Feel Better, Live More with Dr Rangan Chatterjee - BITESIZE | How Exercise Changes Your Brain and Reduces Your Risk of Depression | Dr Anders Hansen #429

Episode Date: February 23, 2024

We all know that exercise is good for our physical health, but exercise can be just as powerful for our brain and mental health. Feel Better Live More Bitesize is my 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.   Today’s clip is from episode 381 of the podcast with psychiatrist, globally renowned speaker and best-selling author Dr Anders Hansen. In this clip he shares how exercise can change our brains and reduce our risk of depression. Support the podcast and enjoy Ad-Free episodes. Try FREE for 7 days on Apple Podcasts https://apple.co/feelbetterlivemore. For other podcast platforms go to https://fblm.supercast.com. Find out more about my NEW Journal here https://drchatterjee.com/journal Show notes and the full podcast are available at drchatterjee.com/381 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 Size, your weekly dose of positivity and optimism to get you ready for the weekend. Today's clip is from episode 381 with psychiatrist, globally renowned speaker and best-selling author, Dr. Anders Hansen. In this clip, he shares how exercise can change our brain and reduce our risk of depression. You say in your book that exercise is a way of hacking evolution and you make the case that exercise is important for not only how we feel, concentration,

memory, stress tolerance. Yeah, so exercise has been shown to be incredibly important for cognition. Basically all of our cognitive function, memory, ability to focus, creativity, even intelligence it seems, is positively affected by exercise. And it also protects us against depressions and anxiety. And the brain actually seems to be the organ in the body that benefits the most from exercise. And one of the best studies on this was done where you scan the size of the hippocampus. And hippocampus is the memory center of the brain. It has many important functions, but one of them is memory.

And hippocampus decreases in size for every year that passes. It peaks in size when you're between 25 to 30, and thereafter it starts to shrink by about 1% per year. Now, this has been thought to be inevitable. You just can't change that. But then researchers in San Diego started believing that maybe this can be changed by exercise. Because they had seen that if you put a wheel into the cage of laboratory rats, the rats run the wheel or the mice run the wheel, and then their hippocampus grows.

It gets bigger. So they tried that same logic for humans. And they had one group walking three times a week, 45 minutes every time, fast walking for one year, and the other group did stretching exercises three times a week, 45 minutes every time. And it turned out that the stretching group, their hippocampus had shrunk by an average of 1.4%. It was 1.4 percent smaller after a year. But the walking group, their hippocampus had grown by an average of two percent. So instead of one

year older, it had gotten two years younger in terms of size. The hippocampus was bigger and they also had improved their memory, especially spatial memories, to learn to find your way around a three-dimensional space. So exercise is actually a way to preserve the function of the brain. It's a way to boost your creativity. We know that the creativity tests, your results on them increase the hour after walking and quite substantially especially the ability to brainstorm that increases by somewhere around 50 percent the hour after you get a temporary bump the hour after walking yes yeah so it just lasts for one hour so if you have a difficult problem go for a fast walk and then think of the problem the hour after you have walked then it increases the chances that you

will find a solution um so and i thought a lot about this, and I wondered, why is it that exercise is so good for the brain? Because we don't need our cognitive functions when we go running. We need our cognitive functions in a meeting room, in front of a computer, or in the classroom. And then I realized that during almost all our history it was when we moved that we needed our cognitive functions the most during the hunt during gathering of plants and so on that's when we needed the focus that's when we got new sensor input that we had to remember

to create memories of that that was when we had to be at our peak in terms of creativity and so on. So Mother Nature has built us in a way that exercise improves our cognition because it was when we moved that we needed our cognitive functions the most. And therefore, exercise becomes, from our perspective, a way to hack evolution, to exploit the mechanism in our brains in order to function better in our modern world. So I always say that to patients and through my books, that exercise has nothing to do with being good at a sport. It has nothing to do with being one of the marathon runners. Exercise is something that the brain evolved for and that is extremely important for us as a species. And you should not mix it up by being good at, by being an athlete.

Make a habit out of exercise. Walk to work, ride your bike to work instead of taking the car, walk in stairs, have children playing during lunch break instead of staring at the screen and so on and so forth. Try to build exercise into your life so that you make a habit out of it. There was also a study you quoted about children. I think it was done in Swedish schools where just six minutes of movement, I think before a class, improved concentration and made the kids better at avoiding distraction. We've often heard about exercise through the lens of physical health. And of course, there are benefits there. But as you say, it all comes down to the brain,

right? The brain is where it's at. Get the brain functioning properly and actually most other things start to come online and the case really is that exercise is critical for the function of our brains yeah the brain seems to be the organ that benefits most from exercise i think there was a cycle test you referenced and how it can predict depression in a few years right exactly that Exactly. That was done in the UK. And if you were to cycle for six minutes as fast as you can on a cycle and then squeeze a handle as hard as you can, do you think that could say anything

of your risk of being depressed from now until 2029? No, you wouldn't think so, would you? No, you wouldn't. I wouldn't at least. I would think that if I become depressed, that would be if someone would get sick in my family or if I lose my job or something.

This was studied on more than 100,000 individuals. They did this cycling test. They squeezed this handle as hard as they could and they were followed for six years. And it turns out that the ones who were in good shape, they had lower prevalence. There were fewer of them who were depressed after six years. And then one thought, the researchers thought that maybe this is because they are more healthy in general.

Maybe they eat better. Maybe they sleep more. Maybe they don't smoke as much. So they excluded all of these factors in the data. And it turned out that exercise was still protective. And then they thought, well, depression is not just black and white. It's a sort of on a spectrum. You could have a mild depression, you could have a severe depression, but no matter where they put this

cutoff of what is a depression and what isn't, exercise protected against it. So it's incredibly important that we move. We will not get immune to depressions, but we lower the risk of it. So it's incredibly important that we move. We will not get immune to depressions, but we lower the risk of it. And I say to my patients who have had several depressions and who really, really want to avoid a new one, most of them want to continue having antidepressant medication because they want to be protected against a new depression. And to them, I say that the most important thing, probably even more important than continuing with medication, is that they exercise to avoid a new depression. Yeah, it's absolutely incredible. And you've outlined so much research on exercise. I'd like to think anyone reading your books is going to be convinced, if they're not already, that

exercise, daily exercise, daily movement, whatever you want to call it, is an absolute must. It's not really an optional extra. It's who we are. And I think that's one of the things I've been thinking a lot about, Anders, over the last few months. You know, I'm 45 now, and I would say the big thing I'm changing in my life at the moment, and have been for a few months, is I'm increasing the amount of movement in my life significantly. I've just, more and more, I'm convinced that, you know, I'm not promoting this, but you can get away with not eating well for a few days. You can't get away with not moving. Yeah. You just can't.

No, you can't. I feel exactly the same. And it's so difficult. I have periods where I don't exercise so much because I work too much or I have an infection or whatever. And then I feel that something is wrong with me. I don't know what it is. And then I go for a run and I realize that was it. And it doesn't matter how many times I talk about this and write about this.

This is difficult stuff. Difficult to do. This is difficult to do. But the good part of this is that on average, people take about five, maybe 5,500 steps a day now, which that's one way to look upon that is saying that that's terrible.

That's too little. Another way to see it is that it's a huge untapped resource. It's something that we could just dig into. It's a treasure chest for our cognitive abilities and for our feelings. And the ones who are to benefit the most are the ones who don't exercise at all. So it's when someone who don't do anything start walking to school or taking the bike to school, that's

where the really big effects come in. It's not when you have the marathon club running a bit more. That doesn't make any difference in terms of brain perspective. Yeah, it's interesting. So the ones who don't do anything, you have this big untapped resource that will make you function better, but even more importantly, feel better. For people listening who feel inspired and want to live happier lives, what are some of your top tips?

I have just one tip, and that is learn more about the brain. When you do that, you will make changes. And this is an incredible time to live in, because we have, for the first time, been able to look inside and see what's happening in our brain when we do certain things. And that means that we are studying the machinery of the soul.

For the first time in our species history, we can do that. And one of these discoveries is how extremely important exercise is for the brain. And of course, I could have summarized my books by saying, you know, sleep more and be cautious about your screens and exercise more and that would be it.

But then no one would have cared. It's when you really understand what this is doing to you, what this is doing to the organ that creates your experience of existence, then you will make changes. Hope you enjoyed that bite-sized clip. I hope you have a wonderful weekend.

And I'll be back next week with my long-form conversational Wednesday and the latest episode of Bite Science next Friday.