Managing Circadian Rhythms and Shift Work

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See website for details. ARAO Original Podcast . Hi, I'm Catherine Ryan and welcome back to Dr. Nicola's Second Opinion, the place where aging myths get busted and the latest research gets a glow-up. Coming up, Dr. Nick's straight up from the lab to give you a heads up on hard science. We've got your questions lined up, and as always, she'll finish up with a quick fix to help you stay younger from the inside out. This week we're talking light and how the sun, vitamin D, and light spectrums can help you age in technicolor. Dr. Nicola's second opinion. So welcome back. And yes, today we are talking about light. And this is something that you probably rarely think about, but it actually controls almost every system in your body, and this is because light is one of the most powerful regulators of your biology, and when it's disrupted, it can really upset your body and it can accelerate aging in ways that we don't immediately see . So, an important place to start is that light doesn't just help you see. It tells your body what time it is, and that really matters more than most people realize. Because inside your brain, there is a tiny cluster of cells called the superchiasmatic nucleus. That is the superchiasmatic nucleus science word of the week. And you don't need to remember that, but just think of it as a master clock. And this clock responds directly to light entering your cells. So when morning light goes in and it hits your retina, it basically signals to your brain that the day has begun. And that signal is very important because it sets off a cascade in your body to prepare your body and your biology for the day. So melatonin, which is the sleep hormone, will be switched off. Our body temperature will shift, our digestion will prepare , and our focus will sharpen. And the amazing thing is that this master clock then sinks clocks in almost every other cell of the body because every cell also has its own clock. Your liver cells have clocks, your gut has a clock, your skin has a clock, and even your immune cells all have clocks. Now these cellular clocks then switch thousands of genes on and off across a 24-hour cycle. And this cycle is known as our circadian rhythm. And research shows that nearly half of all our genes show some sort of circadian variation in activity. In other words, they are switched on and off every 24 hours according to what the light is doing. So light is definitely not a minor detail in our lives. It actually fundamentally alters our biology. So, why is it? Why is it that this light is such an important stimulus? Well, if you think about it, for most of our human history, our ancestors lived in sync with natural light. They had light during the day and they had absolute darkness at night. They didn't have any LED screens, they had no shift work, they had no smartphones , and definitely no artificial lights at midnight. They just had different wavelengths or colors of light that were influencing their biology throughout the day. For example, blue light throughout the day and in the morning was energizing. It suppressed melatonin and it promoted alertness. Whereas the warm red toned light in the evening from things like the sunset is much more calm and it allows the melaton in to rise and prepared the body for rest and sleep . And then overnight there was darkness, and darkness is essential because this is when your cells switch into maintenance mode. This is when they start to repair and they start to clear damage and restore balance in the body. So our bodies have evolved to expect these very predictable light patterns. But now we just don't get this. We are living drastically different lives. We live in a world that is flooded with artificial light, especially blue enriched light, at times when our body is just not expecting it. We're extending our days much longer past sunset, which would never usually have happened, and often we're not even getting outside in the morning and getting any daylight at all. And when this light exposure is mismatched with what our biology expects, our circadian rhythm becomes misaligned and this will disrupt our whole biology. It means that we start to feel sluggish during the day because our biology and our body doesn't realize it's meant to be in daytime go mode, and then at night our sleep quality and our repair is less efficient because our daytime biology doesn't fully get switched off. So bright screens late at night and minimal daylight during the day confuse the systems that are coordinating all the rest and cellular repair in our bodies. Dr. Nicholas's second opinion. So light comes up quite a few times on the What's My Age Again podcast, but not everyone's always so sure why it's important. Now, writer Briany Gordon told me in series one that vitamin D was something she took as a supplement, even if Catherine wasn't so sure why. I do look after myself. So I take HRT, I take vitamin D and omega-3 . It's interesting. So vitamin D and Omega-3 are also two dietary supplements that have also had evidence to show their reverse biological age. So without knowing it, you're actually kind of choosing out the right things that are really benefiting your cells inside. Isn't vitamin D like it's so it's that important? Yeah it's it's it's extremely important in our bodies and hormones are you know often associated, especially the sex hormones, that people think oh they're just for fertility, you know, and that's got nothing to do with the rest of our bodies. But actually, every cell in your body pretty much has an estrogen receptor. So you can imagine the situation when your estrogen suddenly goes down, then all of those cells are sitting there going, well where's where's my estrogen? Like now I can't do these functions. So it's it's amazing that we're now learning more about how this impacts our age, especially in women. We know women can age worse than men, probably because of the hormone effect. And people have been studying women for literally hours. Yeah, yeah, this is a huge problem. It's really great as a science woman. It's good to have you here to know all of this, Nicola. Thank you. We will keep pushing to get the women in clinical trials because we're not as complicated as they think. Yeah, always happy to provide the science and I think the important point that came up with Briney was the really common fact that most people know about light is that it does produce vitamin D in our bodies. And if you want to know more about vitamin D and light, we did a earlier bonus episode on dark nights, which you can go back and listen to. But also hopefully you've learned something new in this episode about the benefits of light in our body. Doctor Nicola's second opinion. Okay, so let's move on to some questions now and Catherine has the first one. Fion a is 38 and from Glasgow, and she says, Hi Dr. Nick, I barely see daylight in winter, and I feel it in my mood and energy. Could you explain how light exposure and vitamin D influence aging and whether light therapy lamps genuinely help? Okay, so as a fellow northerner, I know all too well that living in northern latitudes absolutely makes this more challenging, especially in winter. And as you found, that less daylight definitely affects your mood , and this is largely because when sunlight hits our eyes, it stimulates the production of serotonin, and this is our feel-good hormone. So when morning light goes low, melatonin, which is the sleep hormone, it lingers around in the body for longer, and we don't get the cortisol spike, which basically prepares the body to be alert and ready for the day. And that is why you're probably feeling sluggish and flat. And vitamin D, as you mentioned, is another important piece because this acts like a hormone rather than a vitamin and it plays a hugely important role in your body. But unfortunately when vitamin D levels are low, it can actually increase your biological age. So these light therapy lamps can definitely help if you use them correctly. So you want to be using it first thing in the morning, and they will mimic the light that we naturally should be getting and that our bodies are actually, waiting for. Now they don't replace outdoor light entirely, but they are a very useful tool, especially in the darker climates . And the next question we now have is from Sandra, who's 57, and she says, I've been reading about red light therapy for skin and muscle and recovery. And I'm curious but skeptical about what is actually evidence-based. What does the science say about these therapies and their impact on longevity? Okay, so Sandra, your skepticism is definitely healthy, but we do know that red light therapy will work by delivering specific wavelengths of light, usually from a specific light panel or some sort of mask or device. Now, these red and infrared wavelengths of light will penetrate the skin and are mostly absorbed by our mitochondria. And these mitochondria are the energy generating powerhouses in our cells. And they are actually covered in little receptors that are basically like switches that get switched on and off when this red light hits them. And when this happens, the mitochondria will start producing more energy that cells can make use of. And there's more and more studies now happening to show that there's reasonable evidence it can improve things like skin elasticity, it can reduce fine lines, it can help with wound heal ing and also support muscle recovery. And it also appears to reduce inflammation. So I think there's definitely growing evidence, but you do have to make sure that you are getting quality products that have the right wavelengths. Unfortunately, some of the things that you can buy are quite cheap and will not stimulate the cells in the way that you would hope for. This episode of What's My Age Again is sponsored by MedExpress, the UK online pharmacy. If you've been trying to manage your weight but feel like nothing's really working, MedExpress connects you with UK registered clinicians who assess your situation and create a treatment plan to support your weight management goals. With over 1.5 million customers, MedExpress is one of the country's leading online pharmacies, and they offer access to licensed, evidence-based treatment under medical supervision. And the whole process happens from your laptop or phone. There's no need for face-to-face appointments. They'll post your approved treatment to your door each month. You don't have to worry about getting locked into a contract or subscription either. You can cancel anytime. Your relationship with your body can change over the years, but MedExpress is there to offer you discrete and convenient professional guidance supporting your weight management journey. Visit Medexpress.co.uk to check your eligibility and get forty pounds off with code WMAA