength light that people are exposed to nowadays, especially kids.

    4. GJ

      This is an issue on the same level as, 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, s- the, the light found in LEDs, when we use them, certainly when we use them on, on the retina, 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.

    5. AH

      (instrumental music) 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 ophthalmology 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. 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 organelles within your cells, to allow them to function better by producing more ATP. He also explains how long wavelength 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 zero-cost ways that you can get long wavelength light exposure, and again, not just by getting more sunlight. He explains that long wavelength 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.

  2. 3:12 – 6:25

    Light, Ultraviolet (UV), Visible & Infrared (IR) Light

    1. AH

      Dr. Glenn Jeffrey, welcome.

    2. GJ

      Thank you. Thank you very much.

    3. AH

      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-

    4. GJ

      (laughs)

    5. AH

      ... 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.

    6. GJ

      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... J- just grab the numbers, which you say 400 to 700. That's our, that's our spectrum.

    7. AH

      Nanometers?

    8. GJ

      Yeah, nanometers.

    9. AH

      And there we're talking about the wavelength, how bumpy-

    10. GJ

      Yeah.

    11. AH

      ... those wavelengths of light are.

    12. GJ

      Yeah. Sunlight extends out almost to 3,000 nanometers. Just think about it, whoosh, 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 nanometers. 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.

    13. AH

      Red, orange, yellow, green-

    14. GJ

      Blue.

    15. AH

      ... blue, indigo, violet, right?

    16. GJ

      Yeah.

    17. AH

      We can separate those out by shining light through a prism.

    18. GJ

      Yeah.

    19. AH

      I think the cover of the Pink Floyd-

    20. GJ

      Pink Floyd album. (laughs)

    21. AH

      ... Dark Side of the Moon album.

    22. GJ

      Yeah.

    23. AH

      Um, and that's separating out the different wavelengths. Um,

  3. 6:25 – 9:55

    Light's Impact on the Body & Light, Sunburn, Cataracts

    1. AH

      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 non-ionizing 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-

    2. GJ

      Mm-hmm.

    3. AH

      ... right? So it's radiation energy. But at the short wavelengths, the low 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.

    4. GJ

      I think the important point to think about is not only what the wavelengths are, uh, but also how the 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.

    5. AH

      And with age, some people who get a lot of sun exposure will get cataract.

    6. GJ

      Yes. Yeah.

    7. AH

      Which is a kind of a, um, the lens becomes more opaque.

    8. GJ

      It does. And I've heard that described as being the lens being cooked.

    9. AH

      Mm-hmm.

    10. GJ

      Um, but in actual fact, you know, I used to run, uh, the eye bank at Moorfields 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.

    11. AH

      Mm-hmm.

    12. GJ

      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."

    13. AH

      In the patients?

    14. GJ

      Yeah.

    15. AH

      These are live patients?

    16. GJ

      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.

    17. AH

      Mm-hmm. Mm-hmm.

    18. GJ

      Because the lens was brown, it blocked a lot of the bluer 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, "Uh, yeah, i- uh, uh, it's gone."

    19. AH

      Hmm.

    20. GJ

      And, and the brain kind of re-, re-adapts that visual input from, from the retina, um, but going back over the literature of replacing cataracts is 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 l- 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."

    21. AH

      I see.

    22. GJ

      "That's really sparkly."

    23. AH

      Yeah, the, the sparkliness being those short wavelengths-

    24. GJ

      Yeah.

    25. AH

      ... um, like think o- off the top of water on a really sunny day. So, I think the takeaway

  4. 9:55 – 14:55

    UV Light, All-Cause Mortality, Skin Cancer

    1. AH

      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 are-

    2. GJ

      Yeah.

    3. AH

      ... 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.

    4. GJ

      Mm-hmm.

    5. AH

      Um, do we know how, w- what that, how that works, what that pathway is?

    6. GJ

      Yeah, we've got a fairly good idea, but I want, wanna 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 reevaluating 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 sunburn.

    7. AH

      Mm-hmm.

    8. GJ

      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 'cause 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, aborigines in Australia don't get skin cancer. You know, um, white people there probably are in the wrong place given their evolutionary stage, but it just doesn't-

    9. AH

      Yeah, high levels of skin cancer in Australia.

    10. GJ

      In the Caucasian population.

    11. AH

      Yeah, but maybe they're getting too much sun exposure too fast. The UV index is very high down there, I will say.

    12. GJ

      Yes, exactly.

    13. AH

      You can f- uh, I mean, you-

    14. GJ

      You feel it.

    15. AH

      You g- you got, you feel it, quote, unquote.

    16. GJ

      Yeah, yeah. Yeah, yeah.

    17. AH

      It's interesting. I hosted a, uh, a derm oncologist on this podcast-

    18. GJ

      Mm-hmm.

    19. AH

      ... Teo Sol- Dr. Teo Soleymani. So he's a dermatologist who's also an onco- derm oncology.

    20. GJ

      Mm-hmm.

    21. AH

      So skin cancer is his, uh, spec-

    22. GJ

      His business. (laughs)

    23. AH

      ... 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.

    24. GJ

      Yes. Yeah.

    25. AH

      Those can occur independent of sun exposure-

    26. GJ

      Yeah.

    27. AH

      ... and they often occur on parts of the body that get very little sun exposure.

    28. GJ

      Yeah.

    29. AH

      Like, the melanomas will show up... I think Bob Marley died from, uh, eventually from one that are, that started on his, between his toes or something-

    30. GJ

      Mm-hmm.

  5. 14:55 – 17:58

    Sponsors: Wealthfront & Joovv

    1. AH

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  6. 17:58 – 25:00

    Light Impacts Mitochondria Function & Structure, Long-Wavelength Light (Red/IR), Nano Water

    1. AH

      So let's talk about, um, how light impacts mitochondria and other aspects of cellular function, and maybe use that as a segue into the longer wavelengths.

    2. GJ

      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, a lady called Tina Kareu 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, the 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.

    3. AH

      It's the water that they're surrounded by.

    4. GJ

      It's w- it's their environment.

    5. AH

      Mm-hmm.

    6. GJ

      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-

    7. AH

      Hm.

    8. GJ

      ... what's it surrounded by and how does it influence it? So, the first reaction, I think, is that the motor starts to go round 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."

    9. AH

      Hmm.

    10. GJ

      So, we're finding a lot more protein there, um, that is associated with passing that electron down the pathway to make energy.

    11. AH

      Interesting. So it sounds as if long wavelength light via water is actually changing the structure of mitochondria and its function as well.

    12. GJ

      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-

    13. AH

      Mm-hmm.

    14. GJ

      ... to be synthesized. So, we've got an immediate effect and we've got a longer term effect as well.

    15. AH

      Well, one thing we know about mitochondria is that they started off as independent bits of-

    16. GJ

      Mm.

    17. AH

      ... biology, and then the s- eukaryotic 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-

    18. GJ

      Mm.

    19. AH

      ... 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-

    20. GJ

      Yeah.

    21. AH

      ... and, and genomic DNA, um, they're passed along. And it makes perfect sense to me as to why the... if they're really of bacterial origin, which b- 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, uh, just, uh, mentioning, uh, this business of absorption versus, uh, reflection-

    22. GJ

      Mm-hmm.

    23. AH

      ... 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.

    24. GJ

      Yeah. Yeah, yeah.

    25. AH

      Red stuff does the exact opposite. Like when we see a red apple, it's doing the exact opposite.

    26. GJ

      Yeah.

    27. AH

      It's reflecting the red light back towards us-

    28. GJ

      Yes.

    29. AH

      ... 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, right?

    30. GJ

      Yes, yes.

  7. 25:00 – 30:08

    Long-Wavelength Light Passes Through Clothing & Body; Tissue Scattering

    1. GJ

    2. AH

      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, uh, we'll get to these data soon, but, uh, you published data that long wavelength light can penetrate very deeply and even through the body.

    3. GJ

      Mm-hmm.

    4. AH

      Even when people are wearing a T-shirt, like all the way through the body.

    5. GJ

      Mm-hmm.

    6. AH

      And impact mitochondria all along the way.

    7. GJ

      Yeah.

    8. AH

      So, maybe we should just talk about long wavelength light and how it can penetrate through the skin. You mentioned that UV is- is essentially blocked by the skin.

    9. GJ

      Yeah, yeah.

    10. AH

      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 f- is it scattering? I mean, how f- how deep does this stuff go?

    11. GJ

      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 o'clock in July. The vast majority of long wavelength 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's going to hit inside your, it's going to get through into your body and it's going to bounce around.

    12. AH

      So, it's going to literally go through the skin?

    13. GJ

      It goes through the skin, and let's- th- 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 with-

    14. AH

      Tell us what a radiometer is.

    15. GJ

      A romi- 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. Then what we get from that, the reading we get from that, is that a few percent, a few percent 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, okay? It's-

    16. AH

      Amazing. Which is amazing.

    17. GJ

      Well, i- i- it's very interesting.

    18. AH

      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-

    19. GJ

      Yeah, yeah.

    20. AH

      ... internal organs, and some's getting out the other side.

    21. GJ

      Yeah, so-

    22. AH

      I think that's going to surprise a number of people.

    23. GJ

      (laughs) 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, uh, Bob Fosbury working with me. Bob was, um, lead for analyzing atmospheres on exo-planets with the European Space Agency. He had a lot to do with the European use of Hubble, and he- 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. I think also really annoying issues as well. So, I said, "Bob, um, I really want to measure whether light goes through the body," um. And he said, "We all know that. Forget it. You know, 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."

    24. AH

      Mm-hmm.

    25. GJ

      So yeah, Bob came along and said, "Yeah, it has to, uh, long wavelength li- has to go through." Um, and, um, but it needed demonstrating. Now, the other thing that w- 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 dif- different layers of clothing from his wardrobe and put long wavelength lights behind them. Said, "What goes through clothing?" And the amazing thing is, long wavelength light goes through clothing.

    26. AH

      It goes through clothing?

    27. GJ

      It goes through cloth- okay.

    28. AH

      Any clothing?

    29. GJ

      Well, if you want to wear rubber, I think not. But if you want to wear, um, your standard T-shirt, I think e- I think he used six layers. T-shirt-

    30. AH

      And does color matter? Like, I'm wearing a black shirt right now.

  8. 30:08 – 36:19

    Long-Wavelength Light & Blood Glucose; Mitochondria

    1. AH

      um, use that as an opportunity to talk about a related study, and then we'll circle back to the-

    2. GJ

      Yeah.

    3. AH

      ... the, uh, let's call it the, the light passing through the body study.

    4. GJ

      Yeah.

    5. AH

      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-

    6. GJ

      (laughs)

    7. AH

      ... 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.

    8. GJ

      Hmm.

    9. AH

      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 doors, it has a different effect on your body-"

    10. GJ

      (laughs)

    11. AH

      "... than when you eat indoors."

    12. GJ

      Yeah.

    13. AH

      But there are too many variables there, right? 'Cause when you eat out of doors, typically it's at a picnic, and then you have greenery, and there's socializing-

    14. GJ

      Yeah. Yeah, yeah. Yeah.

    15. AH

      ... and no one's gonna fund a proper study to look at, you know, to parse every variable in a picnic versus an indoor cafeteria.

    16. GJ

      No.

    17. AH

      And it's, 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?

    18. GJ

      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 Palmer. 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... 'Cause it's, the, the journey starts at 5:00 in the morning. The, the... 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, kinda 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 of ourselves. Let's do it with bumblebees," right? So our first experiment was to, to increase-

    19. AH

      Of course, bumblebees, yeah.

    20. GJ

      Of course, why not?

    21. AH

      Yeah, yeah.

    22. GJ

      The, the, the, why... First experiment was on bumblebees 'cause it didn't involve people. Um, it was simple to do, and all we did was, uh, we starved bumblebees overnight, gave them a standard blood glucose test. So, you know, a lot of them-

    23. AH

      Sounds a lot harder than working on humans.

    24. GJ

      (laughs) No, it's not. You just give them a little bit of glucose-

    25. AH

      Okay.

    26. GJ

      ... 'cause they haven't had, and they go blublublublu, and their blood glucose goes up. But you 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.

    27. AH

      So they're using more of the energy?

    28. GJ

      Yeah, so-

    29. AH

      In the red light condition.

    30. GJ

      In the red light condition. In the blue light condition, we're sl- 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 antennae, and you squeeze a bee, and you get a little piece of-

  9. 36:19 – 42:46

    Red Light, Parkinson's Disease, Cell Death; Eye Rods & Aging; Mitochondria Community

    1. GJ

      we're not unique in finding this.

    2. AH

      Mm-hmm.

    3. GJ

      It's just that other people are finding things with red light that are sitting behind different walls. So-... John Mitrofanis, who, in, he did most of his research in, in Australia. Uh, 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 brainstem. Um, but he was reducing the symptoms of Parkinson's disease in these primates very significantly with lights that were being shone on the abdomen. So, in any one of these, you take in insuli-... insulin isolation, and there are many of these studies, and you go, "Yeah, maybe. Yeah."

    4. AH

      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?

    5. GJ

      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, and perhaps we shouldn't. We know that long wavelength light reduces the magnitude of cell death in the body.

    6. AH

      Mm-hmm.

    7. GJ

      Cell death is very often initiated, apoptosis, by mitochondria. When mitochondria get fed up, and th- 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."

    8. AH

      And th- I think they actually present a molecular eat-me signal.

    9. GJ

      Yes.

    10. AH

      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.

    11. GJ

      Yeah. Yeah.

    12. AH

      Yeah. They'll get opsonized, you know, for the people that, uh, you know, think about the immune system opsonization. There's 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.

    13. GJ

      Yeah.

    14. AH

      Okay.

    15. GJ

      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 s- 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.

    16. AH

      Yeah, they're similar to us.

    17. GJ

      Yeah, they're very, very...

    18. AH

      Or us to them.

    19. GJ

      (laughs) Yeah.

    20. AH

      Yeah.

    21. GJ

      Another experiment we did was, (sighs) over life, you will lose a third of your rod photoreceptors in your retina. You-

    22. AH

      Maybe just explain for people what the rod system is.

    23. GJ

      Okay.

    24. AH

      Yeah.

    25. GJ

      The rod system is, the majority of photoreceptors 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.

    26. AH

      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.

    27. GJ

      Yeah. (laughs)

    28. AH

      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 it torch.

    29. GJ

      Yes, yeah.

    30. AH

      Um, 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 y- 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.

  10. 42:46 – 48:22

    Red/IR Light, Skull & Brain; Safe Non-Ionizing Radiation

    1. AH

      Um, I have a question about how far long wavelength light can penetrate and through what tissues. I realize that in the studies we've been talking about, it's long wavelength light exposure to the back, lowering the blood glucose response-

    2. GJ

      Yes.

    3. AH

      ... 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?

    4. GJ

      Oh, d- d- definitely. If you look at, um, if you, if you look at a long wave light source, and again, this is published, uh, Bob Fosbury did this. He put his hand on one, comes 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, uh, yeah, it- it- it's, it's really not affected that much by bone. Um, I was talking to some audiology 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 here. That's not a problem. 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 deoxygenated blood, so you get fantastic pictures of your veins in your hand-

    5. AH

      Mm-hmm.

    6. GJ

      ... um, or in your head. But the most obvious thing that you think is that long wavelength light will be blocked by something thick like a skull, the answer is no.

    7. AH

      So going back to our example of the ocean appearing blue-

    8. GJ

      Mm.

    9. AH

      ... because of blue light getting reflected back and red light getting absorbed-

    10. GJ

      Yes.

    11. AH

      ... I think this is very important to kind of 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, it, and you see the vasculature-

    12. GJ

      Yeah.

    13. AH

      ... this deoxygenated blood. When people see a structure under a particular wavelength of light, the kind of reflex is to 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 opposite.

    14. GJ

      Exactly the other way around.

    15. AH

      It's the stuff you don't see, right, that is, that it's passing through.

    16. GJ

      Yeah.

    17. AH

      And I think a l- uh, I think, uh, for a lot of people, that's just kind of counterintuitive.

    18. GJ

      Yeah.

    19. AH

      So they'll see an image of, of the, the veins, right?

    20. GJ

      Mm-hmm.

    21. AH

      Carrying that deoxygenated blood, and they'll say, "Oh, you know, red light is, uh, is impacting the, the veins," right? But, but the interesting thing is that it's passing through all... uh, 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 emitting device, that it's actually getting into the deep brain tissue through the skull.

    22. GJ

      Mm.

    23. AH

      For, I think for most people, it's j- just not intuitive to think about light passing through things s- that are solid in that way.

    24. GJ

      Yes, and, and I have exa- I had exactly the same problem. Uh, I had exactly the same problem. Um, if you, you put a radiometer and a spectrometer to measure the energy in 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 s- and it's not a sideline, it's actually a very important issue, um, a, a biomedical engineer, Ilias Tachtinidis 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, w- 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.

    25. AH

      Mm.

    26. GJ

      And the readouts that he gets are readouts that are indicative of the potential survival of that neonate.

    27. AH

      Wow.

    28. GJ

      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? Uh, h- he's gone through loads of ethics committees.

    29. AH

      The long wavelength light, red and out towards infrared and near infrared is non-ionizing-

    30. GJ

      Yeah.

  11. 48:22 – 51:04

    Sponsors: AG1 & Rorra

    1. GJ

    2. AH

      By now, I'm sure that many of you have heard me say that I've been taking AG1 for more than a decade, and indeed that's true.The reason I started taking AG1 way back in 2012, and the reason why I still continue to take it every single day, is because AG1 is, to my knowledge, the highest quality and most comprehensive of the foundational nutritional supplements on the market. What that means is that it contains not just vitamins and minerals, but also probiotics, prebiotics, and adaptogens to cover any gaps that you might have in your diet while also providing support for a demanding life. Given the probiotics and prebiotics in AG1, it also helps support a healthy gut microbiome. The gut microbiome consists of trillions of little microorganisms that line your digestive tract and impact things such as your immune status, your metabolic health, your hormone health, and much more. Taking AG1 consistently helps my digestion, keeps my immune system strong, and it ensures that my mood and mental focus are always at their best. AG1 is now available in three new flavors, berry, citrus, and tropical. And while I've always loved the AG1 original flavor, especially with a bit of lemon juice added, I'm really enjoying the new berry flavor in particular. It tastes great. But then again, I do love all the flavors. If you'd like to try AG1 and try these new flavors, you can go to drinkag1.com/huberman to claim a special offer. Just go to drinkag1.com/huberman to get started. Today's episode is also brought to us by RORA. RORA makes what I believe are the best water filters on the market. It's an unfortunate reality, but tap water often contains contaminants that negatively impact our health. In fact, a 2020 study by the Environmental Working Group estimated that more than 200 million Americans are exposed to PFAS chemicals, also known as forever chemicals, through drinking of tap water. These forever chemicals are linked to serious health issues, such as hormone disruption, gut microbiome disruption, fertility issues, and many other health problems. The Environmental Working Group has also shown that over 122 million Americans drink tap water with high levels of chemicals known to cause cancer. It's for all these reasons that I'm thrilled to have RORA as a sponsor of this podcast. I've been using the RORA countertop system for almost a year now. RORA's filtration technology removes harmful substances, including endocrine disruptors and disinfection byproducts, while preserving beneficial minerals like magnesium and calcium. It requires no installation or plumbing. It's built from medical-grade stainless steel. And its sleek design fits beautifully on your countertop. In fact, I consider it a welcome addition to my kitchen. It looks great, and the water is delicious. If you'd like to try RORA, you can go to rora.com/huberman and get an exclusive discount. Again, that's RORA, R-O-R-R-A, .com/huberman.

  12. 51:04 – 59:28

    Offsetting Retinal Aging, Improve Vision & Long-Wavelength Light

    1. AH

      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 long wavelength light. I'm being very careful with my language here 'cause if I say red, people think you have to see it. But there's red, near-infrared, NIR, it's typically shown as N-I-R, infrared light, and I think we- we batch those when we say l- l- long wavelength light. It's going, what, 650 nanometers would be red out to, I guess, as- as far as 900 nanometers or so?

    2. GJ

      Uh, 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- Mm-hmm. ... which is around 700. Mm-hmm. And we're talking about the near-infrared, which is, for practical purposes, is going up to around 900. Mm-hmm. Um, but you know, I- I re- 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, uh, U- U- UV light.

    3. AH

      Do they?

    4. GJ

      Uh, yeah, they do actually, but then, you know, while we were doing the experiment, I wa- I was beginning to say, "Look, I don't know, I'm not believing any of this data 'cause 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.

    5. AH

      Mm-hmm.

    6. GJ

      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.

    7. AH

      Mm-hmm.

    8. GJ

      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.

    9. AH

      Yeah, this explains a lot of people's ideas about whether or not they've seen ghosts, but that's a different-

    10. GJ

      (laughs)

    11. AH

      ... that's a different podcast, uh, ghosts and, uh, UFOs. But an interesting discussion-

    12. GJ

      Yeah.

    13. AH

      ... but for another time. But, um, and, uh, I can't help but mention that, okay, maybe we'll return to this later, but, uh, Glen 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 reindeers-

    14. GJ

      (laughs)

    15. AH

      ... 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?

    16. GJ

      Yeah. So, let's take two pieces of information first. So, one of the main theories of aging is 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've 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, um, 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 resola- 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. Their threshold had improved in every one of those subjects bar one.

    17. AH

      They could see something they couldn't see before.

    18. GJ

      See before.

    19. AH

      By one, I think it's hard f- uh, what, what scale is it on? Like some of these tests, like this is like the Tritan test.

    20. GJ

      Well, so we, we tested Tritan and Protan, so-

    21. AH

      Okay, so this is nerd speak for the different visual tests.

    22. GJ

      (laughs)

    23. AH

      Uh, most people are, are familiar with the Snellen chart when you go to get your driver's license, you have to read the letters of different sizes.

    24. GJ

      Yeah. So that-

    25. AH

      Very different. This is measuring the just noticeable difference between you can see something, you can't see something.

    26. GJ

      Yeah. Yeah.

    27. AH

      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?

    28. GJ

      Okay. It, 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. (laughs) Right?

    29. AH

      Ah, you're saying, "but one."

    30. GJ

      No, no, no.

  13. 59:28 – 1:03:50

    Tool: Long-Wavelength Light & Preserve Retinal Mitochondria; Sunlight

    1. AH

      I have a lot of questions about these studies, so, um, I'm gonna 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 emitting device, do you think it's critical that it be 670 nanometers or could it be 650 out to 800? Uh, how, how narrow band does the, does the light actually have to be in terms of wavelength?

    2. GJ

      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.

    3. AH

      If this is happening, uh, very quickly, you said an hour later the vision is better, thresholds have changed-

    4. GJ

      Yeah.

    5. AH

      ... and it lasts five days. Do you think we can get the same effect from sunlight given that sunlight contains these long wavelengths of light? Or is it that the s- 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're, the way you described it and showed it with your hand for those listening is 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?

    6. GJ

      Well, I'm a big, big fan of s- 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 cutoff point, but there's an enormous difference between the light produced by a flashlight and sunlight. Sunlight is an enormous broad spectrum.

    7. AH

      Mm-hmm.

    8. GJ

      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?

    9. AH

      Mm-hmm.

    10. GJ

      And, and I'm not going to spend whatever is left of my career hunting that down.

    11. AH

      Mm-hmm.

    12. GJ

      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 670. 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. So-

    13. AH

      Yeah, and you're in the UK, so you'd have a lot of days where you don't do experiments at all.

    14. GJ

      We don't do sunlight. (laughs)

    15. AH

      I'm just kidding. Well, I must say g- you know, oftentimes when I tell people to get sunlight in their eyes in the morning to set their circadian rhythm, um, like a, you know, um, like repeating record with that, and I will be till the del- 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, it is cut off. Um, so they're still getting a lot of photons. I mean, compare how bright it is at 9:00 AM-

    16. GJ

      Yeah.

    17. AH

      ... uh, versus midnight the night before. It- their sun is that they can't see the outline of the sun as an object, is what they're referring to.

    18. GJ

      Right. I thi- 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.

    19. AH

      Mm-hmm.

    20. GJ

      There will be an attenuation of the longer wavelength light. It won't be vast, but there will be an attenuation. But more... It would start coming at you in different angles. So when you s- when you're walking on a sunny day and you're walking down the road, sun's in front of you, you feel warm on your chest when you've got clothes on, and it's the 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-

    21. AH

      Mm-hmm.

    22. GJ

      ... my argument, which is the new mantra of the, of the lab to some extent, is get a dog, right?

    23. AH

      (laughs)

    24. GJ

      Get a dog, because you'll have to go out in s- you'll have to go out in daylight two or three times a day.

    25. AH

      Y- You'll get no argument from me.

    26. GJ

      (laughs)

    27. AH

      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 was a English bulldog, half English bulldog, half mastiff. So the next one will also be an English bulldog.

    28. GJ

      (laughs)

    29. AH

      Uh, couple more

  14. 1:03:50 – 1:07:57

    Mitochondrial Theory of Aging, Circadian Rhythm & Mitochondria

    1. AH

      questions, because I know people are curious about long wavelength light emitting devices for their eyes and oth- 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, et cetera, but on the eyes and visual function, seem to be gated by age, right?

    2. GJ

      Yeah.

    3. AH

      If I recall, people younger than 40, um, s- you, you saw less of a- of an effect.

    4. GJ

      Overall, statistically, we saw less of an effect. Uh, b- you know, some people... My, my youngest son responded very, very strongly, and at the time, I think he was about... Uh, 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 impro- 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.

    5. AH

      What was the time of day, so-called circadian effect, uh, of this?

    6. GJ

      Uh, 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 o'clock. 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, 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- it's not the same even over a three-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... You're gonna be doing research on mitochondria and you're not taking account of time of day, y- 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. 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-

    7. AH

      Interesting.

    8. GJ

      ... I think this comes from a very myopic point of view, which is we think about mitochondria as, 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 organelles they need to do.

    9. AH

      Mm-hmm.

    10. GJ

      They are... Over a period of a day, they're making contact with other organelles in the cell, particularly something called the endoplasmic 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 nine o'clock in the morning was not a mitochondria at four o'clock 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.

  15. 1:07:57 – 1:10:44

    Tool: Improve Vision with Long-Wavelength Light

    1. GJ

    2. AH

      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, three inches, six inches, a foot, depending on how bright it is. But if I were gonna 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 three minutes, five minutes of exposure once every five days or so. And is that going to be sufficient?

    3. GJ

      There is the difference between something that has an effect-

    4. AH

      Mm-hmm.

    5. GJ

      ... and then the efficiency-

    6. AH

      Mm-hmm.

    7. GJ

      ... of that effect. So if you take a 670 nanometer light source and you do exactly that, you will have an effect.

    8. AH

      Mm-hmm.

    9. GJ

      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-

    10. AH

      So you don't need a very bright light.

    11. GJ

      No. No, you don't. So we were... The original, uh, experiments, they used watts. They measured it in watts, not lux. Lux 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.

    12. AH

      Mm-hmm.

    13. GJ

      So people started off at, say, 40 milliwatts per centimeter squared. And I looked at that and I thought, "Crikey."

    14. AH

      That's bright.

    15. GJ

      That's bright.

    16. AH

      That's very bright.

    17. GJ

      Big after effect.

    18. AH

      Yeah, that's going to make someone wince. Yeah.

    19. GJ

      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.

    20. AH

      Mm-hmm.

    21. GJ

      But then we had someone in the lab do an experiment, um, and we had flashlights that had batteries in them, which got lovely effect. And we found out the batteries had been run down, and she was getting an effect close at one milliwatt per centimeter squared. That is low.

    22. AH

      That's dim red light.

    23. GJ

      That is low.

    24. AH

      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-

    25. GJ

      Oh, yeah. Yeah.

    26. AH

      ... 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.

    27. GJ

      Yes.

    28. AH

      You've

  16. 1:10:44 – 1:13:59

    Macular Degeneration, Rescuing Vision, Early Intervention

    1. AH

      also looked at this in the context of macular degeneration, which is a very common form of blinding, uh, especially in people as they get older. Uh, what were the results in terms of rescuing vision in people with macular degeneration?

    2. GJ

      Okay, so macular degeneration is when... You could put it crudely that the center of your retina that you're, 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, sorry, if I get you all to live to 100 years, probably 20% of you will have macular degeneration. Uh, remember, the retina's 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... M- more, 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- a point where, you know, people, uh, people working with Glen are getting, getting... Losing enthusiasm. Um, but lo and behold, their husbands, their vision... Th- 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 ophthalmologist called Ben Burton in the UK, he got a great result. He started to get really good result. And when you talk to people about red light, and I talked to people, I talked to Parkinson's Societies, I talked to various groups, and I talked 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.

    3. AH

      Mm-hmm.

    4. GJ

      Right? So, where we need to get into situations is early on in disease. So, w- we thought very much about, at one point, about rheumatism, um, you know, rheumatoid arthritis, and we-

    5. AH

      Yeah, a very common autoimmune condition, yeah.

    6. GJ

      Yeah. And, um, we had absolutely zero effect, but all of the p- all of the subjects we dealt with already had hands that w- were quite twisted. It wasn't people coming in saying, "I've got this ache in my hand," which is where we should have intervened. So, early intervention is absolutely critical. We don't have to give high energies. We don't have to give long exposures. We can improve situations, but where we need to put our effort is the efficacy of how we improve things. If I can improve something 20%, well, that's great for that person, but can we improve it 80%?

    7. AH

      Mm-hmm.

    8. GJ

      And that's all about wavelengths. It's all about energies. It's all about us thinking a little bit more carefully before we set up the experiment.

  17. 1:13:59 – 1:19:09

    Light Effects at Local vs Distant Tissues, Immune System, Body Communication

    1. GJ

    2. AH

      It also makes me think that even though long wavelength light can penetrate the body and it scatters, like for instance, the shining of light, uh, on a four-by-six-inch, uh, rectangle on the back impact blood glucose regulation everywhere-

    3. GJ

      Mm-hmm.

    4. AH

      ... shining long wavelength light into the eyes improved, presumably, mitochondrial function in order to increase, uh, the visual detection ability, um, and on and on. Presumably, the tissue that you focus the light on, if it's a focused light, is going to derive the greatest benefit, right, or at least the most opportunity for mitochondrial change. Then there will, there will be systemic effects. Those mitochondria are talking to other mitochondria. I mean, I'm fascinated by how mitochondria are perhaps transported between cells and around the body. There's, there's a, it's not even a cottage industry anymore. I think a lot of biologists-

    5. GJ

      Mm-hmm.

    6. AH

      ... are thinking about this seriously. But let's say I want to improve the func- the mitochondrial function in i- in my gallbladder. Um, should I shine the red light on my gallbladder? It seems to, uh, stands to reason-

    7. GJ

      (laughs)

    8. AH

      ... that, that it, the answer would be yes.

    9. GJ

      I think the answer is yes. The issue is how quickly the effect takes place in distal and proximal tissues.

    10. AH

      Mm-hmm.

    11. GJ

      So, if you shine the light on your kneecap-

    12. AH

      Mm-hmm.

    13. GJ

      ... something will probably happen within one to two hours, right?

    14. AH

      At the kneecap?

    15. GJ

      At the kneecap.

    16. AH

      Right, right, right.

    17. GJ

      But then if you're examining the response of that, um, on your hand, it's 24 hours later.

    18. AH

      Mm-hmm.

    19. GJ

      Right? So, the message has to get out-

    20. AH

      Mm-hmm.

    21. GJ

      ... and things have to, the story has to spread.

    22. AH

      Mm-hmm.

    23. GJ

      And the spreading of the story, the spreading, it, th- that's an intense kind of area of, o- of activity. What is the signal? Where is it coming from? What is the signal?

    24. AH

      Mm-hmm.

    25. GJ

      And I think we, we poked our finger at that slightly because we found that cytokine expression in the serum changed a lot.

    26. AH

      Inflammatory cytokines are going down?

    27. GJ

      No, um, increase in cytokine expression at low levels is protective.

    28. AH

      Okay.

    29. GJ

      Right?

    30. AH

      Sure, yeah.

  18. 1:19:09 – 1:20:56

    Sponsor: Function

    1. AH

      I'd like to take a quick break and acknowledge one of our sponsors, Function. Last year, I became a Function member after searching for the most comprehensive approach to lab testing. Function provides over 100 advanced lab tests that give you a key snapshot of your entire bodily health. This snapshot offers you with insights on your heart health, hormone health, immune functioning, nutrient levels, and much more. They've also recently added tests for toxins, such as BPA exposure from harmful plastics, and tests for PFASs, or forever chemicals. Function not only provides testing of over a hundred biomarkers key to your physical and mental health, but it also analyzes these results and provides insights from top doctors who are expert in the relevant areas. For example, in one of my first tests with Function, I learned that I had elevated levels of mercury in my blood. Function not only helped me detect that, but offered insights into how best to reduce my mercury levels, which included limiting my tuna consumption, I'd been eating a lot of tuna, while also making an effort to eat more leafy greens and supplementing with NAC and acetylcysteine, both of which can support glutathione production and detoxification. And I should say by taking a second Function test, that approach worked. Comprehensive blood testing is vitally important. There's so many things related to your mental and physical health that can only be detected in a blood test. The problem is, blood testing has always been very expensive and complicated. In contrast, I've been super impressed by Function's simplicity and at the level of cost. It is very affordable. As a consequence, I decided to join their scientific advisory board, and I'm thrilled that they're sponsoring the podcast. If you'd like to try Function, you can go to functionhealth.com/huberman. Function currently has a wait list of over 250,000 people, but they're offering early access to Huberman Podcast listeners. Again, that's functionhealth.com/huberman to get early access to Function.

  19. 1:20:56 – 1:28:39

    Short-Wavelength Light, LED Light, Mitochondria & Serious Health Detriments

    1. AH

      I'd like to, um, talk a little bit about the other end of the wavelength spectrum, short wavelength light. And here I'd like to move to artificial lighting, um, and point to what I think is a very serious concern. I, I know it might seem a little bit, uh, extreme, but I am very concerned about the fact that people are exposed to so much short wavelength, what's commonly referred to as blue light, but I don't think that really captures it because people hear the words "blue light" and they think, "Oh, if a, if a light source looks, appears blue, then that might be messing with my melatonin at night and might be messing with my mitochondria even." But it's the white light coming from LED sources, which are basically what we use as lighting sources nowadays, that yes, they contain blue light, but they also contain, you know, violet light and stuff that doesn't appear blue because you've got the other wavelengths in there. In other words, white light coming from LEDs is very short wavelength enriched. To me, that's a problem if short wavelength light is causing dysfunction of mitochondria, and I do believe that's the case, unless it's balanced by the longer wavelengths.

Episode duration: 2:14:25

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