Using Light to Optimize Health | Huberman Lab Essentials

Welcome to Huberman Lab Essentials, Welcome to Huberman Lab Essentials, where we revisit past episodes for the where we revisit past episodes for the where we revisit past episodes for the most potent and actionable science-based most potent and actionable science-based most potent and actionable science-based tools for mental health, physical tools for mental health, physical tools for mental health, physical health, and performance. health, and performance. health, and performance. I'm Andrew Huberman and I'm a professor I'm Andrew Huberman and I'm a professor I'm Andrew Huberman and I'm a professor of neurobiology and opthalmology at of neurobiology and opthalmology at of neurobiology and opthalmology at Stanford School of Medicine. Today we Stanford School of Medicine. Today we Stanford School of Medicine. Today we are going to discuss light and the many are going to discuss light and the many are going to discuss light and the many powerful uses of light to optimize our powerful uses of light to optimize our powerful uses of light to optimize our health. One of the reasons why light has health. One of the reasons why light has health. One of the reasons why light has such powerful effects on so many such powerful effects on so many such powerful effects on so many different aspects of our biology is that different aspects of our biology is that different aspects of our biology is that it can be translated into electrical it can be translated into electrical it can be translated into electrical signals in our brain and body into signals in our brain and body into signals in our brain and body into hormone signals in our brain and body hormone signals in our brain and body hormone signals in our brain and body and indeed into what we call cascades of and indeed into what we call cascades of and indeed into what we call cascades of biological pathways. Meaning light can biological pathways. Meaning light can biological pathways. Meaning light can actually change the genes that the cells actually change the genes that the cells actually change the genes that the cells of your bodies express. And that is true of your bodies express. And that is true of your bodies express. And that is true throughout the lifespan. Light is throughout the lifespan. Light is throughout the lifespan. Light is electromagnetic energy. It can cause electromagnetic energy. It can cause electromagnetic energy. It can cause reactions in cells of your body. It can reactions in cells of your body. It can reactions in cells of your body. It can cause reactions in fruit, for instance, cause reactions in fruit, for instance, cause reactions in fruit, for instance, right? You see a piece of fruit and it's right? You see a piece of fruit and it's right? You see a piece of fruit and it's not ripe, but it gets a lot of sunlight not ripe, but it gets a lot of sunlight not ripe, but it gets a lot of sunlight and it ripens. That's because the and it ripens. That's because the and it ripens. That's because the electromagnetic energy of sunlight had electromagnetic energy of sunlight had electromagnetic energy of sunlight had an impact on that plant or that tree or an impact on that plant or that tree or an impact on that plant or that tree or even on the fruit directly. Now, the even on the fruit directly. Now, the even on the fruit directly. Now, the second thing that you need to understand second thing that you need to understand second thing that you need to understand about the physics of light is that light about the physics of light is that light about the physics of light is that light has many different wavelengths. And the has many different wavelengths. And the has many different wavelengths. And the simplest way to conceptualize this is to simplest way to conceptualize this is to simplest way to conceptualize this is to imagine that cover of that Pink Floyd imagine that cover of that Pink Floyd imagine that cover of that Pink Floyd album where there's a prism. You have a album where there's a prism. You have a album where there's a prism. You have a white beam of light going into that white beam of light going into that white beam of light going into that prism and then the prism splits that prism and then the prism splits that prism and then the prism splits that beam of light into what looks like a beam of light into what looks like a beam of light into what looks like a rainbow. So you got your reds, your rainbow. So you got your reds, your rainbow. So you got your reds, your orange, your greens, your blues, your orange, your greens, your blues, your orange, your greens, your blues, your purples, etc. Now the third bullet point purples, etc. Now the third bullet point purples, etc. Now the third bullet point to understand about the physics of light to understand about the physics of light to understand about the physics of light is that different wavelengths of light is that different wavelengths of light is that different wavelengths of light because of the way that their wave because of the way that their wave because of the way that their wave travels can penetrate tissues to travels can penetrate tissues to travels can penetrate tissues to different depths. Every biological different depths. Every biological different depths. Every biological function of light has to do with the function of light has to do with the function of light has to do with the absorbance or the reflectance of light absorbance or the reflectance of light absorbance or the reflectance of light or light passing through that particular or light passing through that particular or light passing through that particular thing, meaning that particular cell or thing, meaning that particular cell or thing, meaning that particular cell or compartment within a cell. I'd like to compartment within a cell. I'd like to compartment within a cell. I'd like to make it clear how this works by using make it clear how this works by using make it clear how this works by using the three primary examples of how you the three primary examples of how you the three primary examples of how you take light in your environment and take light in your environment and take light in your environment and convert it into biological events. We convert it into biological events. We convert it into biological events. We have photo receptors in the back of our have photo receptors in the back of our have photo receptors in the back of our eyes. These photo receptors come in two eyes. These photo receptors come in two eyes. These photo receptors come in two major types. The so-called rods and the major types. The so-called rods and the major types. The so-called rods and the cones. The rods are very elongated. They cones. The rods are very elongated. They cones. The rods are very elongated. They look like rods. And the cones look like look like rods. And the cones look like look like rods. And the cones look like little triangles. The other place of little triangles. The other place of little triangles. The other place of course where light can impact our body course where light can impact our body course where light can impact our body is on our surface on our skin. In the is on our surface on our skin. In the is on our surface on our skin. In the top layer of skin which is called the top layer of skin which is called the top layer of skin which is called the epidermis. We have caratinosytes and we epidermis. We have caratinosytes and we epidermis. We have caratinosytes and we have melanocytes. With light exposure, have melanocytes. With light exposure, have melanocytes. With light exposure, those melanocytes will turn on genetic those melanocytes will turn on genetic those melanocytes will turn on genetic programs and other biological programs programs and other biological programs programs and other biological programs that lead to enhanced pigmentation of that lead to enhanced pigmentation of that lead to enhanced pigmentation of the skin, which we call tanning. And the the skin, which we call tanning. And the the skin, which we call tanning. And the third example I'd like to provide is third example I'd like to provide is third example I'd like to provide is that of every cell of your body. And that of every cell of your body. And that of every cell of your body. And what I mean by that is that every cell what I mean by that is that every cell what I mean by that is that every cell of your body, meaning a cell that is of your body, meaning a cell that is of your body, meaning a cell that is part of your bone tissue or your bone part of your bone tissue or your bone part of your bone tissue or your bone marrow or heart tissue or liver or marrow or heart tissue or liver or marrow or heart tissue or liver or spleen, if light can access those cells, spleen, if light can access those cells, spleen, if light can access those cells, it will change the way that those cells it will change the way that those cells it will change the way that those cells function for better or for worse. For function for better or for worse. For function for better or for worse. For many organs within our body that reside many organs within our body that reside many organs within our body that reside deep to our skin, light never arrives at deep to our skin, light never arrives at deep to our skin, light never arrives at those cells. A really good example of those cells. A really good example of those cells. A really good example of this is the spleen. Light will never this is the spleen. Light will never this is the spleen. Light will never land directly on your spleen, but the land directly on your spleen, but the land directly on your spleen, but the spleen still responds to light spleen still responds to light spleen still responds to light information through indirect pathways. information through indirect pathways. information through indirect pathways. Light arriving on the eyes Light arriving on the eyes Light arriving on the eyes is absorbed by a particular cell type is absorbed by a particular cell type is absorbed by a particular cell type called the intrinsically photosensitive called the intrinsically photosensitive called the intrinsically photosensitive ganglen cell. It's just a name. You ganglen cell. It's just a name. You ganglen cell. It's just a name. You don't need to know the name, but if you don't need to know the name, but if you don't need to know the name, but if you want, it's the so-called intrinsically want, it's the so-called intrinsically want, it's the so-called intrinsically photosensitive ganglen cell, also called photosensitive ganglen cell, also called photosensitive ganglen cell, also called the melanopsin cell, because it contains the melanopsin cell, because it contains the melanopsin cell, because it contains an opsin, a photo pigment that absorbs an opsin, a photo pigment that absorbs an opsin, a photo pigment that absorbs shortwavelength light that arrives shortwavelength light that arrives shortwavelength light that arrives through sunlight. Those cells through sunlight. Those cells through sunlight. Those cells communicate to particular stations in communicate to particular stations in communicate to particular stations in the brain that in turn can connect to the brain that in turn can connect to the brain that in turn can connect to your so-called pineal gland, which is your so-called pineal gland, which is your so-called pineal gland, which is this little P-sized gland in the middle this little P-sized gland in the middle this little P-sized gland in the middle of your brain that releases a hormone of your brain that releases a hormone of your brain that releases a hormone called melatonin. And the only thing you called melatonin. And the only thing you called melatonin. And the only thing you need to know is that light activates need to know is that light activates need to know is that light activates these particular cells, the these particular cells, the these particular cells, the intrinsically photosensitive melanopsin intrinsically photosensitive melanopsin intrinsically photosensitive melanopsin cells, which in turn shuts down the cells, which in turn shuts down the cells, which in turn shuts down the production of melatonin from the pineal production of melatonin from the pineal production of melatonin from the pineal gland. So melatonin is a transducer. gland. So melatonin is a transducer. gland. So melatonin is a transducer. It's a communicator of how much light on It's a communicator of how much light on It's a communicator of how much light on average is in your physical environment. average is in your physical environment. average is in your physical environment. What this means is for people living in What this means is for people living in What this means is for people living in the northern hemisphere, you're getting the northern hemisphere, you're getting the northern hemisphere, you're getting more melatonin release in the winter more melatonin release in the winter more melatonin release in the winter months than you are in the summer months than you are in the summer months than you are in the summer months. So you have a calendar system months. So you have a calendar system months. So you have a calendar system that is based in a hormone and that that is based in a hormone and that that is based in a hormone and that hormone is using light in order to hormone is using light in order to hormone is using light in order to determine where you are in that journey determine where you are in that journey determine where you are in that journey around the sun. Now this is beautiful. around the sun. Now this is beautiful. around the sun. Now this is beautiful. At least to me, it's beautiful because At least to me, it's beautiful because At least to me, it's beautiful because what it means is that the environment what it means is that the environment what it means is that the environment around us is converted into a signal around us is converted into a signal around us is converted into a signal that changes the environment within us. that changes the environment within us. that changes the environment within us. That signal is melatonin. And melatonin That signal is melatonin. And melatonin That signal is melatonin. And melatonin is well known for its role in making us is well known for its role in making us is well known for its role in making us sleepy each night and allowing us to sleepy each night and allowing us to sleepy each night and allowing us to fall asleep. Many of you have probably fall asleep. Many of you have probably fall asleep. Many of you have probably heard before, I am not a big fan of heard before, I am not a big fan of heard before, I am not a big fan of melatonin supplementation for a number melatonin supplementation for a number melatonin supplementation for a number of reasons, but just as a quick aside, of reasons, but just as a quick aside, of reasons, but just as a quick aside, the levels of melatonin that are in most the levels of melatonin that are in most the levels of melatonin that are in most supplements are far too high to really supplements are far too high to really supplements are far too high to really be considered physiological. They are be considered physiological. They are be considered physiological. They are indeed super physiological in most indeed super physiological in most indeed super physiological in most cases. And melatonin can have a number cases. And melatonin can have a number cases. And melatonin can have a number of different effects, not just related of different effects, not just related of different effects, not just related to sleep. But that's supplemented to sleep. But that's supplemented to sleep. But that's supplemented melatonin. Here I'm talking about our melatonin. Here I'm talking about our melatonin. Here I'm talking about our natural production and release of natural production and release of natural production and release of melatonin according to where we are in melatonin according to where we are in melatonin according to where we are in the 365day calendar year. Indogenous the 365day calendar year. Indogenous the 365day calendar year. Indogenous melatonin, meaning the melatonin that we melatonin, meaning the melatonin that we melatonin, meaning the melatonin that we make within our bodies naturally, not make within our bodies naturally, not make within our bodies naturally, not melatonin that's supplemented, has two melatonin that's supplemented, has two melatonin that's supplemented, has two general categories of of effects. The general categories of of effects. The general categories of of effects. The first set of effects are so-called first set of effects are so-called first set of effects are so-called regulatory effects and the others are regulatory effects and the others are regulatory effects and the others are protective effects. The regulatory protective effects. The regulatory protective effects. The regulatory effects are for instance that melatonin effects are for instance that melatonin effects are for instance that melatonin can positively impact bone mass. can positively impact bone mass. can positively impact bone mass. Melatonin is also involved in maturation Melatonin is also involved in maturation Melatonin is also involved in maturation of the gonads during puberty, the of the gonads during puberty, the of the gonads during puberty, the ovaries and the testes. Although there ovaries and the testes. Although there ovaries and the testes. Although there the effects of melatonin tend to be the effects of melatonin tend to be the effects of melatonin tend to be suppressive on maturation of the ovaries suppressive on maturation of the ovaries suppressive on maturation of the ovaries and testes. meaning high levels of and testes. meaning high levels of and testes. meaning high levels of melatonin tend to reduce testicle volume melatonin tend to reduce testicle volume melatonin tend to reduce testicle volume and reduce certain functions within the and reduce certain functions within the and reduce certain functions within the testes including sperm production and testes including sperm production and testes including sperm production and testosterone production and within the testosterone production and within the testosterone production and within the ovaries melatonin can suppress the ovaries melatonin can suppress the ovaries melatonin can suppress the maturation of eggs etc. Now, I don't maturation of eggs etc. Now, I don't maturation of eggs etc. Now, I don't want anyone to get scared if you've been want anyone to get scared if you've been want anyone to get scared if you've been taking melatonin. Most of the effects of taking melatonin. Most of the effects of taking melatonin. Most of the effects of melatonin on those functions are melatonin on those functions are melatonin on those functions are reversible. But I should point out that reversible. But I should point out that reversible. But I should point out that one of the reasons why children don't go one of the reasons why children don't go one of the reasons why children don't go into puberty until a particular age is into puberty until a particular age is into puberty until a particular age is that young children tend to have that young children tend to have that young children tend to have chronically high indogenous melatonin, chronically high indogenous melatonin, chronically high indogenous melatonin, and that is healthy to keep them out of and that is healthy to keep them out of and that is healthy to keep them out of puberty until it's the right time for puberty until it's the right time for puberty until it's the right time for puberty to happen. I should also mention puberty to happen. I should also mention puberty to happen. I should also mention that melatonin is a powerful modulator that melatonin is a powerful modulator that melatonin is a powerful modulator of placental development. So for anyone of placental development. So for anyone of placental development. So for anyone that's pregnant, if you're considering that's pregnant, if you're considering that's pregnant, if you're considering melatonin supplementation, please, melatonin supplementation, please, melatonin supplementation, please, please, please talk to your OB/GYN, talk please, please talk to your OB/GYN, talk please, please talk to your OB/GYN, talk to your other doctor as well, you want to your other doctor as well, you want to your other doctor as well, you want to be very, very cautious because of the to be very, very cautious because of the to be very, very cautious because of the powerful effects that melatonin can have powerful effects that melatonin can have powerful effects that melatonin can have on the developing fetus and placenta. So on the developing fetus and placenta. So on the developing fetus and placenta. So when we think about light impacting our when we think about light impacting our when we think about light impacting our biology, the reason I bring up melatonin biology, the reason I bring up melatonin biology, the reason I bring up melatonin as the primary example of that is a as the primary example of that is a as the primary example of that is a because melatonin impacts so many because melatonin impacts so many because melatonin impacts so many important functions within our brain and important functions within our brain and important functions within our brain and body, but also because hormones in body, but also because hormones in body, but also because hormones in general, not always, but in general are general, not always, but in general are general, not always, but in general are responsible for these slow modulatory responsible for these slow modulatory responsible for these slow modulatory effects on our biology. And so I'm using effects on our biology. And so I'm using effects on our biology. And so I'm using this as an example of how light this as an example of how light this as an example of how light throughout the year is changing the way throughout the year is changing the way throughout the year is changing the way that your the different cells and that your the different cells and that your the different cells and tissues and organs of your body are tissues and organs of your body are tissues and organs of your body are working and that melatonin is the working and that melatonin is the working and that melatonin is the transducer of that signal. So in order transducer of that signal. So in order transducer of that signal. So in order to get light information to the pineal to get light information to the pineal to get light information to the pineal and thereby get the proper levels of and thereby get the proper levels of and thereby get the proper levels of melatonin melatonin melatonin according to the time of year, we should according to the time of year, we should according to the time of year, we should all try and get outside as much as all try and get outside as much as all try and get outside as much as possible during the long days of summer possible during the long days of summer possible during the long days of summer and spring. And in the winter months, it and spring. And in the winter months, it and spring. And in the winter months, it makes sense to spend more time indoors. makes sense to spend more time indoors. makes sense to spend more time indoors. For those of you that suffer from For those of you that suffer from For those of you that suffer from seasonal effective disorder, which is a seasonal effective disorder, which is a seasonal effective disorder, which is a seasonal depression, or feel low during seasonal depression, or feel low during seasonal depression, or feel low during the fall and winter months, there are the fall and winter months, there are the fall and winter months, there are ways to offset this. We did an entire ways to offset this. We did an entire ways to offset this. We did an entire episode on mood and circadian rhythms episode on mood and circadian rhythms episode on mood and circadian rhythms where we describe this. So, it does make where we describe this. So, it does make where we describe this. So, it does make sense for some people to get more bright sense for some people to get more bright sense for some people to get more bright light in their eyes early in the morning light in their eyes early in the morning light in their eyes early in the morning and throughout the day during the winter and throughout the day during the winter and throughout the day during the winter months as well. But nonetheless, changes months as well. But nonetheless, changes months as well. But nonetheless, changes in melatonin, meaning changes in the in melatonin, meaning changes in the in melatonin, meaning changes in the duration of melatonin release across the duration of melatonin release across the duration of melatonin release across the year are normal and healthy. So provided year are normal and healthy. So provided year are normal and healthy. So provided that you're not suffering from that you're not suffering from that you're not suffering from depression, it's going to be healthy to depression, it's going to be healthy to depression, it's going to be healthy to somewhat modulate your amount of indoor somewhat modulate your amount of indoor somewhat modulate your amount of indoor and outdoor time across the year. The and outdoor time across the year. The and outdoor time across the year. The other thing to understand is the very other thing to understand is the very other thing to understand is the very firmly established fact, which is that firmly established fact, which is that firmly established fact, which is that light powerfully inhibits melatonin. light powerfully inhibits melatonin. light powerfully inhibits melatonin. If you wake up in the middle of the If you wake up in the middle of the If you wake up in the middle of the night and you go into the bathroom and night and you go into the bathroom and night and you go into the bathroom and you flip on the lights and those are you flip on the lights and those are you flip on the lights and those are very bright overhead fluorescent lights, very bright overhead fluorescent lights, very bright overhead fluorescent lights, your melatonin levels, which would your melatonin levels, which would your melatonin levels, which would ordinarily be quite high in the middle ordinarily be quite high in the middle ordinarily be quite high in the middle of the night because you've been eyes of the night because you've been eyes of the night because you've been eyes closed in the dark presumably, will closed in the dark presumably, will closed in the dark presumably, will immediately plummet to near zero or immediately plummet to near zero or immediately plummet to near zero or zero. If you do that every once in a zero. If you do that every once in a zero. If you do that every once in a while, it's not going to be a problem. while, it's not going to be a problem. while, it's not going to be a problem. But if you're doing that night after But if you're doing that night after But if you're doing that night after night, you are really disrupting this night, you are really disrupting this night, you are really disrupting this fundamental signal that occurs every fundamental signal that occurs every fundamental signal that occurs every night regardless of winter, spring, night regardless of winter, spring, night regardless of winter, spring, summer, etc. And that is communicating summer, etc. And that is communicating summer, etc. And that is communicating information about where your brain and information about where your brain and information about where your brain and body should be in time. In animals such body should be in time. In animals such body should be in time. In animals such as mice, but also in humans, exposure to as mice, but also in humans, exposure to as mice, but also in humans, exposure to light, in particular, UV blue light, so light, in particular, UV blue light, so light, in particular, UV blue light, so short wavelengths of light, can trigger short wavelengths of light, can trigger short wavelengths of light, can trigger increases in testosterone and estrogen increases in testosterone and estrogen increases in testosterone and estrogen and the desire to mate. But it is not and the desire to mate. But it is not and the desire to mate. But it is not the exposure of light to the eyes. It the exposure of light to the eyes. It the exposure of light to the eyes. It turns out that it is the exposure of turns out that it is the exposure of turns out that it is the exposure of your skin to particular wavelengths of your skin to particular wavelengths of your skin to particular wavelengths of light that is triggering increases in light that is triggering increases in light that is triggering increases in the hormones testosterone and estrogen. the hormones testosterone and estrogen. the hormones testosterone and estrogen. I think the results are best understood I think the results are best understood I think the results are best understood by simply going through the primary by simply going through the primary by simply going through the primary data, meaning the actual research on data, meaning the actual research on data, meaning the actual research on this topic. And to do so, I'm going to this topic. And to do so, I'm going to this topic. And to do so, I'm going to review a paper that was published in the review a paper that was published in the review a paper that was published in the journal cell reports, cell press journal cell reports, cell press journal cell reports, cell press journal, excellent journal, entitled journal, excellent journal, entitled journal, excellent journal, entitled skin exposure to UVB light induces a skin exposure to UVB light induces a skin exposure to UVB light induces a skin brain gonad axis and sexual skin brain gonad axis and sexual skin brain gonad axis and sexual behavior. And I want to emphasize that behavior. And I want to emphasize that behavior. And I want to emphasize that this was a paper that focused on mice in this was a paper that focused on mice in this was a paper that focused on mice in order to address specific mechanisms order to address specific mechanisms order to address specific mechanisms because in mice you can so-called knock because in mice you can so-called knock because in mice you can so-called knock out particular genes. You can remove out particular genes. You can remove out particular genes. You can remove particular genes to understand particular genes to understand particular genes to understand mechanism. You just can't do that in mechanism. You just can't do that in mechanism. You just can't do that in humans in any kind of controlled way at humans in any kind of controlled way at humans in any kind of controlled way at least not at this point in time. And least not at this point in time. And least not at this point in time. And this study also explores humans and this study also explores humans and this study also explores humans and looked at human subjects both men and looked at human subjects both men and looked at human subjects both men and women. The basic finding of this study women. The basic finding of this study women. The basic finding of this study was that when mice or humans were was that when mice or humans were was that when mice or humans were exposed to UVB, meaning ultraviolet blue exposed to UVB, meaning ultraviolet blue exposed to UVB, meaning ultraviolet blue light, so short wavelength light of the light, so short wavelength light of the light, so short wavelength light of the sort that comes through in sunshine, but sort that comes through in sunshine, but sort that comes through in sunshine, but is also available through various is also available through various is also available through various artificial sources. artificial sources. artificial sources. If they received enough exposure of that If they received enough exposure of that If they received enough exposure of that light to their skin, light to their skin, light to their skin, there were increases in testosterone there were increases in testosterone there were increases in testosterone that were observed within a very brief that were observed within a very brief that were observed within a very brief period of time. also increases in the period of time. also increases in the period of time. also increases in the hormone estrogen. And I should point out hormone estrogen. And I should point out hormone estrogen. And I should point out that the proper ratios of estrogen and that the proper ratios of estrogen and that the proper ratios of estrogen and testosterone were maintained in both testosterone were maintained in both testosterone were maintained in both males and females, at least as far as males and females, at least as far as males and females, at least as far as these data indicate. And mice tended to these data indicate. And mice tended to these data indicate. And mice tended to seek out mating more and mate more. seek out mating more and mate more. seek out mating more and mate more. There were also increases in gonatal There were also increases in gonatal There were also increases in gonatal weight, literally increases in testes weight, literally increases in testes weight, literally increases in testes size and in ovarian size when mice were size and in ovarian size when mice were size and in ovarian size when mice were exposed to this UVB light past a certain exposed to this UVB light past a certain exposed to this UVB light past a certain threshold. They did not look at testes threshold. They did not look at testes threshold. They did not look at testes size or ovarian size in the human size or ovarian size in the human size or ovarian size in the human subjects. However, because they are subjects. However, because they are subjects. However, because they are humans, they did address the psychology humans, they did address the psychology humans, they did address the psychology of these human beings and address of these human beings and address of these human beings and address whether or not they had increases in, whether or not they had increases in, whether or not they had increases in, for instance, aggressiveness or in for instance, aggressiveness or in for instance, aggressiveness or in passionate feelings and how their passionate feelings and how their passionate feelings and how their perception of other people changed when perception of other people changed when perception of other people changed when they were getting a lot of UVB they were getting a lot of UVB they were getting a lot of UVB light exposure to the skin. UVB light light exposure to the skin. UVB light light exposure to the skin. UVB light exposure also changed various aspects of exposure also changed various aspects of exposure also changed various aspects of female biology related to fertility in female biology related to fertility in female biology related to fertility in particular follicle growth. Follicle and particular follicle growth. Follicle and particular follicle growth. Follicle and egg maturation are well-known indices of egg maturation are well-known indices of egg maturation are well-known indices of fertility and of course correlate with fertility and of course correlate with fertility and of course correlate with the menstrual cycle in adult humans and the menstrual cycle in adult humans and the menstrual cycle in adult humans and is related overall to the propensity to is related overall to the propensity to is related overall to the propensity to become pregnant. UVB light exposure become pregnant. UVB light exposure become pregnant. UVB light exposure enhanced maturation of the follicle enhanced maturation of the follicle enhanced maturation of the follicle which just meant that more healthy eggs which just meant that more healthy eggs which just meant that more healthy eggs were being produced. So in terms of were being produced. So in terms of were being produced. So in terms of thinking about a protocol to increase thinking about a protocol to increase thinking about a protocol to increase testosterone and estrogen, mood and testosterone and estrogen, mood and testosterone and estrogen, mood and feelings of passion, the idea is that feelings of passion, the idea is that feelings of passion, the idea is that you would want to get this two to three you would want to get this two to three you would want to get this two to three exposures per week minimum of 20 to 30 exposures per week minimum of 20 to 30 exposures per week minimum of 20 to 30 minutes of sunlight exposure onto as minutes of sunlight exposure onto as minutes of sunlight exposure onto as much of your body as you can reasonably much of your body as you can reasonably much of your body as you can reasonably expose it to. Another set of very expose it to. Another set of very expose it to. Another set of very impressive effects of UVB light, whether impressive effects of UVB light, whether impressive effects of UVB light, whether or not it comes from sunlight or from an or not it comes from sunlight or from an or not it comes from sunlight or from an artificial source, is the effect of UVB artificial source, is the effect of UVB artificial source, is the effect of UVB light on our tolerance for pain. It light on our tolerance for pain. It light on our tolerance for pain. It turns out that our tolerance for pain turns out that our tolerance for pain turns out that our tolerance for pain varies across the year and that our pain varies across the year and that our pain varies across the year and that our pain tolerance is increased in longer day tolerance is increased in longer day tolerance is increased in longer day conditions. This is occurring via UVB conditions. This is occurring via UVB conditions. This is occurring via UVB exposure to the skin and UVB exposure to exposure to the skin and UVB exposure to exposure to the skin and UVB exposure to the eyes. I want to just describe two the eyes. I want to just describe two the eyes. I want to just describe two studies that really capture the essence studies that really capture the essence studies that really capture the essence of these results. The first study is of these results. The first study is of these results. The first study is entitled skin exposure to ultraviolet B entitled skin exposure to ultraviolet B entitled skin exposure to ultraviolet B rapidly activate systemic neuroendocrine rapidly activate systemic neuroendocrine rapidly activate systemic neuroendocrine and immunosuppressive responses. and immunosuppressive responses. and immunosuppressive responses. Basically what they observed is that Basically what they observed is that Basically what they observed is that even one exposure to UVB light change even one exposure to UVB light change even one exposure to UVB light change the output of particular hormones and the output of particular hormones and the output of particular hormones and neurochemicals in the body such as neurochemicals in the body such as neurochemicals in the body such as corticotropen hormone and betaendorphins corticotropen hormone and betaendorphins corticotropen hormone and betaendorphins which are these endogenous opioids in which are these endogenous opioids in which are these endogenous opioids in order to counter pain and act as a order to counter pain and act as a order to counter pain and act as a somewhat of a psychological soother somewhat of a psychological soother somewhat of a psychological soother also. What they found was that exposure also. What they found was that exposure also. What they found was that exposure to UVB light increased the release of to UVB light increased the release of to UVB light increased the release of these beta endorphins. Now a second these beta endorphins. Now a second these beta endorphins. Now a second study published in the journal Neuron study published in the journal Neuron study published in the journal Neuron cell press journal excellent journal is cell press journal excellent journal is cell press journal excellent journal is entitled a visual circuit related to the entitled a visual circuit related to the entitled a visual circuit related to the perryqueductal gray area for the perryqueductal gray area for the perryqueductal gray area for the anti-nosceptive effects of bright light anti-nosceptive effects of bright light anti-nosceptive effects of bright light treatment. I'll translate a little bit treatment. I'll translate a little bit treatment. I'll translate a little bit of that for you. The perryqueductal gray of that for you. The perryqueductal gray of that for you. The perryqueductal gray is a region of the midbrain that is a region of the midbrain that is a region of the midbrain that contains a lot of neurons that can contains a lot of neurons that can contains a lot of neurons that can release indogenous opioids. things like release indogenous opioids. things like release indogenous opioids. things like beta eneopioid. These are all names of chemicals that These are all names of chemicals that your body can manufacture that act as your body can manufacture that act as your body can manufacture that act as endogenous painkillers and increase your endogenous painkillers and increase your endogenous painkillers and increase your tolerance for pain. They actually make tolerance for pain. They actually make tolerance for pain. They actually make you feel less pain overall by shutting you feel less pain overall by shutting you feel less pain overall by shutting down some of the neurons that perceive down some of the neurons that perceive down some of the neurons that perceive pain. They're not going to block the pain. They're not going to block the pain. They're not going to block the pain response so that you burn yourself pain response so that you burn yourself pain response so that you burn yourself unnecessarily or harm yourself unnecessarily or harm yourself unnecessarily or harm yourself unnecessarily, but they act as a bit of unnecessarily, but they act as a bit of unnecessarily, but they act as a bit of a painkiller from the inside. The key a painkiller from the inside. The key a painkiller from the inside. The key finding of this study is that it is finding of this study is that it is finding of this study is that it is light landing on the eyes is captured by light landing on the eyes is captured by light landing on the eyes is captured by these melanopsin cells. They absorb that these melanopsin cells. They absorb that these melanopsin cells. They absorb that light, translate that light into light, translate that light into light, translate that light into electrical signals that are handed off electrical signals that are handed off electrical signals that are handed off to areas of the brain to evoke the to areas of the brain to evoke the to areas of the brain to evoke the release of these indogenous opioids that release of these indogenous opioids that release of these indogenous opioids that soothe you and lead to less perception soothe you and lead to less perception soothe you and lead to less perception of pain. So for those of you that are of pain. So for those of you that are of pain. So for those of you that are thinking tools and protocols, try to get thinking tools and protocols, try to get thinking tools and protocols, try to get some UVB exposure, ideally from some UVB exposure, ideally from some UVB exposure, ideally from sunlight. I think the 20 to 30 minute sunlight. I think the 20 to 30 minute sunlight. I think the 20 to 30 minute protocol two or three times per week is protocol two or three times per week is protocol two or three times per week is an excellent one. Even on a cloud an excellent one. Even on a cloud an excellent one. Even on a cloud covered day, you are going to get far covered day, you are going to get far covered day, you are going to get far more light energy, photons through cloud more light energy, photons through cloud more light energy, photons through cloud cover than you are going to get from an cover than you are going to get from an cover than you are going to get from an indoor light source, an artificial light indoor light source, an artificial light indoor light source, an artificial light source. If you see some sunlight source. If you see some sunlight source. If you see some sunlight throughout the day, you would do throughout the day, you would do throughout the day, you would do yourself a great favor to try and chase yourself a great favor to try and chase yourself a great favor to try and chase some of that sunlight and get into that some of that sunlight and get into that some of that sunlight and get into that sunlight. Never ever look at any light, sunlight. Never ever look at any light, sunlight. Never ever look at any light, artificial sunlight or otherwise, that's artificial sunlight or otherwise, that's artificial sunlight or otherwise, that's so bright that it's painful to look at. so bright that it's painful to look at. so bright that it's painful to look at. It's fine to get that light arriving on It's fine to get that light arriving on It's fine to get that light arriving on your eyes indirectly. It's fine to wear your eyes indirectly. It's fine to wear your eyes indirectly. It's fine to wear eyeglasses or contact lenses. In fact, eyeglasses or contact lenses. In fact, eyeglasses or contact lenses. In fact, if you think about the biology of the if you think about the biology of the if you think about the biology of the eye and the way that those lenses work, eye and the way that those lenses work, eye and the way that those lenses work, they will just serve to focus that light they will just serve to focus that light they will just serve to focus that light onto the very cells that you want those onto the very cells that you want those onto the very cells that you want those light beams to be delivered to. Whereas light beams to be delivered to. Whereas light beams to be delivered to. Whereas sunglasses that are highly reflective or sunglasses that are highly reflective or sunglasses that are highly reflective or trying to get your sunlight exposure trying to get your sunlight exposure trying to get your sunlight exposure through a windshield of a car or through through a windshield of a car or through through a windshield of a car or through a window simply won't work. Most windows a window simply won't work. Most windows a window simply won't work. Most windows are designed to filter out the UVB are designed to filter out the UVB are designed to filter out the UVB light. And if you're somebody who's light. And if you're somebody who's light. And if you're somebody who's really keen on blue blockers and you're really keen on blue blockers and you're really keen on blue blockers and you're wearing your blue blockers all day, wearing your blue blockers all day, wearing your blue blockers all day, well, don't wear them outside. And in well, don't wear them outside. And in well, don't wear them outside. And in fact, you're probably doing yourself a fact, you're probably doing yourself a fact, you're probably doing yourself a disservice by wearing them in the disservice by wearing them in the disservice by wearing them in the morning and in the daytime. There morning and in the daytime. There morning and in the daytime. There certainly is a place for blue blockers certainly is a place for blue blockers certainly is a place for blue blockers in the evening and nighttime if you're in the evening and nighttime if you're in the evening and nighttime if you're having issues with falling and staying having issues with falling and staying having issues with falling and staying asleep. But if you think about it, blue asleep. But if you think about it, blue asleep. But if you think about it, blue blockers, what they're really doing is blockers, what they're really doing is blockers, what they're really doing is blocking those short wavelength UVB blocking those short wavelength UVB blocking those short wavelength UVB wavelengths of light that you so wavelengths of light that you so wavelengths of light that you so desperately need to arrive at your desperately need to arrive at your desperately need to arrive at your retina and of course also onto your skin retina and of course also onto your skin retina and of course also onto your skin in order to get these powerful in order to get these powerful in order to get these powerful biological effects on hormones and on biological effects on hormones and on biological effects on hormones and on pain reduction. These data also might pain reduction. These data also might pain reduction. These data also might make you think a little bit about make you think a little bit about make you think a little bit about whether or not you should wear short whether or not you should wear short whether or not you should wear short sleeves or long sleeves, whether or not sleeves or long sleeves, whether or not sleeves or long sleeves, whether or not you want to wear shorts or a skirt or you want to wear shorts or a skirt or you want to wear shorts or a skirt or pants. But you might take into pants. But you might take into pants. But you might take into consideration that it is the total consideration that it is the total consideration that it is the total amount of skin exposure that is going to amount of skin exposure that is going to amount of skin exposure that is going to allow you to capture more or fewer allow you to capture more or fewer allow you to capture more or fewer photons depending on, for instance, if photons depending on, for instance, if photons depending on, for instance, if you're completely cloaked in clothing you're completely cloaked in clothing you're completely cloaked in clothing and you're just, you know, exposed in and you're just, you know, exposed in and you're just, you know, exposed in the hands, uh, neck and face such as I the hands, uh, neck and face such as I the hands, uh, neck and face such as I am now, or whether or not you're outside am now, or whether or not you're outside am now, or whether or not you're outside in shorts and a t-shirt, you're going to in shorts and a t-shirt, you're going to in shorts and a t-shirt, you're going to get very, very different patterns of get very, very different patterns of get very, very different patterns of biological signaling activation in those biological signaling activation in those biological signaling activation in those two circumstances. Many of you, I'm two circumstances. Many of you, I'm two circumstances. Many of you, I'm guessing, are wondering whether or not guessing, are wondering whether or not guessing, are wondering whether or not you should seek out UVB exposure you should seek out UVB exposure you should seek out UVB exposure throughout the entire year or only in throughout the entire year or only in throughout the entire year or only in the summer months. And that's sort of the summer months. And that's sort of the summer months. And that's sort of going to depend on whether or not you going to depend on whether or not you going to depend on whether or not you experience experience experience depression in the winter months, depression in the winter months, depression in the winter months, so-called seasonal effective disorder. so-called seasonal effective disorder. so-called seasonal effective disorder. Some people have mild, some people have Some people have mild, some people have Some people have mild, some people have severe forms of seasonal effective severe forms of seasonal effective severe forms of seasonal effective disorder. Some people love the fall and disorder. Some people love the fall and disorder. Some people love the fall and winter and the shorter days. Really, it winter and the shorter days. Really, it winter and the shorter days. Really, it has to be considered on a case- by case has to be considered on a case- by case has to be considered on a case- by case basis. I personally believe, and this basis. I personally believe, and this basis. I personally believe, and this was reinforced by the director of the was reinforced by the director of the was reinforced by the director of the chronobiology unit at the National chronobiology unit at the National chronobiology unit at the National Institutes of Mental Health, Samaritar, Institutes of Mental Health, Samaritar, Institutes of Mental Health, Samaritar, that we would all do well to get more that we would all do well to get more that we would all do well to get more UVB exposure from sunlight throughout UVB exposure from sunlight throughout UVB exposure from sunlight throughout the entire year, provided we aren't the entire year, provided we aren't the entire year, provided we aren't burning our skin or damaging our eyes in burning our skin or damaging our eyes in burning our skin or damaging our eyes in some way. In addition to that, during some way. In addition to that, during some way. In addition to that, during the winter months, if you do experience the winter months, if you do experience the winter months, if you do experience some drop in energy or increase in some drop in energy or increase in some drop in energy or increase in depression or psychological lows, it can depression or psychological lows, it can depression or psychological lows, it can be very beneficial to access a sad lamp be very beneficial to access a sad lamp be very beneficial to access a sad lamp or if you don't want to buy a sad lamp or if you don't want to buy a sad lamp or if you don't want to buy a sad lamp because often times they can be very because often times they can be very because often times they can be very expensive. You might do well to simply expensive. You might do well to simply expensive. You might do well to simply get a LED lighting panel. Very get a LED lighting panel. Very get a LED lighting panel. Very inexpensive compared to the typical SAD inexpensive compared to the typical SAD inexpensive compared to the typical SAD lamp. I actually have one and I position lamp. I actually have one and I position lamp. I actually have one and I position on my desk all day long. I also happen on my desk all day long. I also happen on my desk all day long. I also happen to have skylights above my desk. I'm to have skylights above my desk. I'm to have skylights above my desk. I'm fairly sensitive to the effects of fairly sensitive to the effects of fairly sensitive to the effects of light, so in longer days, I feel much light, so in longer days, I feel much light, so in longer days, I feel much better than I do in shorter days. I've better than I do in shorter days. I've better than I do in shorter days. I've never suffered from full-blown seasonal never suffered from full-blown seasonal never suffered from full-blown seasonal effective disorder, but I keep that effective disorder, but I keep that effective disorder, but I keep that light source on throughout the day light source on throughout the day light source on throughout the day throughout the year. But I also make it throughout the year. But I also make it throughout the year. But I also make it a point to get outside and get sunlight a point to get outside and get sunlight a point to get outside and get sunlight early in the morning and several times early in the morning and several times early in the morning and several times throughout the day. People that are throughout the day. People that are throughout the day. People that are blind, provided they still have eyes, blind, provided they still have eyes, blind, provided they still have eyes, often maintain these melanopsin cells. often maintain these melanopsin cells. often maintain these melanopsin cells. So even if you're low vision or no So even if you're low vision or no So even if you're low vision or no vision, getting UVB exposure to your vision, getting UVB exposure to your vision, getting UVB exposure to your eyes can be very beneficial for sake of eyes can be very beneficial for sake of eyes can be very beneficial for sake of mood, hormone pathways, pain reduction mood, hormone pathways, pain reduction mood, hormone pathways, pain reduction and so forth. A cautionary note, people and so forth. A cautionary note, people and so forth. A cautionary note, people who have retinitis pigmentotosa, macular who have retinitis pigmentotosa, macular who have retinitis pigmentotosa, macular degeneration or glaucoma, as well as degeneration or glaucoma, as well as degeneration or glaucoma, as well as people who are especially prone to skin people who are especially prone to skin people who are especially prone to skin cancers should definitely consult with cancers should definitely consult with cancers should definitely consult with your opthalmologist and dermatologist your opthalmologist and dermatologist your opthalmologist and dermatologist before you start increasing the total before you start increasing the total before you start increasing the total amount of UVB exposure that you're amount of UVB exposure that you're amount of UVB exposure that you're getting from any source, sunlight or getting from any source, sunlight or getting from any source, sunlight or otherwise. There are additional very otherwise. There are additional very otherwise. There are additional very interesting and powerful effects of UVB interesting and powerful effects of UVB interesting and powerful effects of UVB light in particular on immune function. light in particular on immune function. light in particular on immune function. All the organs of our body are inside All the organs of our body are inside All the organs of our body are inside our skin. And so information about our skin. And so information about our skin. And so information about external conditions, meaning the external conditions, meaning the external conditions, meaning the environment that we're in, need to be environment that we're in, need to be environment that we're in, need to be communicated to the various organs of communicated to the various organs of communicated to the various organs of your body, such as your spleen, which is your body, such as your spleen, which is your body, such as your spleen, which is involved in the creation of molecules involved in the creation of molecules involved in the creation of molecules and cells that combat infection. There and cells that combat infection. There and cells that combat infection. There are beautiful studies showing that if we are beautiful studies showing that if we are beautiful studies showing that if we get more UVB exposure from sunlight or get more UVB exposure from sunlight or get more UVB exposure from sunlight or from appropriate artificial sources from appropriate artificial sources from appropriate artificial sources that spleen and immune function are that spleen and immune function are that spleen and immune function are enhanced and there's a very logical enhanced and there's a very logical enhanced and there's a very logical wellestablished circuit as to how that wellestablished circuit as to how that wellestablished circuit as to how that happens. Your brain actually connects to happens. Your brain actually connects to happens. Your brain actually connects to your spleen. UVB light arriving on the your spleen. UVB light arriving on the your spleen. UVB light arriving on the eyes is known to trigger activation of eyes is known to trigger activation of eyes is known to trigger activation of the neurons within the so-called the neurons within the so-called the neurons within the so-called sympathetic nervous system. These sympathetic nervous system. These sympathetic nervous system. These neurons are part of the larger thing neurons are part of the larger thing neurons are part of the larger thing that we call the autonomic nervous that we call the autonomic nervous that we call the autonomic nervous system, meaning it's below or not system, meaning it's below or not system, meaning it's below or not accessible by conscious control. It's accessible by conscious control. It's accessible by conscious control. It's the thing that controls your heartbeat, the thing that controls your heartbeat, the thing that controls your heartbeat, controls your breathing, and that also controls your breathing, and that also controls your breathing, and that also activates or flips on the switch of your activates or flips on the switch of your activates or flips on the switch of your immune system. When we get a lot of UVB immune system. When we get a lot of UVB immune system. When we get a lot of UVB light in our eyes or I should say light in our eyes or I should say light in our eyes or I should say sufficient UVB light in our eyes, a sufficient UVB light in our eyes, a sufficient UVB light in our eyes, a particular channel, a particular set of particular channel, a particular set of particular channel, a particular set of connections within the sympathetic connections within the sympathetic connections within the sympathetic nervous system is activated and our nervous system is activated and our nervous system is activated and our spleen deploys immune cells and spleen deploys immune cells and spleen deploys immune cells and molecules that scavenge for and combat molecules that scavenge for and combat molecules that scavenge for and combat infection. In other words, the soldiers infection. In other words, the soldiers infection. In other words, the soldiers of your immune system, the chemicals and of your immune system, the chemicals and of your immune system, the chemicals and cell types of your immune system that cell types of your immune system that cell types of your immune system that combat infection are in a more ready combat infection are in a more ready combat infection are in a more ready deployed stance, if you will. So, we deployed stance, if you will. So, we deployed stance, if you will. So, we often think about the summer months and often think about the summer months and often think about the summer months and the spring months as fewer infections the spring months as fewer infections the spring months as fewer infections floating around, but in fact, there floating around, but in fact, there floating around, but in fact, there aren't fewer infections floating around. aren't fewer infections floating around. aren't fewer infections floating around. We are simply better at combating those We are simply better at combating those We are simply better at combating those infections and therefore there's less infections and therefore there's less infections and therefore there's less infection floating around. What does infection floating around. What does infection floating around. What does this mean in terms of a tool? What it this mean in terms of a tool? What it this mean in terms of a tool? What it means is that during the winter months, means is that during the winter months, means is that during the winter months, we should be especially conscious of we should be especially conscious of we should be especially conscious of accessing UVB light to enhance our accessing UVB light to enhance our accessing UVB light to enhance our spleen function to make sure that our spleen function to make sure that our spleen function to make sure that our sympathetic nervous system is activated sympathetic nervous system is activated sympathetic nervous system is activated to a sufficient level to keep our immune to a sufficient level to keep our immune to a sufficient level to keep our immune system deploying all those killer T- system deploying all those killer T- system deploying all those killer T- cells and B cells and cytoines so that cells and B cells and cytoines so that cells and B cells and cytoines so that when we encounter the infections, as we when we encounter the infections, as we when we encounter the infections, as we inevitably will, we can combat those inevitably will, we can combat those inevitably will, we can combat those infections well. And as just a brief infections well. And as just a brief infections well. And as just a brief aside, but I should mention a brief aside, but I should mention a brief aside, but I should mention a brief aside that's related to tens of aside that's related to tens of aside that's related to tens of thousands of quality studies. It is well thousands of quality studies. It is well thousands of quality studies. It is well known that wound healing is faster when known that wound healing is faster when known that wound healing is faster when we are getting sufficient UVB exposure. we are getting sufficient UVB exposure. we are getting sufficient UVB exposure. It is known that turnover of hair cells. It is known that turnover of hair cells. It is known that turnover of hair cells. The very cells that give rise to hair The very cells that give rise to hair The very cells that give rise to hair cells are called stem cells. They live cells are called stem cells. They live cells are called stem cells. They live in little so-called niches in our skin in little so-called niches in our skin in little so-called niches in our skin with these hair stem cells and your hair with these hair stem cells and your hair with these hair stem cells and your hair grows faster in longer days. That too is grows faster in longer days. That too is grows faster in longer days. That too is triggered by UVB exposure. not just to triggered by UVB exposure. not just to triggered by UVB exposure. not just to the skin but to the eyes. That's right. the skin but to the eyes. That's right. the skin but to the eyes. That's right. There was a study published in the There was a study published in the There was a study published in the proceedings of the National Academy of proceedings of the National Academy of proceedings of the National Academy of Sciences a couple of years ago that Sciences a couple of years ago that Sciences a couple of years ago that showed that the exposure of those showed that the exposure of those showed that the exposure of those melanops and ganglin cells in your eyes melanops and ganglin cells in your eyes melanops and ganglin cells in your eyes is absolutely critical for triggering is absolutely critical for triggering is absolutely critical for triggering the turnover of stem cells in both the the turnover of stem cells in both the the turnover of stem cells in both the skin and hair and also it turns out in skin and hair and also it turns out in skin and hair and also it turns out in nails. So, if you've noticed that your nails. So, if you've noticed that your nails. So, if you've noticed that your skin, your hair, and your nails look skin, your hair, and your nails look skin, your hair, and your nails look better and turn over more, meaning grow better and turn over more, meaning grow better and turn over more, meaning grow faster in longer days, that is not a faster in longer days, that is not a faster in longer days, that is not a coincidence. That is not just your coincidence. That is not just your coincidence. That is not just your perception. In fact, hair grows more. perception. In fact, hair grows more. perception. In fact, hair grows more. Skin turns over more, meaning it's going Skin turns over more, meaning it's going Skin turns over more, meaning it's going to look more youthful. You're going to to look more youthful. You're going to to look more youthful. You're going to essentially remove older skin cells and essentially remove older skin cells and essentially remove older skin cells and replace them with new cells. and all the replace them with new cells. and all the replace them with new cells. and all the renewing cells and tissues of our body renewing cells and tissues of our body renewing cells and tissues of our body are going to proliferate are going to are going to proliferate are going to are going to proliferate are going to recreate themselves more when we're recreate themselves more when we're recreate themselves more when we're getting sufficient UVB light to our eyes getting sufficient UVB light to our eyes getting sufficient UVB light to our eyes and also to our skin. There's also and also to our skin. There's also and also to our skin. There's also another time of day or rather I should another time of day or rather I should another time of day or rather I should say a time of night in which UVB can be say a time of night in which UVB can be say a time of night in which UVB can be leveraged in order to improve mood but leveraged in order to improve mood but leveraged in order to improve mood but it's actually the inverse of everything it's actually the inverse of everything it's actually the inverse of everything we've been talking about up until now. we've been talking about up until now. we've been talking about up until now. We have a particular neural circuit that We have a particular neural circuit that We have a particular neural circuit that originates with those melanopsin cells originates with those melanopsin cells originates with those melanopsin cells in our eye that bypass all the areas of in our eye that bypass all the areas of in our eye that bypass all the areas of the brain associated with circadian the brain associated with circadian the brain associated with circadian clocks. So everything related to sleep clocks. So everything related to sleep clocks. So everything related to sleep and wakefulness that's specifically and wakefulness that's specifically and wakefulness that's specifically dedicated to the pathways involving the dedicated to the pathways involving the dedicated to the pathways involving the release of molecules like dopamine and release of molecules like dopamine and release of molecules like dopamine and other molecules as well including other molecules as well including other molecules as well including serotonin and some of those indogenous serotonin and some of those indogenous serotonin and some of those indogenous opioids that we talked about before. opioids that we talked about before. opioids that we talked about before. That particular pathway involves a brain That particular pathway involves a brain That particular pathway involves a brain structure called the perihabenular structure called the perihabenular structure called the perihabenular nucleus. The perihabenular nucleus gets nucleus. The perihabenular nucleus gets nucleus. The perihabenular nucleus gets input from the cells in the eye that input from the cells in the eye that input from the cells in the eye that respond to UVB light and frankly to respond to UVB light and frankly to respond to UVB light and frankly to bright light of other wavelengths as bright light of other wavelengths as bright light of other wavelengths as well because as you recall if a light is well because as you recall if a light is well because as you recall if a light is bright enough even if it's not UV or bright enough even if it's not UV or bright enough even if it's not UV or blue light it can activate those cells blue light it can activate those cells blue light it can activate those cells in the eye those cells in the eye in the eye those cells in the eye in the eye those cells in the eye communicate to the perihabenular nucleus communicate to the perihabenular nucleus communicate to the perihabenular nucleus and as it turns out if this pathway is and as it turns out if this pathway is and as it turns out if this pathway is activated at the wrong time of each activated at the wrong time of each activated at the wrong time of each 24-hour cycle mood gets worse. Dopamine 24-hour cycle mood gets worse. Dopamine 24-hour cycle mood gets worse. Dopamine output gets worse. Molecules that are output gets worse. Molecules that are output gets worse. Molecules that are there specifically to make us feel good there specifically to make us feel good there specifically to make us feel good actually are reduced in their output. actually are reduced in their output. actually are reduced in their output. Avoiding UVB light at night is actually Avoiding UVB light at night is actually Avoiding UVB light at night is actually a way in which we can prevent activation a way in which we can prevent activation a way in which we can prevent activation of this eye to perihabular pathway that of this eye to perihabular pathway that of this eye to perihabular pathway that can actually turn on depression. to be can actually turn on depression. to be can actually turn on depression. to be very direct and succinct about this. very direct and succinct about this. very direct and succinct about this. Avoid exposure to UVB light from Avoid exposure to UVB light from Avoid exposure to UVB light from artificial sources between the hours of artificial sources between the hours of artificial sources between the hours of 10 p.m. and 4:00 a.m. If you view UVB 10 p.m. and 4:00 a.m. If you view UVB 10 p.m. and 4:00 a.m. If you view UVB light, you activate those neurons in light, you activate those neurons in light, you activate those neurons in your eye very potently. And if those your eye very potently. And if those your eye very potently. And if those cells communicate to the perihabular cells communicate to the perihabular cells communicate to the perihabular nucleus, which they do, you will nucleus, which they do, you will nucleus, which they do, you will truncate or reduce the amount of truncate or reduce the amount of truncate or reduce the amount of dopamine that you release. dopamine that you release. dopamine that you release. So if you want to keep your mood So if you want to keep your mood So if you want to keep your mood elevated, get a lot of light, UVB light elevated, get a lot of light, UVB light elevated, get a lot of light, UVB light throughout the day. And at night, really throughout the day. And at night, really throughout the day. And at night, really be cautious about getting UVB exposure be cautious about getting UVB exposure be cautious about getting UVB exposure from artificial sources. Now, I wouldn't from artificial sources. Now, I wouldn't from artificial sources. Now, I wouldn't want people to become so neurotic about want people to become so neurotic about want people to become so neurotic about UVB exposure that they won't flip on a UVB exposure that they won't flip on a UVB exposure that they won't flip on a light at all. But you would do well, for light at all. But you would do well, for light at all. But you would do well, for instance, to put any artificial lights instance, to put any artificial lights instance, to put any artificial lights that you have on in the evening, kind of that you have on in the evening, kind of that you have on in the evening, kind of low in your physical environment. low in your physical environment. low in your physical environment. Because these melanopsin cells reside in Because these melanopsin cells reside in Because these melanopsin cells reside in the lower half of our eyes, they view the lower half of our eyes, they view the lower half of our eyes, they view the upper visual field. That makes sense the upper visual field. That makes sense the upper visual field. That makes sense because they were designed to because they were designed to because they were designed to essentially respond to sunlight coming essentially respond to sunlight coming essentially respond to sunlight coming from above us from above us from above us and try and dim those lights as far down and try and dim those lights as far down and try and dim those lights as far down as you safely can. Now, I'd like to as you safely can. Now, I'd like to as you safely can. Now, I'd like to shift our attention to the other end of shift our attention to the other end of shift our attention to the other end of the spectrum, meaning the light the spectrum, meaning the light the spectrum, meaning the light spectrum, to talk about red light and spectrum, to talk about red light and spectrum, to talk about red light and infrared light, which is long wavelength infrared light, which is long wavelength infrared light, which is long wavelength light. So, you're probably asking, or at light. So, you're probably asking, or at light. So, you're probably asking, or at least you should be asking, how is it least you should be asking, how is it least you should be asking, how is it that shining red light on our skin can that shining red light on our skin can that shining red light on our skin can impact things like acne and wound impact things like acne and wound impact things like acne and wound healing, etc. To understand that, we healing, etc. To understand that, we healing, etc. To understand that, we have to think back to the beginning of have to think back to the beginning of have to think back to the beginning of the episode where I described how the episode where I described how the episode where I described how longwavelength light such as red light longwavelength light such as red light longwavelength light such as red light and near infrared light which is even and near infrared light which is even and near infrared light which is even longer than red light can pass through longer than red light can pass through longer than red light can pass through certain surfaces including our skin. So certain surfaces including our skin. So certain surfaces including our skin. So our skin has an epidermis which is on our skin has an epidermis which is on our skin has an epidermis which is on the outside and the dermis which is in the outside and the dermis which is in the outside and the dermis which is in the deeper layers. Red light and the deeper layers. Red light and the deeper layers. Red light and infrared light can pass down into the infrared light can pass down into the infrared light can pass down into the deeper layers of our skin where it can deeper layers of our skin where it can deeper layers of our skin where it can change the metabolic function of change the metabolic function of change the metabolic function of particular cells. So let's just take particular cells. So let's just take particular cells. So let's just take acne as an example. Within the dermis, acne as an example. Within the dermis, acne as an example. Within the dermis, the deep layers of our skin, we have the deep layers of our skin, we have the deep layers of our skin, we have what are called sebaceous glands that what are called sebaceous glands that what are called sebaceous glands that actually make the oil that is present in actually make the oil that is present in actually make the oil that is present in our skin. Those sebaceous glands are our skin. Those sebaceous glands are our skin. Those sebaceous glands are often nearby hair follicles. So if often nearby hair follicles. So if often nearby hair follicles. So if you've ever had a infected hair you've ever had a infected hair you've ever had a infected hair follicle, that's not a coincidence that follicle, that's not a coincidence that follicle, that's not a coincidence that hair follicles tend to get infected. hair follicles tend to get infected. hair follicles tend to get infected. Part of it is because there's actually a Part of it is because there's actually a Part of it is because there's actually a portal down and around the hair portal down and around the hair portal down and around the hair follicle. But the sebaceous gland is follicle. But the sebaceous gland is follicle. But the sebaceous gland is where the oil is created that is going where the oil is created that is going where the oil is created that is going to give rise to for instance acne to give rise to for instance acne to give rise to for instance acne lesions. Also in the dermis in the deep lesions. Also in the dermis in the deep lesions. Also in the dermis in the deep layers of the skin are the melanocytes. layers of the skin are the melanocytes. layers of the skin are the melanocytes. They're not just in the epidermis. They're not just in the epidermis. They're not just in the epidermis. They're also in the deeper layers of the They're also in the deeper layers of the They're also in the deeper layers of the skin. And you have the stem cells that skin. And you have the stem cells that skin. And you have the stem cells that give rise to additional skin cells. If give rise to additional skin cells. If give rise to additional skin cells. If the top layers of the epidermis are the top layers of the epidermis are the top layers of the epidermis are damaged, those stem cells can become damaged, those stem cells can become damaged, those stem cells can become activated. And you also have the stem activated. And you also have the stem activated. And you also have the stem cells that give rise to hair follicles. cells that give rise to hair follicles. cells that give rise to hair follicles. What happens is the top layers of the What happens is the top layers of the What happens is the top layers of the skin are basically burned off by a very skin are basically burned off by a very skin are basically burned off by a very low level of burn andor the cells in the low level of burn andor the cells in the low level of burn andor the cells in the deeper layer start to churn out new deeper layer start to churn out new deeper layer start to churn out new cells which go and rescue the lesion cells which go and rescue the lesion cells which go and rescue the lesion essentially clear out the lesion and essentially clear out the lesion and essentially clear out the lesion and replace that lesion with healthy skin replace that lesion with healthy skin replace that lesion with healthy skin cells. cells. cells. This does work in the context of wound This does work in the context of wound This does work in the context of wound healing getting scars to disappear. It healing getting scars to disappear. It healing getting scars to disappear. It also works to remove certain patches of also works to remove certain patches of also works to remove certain patches of pigmentation. Long wavelength light can pigmentation. Long wavelength light can pigmentation. Long wavelength light can actually get deep into the skin. I actually get deep into the skin. I actually get deep into the skin. I mentioned that before, but can also get mentioned that before, but can also get mentioned that before, but can also get into individual cells and can access the into individual cells and can access the into individual cells and can access the so-called organels. In particular, they so-called organels. In particular, they so-called organels. In particular, they can access the mitochondria which are can access the mitochondria which are can access the mitochondria which are responsible for producing ATP. As cells responsible for producing ATP. As cells responsible for producing ATP. As cells age, and in particular in very age, and in particular in very age, and in particular in very metabolically active cells, metabolically active cells, metabolically active cells, they accumulate what are called ROS's, they accumulate what are called ROS's, they accumulate what are called ROS's, reactive oxygen species. And as reactive reactive oxygen species. And as reactive reactive oxygen species. And as reactive oxygen species go up, ATP energy oxygen species go up, ATP energy oxygen species go up, ATP energy production in those cells tends to go production in those cells tends to go production in those cells tends to go down. It's a general statement, but it's down. It's a general statement, but it's down. It's a general statement, but it's a general statement that in most cases a general statement that in most cases a general statement that in most cases is true. So the way to think about this is true. So the way to think about this is true. So the way to think about this is that red light passes into the deeper is that red light passes into the deeper is that red light passes into the deeper layers of the skin, activates layers of the skin, activates layers of the skin, activates mitochondria, which increases ATP and mitochondria, which increases ATP and mitochondria, which increases ATP and directly or indirectly reduces these directly or indirectly reduces these directly or indirectly reduces these reactive oxygen species. These reactive reactive oxygen species. These reactive reactive oxygen species. These reactive oxygen species are not good. We don't oxygen species are not good. We don't oxygen species are not good. We don't want them. They cause cellar damage, want them. They cause cellar damage, want them. They cause cellar damage, cellar death, and for the most part just cellar death, and for the most part just cellar death, and for the most part just inhibit the way that our cells work. So, inhibit the way that our cells work. So, inhibit the way that our cells work. So, if you've heard of red light or near if you've heard of red light or near if you've heard of red light or near infrared light therapies designed to infrared light therapies designed to infrared light therapies designed to heal skin or improve skin quality or heal skin or improve skin quality or heal skin or improve skin quality or remove lesions or get rid of scars or remove lesions or get rid of scars or remove lesions or get rid of scars or unwanted pigmentation. That is not unwanted pigmentation. That is not unwanted pigmentation. That is not pseudocience. That is not woo science. pseudocience. That is not woo science. pseudocience. That is not woo science. That is grounded in the very biology of That is grounded in the very biology of That is grounded in the very biology of how light interacts with mitochondria how light interacts with mitochondria how light interacts with mitochondria and reactive oxygen species. The key and reactive oxygen species. The key and reactive oxygen species. The key point here is that light is activating point here is that light is activating point here is that light is activating particular pathways in cells that can particular pathways in cells that can particular pathways in cells that can either drive death of cells or can make either drive death of cells or can make either drive death of cells or can make those cells essentially younger by those cells essentially younger by those cells essentially younger by increasing ATP by way of improving increasing ATP by way of improving increasing ATP by way of improving mitochondrial function. And in recent mitochondrial function. And in recent mitochondrial function. And in recent years, there have been some just years, there have been some just years, there have been some just beautiful examples that exist not only beautiful examples that exist not only beautiful examples that exist not only in the realm of skin biology, but in the in the realm of skin biology, but in the in the realm of skin biology, but in the realm of neurobiology, realm of neurobiology, realm of neurobiology, whereby red light and near infrared whereby red light and near infrared whereby red light and near infrared light can actually be used to enhance light can actually be used to enhance light can actually be used to enhance the function of the cells that for the function of the cells that for the function of the cells that for instance allow us to see better and instance allow us to see better and instance allow us to see better and indeed cells that allow us to think indeed cells that allow us to think indeed cells that allow us to think better. And these are the data from Dr. better. And these are the data from Dr. better. And these are the data from Dr. Glenn Jeffrey at University College Glenn Jeffrey at University College Glenn Jeffrey at University College London who again is a long-standing London who again is a long-standing London who again is a long-standing member of the neuroscience community member of the neuroscience community member of the neuroscience community working on visual neuroscience and who working on visual neuroscience and who working on visual neuroscience and who over the last decade or so has really over the last decade or so has really over the last decade or so has really emphasized the exploration of red light emphasized the exploration of red light emphasized the exploration of red light and near infrared light for restoration and near infrared light for restoration and near infrared light for restoration of neuronal function as we age. The of neuronal function as we age. The of neuronal function as we age. The Jeffrey Lab has published two studies in Jeffrey Lab has published two studies in Jeffrey Lab has published two studies in recent years on humans that looked recent years on humans that looked recent years on humans that looked directly at how red light and near directly at how red light and near directly at how red light and near infrared light can improve visual infrared light can improve visual infrared light can improve visual function. The Jeffrey Lab approached function. The Jeffrey Lab approached function. The Jeffrey Lab approached these studies with that understanding of these studies with that understanding of these studies with that understanding of how mitochondria and reactive oxygen how mitochondria and reactive oxygen how mitochondria and reactive oxygen species and ATP work. And what they did species and ATP work. And what they did species and ATP work. And what they did is they had people, subjects that were is they had people, subjects that were is they had people, subjects that were either younger, so in their 20s, or 40 either younger, so in their 20s, or 40 either younger, so in their 20s, or 40 years old or older, years old or older, years old or older, view red light of about 670 nanometers. view red light of about 670 nanometers. view red light of about 670 nanometers. 670 nanometers would appear red to you 670 nanometers would appear red to you 670 nanometers would appear red to you and me. They had they had them do that, and me. They had they had them do that, and me. They had they had them do that, excuse me, at a distance that was safe excuse me, at a distance that was safe excuse me, at a distance that was safe for their eyes. So at about a foot away. for their eyes. So at about a foot away. for their eyes. So at about a foot away. And they had them do that anywhere from And they had them do that anywhere from And they had them do that anywhere from 2 to 3 minutes per day. And in one study 2 to 3 minutes per day. And in one study 2 to 3 minutes per day. And in one study they had them do that for a long period they had them do that for a long period they had them do that for a long period of time of about 12 weeks. And in the of time of about 12 weeks. And in the of time of about 12 weeks. And in the other study they had them do that just other study they had them do that just other study they had them do that just for a couple of weeks. The major for a couple of weeks. The major for a couple of weeks. The major findings were that in individuals 40 findings were that in individuals 40 findings were that in individuals 40 years old or older, so in the 40 to 72 years old or older, so in the 40 to 72 years old or older, so in the 40 to 72 year old bracket, but not in the year old bracket, but not in the year old bracket, but not in the subjects younger than 40 years old. They subjects younger than 40 years old. They subjects younger than 40 years old. They saw an improvement in visual function. saw an improvement in visual function. saw an improvement in visual function. That improvement in visual function was That improvement in visual function was That improvement in visual function was an improvement in visual acuity meaning an improvement in visual acuity meaning an improvement in visual acuity meaning the ability to resolve fine detail and the ability to resolve fine detail and the ability to resolve fine detail and using a particular measure of visual using a particular measure of visual using a particular measure of visual function which is called the Triton exam function which is called the Triton exam function which is called the Triton exam tr I tan Triton exam which specifically tr I tan Triton exam which specifically tr I tan Triton exam which specifically addresses the function of the so-called addresses the function of the so-called addresses the function of the so-called shortwavelength cones the ones that shortwavelength cones the ones that shortwavelength cones the ones that respond to green and blue light they saw respond to green and blue light they saw respond to green and blue light they saw a 22% improvement in visual acuity which a 22% improvement in visual acuity which a 22% improvement in visual acuity which in the landscape of visual testing is an in the landscape of visual testing is an in the landscape of visual testing is an extremely exciting result. As we age, we extremely exciting result. As we age, we extremely exciting result. As we age, we tend to lose rods. We tend to lose other tend to lose rods. We tend to lose other tend to lose rods. We tend to lose other cells within the retina, including the cells within the retina, including the cells within the retina, including the cells that connect the eye to the brain, cells that connect the eye to the brain, cells that connect the eye to the brain, the so-called ganglen cells. However, the so-called ganglen cells. However, the so-called ganglen cells. However, because rods and cones, both are not because rods and cones, both are not because rods and cones, both are not just among the most metabolically active just among the most metabolically active just among the most metabolically active cells in your entire body, but the most cells in your entire body, but the most cells in your entire body, but the most metabolically active cells in your metabolically active cells in your metabolically active cells in your entire body. Those cells tend to entire body. Those cells tend to entire body. Those cells tend to accumulate a lot of reactive oxygen accumulate a lot of reactive oxygen accumulate a lot of reactive oxygen species as we age. Red light of the sort species as we age. Red light of the sort species as we age. Red light of the sort used in these studies was able to reduce used in these studies was able to reduce used in these studies was able to reduce the amount of reactive oxygen species in the amount of reactive oxygen species in the amount of reactive oxygen species in the rods and cones and to rescue the the rods and cones and to rescue the the rods and cones and to rescue the function of this particular cone type, function of this particular cone type, function of this particular cone type, the short wavelength and medium the short wavelength and medium the short wavelength and medium wavelength cones. The important takeaway wavelength cones. The important takeaway wavelength cones. The important takeaway here is that viewing red light and near here is that viewing red light and near here is that viewing red light and near infrared light at a distance at which it infrared light at a distance at which it infrared light at a distance at which it is safe for just a couple of minutes is safe for just a couple of minutes is safe for just a couple of minutes each day allowed a reversal of the aging each day allowed a reversal of the aging each day allowed a reversal of the aging process of these neurons. So here we're process of these neurons. So here we're process of these neurons. So here we're seeing a reversal of the aging process seeing a reversal of the aging process seeing a reversal of the aging process in neurons by shining red light on those in neurons by shining red light on those in neurons by shining red light on those neurons. So a little bit more about the neurons. So a little bit more about the neurons. So a little bit more about the studies from the Jeffrey lab. One of the studies from the Jeffrey lab. One of the studies from the Jeffrey lab. One of the things that they observed was a things that they observed was a things that they observed was a reduction in so-called dusen duen. reduction in so-called dusen duen. reduction in so-called dusen duen. Dusen are little fatty deposits, little Dusen are little fatty deposits, little Dusen are little fatty deposits, little cholesterol deposits that accumulate in cholesterol deposits that accumulate in cholesterol deposits that accumulate in the eye as we age. Our neural retina the eye as we age. Our neural retina the eye as we age. Our neural retina being so metabolically active requires a being so metabolically active requires a being so metabolically active requires a lot of blood flow. It's heavily lot of blood flow. It's heavily lot of blood flow. It's heavily vascularized and dusen are a special vascularized and dusen are a special vascularized and dusen are a special form of cholesterol that accumulate in form of cholesterol that accumulate in form of cholesterol that accumulate in the eye. As it turns out, these red the eye. As it turns out, these red the eye. As it turns out, these red light and near infrared light therapies light and near infrared light therapies light and near infrared light therapies explored by the Jeffrey lab were able to explored by the Jeffrey lab were able to explored by the Jeffrey lab were able to actually reduce or reverse some of the actually reduce or reverse some of the actually reduce or reverse some of the accumulation of dusen. And so in accumulation of dusen. And so in accumulation of dusen. And so in addition to reducing reactive oxygen addition to reducing reactive oxygen addition to reducing reactive oxygen species, the idea in mind now is that species, the idea in mind now is that species, the idea in mind now is that red light may actually reduce red light may actually reduce red light may actually reduce cholesterol deposits and reactive oxygen cholesterol deposits and reactive oxygen cholesterol deposits and reactive oxygen species in order to improve neuronal species in order to improve neuronal species in order to improve neuronal function. So what should you and I do function. So what should you and I do function. So what should you and I do with these results or should we do with these results or should we do with these results or should we do anything with these results? Well, first anything with these results? Well, first anything with these results? Well, first of all, I want to emphasize that even of all, I want to emphasize that even of all, I want to emphasize that even though these studies are very exciting, though these studies are very exciting, though these studies are very exciting, they are fairly recent and so more data they are fairly recent and so more data they are fairly recent and so more data as always are needed. There's some as always are needed. There's some as always are needed. There's some additional features of these studies additional features of these studies additional features of these studies that I think are also important to that I think are also important to that I think are also important to consider. First of all, the exposure to consider. First of all, the exposure to consider. First of all, the exposure to red light needed to happen early in the red light needed to happen early in the red light needed to happen early in the day, at least within the first 3 hours day, at least within the first 3 hours day, at least within the first 3 hours of waking. of waking. of waking. How would one do that? Well, nowadays How would one do that? Well, nowadays How would one do that? Well, nowadays there are a number of different red there are a number of different red there are a number of different red light panels and different red light light panels and different red light light panels and different red light sources that certainly fall within the sources that certainly fall within the sources that certainly fall within the range of red light and near infrared range of red light and near infrared range of red light and near infrared light that one could use. So, if you're light that one could use. So, if you're light that one could use. So, if you're somebody who wants to explore red light somebody who wants to explore red light somebody who wants to explore red light therapy, here's what you need to do. You therapy, here's what you need to do. You therapy, here's what you need to do. You need to make sure that that red light need to make sure that that red light need to make sure that that red light source, it's not so bright that you're source, it's not so bright that you're source, it's not so bright that you're damaging your eye. A good rule of thumb damaging your eye. A good rule of thumb damaging your eye. A good rule of thumb is that something isn't painful to look is that something isn't painful to look is that something isn't painful to look at. And in fact, I should just emphasize at. And in fact, I should just emphasize at. And in fact, I should just emphasize that anytime you look at any light that anytime you look at any light that anytime you look at any light source, sunlight or otherwise, that it's source, sunlight or otherwise, that it's source, sunlight or otherwise, that it's painful and makes you want to squint or painful and makes you want to squint or painful and makes you want to squint or close your eyes, that means it's too close your eyes, that means it's too close your eyes, that means it's too bright to look at without closing your bright to look at without closing your bright to look at without closing your eyes. Okay, that's sort of a duh, but I eyes. Okay, that's sort of a duh, but I eyes. Okay, that's sort of a duh, but I would loathe to think that anyone would would loathe to think that anyone would would loathe to think that anyone would harm themselves with bright light in any harm themselves with bright light in any harm themselves with bright light in any way. I don't just say that to protect way. I don't just say that to protect way. I don't just say that to protect us. I say that to protect you, of us. I say that to protect you, of us. I say that to protect you, of course, because you are responsible for course, because you are responsible for course, because you are responsible for your health. And again, retinal neurons your health. And again, retinal neurons your health. And again, retinal neurons do not regenerate. Once they are gone do not regenerate. Once they are gone do not regenerate. Once they are gone and dead, they do not come back. The and dead, they do not come back. The and dead, they do not come back. The wavelength of light is important. It is wavelength of light is important. It is wavelength of light is important. It is red light and near infrared light that red light and near infrared light that red light and near infrared light that is going to be effective in this is going to be effective in this is going to be effective in this scenario. The authors of this study scenario. The authors of this study scenario. The authors of this study emphasized that it was red light of 670 emphasized that it was red light of 670 emphasized that it was red light of 670 nanometers in wavelength and near nanometers in wavelength and near nanometers in wavelength and near infrared light of 790 nanometers in infrared light of 790 nanometers in infrared light of 790 nanometers in wavelength that were effective and that wavelength that were effective and that wavelength that were effective and that those wavelengths could be those wavelengths could be those wavelengths could be complimentary. A lot of the commercially complimentary. A lot of the commercially complimentary. A lot of the commercially available red light panels that you'll available red light panels that you'll available red light panels that you'll find out there combine both red light find out there combine both red light find out there combine both red light and near infrared light. However, I want and near infrared light. However, I want and near infrared light. However, I want to emphasize that most of the panels to emphasize that most of the panels to emphasize that most of the panels that are commercially available are that are commercially available are that are commercially available are going to be too bright to safely look at going to be too bright to safely look at going to be too bright to safely look at very close up. And in fact, that's why very close up. And in fact, that's why very close up. And in fact, that's why most of those red light panels are most of those red light panels are most of those red light panels are designed for illumination of the skin designed for illumination of the skin designed for illumination of the skin and oftentimes arrive in their packaging and oftentimes arrive in their packaging and oftentimes arrive in their packaging with eye protectors that are actually with eye protectors that are actually with eye protectors that are actually designed to shield out all the red designed to shield out all the red designed to shield out all the red light. So take the potential dangers of light. So take the potential dangers of light. So take the potential dangers of excessive illumination of the eyes with excessive illumination of the eyes with excessive illumination of the eyes with any wavelength of light seriously. But any wavelength of light seriously. But any wavelength of light seriously. But if you're going to explore 670 and 790 if you're going to explore 670 and 790 if you're going to explore 670 and 790 nanometer light for sake of enhancing nanometer light for sake of enhancing nanometer light for sake of enhancing neuronal function, set it at a distance neuronal function, set it at a distance neuronal function, set it at a distance that's comfortable to look at and that that's comfortable to look at and that that's comfortable to look at and that doesn't force you to squint or doesn't doesn't force you to squint or doesn't doesn't force you to squint or doesn't make you feel uncomfortable physically make you feel uncomfortable physically make you feel uncomfortable physically as if you need to turn away during the as if you need to turn away during the as if you need to turn away during the period of that two to three minute period of that two to three minute period of that two to three minute illumination each day. So the studies I illumination each day. So the studies I illumination each day. So the studies I just described once again involve the just described once again involve the just described once again involve the use of red light early in the day within use of red light early in the day within use of red light early in the day within three hours of waking and are for the three hours of waking and are for the three hours of waking and are for the sake of improving neuronal function. Red sake of improving neuronal function. Red sake of improving neuronal function. Red light has also been shown to be light has also been shown to be light has also been shown to be beneficial beneficial beneficial late in the day and even in the middle late in the day and even in the middle late in the day and even in the middle of the night. And when I say middle of of the night. And when I say middle of of the night. And when I say middle of the night, I'm referring to studies that the night, I'm referring to studies that the night, I'm referring to studies that explored the use of red light for shift explored the use of red light for shift explored the use of red light for shift workers. I realize that many people are workers. I realize that many people are workers. I realize that many people are doing shift work or they have to work doing shift work or they have to work doing shift work or they have to work certainly past 10 p.m. or maybe they're certainly past 10 p.m. or maybe they're certainly past 10 p.m. or maybe they're taking care of young children in the taking care of young children in the taking care of young children in the middle of the night and they have to be middle of the night and they have to be middle of the night and they have to be up. In that case, red light can actually up. In that case, red light can actually up. In that case, red light can actually be very beneficial. And nowadays, there be very beneficial. And nowadays, there be very beneficial. And nowadays, there are a lot of sources of red light are a lot of sources of red light are a lot of sources of red light available just as red light bulbs. You available just as red light bulbs. You available just as red light bulbs. You don't need a panel. So, what I'm don't need a panel. So, what I'm don't need a panel. So, what I'm basically saying is that it can be basically saying is that it can be basically saying is that it can be beneficial to use red lights at night. beneficial to use red lights at night. beneficial to use red lights at night. The study I'd like to emphasize in this The study I'd like to emphasize in this The study I'd like to emphasize in this context is entitled red light, a novel context is entitled red light, a novel context is entitled red light, a novel non-farmacological intervention to non-farmacological intervention to non-farmacological intervention to promote alertness in shift workers. The promote alertness in shift workers. The promote alertness in shift workers. The takeaway from this study is very clear. takeaway from this study is very clear. takeaway from this study is very clear. If you need to be awake late at night If you need to be awake late at night If you need to be awake late at night for sake of shift work or studying or for sake of shift work or studying or for sake of shift work or studying or taking care of children, etc., Red light taking care of children, etc., Red light taking care of children, etc., Red light is going to be your best choice because is going to be your best choice because is going to be your best choice because if the red light is sufficiently dim, if the red light is sufficiently dim, if the red light is sufficiently dim, it's not going to inhibit melatonin it's not going to inhibit melatonin it's not going to inhibit melatonin production and it's not going to production and it's not going to production and it's not going to increase cortisol at night. Cortisol increase cortisol at night. Cortisol increase cortisol at night. Cortisol should be high early in the day or at should be high early in the day or at should be high early in the day or at least should be elevated relative to least should be elevated relative to least should be elevated relative to other times of day if you are healthy. A other times of day if you are healthy. A other times of day if you are healthy. A late shifted increase in cortisol, late shifted increase in cortisol, late shifted increase in cortisol, however, 9M cortisol, 10 p.m. cortisol however, 9M cortisol, 10 p.m. cortisol however, 9M cortisol, 10 p.m. cortisol is well known to be associated with is well known to be associated with is well known to be associated with depression and other aspects of mental depression and other aspects of mental depression and other aspects of mental health, rash, as a mental illness. So, health, rash, as a mental illness. So, health, rash, as a mental illness. So, if you do need to be awake at night or if you do need to be awake at night or if you do need to be awake at night or even all night, red light is going to be even all night, red light is going to be even all night, red light is going to be the preferred light source. And in terms the preferred light source. And in terms the preferred light source. And in terms of how bright to make it, well, as dim of how bright to make it, well, as dim of how bright to make it, well, as dim as you can while still being able to as you can while still being able to as you can while still being able to perform the activities that you need to perform the activities that you need to perform the activities that you need to perform. That's going to be your best perform. That's going to be your best perform. That's going to be your best guide. Today I covered what I would say guide. Today I covered what I would say guide. Today I covered what I would say is a lot of information. My goal was to is a lot of information. My goal was to is a lot of information. My goal was to give you an understanding of how light give you an understanding of how light give you an understanding of how light can be used to change the activities of can be used to change the activities of can be used to change the activities of cells, organels within those cells, cells, organels within those cells, cells, organels within those cells, entire organs, and how that can happen entire organs, and how that can happen entire organs, and how that can happen locally and systemically. So, thank you locally and systemically. So, thank you locally and systemically. So, thank you once again for joining me today for this once again for joining me today for this once again for joining me today for this deep dive discussion into deep dive discussion into deep dive discussion into phototherapies, meaning the power of phototherapies, meaning the power of phototherapies, meaning the power of light to modulate our biology and light to modulate our biology and light to modulate our biology and health. And as always, thank you for health. And as always, thank you for health. And as always, thank you for your interest in science.