Feel Better, Live More with Dr Rangan Chatterjee - #152 BITESIZE | How Food can Improve Your Mood | Felice Jacka

Episode Date: January 29, 2021

We know that poor diet can affect our physical health, but it can negatively affect our mental health too. 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 world-leading expert in the field of nutritional psychiatry, Professor Felice Jacka. We discuss the fascinating findings of her ground-breaking research into the link between food and our mental health. Felice explains the important role our gut microbiome plays in our health and wellbeing, and how a diet rich in diversity is key to good physical and mental health. Show notes and the full podcast are available at drchatterjee.com/74 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. 

Today's Bite Size episode is brought to you by AG1, a science-driven daily health drink with over 70 essential nutrients to support your overall health. It includes vitamin C and zinc, which helps support a healthy immune system, something that is really important at this time of year. It also contains prebiotics and digestive enzymes that help support your gut health. It's really tasty and has been in my own life for over five years. Until the end of January, AG1 are giving a limited time offer. Usually they offer my listeners a one-year supply of vitamin D and K2 and five free travel packs with their first order. But until the end of January, they are doubling the five free travel packs to

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 optimism and positivity to get you ready for the weekend. Today's clip is from episode 74 of the podcast with Professor Felice Jacker, a world leading expert in the field of nutritional psychiatry. Now in this clip, we discuss her groundbreaking research into the link between food and moods, the importance of our gut microbiome, and how a diet rich in diversity is key. Adversity is key.

Until recently, as a conventional medical doctor, the widespread view was that our diets don't really play that much impact in terms of the way that we feel. What is going on there? Yeah, I think, you know, there's been this longstanding, I guess, dichotomy between mind and body, this idea that somehow the brain was up here and the body was down here and they really didn't have a lot to do with each other. But what really got me interested in the link between nutrition and mental and brain health was the understanding, probably, you know, late 1990s, early 2000s, that the immune system seemed to be really central, particularly with depression. It seemed to be both cause and consequence of depressive illnesses. And of course, nutrition is a really strong driver of immune function. And also in the early 2000s,

a lot of neuroscience work coming out of America that looked at the impact of nutrition as well as exercise on brain plasticity, in particular, this region of the brain called the hippocampus, which is really important for learning and memory as well as for mental health, and showing that you could manipulate that in animal studies rapidly by altering diet and also exercise. So there was this emerging evidence that, of course, the mind and the body were one highly complex integrated system. And our new knowledge around the gut and the gut microbiota is really solidifying that knowledge and giving us some more insights and targets for our research and potentially our prevention and treatment strategies.

The SMILES trial that you did literally, I think, will go down as being one of the most game-changing trials in terms of research on diet and mental health. I think it's incredible and it's helping to give real weight globally to the notion that our diet can improve our mood and our mental health. I designed it when I was a very early postdoc, the SMILES trial. We recruited people with major clinical depression and we randomly assigned them to get either social support or dietary support. Now, the social support, we already know that that's helpful for people with depression. That's just going and talking to someone. You could be talking about the football

or your grandchildren or whatever. The other groups are a clinical dietitian for three months and that dietitian just worked with those people to help them to gradually make positive changes to their diet, to set some goals, to do it in a way that was feasible and achievable for them, swapping out their refined carbs, their white flour, white bread, et cetera, for whole grain versions, increasing the amount of vegetables and fruit in their diet, starting to eat more legumes, so your lentils and chickpeas, etc., having some nuts and seeds, eating fish, getting some olive oil into their diet, but also really importantly, reducing the intake of the junk and processed foods.

And at the end of the study, there was just this massive difference in the depression scores, and we were just completely blown away. How big a difference? Well, to put it into, I guess, a meaningful context, more than 30% of the people in the dietary group achieved what we would call full remission, where they just weren't depressed at all anymore. And that was compared to about 8% in the social support group. So, hold on, we just got to pause there because that is absolutely remarkable. You were talking about people who have got moderate or severe depression. If you change your diet, within 12 weeks, you got above a 30% remission rate

in symptoms of depression. That is absolutely staggering. There's a few really important things that came out of that study. The first thing is that most people were able to make positive changes to their diet. That's really important because so many clinicians, I think, are very sceptical about patients' ability to take dietary advice and act upon it. And we found that people loved this. It was something that was under their own control, unlike so many other things in their life. Secondly, the degree of dietary change correlated very closely with the degree of improvement in their depression. So, the more you change your diet, the more you would improve. Exactly, exactly. Third, we did a very detailed cost analysis of the diet that we were recommending compared to

the cost of the diet that they were eating when they came into the study. Our diet was a whole lot cheaper. So, it put to bed this idea that it has to be expensive to eat a healthy diet. The worst case scenario here, worst case scenario is that someone changes their diet, they don't feel any better. There's no downside, right? That's exactly right. Let's talk a little bit about diversity of foods and let's talk a little bit about the gut microbiome and why that is so important. We know that the gut microbiome is so important for our immune system,

for our metabolism and body system, for our metabolism and body weight, for our brain health. This knowledge that these bacteria that have co-evolved with us have such an important role in our health is really giving us some new insights that we can act on to, I think, improve a lot of health outcomes. So the bacteria in your gut in particular, very, very simply speaking, they break down the fibrous foods that our human enzymes can't break down. So fiber is found in plant foods, things such as vegetables, fruits, whole grain cereals, legumes, beans and lentils,

et cetera. So all sorts of different types of plant foods have dietary fiber. The gut microbes break that down by a process of fermentation. And in that process of fermentation, they produce many, many, many metabolites. And it's the production of these metabolites that seems to be so important. And we know that they, for example, interact with every cell in the body. It's very complex. We're really only just scratching the surface. But I think the key understanding is we already know what sort of diet is consistently linked to longevity.

And that's a diet that is high in plant foods and high in a diversity of plant foods. Because the more diverse your diet, the more diverse your gut microbiome. And that seems to be a marker of gut health. It's incredible. And there's a huge amount of research that's being done across the world now in this field, which is wonderful because it means that we're getting advances in our knowledge very quickly. But at this point, what we know is that diet is the most important thing that affects the gut microbiota, and that you can change your gut microbiota and your gut health within a very short space of time,

like even within days by changing your diet. And that's such a powerful thing to understand. Hope you enjoyed that bite-sized clip. Please do spread the love by sharing this episode with your friends and family. And if you want more, why not go back and listen to the full conversation with my guest. And if you enjoyed this episode, I think you will really enjoy my new bite-sized Friday email. It's called the Friday Five. And each week I share things

that I do not share on social media. It contains five short doses of positivity, articles or books that I'm reading, quotes that I'm thinking about, exciting research I've come across and so much more. I really think you're going to love it. The goal is for it to be a small yet powerful dose of feel good to get you ready for the weekend. You can sign up for it at drchatterj.com forward slash friday five i hope you have a wonderful weekend make sure you have pressed subscribe and i'll be back next week with my long-form conversational wednesday and the latest episode of bite science next friday