Feel Better, Live More with Dr Rangan Chatterjee - #141 BITESIZE | The Power of Light To Transform Your Health | Linda Geddes

Episode Date: December 18, 2020

Sleep is one of the most important pillars of health. Our bodies and our brains are designed to function during the day and rest at night. Feel Better Live More Bitesize is my new weekly podcast for your mind, body and heart. Each week I’ll be featuring inspirational stories and practical tips from some of my former guests. This week’s guest is award-winning journalist, Linda Geddes. Circadian rhythms are 24-hour cycles that are kept in time by light and dark cycles. These rhythms can become disrupted by changing our exposure to light which can affect our sleep and make us feel sluggish during the day. Exposure to bright light after sunset is a modern phenomenon. Darkness is a signal to our bodies that it’s time to rest and access to bright light and screens at night disrupts these signals. There are simple things that we can do to help reset our circadian rhythms. Linda shares the findings of her own experiment of getting rid of light at night in her own home. Finally, she gives her tips on what we can all do to get more light into our days and darken our nights. Access to sunlight, even in winter, is crucial for living a happy and fulfilling life. I hope you feel inspired to get outside! Show notes and the full podcast are available at drchatterjee.com/77 Follow me on instagram.com/drchatterjee/ Follow me on facebook.com/DrChatterjee/ Follow me on twitter.com/drchatterjeeuk DISCLAIMER: The content in the podcast and on this webpage is not intended to constitute or be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your doctor or other qualified health care provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have heard on the podcast or on my website. 

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10. And these packs are perfect for keeping in your backpack, office, or car. If you want to take advantage of this limited time offer, all you have to do is go to drinkag1.com forward slash live more. Welcome to Feel Better Live More, bite-sized your weekly dose of optimism and positivity to get you ready for the weekend. Today's clip is from episode 77 of the podcast with the award-winning journalist, Linda Geddes. And with this clip, she explains why light is so important for our health and why even in winter, we should find ways to brighten up our days and darken our nights. In all our discussions on our health, have we missed a big piece in the jigsaw? Could our exposure to light potentially be more important than the food that we eat?

Our biology is kind of set up to work with this 24-hour cycle of light and darkness. And if you mess with that, things start to happen to, first of all, to these circadian rhythms, so these 24-hour fluctuations in our biology. So if you're exposed to light at night, one thing that does is it pushes your circadian rhythms later. That's not necessarily a bad thing unless you have to wake up to go to work or school the next morning. And if you're kind of seeing light late at night and your circadian rhythms are being pushed later, that means the time when you feel sleepy and want to go to sleep is pushed later. So you potentially get less sleep. And if you get less sleep, that's going to have an impact on your alertness, on your mental functioning, on your mood. But it's more than that because

seeing bright light is also a kind of brain stimulant. It boosts your alertness. So if you see light late at night, you're going to feel more awake. But also, if you don't see light in the daytime, you're going to feel more sluggish and less alert. And there are increasingly studies showing that bright light actually, it literally wakes us up. So, you know, we now spend 90% of our daytimes indoors where the light levels are like an order of magnitude lower than they are outdoors. Luminance or brightness is measured in this unit called lux. Today is kind of grey and rainy and gloomy and on a day like today it's about 5,000 lux outside. On a bright sunny day in the middle of summer it could be as high as 100 000 lux outside but indoors in the

kind of standard office it might be two to three hundred lux so it's you know it's hugely dimmer inside than it is outside even even on a cloudy day even on a cloudy day we have evolved to actually have at least five ten thousand lux of light exposure through our eyes into our body with all your knowledge with your research with your own experience what has managed to stick in you and your family's lifestyle yeah dimming the lights in the evening so my idea was um what would happen if we go cold turkey on artificial light after dark that was my original thing i was just interested in what happen if we go cold turkey on artificial light after dark that was my original thing i was just interested in what happens if we get rid of all this artificial light and so i went and saw these sleep researchers at the university of surrey and and said i'd like to

do this experiment will you help me and they said yes um but what we'd like you to always also think about is to try and boost your daylight exposure, which is how I first came across all this research or emerging research about the importance of daylight. So the idea was that from 6pm onwards, there would be no electric light and we would use candles instead. And then in the daytime, I would try, even though it was the middle of winter, I would try and even though I'm bound to a desk in my work, I would do everything I could to get as much bright light exposure as possible. So that was things like, you know, after the school drop off in the morning, just, you know, sitting in the park with my

notepad doing my to do list outside, rather than at the kitchen table where it's really dark. When I made my breakfast in the morning, just going outside with my cup of tea and just, you know, standing in the garden and eating my cup of tea and my bit of toast, swapping going to the gym in like a windowless exercise studio for doing the same kind of exercise outdoors. By the end of living like this, you know, we did this on off for six weeks in the middle of December. Well, it was beginning of December until mid January. And by the end of it, it was my six-year-old daughter who was the one who was saying, I really like it. It's really cozy and nice in the evening to have the lights dimmed.

What was the impact of doing this? I was definitely sleepier earlier in the evenings. I wanted to go to bed at 9, 10 o'clock rather than 11 or 12 o'clock. I didn't always do that because of social obligations, but I wanted to. Once a week, we took readings of my melatonin. Now, melatonin is a hormone that you release. It's under the control of the circadian clock and you release it in the evening at night. And it's basically a kind of biological signal to your whole body that it's time to shift change into night mode. And one thing it does is it impacts on the sleep centers. So it does tend to, you know, you release melatonin and your brain kind of goes,

ah, nighttime, it's time to feel sleepy. Here's some sleep signals. And what we found was that I started secreting melatonin between one and a half and two hours earlier than when I lived normally. So that explains why I was feeling sleepier earlier because my body was saying it's night time two hours earlier. I mean for people listening I just want to emphasize how striking a point you just made. We're talking about a very important hormone in our body. Yes it's associated with sleep. There are other studies suggesting it's an antioxidant that it may have some anti-cancer properties potentially this is an important hormone that is under this circadian clock that simply by switching off artificial light in the evening you are shifting maybe two hours beforehand you're changing an important hormone's

secretion by two hours yes that is significant if a drug was doing that we'd be talking about it there would be a list of side effects on it yet we're sort of many of us are doing that every evening yeah on our devices without the awareness of the implications so what are some of your top tips that you think are practical for most people you can do simple things like turn off the overhead ceiling lights, switch to dimmer table lamps, those kinds of things. Make sure that if you're using screens that you try and put them on night mode. So just try and kind of go for that kind of more orangey, softer, warm lighting and keep it dim and kind of cozy, kind of romantic lighting is what you should be aspiring to in the evenings. I think there are little things you can do to just boost your light exposure, you know,

like walk to work, cycle to work, go for a walk around the block. It doesn't have to take huge amount of time. Dim your evenings and brighten your days. When you start doing it, you'll realise you feel better when you live like that. I hope you enjoyed this week's Feel Better Live More Bite Size, your weekly dose of optimism and positivity to get you ready for the weekend. Please do spread the love and the feel-good vibes by sharing this episode with your friends and family. And for more content from me, please do sign up for my weekly newsletter at drchatterjee.com forward slash subscribe, where I share every week things that I do not share on social media, topics that I'm thinking

about, quotes that I'm pondering and articles that have moved me that I think may move you as well. And sometimes even music that I'm currently listening to. Around 100,000 people already subscribe. You can check it out at drchastity.com forward slash subscribe. As always, I'll be back next week with the long form conversation on Wednesday and the latest episode of Bite Size next Friday. Have a wonderful weekend.