The Mitochondria Scientist: This Light Is Silently Aging You Faster | Dr Glen Jeffery opens a useful window into light as a mitochondrial cue. The conversation is not a shortcut or a spectacle. It is a reminder that healthspan is built through signals the body can understand and repeat.
And a really good example of this this these systemic problems is a fantastic paper published by NASA um few years ago in a very very high-profile journal called cell and it said our astronauts referring to astronauts on the international space station have a mitochondrial problem. What's happening to them? They're all becoming or many of these super fit people are becoming pre-diabetic. So if you close your mitochondria down, they demand less glucose from your blood. That means your blood glucose levels increase. So all these fit people that being monitored all the time, something else happened which a few aging people may have predicted. I didn't predict it at all. They're starting to age faster. Now, mitochondria regulate the pace of aging. Now, there are some great there's a great photograph out there, and that is a photograph of the lady who was up on the space station for about a year when she should have been there for a few weeks before and after. Look at the comparison between the two. She has aged enormously. Now, everybody kind of seemed to pass by that photograph, but a lot of the aging people went, "Hang on, what's going on here?" Hello, Dr. Jeffrey. You are a professor of neuroscience at the University College London. So, welcome to Modern Healthspan and thank you so much for coming back on the channel today. A pleasure to be talking to you again. Thank you. So, Dr. Jeffrey, that's the last time we spoke mostly about the beneficial effects of red light and I have linked the talk above for anyone who's interested. However, so just as light can have positive effects on the body, it can also have detrimental effects. So today, what I'd like to kind
effects. So today, what I'd like to kind of dive into is what the impact of excessive blue light is and what we can do about it. So kind of starting you have been doing some research on the effect of blue light on and it seems to be again mito mitochondria just like the red light it's the mitochondria. So what are we seeing in terms of the impact that uh blue light has on the mitochondria. Okay. Well as as with red light improves mitochondrial performance blue light undermines mitochondrial performance. Now, as we walk around in the world outside, we have a balance between blue and red light. And that balance is a balance been there for billions of years. Um, why should we pay attention to blue light? We should pay attention to blue light because suddenly in the built environment, we're getting vast amounts of blue light that we've never had before. And that is for two reasons. The first reason is LEDs that are now the standard form of lighting in the built environment um have a very very restricted spectra only to the light we see not to other wavelengths. But the LED also has a very big spike in the blue range at around 420 450 nanometers. Now, it doesn't really make too much difference if it's a warm blue or a warm LED or a cold LED. Still got this big blue spike. Now, we know mitochondria absorb light very specifically at 420 nanometers. So, that wavelength of light that is spiking in your LED, your mitochondria are responding to that and they respond to it pretty rapidly.
they respond to it pretty rapidly. When they do absorb those wavelengths of light, it upsets their balance. They stop producing cellular energy and they start to produce what we call free oxygen oxygen singlets and they are highly inflammatory. Right? So we know I mean the science behind that one is absolutely clear. We also know that if you do something to the mitochondria in your foot, by the end of the day, the mitochondria in your foot have told the rest of the mitochondria in your body there's an issue. They operate as a community. They are a complete community. There are occasions when that community gets disrupted. So cancer is a very very good example because in cancer the cancer cells and their mitochondria run off and do something different. But on the whole, mitochondria act as a community. So if you wander around in blue light, the blue light actually doesn't get through your skin. It really is just absorbed by the surface and by your eyes. But when it is absorbed by those regions, the rest of the body know about it. So the detrimental effects can become systemic. That's the bad news. it can become systemic and a really good example of this this these systemic problems is a fantastic paper published by NASA um few years ago in a very very high-profile journal called cell and it said our astronauts referring to astronauts on the international space station have a mitochondrial problem what's happening to them they're all becoming or many of these super fit people becoming pre-diabetic. So if you close your mitochondria down, they demand less glucose from your
they demand less glucose from your blood. That means your blood glucose levels increase. So all these fit people, they're being monitored all the time. Something else happened which a few aging people may have predicted. I didn't predict it at all. They're starting to age faster now. Mitochondria regulate the pace of aging. Now, there are some great there's a great photograph out there and that is a photograph of the lady who was up on the space station for about a year when she should have been there for a few weeks before and after. Look at the comparison between the two. She has aged enormously. Now, everybody kind of seemed to pass by that photograph, but a lot of the aging people went, "Hang on. What's going on here? That environment in the International Space Station is solid, hard white LEDs." So, NASA have admitted it's a mitochondrial problem. They haven't put their finger on exactly what it is, but I think the path is actually rather clear. they are suffering from excess shortwavelength light dampening their mitochondrial responses. Great example. So the the NASA team must measure a lot of parameters for their astronauts while they're up there. Um do you know what they used? So did NASA say that they aged more or was it just kind of like visually she looks older? They said the whole team was showing signs of premature aging. So NASA put their hand up and I think they put their hand up rather naively. Now think about the consequences. NASA and the American government want to unload space flights to Mars. They want to unload them to a commercial company. Now, if you're a commercial company having employees that you're
company having employees that you're sending out to Mars and those employees all start to age quickly and all start developing diabetes, there going to be some lawsuits, you know, that that is going to be really bad news. So, I don't know what's bubbling on below the surface, but there is conversations about this. And if I were running a private space company, um I would probably dump the idea of longhaul space flight unless we can find a way to balance the mitochondria in the people on longhaul flights. So yeah, I let's come back to some of the things we can do and but can we talk a little bit more about what is the impact of blue light and and what is what in what data do we have about the impact that blue light has on mitochondria and so we have you've done some mouse studies or there have been some mouse studies but in fact you mentioned one I I think where they they shone light on mice for I don't know six hours a day. What was the impact of that? Oh, the impact on that was quite shocking. Um and I was genuinely surprised. Really surprised. This is a study which is uh probably probably be submitted in the next couple of months. The data all super clear. When the data came out, my first response was to say go away and do that again. I don't I I'm not happy. Go away. I want to see the inside of your animal house. I want to make sure there's nothing in there that's nasty. So, they took the le they took a LED panel um which was producing 420 450 nanometers which is the big spike in our environment. And they exposed mice to it for I think it was about 5 hours a day on a 1212 light dark cycle. So, they did all the things
dark cycle. So, they did all the things that you should do. And then people noticed a few things. I mean, it's already already been published that mice under blue light put on weight. They put on actually quite a lot of weight. Well, that's fine. I can get my head around that because mitochondria consume glucose and oxygen to function. If you reduce their function, they're going to demand less glucose. So, you're going to have more blood glucose. You're probably going to start storing that as fat. So when they did the second study which is yet to be published I said well let's have a look at the whole body you know so fat where is this fat you know is it fat in the normal place so the first thing that came back was no the fat's not in the normal place the fat is building up in places we weren't expecting it okay so they'd open the animals the mice up to do that and pictures of these horrible pictures of mice with you uh pinned out looking at fat deposition. But then I said, well, if you're going to do that, let's go for the whole body. Let's just look at let's look at systemic impacts. We know there's a systemic impact. Mitochondria talk to one another. So the first thing they did was they took out the key organs from the mice. And much to my surprise, liver, heart, kidney were all smaller. They weighed less. Uh I was really surprised at that. So you know next thing is it if it's smaller let's do the hystopathology. Let's cut the tissue. Let's put it under a microscope. Let's see what's going on. And the tissue is pathological. You know these are middle-aged mice. They shouldn't be like that. The controls that were under normal lighting didn't have this. Then there are some tests that you can do very easy for function. So there are some blood tests
function. So there are some blood tests which done very standardly routinely in hospitals for liver function and I said let's run functional tests not just look at it let's run a functional test. So liver alt function um that goes up with age goes up if you booze a lot um goes up with pathology alt really high in these animals. So something is happening which is systemic. We know that these animals get fat. We know these animals are a bit behaviorally a bit dodgy. They they don't like open field environments very much. They kind of look as if they're a bit stressed. Um and we've got a systemic effect on on their key organs. Um we haven't looked at the brain. Um it's a key one but are a bit overwhelmed with it so far. So the only thing those mice had was around 5 hours exposure to shortwavelength light in a spectral range that you find in LEDs. So I find that really put that together with NASA. Something is going on here. Now there are other little things out there that tell us something. Um, an experiment done at Surrey University was where they canulated people so they can sample their blood all the time and they move them between different LED environments, move them into that spectral range and their heart rate and their blood pressure change very rapidly. So, we're being bombarded by data that is telling us there is something wrong with a short spectral range that is a major component in LED lighting. Um, it's not only affecting our mitochondria, it's knocking on to blood sugars, it's knocking on to
sugars, it's knocking on to changes in key organs. Um, deeply I I find that deeply worrying. Um, so I was always running around saying to people, you change your light bulbs. Change your light bulbs because you want more red light in them. So get an old incandescent light bulb. That was my argument. I've got two arguments now. Change your light bulbs because the old incandescent light bulbs got lots of red in them and also it doesn't have that big blue spike. Now, as you wander around the world from building to building, you're wandering around from different LED lighting settings. And you may think the lighting's different. You may think this is a bit more comfortable. You may They've all got that big blue spike. So, I think that's going to be the talking point as an issue of public health in the not too distant future. We're constantly surrounded by invisible signals, Wi-Fi, Bluetooth, 5G, and we rarely consider their impact on our bodies. Some researchers suggest these signals can open channels in our cells, letting in excess calcium. Too much calcium triggers stress and disrupts your balance. Magnesium helps keep these channels in check. It's your body's natural way to stay calm and steady. But when you're exposed to EMFs, you burn through magnesium faster, and most people are already deficient. Many magnesium supplements use just one or two forms your body can't absorb well. That's why I take Magnesium Breakthrough by Bioptimizers. It's the formula with all seven essential forms. It helps me sleep better and stay calm and focused. Go to bioimmizers. com / modern and use code modern10 to save 15%. They offer a full 365day money back guarantee. And if you
money back guarantee. And if you subscribe, you'll get great discounts, free gifts, and a guaranteed monthly supply. The So, in the mouse experiment, do we know what the power was? I mean, often in in like animal experiments, like we give them a very high dose or something like that. Yeah. Right. So, is it the same? Was it like an overpowered blue light or just the same as normal humans get? No, it was greater. Um, I would say it's approximately in the ballpark of two or three times greater than the energy you would receive from an LED lighting in your immediate environment. By that I mean a desk light. Um, and it was given over a series of months. So, we have higher energy. We have uh an older mice. Older mice are always like us, more vulnerable. And um we ran it for a number of months. So yeah, it was a little bit more extreme than you might get in our world, but our world, let's say you're up for 12 to 14 hours a day, particularly in places in winter and if you're working in an office, you are then exposed for 12 to 14 hours a day to LED lighting. Go home, read your book in bed for 20 minutes before you go to bed, LED lighting. So, it's difficult to balance exactly the mouse experiments with the human experience, but there's enough warning signals there flashing at you telling you LED lighting may not be great news for you. It's great news for your energy bills, but it's not great news for your health. So I in the human trial well it wasn't actually it was a human trial right where they they went from different through these different environments I believe like the blood pressure went down is that correct
down is that correct yeah and the heart rate went up so okay so some physicians say well hang on that's good news and the people that published the story published it under a title it was in the European Journal of Cardiology and they published it under a good news banner basically. Uh I don't want to walk from one environment to another and have a profound effect on my physiology. I don't want that to happen. Um we've already just dipped our toe in some of these problems. Where's the bottom? I don't know where the bottom is. And I want to be able to walk around the world in natural light and not have man-made light disrupt my physiology. And and I I'm not overtly um it's not the best phrase ever, but I'm not overtly a tree hugger. I believe in general health and I believe in minimal intervention to obtain general health. So I think there there are lights flashing on this one. Definitely. I I one question I had. So the if you have the the red light, it improves your glucose control and the blue light decreases it. If you were on a ketogenic diet, would it have the same effect? If it's not glucose, you're talking about ketones. I don't know. I genuinely and that's a phrase that scientists use a lot should be using a lot more often particularly in a field that's expanding at at a vast rate like this is there are so many big questions we don't know I don't know the answers to that and I'd love to I I would genuinely love to um we are very limited by resource um but another issue that I would throw in here is that one of the experiments are expensive.
one of the experiments are expensive. They're really expensive. How do you get around it? And and I can't do them on humans because it's immoral. Um so one of the things you fall back on is doing things doing experiments on things like flies. So in my lab at the moment I've got whole series of fly incubators all with different light bulbs in them. And all I'm doing is checking how long they live. It is super clear that that flies under LED lighting have much shorter lifespans than flies under incandescent lighting that has got a spectral range similar to sunlight. Now, I I get in in the morning at 8: 00. You know, the first thing I do, I I run into the lab and I I lift these vials of flies up and I'm going 1, two, three, four, five. And yeah, it's really exciting. Quite sad that I'm saying that, but it is really exciting. And it's consistent time after time that the LED lighting with its big blue component is killing flies faster than it would do under their normal light, which is a actually not great. is a strip light, small fluorescent light that you get in incubators, and it's killing them hell of a lot quicker than under old incandescent light. The incandescent light's the winner. I rush I'm rushing in at the moment to see if my five cuz I've got five flies that live live longer than any flies I've come across. I still alive this morning. They're sitting there not doing much, but technically they're alive. So, that's a plus. So we can think about all these mitochondrial effects. We can think about lifespan. Our astronaut came back looking really old. Our flies in the incubator under LED light just dying quickly. Flies under the incandescent light like daylight doing super well. I was Yeah, just thinking about the ketones thing. I mean, by the time it
ketones thing. I mean, by the time it gets into the mitochondria, um, it's pretty much the same chemical, I think, whether it comes from a fat or it comes from a sugar. So, just thinking about it sounds like, but yes, we need it. You we need to test. Yeah, we do. Do you know why there's that big blue th that big blue thing in LEDs? that the big blue spike is is it like a choice or is it something in the way LEDs are made? Okay, I'm I'm certainly not an electrical engineer. However, my understanding is and um uh I'm not not writing this in concrete. And one of the guys in the lab is an LED designer is that the fundamental light in an LED is a blue light and that blue light then falls on a phosphor surface and it's a stimulation of that phosphor surface that produces the wider spectral range. So my understanding is the fundamental light in the modern LED is blue. Now can you get around that in a different way? I don't know. But one experiment we have done which I have extended towards humans is let's take an LED a bog standard LED bulb. Let's take the front off and then let's plug into that bulb a um a long wavelength LED. So so we've got all these LEDs. Let's now plug in something that hasn't got which is say 850 nmters. 850 nmters of wavelength. I play with it improves loads of things. Let's put the bulb back together again and let's hand the bulbs out. Now, the people with the standard LED bulb do badly on color discrimination. But the people who have the LED bulb
But the people who have the LED bulb where we've plugged a long wavelength into it do as good as normals. So, we can potentially correct the problem. Okay. we can add something into the system to try and rebalance the system so that blue is not this big dominant feature in the LED and that could be done commercially. Okay. In terms of sources of blue light, so we've been talking about LEDs, but screens give off lots of blue light too, like computer screens. Yes. Is that a significant component or is it it's just small compared with the LED? It's really small compared to the other. Well, first of all, yeah, I mean, we're all concerned about our blue backgrounds. Um, it's just beyond that nanometer range. It is, putting it crudely, it's a lighter blue and it's a blue that our mitochondria don't really respond to particularly badly. It's just beyond their range of absorption. So, we've had people sit down staring at blue computer screens, including myself, for three or four hours. Um, this was some time ago. I can't find any detrimental effects. Um, we've had people walking around with yellow glasses on all day to try and block blue and see, you know, do they get an effect? And we don't really get an effect on that. And I'm really pleased because everyone else I've talked to, they've not got an effect either. So, we're talking about very specific tight wavelength ranges that just happen to be in LEDs. They're not on computer screens and they're not on your mobile phones. That doesn't mean that that it's okay to look at computer screens for for ages or particularly for kids to spend ages looking at screens, but the blue light
looking at screens, but the blue light effect if it's there is minimal and I can't detect it. So, you said blue light doesn't get through skin. Does it get through clothes? No, it doesn't very well. Um, we published a paper a few months ago showing that longwavelength light goes through your body. Um, and we did get um we did get a whole pile of M & S clothing and we hung it up and we put different deep infrared lights behind it and they shone through it brilliantly. Uh, no. Doesn't go through clothes and and it obviously doesn't because on a really sunny day, hot sunny day, and you're walking around with a shirt on, a shortly short sleeve shirt, your arms get sunburnt, which is short wavelength light absorption, but it doesn't you don't get a suntan generally through your clothing. Not unless you're wearing a string vest or something like that. So, clothing is a very effective blocker of short wavelength light. um as is window glass. You tend not to get um sunburn um through light coming through your window. Uh you it needs to be direct contact on the body. I wonder whether would sunscreen protect you. Well, sunscreen sunscreen certainly protects you from from ultraviolet and sunblue. Yeah. Uh I think it depends on the sunscreen because I did look at that and not all sunscreens are exactly the same. So the sunscreens that have got a refle high high reflective surface and I think it's they have aluminium in them or something like that. Anything that reflects light away from the body. Yes. Yeah. But what about if like me you're really thin on top and you don't put enough sunscreen on your head and you leave a square inch. Well, that square inch will get blue light. The mitochondria will go, "We don't like this." And they'll tell the rest of the mitochondria in your body. So, um
mitochondria in your body. So, um yeah. It's you don't have to leave you Yeah. It's you don't have to leave much area of the body surface uh unexposed to get a significant effect. When we played with blood sugars uh with red light, we were playing with a really small percentage of body surface area. So I know I don't know what the minimum is um but you know I'm thinking along the lines of minimum is probably about you know four or five square cm if you go below that you won't get too much of an effect. Do you see that there is understanding in the building environment like in in the I guess the architects or the engineering departments that this is a problem? I mean is is the industry kind of trying to address it? Well, uh, the architects are becoming very aware and they're becoming aware, I think, for one solid reason. They're worried that in 5 years time, someone is going to come along having, you know, become pre-diabetic and start prosecuting architects. So, the architects are very aware. They're starting to become very aware. Um, the architects are and some of the lighting engineers are thinking very hard. And I think we'll be in a different situation in a few years time. But let me give you a terrible example. Um I'm in University College London at the Institute of Opthalmology and right next to my building is Morfield's Eye Hospital. Um you know I'm in and out of there once or twice a week. The basement of Morfield Eye Hospital are one of my colleagues said and she was a Scandinavian architect. She said, "I could not put this lighting in a prison." So, the lighting is absolutely terrible. We we've undertaken a lighting survey of the building, but the building is going to be pulled down in four years time. And there's a new Morfield's Eye
And there's a new Morfield's Eye Hospital going up and it's all in glass and it's all going to have horrible LEDs in it. And here we have an eye hospital full of horrible LEDs. And you might think, "Oh my god, that's terrible for the patients." Well, actually, as the nursing staff said, well, I'm not too worried about the patients. I'm worried about the nurses because they're here from 8: 00 in the morning till about 6: 00 in the evening. The staff are the people that suffer and you know, so people are paying attention and the right people are paying attention, but the time lag is really long. the time lag. I' I've told all the authorities about the lighting and I think their attitude is well by the time you know the problem might arise I'll have retired. That was the attitude I got. So there are many examples and the defense industry is just beginning to pick up on it as well. What happens with members of the defense industry when they're in environments without daylight for long periods of time, extended periods under economic blue rich LEDs. So it's there. I think we'll be in a very different situation in 5 years time, but we should be making those changes now. Okay. But okay, so the strip lights, the incandescent, they're not incandescent. The strip lights don't have the same problem. So it's only LEDs. So the strip lights, fluorescent tubes, their spectral output is a series of spikes. They are not good news, but they're nowhere near as bad news as LEDs. Okay. So, they've got some spikes in in the nasty blue range, but they're not very big spikes. As a proportion of the light that they produce, it's relatively small. If you look at the proportion of light that an LED
the proportion of light that an LED makes that is in that unpleasant range, and it is it's a it's not part of the big spectrum. It's it's almost a separate spectrum point. You know, I'm guessing completely off the top of my head, but it's 15 to 20% and there's no long wavelength light there to correct it. There's almost nothing about above 650 nanometers. Even if you've got this warm LED light, you know, which certainly is a lot easier on the eye. Do you know when was it when did LEDs start becoming the standard in office? So I'm just wondering, you know, are we going to see everybody getting well, everyone is getting diabetes, but even more people getting diabetes in Yes. So this became popular in the early 2000s and and there was a very obvious push for it. Now couple of guys got the Nobel Prize for LED for developing LEDs which I think was in the 1980s 1990s. So because they are so efficient in the light that they produce, they only produce light that we can see. Um there was a very very strong argument for putting them in all buildings. We're not wasting energy. The incandescent light bulb wastes lots of energy because you can touch it and it's hot. that light is coming out as heat rather than light. So from about the you know the early 2000s we start to get the uh LED. So I'm when I'm walking to when I'm talking to architects I start saying right hang on we got to change the lighting here and they say oh hang on in the UK building regulations now do not allow you to put in incandescent light. So we then start talking about what about if you've got an art feature? What about in your canteen where people are for a
your canteen where people are for a proportion of the day? Um so we we struggle with that and their first reaction of architects is we can't do that building regulations on a new building. So we're working with some architects on a a complete refurb of a building in central London. um it's been stripped out to its core and we're talking to them about how we can balance light to get around building regulations. Where can we put light where we can say this isn't standard light? It's not standard office light. It is light related to a very specific feature. Now, we're lucky in the UK we can wiggle our way around these problems. In America, they're going to be banned completely. Right? But no question they're going to be banned. And that I think is going through Congress sometime in the very near future. And there there are rumbles coming from some elements in the uh in America trying to get petitions running to say, okay, let's restrict the use of incandescent light bulbs, but let's still have it as an option. I'm not sure whether that will be successful or not. Is is anyone trying to fix the LED so that it works better? I mean, so that it's more human friendly. Yeah. Um, yeah. So, there's a company that we we asked to put those 850 LEDs in. Um, and yeah, we got some good effects from that. Um, and it would be relatively easy to do, but this is a very limited patch on a problem if so we took an environment with only LEDs in it and we and no windows, supplemented that with 60W incandescent light bulbs, big, it was a big space where architects had
it was a big space where architects had their models made. Um, and people were not sitting by their desks, they were moving around and coming back to their desk. So, we changed environmental lighting in a realworld situation. Now, when we took that light, so they had a big improvement in their color perception, which is our metric because I'm a vision person. I've got the toys to do that. Um, when we took the lighting away, the improvements lasted for a couple of months. Now, if you now compare that with an LED, the improvements you get with an LED, say an 850 or a 670 LED, the improvements are not as great and they only last 5 days. So, the importance of the light and I I there's a lot to be done here. The importance of the incandescent light was the fact that it's like sunlight. It's smooth. Its spectrum is very very smooth. Whereas if you look at LED lighting, it's a series of peaks. So we've tried to make LEDs like sunlight. First of all, doesn't matter how we engineer it, it's really difficult to iron out those peaks. So, you add loads and loads of LEDs. In the end, you're drawing more power than you would do with an incandescent light bulb, and you've got something really big and clunky. That's not going to be acceptable. It really isn't going to be acceptable. So, I don't know how we get around that at the moment. I mean, people are talking about OLEDs. Um, that's fine, but the energy that the amount of energy they kick out is actually quite small. Um it's going to take a major change in the way that we think. Um but some people caught on. I
think. Um but some people caught on. I spent some time in two critical care units at major London hospitals where there has been talk about LED lighting and the problems of LED lighting. Certainly, if you've got someone who's on the who is struggling on the point of light and life and death, you do not want them under an LED light. And I think there's a few smart people in critical care who are thinking, is this an issue? Cuz you've got someone on the point of life and death, you can give them an extra 3 or 4% on the positive side of the fence, that might make a very big difference. So, a few people are coming in from different sides. Some of the architects are coming in and saying what would happen if we changed the ratio of blue to red light in the changing rooms of major football clubs. Well, I don't know. I'm I'm really not that interested in football. But it implies that people are thinking different situations. You know what where are the situations where this is important. So again, it's another example of me saying five years time, we're going to be in a different place. Yeah, that's good. So I did want to uh kind of review a little bit of the benefits and maybe an update from of what you see from red light. So, as I recall from last time, we we talked about the benefits of red light and it makes the mitochondria more active. They use more glucose to create more ATP. Uh so, have you what have you done with that? It was actually a year ago we spoke last year ago. Okay. And this is a fastm moving field. Um there are things that have gone on. First of all, there's been much greater attraction. People are paying attention
attraction. People are paying attention and you can see that in the commercial market. All these commercial sort of things for red light, which you know, we don't have a commercial interest. We're separate from that. So, there's an explosion in red light masks. There's an explosion in gyms with, you know, red light devices, most of which are far too powerful. You do not want to put vast amounts of energy into your body. You really don't. Um I'd say two things have happened. The first thing is we have now a much better understanding of the mechanism. Um and that's really been done by uh a guy called Bob Fosbury who's an astronomer and he has you know fundamentally he said well here's a mitochondria and to make a mitochondria work it has to pass an electron along it and when it gets to the end then you produce more cellular energy. and he said okay the resistance along that circuit is matched by the amount of energy that long wavelength photons carry with them. So this year we published an article showing that longwavelength light sunlight and then also in the lab passes through the body. We can measure it coming through the body. Bob Fosbur's come up with a really great explanation for why the red light works which is it overcomes the resistance in this what we might can imagine as a circuit in the mitochondria. So that's one thing. Second thing which I think is really interesting not done by me done by a group of workers at Westminster University in London and they've just broadened it out. So they've taken those light bulbs with an 850 nanometer bulb in it, so they're redri. And they found that people's grip strength improves. Now that is really
strength improves. Now that is really important. It's really important because it's not Glenn talking about vision all the time. It's I'm saying to people, look, these are systemic effects. They're systemic effects. You should be getting effects in other places. They've got an effect on grip strength. Think about that for the older person in the care home. Their ability to grab hold of that zimmer as they're walking along. Grabbing hold of the zimmer means less chance of falls, less chance of broken hips, increased probability of survival. They've also done at Westminster some absolutely great experiments by taking significant amounts of blood from people exposed to red light and they're finding a whole range of messages in the blood which we were very very suspicious that they were there but a whole range of messages in the blood that are consistent with the notion that your physiology is improving. So on both counts, it's not about Glenn doing things with vision with people, which is fun and all the rest of that, and my it's my toys. Other people are coming in with their toys, doing different things, and are producing data, which I'd like to believe I could have predicted, but we really need it out there. And the final actual point which is I think is terribly important which is the government agency in the UK for assessment of new drugs etc called nice have started to ask questions. So they've sent me a long letter asking me my opinions about various things. They must have sent it to other key workers, other key researchers. Don't know who they are yet. Um so government is saying okay hang on maybe there's something in this maybe we should be paying attention and one of the commercial companies which was having a bit of success for
which was having a bit of success for macular degeneration luma has just been bought out by alcon is a massive player in um opthromology a real I mean big international company So I think that the I I think that the product that was made by Luma was questionable as to whether it suited the patient but a big international company has said let's buy this out we think it's got legs. So in the last year since we've spoken quite a lot has actually happened and I think that you can encapsulate that in the phrase that it's got a lot more traction. people are not um I I get less stick along the lines of total and utter disbelief and I get more questions now. People ask me questions and they ask me questions about application. How do we apply it? They don't I don't get socially shunned in the way that I certainly did at some point. But you know, someone walks into the room and says, you know, we can slow the pace of aging. We can do do this, you know, just by changing the lights. But of course, it reeks of of magic crystals, doesn't it? So, you've got to work hard at the cutting edge to to say this is not about belief. This is about scientific evidence. And I I think, you know, I don't know how much longer I've got before I retire, but I'm it's very nice to know that I could walk away from this and it's going to run without me now. It doesn't need me. That is really good. I saw did you do a study with like an an 850 nanometer wall panel? Yeah, we did that. So what we did with that was the light through the human body. So I lined up my colleagues outside on a sunny day in actually ah yeah just over a year ago June last year and I didn't need to get them to
and I didn't need to get them to take their tops off but I did and I stuck on their back a radiometer and they were standing in sunlight pushed it hard into their back or onto their chest and I measured light coming through their body no one people what light goes yeah the light you can't See the long wavelength light goes through your body. The peak in that light peak the peak kind of frequency was around 800 850 nanometers. So I then had a wall panel made. actually wasn't a wall. It was a ceiling tile to a ceiling tile and we stuck a whole load of 850 nanometer LEDs on it and we got people to stand in a room without looking at it and we found we improved their vision. That I then started to get a bit jumpy and and the people we were doing this to, the subjects were all lighting engineers from a major um engineering company. Um, if I'm sure they won't mind the advert. It was Hi in London. And then I thought, hang on. Is this light? Where's this light going? I started measuring light around the room. And long wavelength light bounces everywhere. So then I thought, I have to differentiate between what they see and what their body experiences. So these lovely characters from Hi, I then started wrapping their head in aluminium foil so that I could guarantee that no light went in the eye. Um and only only light that hit their body surface was having this effect on vision. And yep, uh when we wrapped their head in aluminium foil, we got a significant effect. It wasn't as good as the effect without the aluminium foil, but the point was, and this kind of bounces back to blue light as well, the light does not have to hit your eyes,
light does not have to hit your eyes, right? So the aluminium foil clearly demonstrated that the effect on your vision was being mediated by longwavelength light hitting your body at a wavelength that is present in sunlight and that we know not much of it comes out the other side of your your body when I shine light and you because most of it is absorbed by the mitochondria in your body. But I can measure it coming out the other side as long as you keep really still and I've got an expensive radiometer to do it. So, uh, the physicist again, Bob Fosby said, "Well, of course it's going to go through long wavelength." I'm going, "Everyone's saying you can't. Doesn't work." Um, so yeah, so with sunlight, then I had to take that experiment into a laboratory into a darkened room to test vision. And yeah, the color vision of those people improved quite a lot. And in that that was a study where we we also put light through people's hands. You could see it with a an infrared camera, the light coming through and through their bodies. Um again, you could see it coming through if you got a sensitive infrared camera. It was I must say the reason I do the things I do is because I find them fun and I enjoy it. And that was a fun experiment. We all enjoyed it. We thought it was really fun finding out the sunlight goes through your body. Really fun. Yeah. Everyone saw the funny side of wrapping their head in aluminium foil. Yeah. No conspiracy theories, right? Okay. So is So what can we So many many people do not control the environment they work in. Um you kind of have some control at home, right? But we still have LEDs. Uh so is there anything that we can do right now? Um I mean
right now? Um I mean yeah I mean we could wrap our head from head to foot I guess in in clothes or but anyway yeah is there anything that we can do now? Well I I go back to the same point every time. Sunlight. Go out in sunlight when you've got your even if it's cloudy, right? there's there's loads of infrared light. It bounces round more because it gets bounced around by uh water in the atmosphere. Go outside. Secondly, if you are going to sit for absolutely, you know, enormous periods of time in front of LED lighting, well, I'm not going to recommend a commercial device, but there are some devices that are just simple LED lights that have got 850 or 700 nanometers in them. Supplement it or just get an incandescent light bulb. I'm sitting, I've got two lights in my desk. They're both incandescent light bulbs. And then people go, "Oh, I got to replace them, you know, every so months." Go and spend £ 10 on Amazon, buy a dimmer switch and get a 100 W incandescent light bulb and run it at quarter power. It'll last forever. It'll give you vast amounts of infrared light. Um, and it will counter affect the negative side that you get from your blue LEDs. It it, you know, it works. We've done it. Um, and so $ 9. 99 Amazon. I don't work for Amazon for a dimmer switch, standard bog standard dimmer switch. And on Amazon, you can still buy incandescent light bulbs. Don't buy incandescent like light bulbs. Buy incandescent light bulbs. Yeah.
Buy incandescent light bulbs. Yeah. Simple. Cool. Okay. But the LEDs so there aren't any kind of LEDs. Yeah. I was thinking about that whether there was any any LEDs we could get. Okay. Is there any way for a consumer like an ordinary person to check their environment? I mean would like a spectrometer on a mobile phone would that give you any data meaningful? The sad thing is and this applies to many of the people flogging stuff on the marketplace is they don't have the right spectrometers and the right radiometers. The spectrometers to measure the wavelength, the radiometers to measure the amount of energy. Um the unit cost of each of those for a decent one that's doing what it should do is around 5k. So people don't have it. Take it as red that if you grab hold of your lighting and you can keep your hand there for one or two seconds that is an LED. LEDs are universal in having that blue spike. Okay. So you you just the simplest way forward is take it as red. If you've got an incandescent light bulb and you turn it on, you put your hand on it and you go, "Ouch, "you've got an incandescent light and that is giving vast amounts of infrared and it balances out the negative effect of the blue spike in in LEDs that you know, you may have LEDs above you. I mean, when we go and we do experiments in environments, we do them where they're all LEDs. We just give people desk lights, simple small little desk lights, cheap ones, and an incandescent light bulb. At the moment, it's the cheapest and best way forward, right? And you're looking for this to be continuous background lighting. So, like sitting in front of a red light LED
sitting in front of a red light LED panel for 20 minutes would not have a big difference. Well, it would be better than nothing, but the incandescent light bulb, the old incandescent light is doing so much more than those LED panels that you can buy on Amazon. And and I'm I'm I I think this is going to cause a little bit of a wave because people are investing in all these red light devices. I've got loads of them that people send me asking me for opinion. Um and they cost a fortune. Um, but they are not doing the same as a broadspectctrum incandescent light bulb. No. And that generally they're pumping far too much energy into your body. God knows what's going to happen to you in 5 years time. I have no idea. Okay. We'll leave that there. Okay. So, just a thought that occurred to me. So, we we looked at you've looked at blue light 450 420 and red light. So, Have people looked at all the other wavelengths of light to see what they do? Or is it that nobody's looked or that it doesn't do anything? Um, I think that my first response for that is, you know, I've only got so many heartbeats left. Um, and and this could be an infinite series. Secondly though, when I look at when I look generally across the data sets, you can see that mitochondria respond to blue and you can see mitochondria respond to red. Now, it may well be the case that mitochondria respond to yellow and green, but it's not a big effect. I mean, we're talking about very, I think, relatively small issues. We pay scientifically if you take out eyes and you take away plants, we pay very very little attention to light and the body and and that's one of the reasons why we've got ourselves into this issue with LEDs. Um,
ourselves into this issue with LEDs. Um, so there's a big hole in our understanding, but I don't think at the moment it's worth driving down into the deep into the full spectral range to see what's going on. There may be something in there, but it would take an army of people to work it out. And it's not where the big lowhanging fruit is scientifically. You know, it's to be frank, it's tedium. you're not I don't think you're going to find much there. I could be wrong. Right. No, that that absolutely makes sense. And there's so much that we still need to understand about the the wavelengths that we are looking at or that you are looking at. It's not not like we need to. Okay. So, Dr. Jeffrey, so where can people go to follow your work? What? Well, everyone says, Glenn, you need a web page. You need And Glenn doesn't have one. Um Glenn doesn't have one because he's struggling to to get stuff done as it is. If you want to look for for the science, then you can always find me on PubMed, which is an open access site that shows all the publications that people do in biio medicine. And you just type in Glen Jeffrey. spell it right correctly. E R Y, not R E Y. Um, and maybe one day, one day I will get a website set up. But it's people like you that are actually doing us the big favors. So, we've run a number we've had a number of interviews like this and you spread the word for us. You know, I get people emailing me saying, "I heard this podcast. Was that you?"you know, and I'll always try and answer um you that you know, my job I I suppose is doing the science. I'm no good at advertising and certainly no good at
at advertising and certainly no good at advertising myself. Uh but you you people do that for me and that's absolutely great. So, you can type in Glenn Jeffrey UCL and podcast and you'll probably find a few of them you find a few of them coming out. Um, sadly, don't listen to more than two because I think I'm saying the same thing every time. Um, but but that that's your field. It's not really mine, but if anyone wants to contact me, I'll always do my best to respond. Excellent. Thank you. Yes. And and yeah, I I have read your papers, so they're definitely there and they're they're all open access, as I recall. I don't publish anything that isn't open access. Everybody should have access to the things that we do. Taxpayer fundamentally pays my salary. So the taxpayer should have access to what we do. Brilliant. Love it. Okay. Thank you so much. Uh total pleasure and thank you for doing it. Okay. You are welcome. [Music]
Transcript auto-generated by YouTube. Verbatim — duplicates intentionally preserved.
The body reads light as timing, not decoration. Morning light, dim evenings, and the balance between natural and artificial exposure help set circadian rhythm and cellular energy.
Mitochondria sit at the center of energy production. When daily light patterns drift away from natural cues, sleep, metabolism, and repair can feel less steady.
Aging is shaped by repeated signals. Getting outside early, lowering harsh evening light, and protecting sleep are simple practices with an outsized influence on how the body feels.
"The body changes when the signal is clear, repeated, and followed by recovery."
Get natural outdoor light early in the day when possible.
Reduce bright artificial light in the evening to support circadian rhythm.
Treat light hygiene as part of mitochondrial care, alongside movement and recovery.
The strongest idea running through this conversation is restraint. Longevity is not built by chasing every new lever. It is built by understanding which signals matter, applying them deliberately, and allowing the body enough calm to adapt.
