Skip to content

By playing, you agree to uListen's Terms and Privacy Policy and YouTube's Terms of Service.

Dr Rangan ChatterjeeDr Rangan Chatterjee

Professor REVEALS How Your Diet Can Reduce STRESS & ANXIETY! | Felice Jacka

We all know that a poor diet negatively impacts our physical health but the effects on our mental health can also be devastating.

Felice JackaguestDr. Rangan Chatterjeehost
Jan 31, 20221h 7mWatch on YouTube

Summaries, chapters, transcripts, and FAQs on this page are made by uListen, not YouTube.

Great conversations run long. Their best ideas don't have to.

uListen is free on iPhone, iPad, Android, Chrome, and Claude.

See how

Transcript

  1. 0:00 – 0:25

    Why diet matters for depression and anxiety

    1. FJ

      That is still problematic for mental health. So the fact that the two things are linked is incredibly important. So women who had less than the recommended intake, they were twice as likely to have a clinical depressive or anxiety disorder. What you eat really does matter to your mental and brain health, and that's such a powerful thing to understand. [upbeat music]

    2. RC

      Diet and mental health.

    3. FJ

      Mm.

  2. 0:25 – 1:54

    How the field emerged: immune function, brain plasticity, and the gut

    1. RC

      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?

    2. FJ

      Yeah, I think, you know, there's been this long-standing, 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. 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. Um, it seemed to be both, uh, 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, uh, emerging evidence that of course the, the mind and the body were m- you know, 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, uh, insights and targets for our research and potentially our prevention and treatment strategies.

  3. 1:54 – 3:37

    Felice Jacka’s path into nutritional psychiatry and early skepticism

    1. RC

      Yeah, absolutely. Well, the research is emerging all the time and continuing to evolve, but what led you to this? What were you doing? What was happening? Were you having problems with your own health? What, what, what took you on this journey?

    2. FJ

      Yeah, so my first degree was in fine art, but back in the 1980s, you know, I was gonna be an artist. If someone had told me that I might end up being a scientist, I would've just laughed my head off. But I had a lot of, uh, common mental disorders, so depression and anxiety during my, uh, adolescence, and probably even before that. And I was drawn towards psychology and the study of psychology because of that personal experience. And as I studied psychology, I became pretty clear that I didn't really want to be a clinician, but I really liked, I like statistics. Sorry, that's so nerdy. But, um, [laughs] so I ended up volunteering while I was doing my undergraduate degree to do some research with a, a very well-known professor of psychiatry, and really loved it. And so I went on and I finished my undergrad degree, did my honors degree looking at, um, the link between depression and bone health using epidemiology and learned a lot of the basics there. But while I was doing that, I, I started to realize that there were really very little data, very few data on the role of nutrition and mental and brain health. You know, there'd been a few randomized control trials of supplements. Um, some of them were pretty terrible, some of them were okay in terms of the, the rigor, and there had been a few epidemiological studies looking at individual, um, aspects of diet such as fish consumption and depression. But really, the-- compared to the wider field of medicine and chronic disease,

  4. 3:37 – 4:57

    Early landmark findings and the field’s growing credibility

    1. FJ

      there were very few data on the role of nutrition in mental health. So for my PhD, I decided that that's what I wanted to actually tackle. And I met with a lot of skepticism and I guess some, um, almost sniggers [laughs] you know, because a- as you say, there just wasn't this idea that nutrition or what you put in your mouth might have an influence on your mental and brain health. But I undertook that study for my PhD. I looked at data from more than 1,000 women, highly representative sample of the population, and looked in detail at their diet and their mental health using proper clinical assessments and, of course, all of the other factors that you need to consider, like income and education and those sorts of things, and found the, the links that I expected to see. Um, and this ended up being quite, uh, influential. It was published on the front cover of the American Journal of Psychiatry in 2010, and each, along with two other prospective studies that were published around the same time, one from Spain and one from the UK, really kickstarted a whole lot of interest in this field. And, you know, for me, it made perfect sense. But for, for others in the scientific community or clinical, um, community, it really was quite revolutionary and there was a lot of skepticism and, uh, that's only really started to abate in the last three years or so.

  5. 4:57 – 8:33

    Modern food environment, chronic disease, and why prevention matters

    1. RC

      Before we delve into the research, and I really wanna get deep into the research, uh, we have a lot of healthcare professionals listen to this podcast, but also, you know, thousands of members of the public who, who listen to these to actually just get information to help improve the way that they feel and get more out of life. I just wanna really try and understand the scale of the problem. So we know that mental health problems in general are on the rise. There's many reasons for that. Uh, and many things in the modern environments have improved, haven't they? Whether it's, um, you know, things like sanitation, hygiene, these things have all got better.

    2. FJ

      Mm.

    3. RC

      But it's pretty hard to make a case that our diets have got better.

    4. FJ

      Mm.

    5. RC

      So how much of a problem is the modern food environment, do you think, in terms of these increasing rates of mental illness?

    6. FJ

      Well, you know, the, the scope of the problem is actually mind-boggling. We-- So we now know from the very large studies that have been done, the Global Burden of Disease studies, that poor diet, unhealthy diet, largely as a result of the, the changes to the food system that are prompted by big food industry making a lot of profits from these ultra-processed food products- But poor diet is now the leading cause of early death in men and number two in women across the globe. And obesity now kills more people than undernutrition. The WHO have said, you know, by 2030 it's gonna cost the global community, uh, upwards of $30 trillion, and made the point that there's no economy in the world that can actually cope with the cost, the, the poor, um, health outcomes of unhealthy diet. And yet there's been very little action to kind of change the food environment at the, the policy and legislative level. At the same time, we know that mental disorders, mental and substance use disorders account for the leading global burden of disability. So even though they may not directly always lead to early death, although they do have an impact on that, they cause a massive amount of disability across the globe, and unipolar depression in particular is in the top five causes of disability across the globe continually. So the fact that the two things are linked is incredibly important for, for prevention and for treatment. The fact that poor diet is such a major issue globally for health really highlights the, um, the craziness of medical practitioners getting so little training on nutrition during their, during their, you know, uh, residencies, et cetera. It, it's a major issue. How much poor diet feeds into mental health problems is yet to be established. And, and that's a really important question, but I suspect it varies enormously from individual to individual. And it should be always said that, uh, you know, something like depression is a very multifactorial disorder. There are so many things that drive into it. But if you think about the risk factors for mental illness, they're very often things that you can't readily change. They're things like family history and early life trauma and life events and poverty and disadvantage and interpersonal violence. These are things that are often very challenging for societies to address. So we need to be looking for the things that we can modify, particularly if we wanna think about prevention, because half of all mental disorders start before the age of 14. So we want to be able to prevent as many cases as we can. So if we know that diet and physical activity are both modifiable risk factors for depression in particular, which we absolutely know from very extensive data from around the world, then this is where we should be targeting, um, our interventions as, as the low-hanging fruit.

  6. 8:33 – 11:41

    Lifestyle psychiatry: shared drivers, bidirectional risk, and economic value

    1. RC

      Yeah, it-- I have so many thoughts going through my head at the moment. You know, you mentioned diets and physical activity are modifiable risk factors for depression, but they're also modifiable risk factors for obesity. They're also modifiable risk factors for other conditions, which-

    2. FJ

      Mm-hmm

    3. RC

      ... therefore in my head, you extend that thinking further and say, well, why-- well, how could these two things modify your risk of a whole variety of different conditions? Maybe all the different conditions aren't quite as separate as we think they are. Maybe there is a common underlying driver, such as inflammation. [laughs]

    4. FJ

      Yeah.

    5. RC

      You know, I, I really think about this a lot. The more science that emerges in various fields of health and medicine, the more we often find that the lifestyle factors that we are promoting to help reduce the likelihood or even help treat those conditions are quite similar. [laughs]

    6. FJ

      Absolutely, and I think this recognition of, um, certainly the common mental disorders such as depression as another of the chronic non-communicable diseases is a really important one because we certainly think on the basis of the research that they all have common drivers. But apart from anything else, it just makes so much sense to be tackling this, and I mean, we're really pushing for this lifestyle psychiatry or lifestyle medicine as a fundamental principle in psychiatry. Because if you think about depression, you think about how common it is, and recognize that if you are depressed, your risk for heart disease and obesity and a whole lot of metabolic problems goes right up. If you have those conditions, in turn, your risk for depression goes right up. And then if you look at the serious mental illnesses such as psychosis and schizophrenia, we know that that patient group has a massively reduced lifespan compared to the general population because of their lifestyle behaviors and the impact of the drugs that they ha- are given. And we also know that if you tackle their lifestyle behaviors and support them to have a healthy diet and do exercise, it actually can mitigate nearly all of that, uh, noxious impact on their metabolic health. And then finally, if you go and look at the, um, the, the two intervention studies, the SMILES trial that we led and the one that, um, came after us in South Australia, where they did a detailed economic evaluation of both of them, and we showed that there was a massive cost saving because the people who, certainly in the SMILES trial, who got, uh, the dietary support compared to the social support, there was an average cost saving of about 3,000 Australian dollars. And that's because the participants lost less time out of role and they saw health professionals less often. And the HealthyMed study in South Australia found very similar. So what it's saying is if you take this lifestyle medicine approach to supporting people with, uh, mental health problems, in this case depression, but it will also be the same in schizophrenia based on what we know so far, you're gonna get, uh, huge benefits across the board. It's not just targeting a particular molecule or particular, um, you know, brain pathway. It's, it, it's targeting the whole person.

    7. RC

      Yeah.

  7. 11:41 – 15:34

    Why guidelines aren’t translating into practice (and what helps)

    1. FJ

      And, and so it makes all sorts of sense. Now, in 2015, the updated clinical guidelines for the treatment of mood disorders were published in Australia by the Royal Australian New Zealand College of Psychiatry. I had quite a bit of impact-- uh, input into that. And they said step zero, if you have a patient with, um, depression, step zero should be basically lifestyle medicine. It should be diet, exercise, sleep hygiene, smoking cessation, substance abuse.

    2. RC

      In, in 2015?

    3. FJ

      That was in 2015. And we-

    4. RC

      See, see, that is not being translated to clinical practice.

    5. FJ

      No, that's right. That's right, and we really need to change the way we, we train practitioners. And I think, you know, obviously the pharmaceutical industry has had a big part to play in pushing a sort of a, you know, a pharmaceutical approach to treatment, and certainly this is not an either/or question.

    6. RC

      No.

    7. FJ

      You know, we absolutely... Everyone in the SMILES trial was on-- well, most people were on other forms of treatment, but it's saying that this should be the starting point, the, the fundamental. And if clinicians take it seriously and they give diet and exercise advice as a prescription, and they say, "This is actually really important," we think that that will h- uh, help people to change their behaviors.

    8. RC

      Yeah, Felice, I think th- that last point is something I keep trying to hammer home, um, when I'm talking to healthcare professionals and, which is this whole point that first of all, some people are very, uh, closed to the idea that food can make a difference in mental health. I was, um, giving a talk in Bristol for the Royal College of GPs to I think 100, 150 doctors there, and at the start I asked them, "How many of you will discuss a patient's nutrition or their, or their food and someone who comes up with a mental health problem?" And roughly 5% of the room put their hand up. This is only-- this is after the SMI- this was 2018, I think, actually. J- I think January, February 2018. And then I, I literally gave a 20-minute talk, just a, an overview of some of the research. Um, some of it I knew was yours, some of it I'd quoted up yours, but I didn't realize it was yours. [laughs]

    9. FJ

      [laughs]

    10. RC

      Um, and at the end of it I said, "How many of you are gonna do it now?" And they almost all put their hand up. And so it's really that slightly frustrating whereas there is research out there, guidelines are being written, but they're not being translated to clinical practice. And, um, this led me a few years ago with a colleague create something called a Prescribing Lifestyle Medicine course that, you know, we're delighted the Royal College of GPs has accredited for the second year running, and we- we've trained I think about 1,000 clinicians now, doctors, pharmacists, we've had a few psychiatrists, cardiologists, 'cause this is not just for a general practice problem, this is a problem across medicine. And again, we are n- we're not training them in nutrition, we're training them in a lifestyle medicine approach, how you evaluate their patients, how you can start to input various things from their symptoms a- and start to deliver a personalized lifestyle prescription. And, you know, 95% of attendees love it and say it significantly influenced the way that they practice because we're not being given this information. And I, I, like you, share that passion, that lifestyle medicine, lifestyle psychiatry, these things... You know, if you think about it, the l- the worst case scenario here, worst case scenario is that someone changes their diet, they, they don't feel any better. There's no downside, right?

    11. FJ

      No.

    12. RC

      And-

    13. FJ

      That's exactly right.

    14. RC

      Well, let- let's dive into that research because I, I think the SMILES trial, which is... You know, I remember seeing that when it came out thinking, "Oh my God, this is the first time that I had seen a randomized control trial showing how diet can improve symptoms of depression," you know, using the same level of evidence that we would expect from a ph- pharmaceutical drug, and that was the really exciting thing. Let's dive into what happened in that trial, why you thought of it, what the results were, but also for, for, for the members of the general public who are listening, um, nutritional research is quite complicated to do, isn't it?

    15. FJ

      Yeah.

    16. RC

      And you've mentioned terms like observational studies, epidemiological studies-

    17. FJ

      Mm

    18. RC

      ... intervention studies. Could you, could you just briefly explain what those are so people understand the difference?

  8. 15:34 – 17:36

    Research methods explained: observational vs intervention studies in nutrition

    1. FJ

      Yeah. And this is-- I, I have a chapter in the book that talks about this because it is so important that people understand this concept of, uh, the fact that correlation doesn't equal causation. And doing research in general is really difficult, but doing nutrition research is just horrendous. [laughs] But, um, so observational, uh, studies or also called epidemiological studies are where you collect lots and lots of information from people that you believe are representative of the population or representative of a, of a particular group of the population, and you use statistics to put those data together and to test hypotheses. Now, we led many, many studies in adults, including that first one, which was my PhD. Then we went on and we looked in adolescents, a primary age of onset, really important to, to look at this in, in young people. Then in pregnant women and in children early in life, and then older adults, and we were joined by many other people from around the world. And from all of those observational studies, we can say that, uh, adherence to a healthy diet seems to reduce the risk of depression by about 30%. But w- to know whether that is actually a causal relationship, whether diet is causing the mental health, you need to do experiments where you actually change diet to see if you can change mental health, and that's an intervention study. Now, the obvious problem with doing something like that in nutrition is that you can't blind people to the, to what they're getting.

    2. RC

      They know what they're eating.

    3. FJ

      They know what they're eating. You can't have a placebo diet, you know? And there's no information to say that one particular form of healthy diet is better than another particular form. You can't ethically put one group of people on a junk food diet [laughs] and see what happens. So you've always got-

    4. RC

      Although Tim Spector did that to his son.

    5. FJ

      Yeah. [laughs]

    6. RC

      You know? Which is, which is actually episode one of this podcast. It was the very first conversation I had was with T- Tim, and he explained that he-- that's exactly what he did to his son. Like, any good research commission would, w- a scientist would do. But you're right, you can't ethically do that. [laughs]

  9. 17:36 – 20:27

    Inside the SMILES trial: design, recruitment barriers, and surprising results

    1. FJ

      But so you, you have to do the best that you can, and you also have to, to triangulate the data, so you have to look at the human data, you look at the animal studies, and the animal studies are really useful 'cause of course you can tightly control diet and then you can chop their heads off at the end and see what's going on in the brain and that sort of thing. But with the human, uh, data, I, I designed it when I was a very early postdoc, the SMILES trial, and, um, it took me a couple of years to get funding for it, but we got the funding, but they slashed the budget by 35%, so we really did it on the smell of an oily rag. You know, it was a really, really difficult and challenging study to do. We really struggled to recruit people, and I think-

    2. RC

      Really?

    3. FJ

      Yeah. This is really interesting because we, we had hoped to recruit about 180 patients with major depressive disorder. After three and a half very long, hard years, we'd recruited 67. Now, I think that's for two reasons. One is that people in general were skeptical that diet was gonna have an impact on something as serious as major depressive disorder. But really importantly, clinicians, they were just completely skeptical, so none of them sent their patients to us to enroll in the trial. So that was really challenging. Um, but what we did in that study was we, we recruited people with major clinical depression, and we randomly assigned them to get either social support or dietary support for a period of three months. Now, the social support, we already know that that's helpful for people with depression.

    4. RC

      Yeah.

    5. FJ

      That's just going and talking to someone. You could be talking about the football or your grandchildren or whatever, but it, we know that it's helpful, and it's called a befriending protocol. They often use it in psychotherapy trials as a control condition. And then the other g- groups saw a clinical dietician for three months, and that dietician 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. And that was things like swapping out their, you know, 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, et cetera, having some nuts and seeds, eating fish, getting some olive oil into their diet. But also, really importantly, reducing the intake of, you know, the junk and processed foods, the sweets and cakes and chocolate and fried foods, over a three-month period. And at the end of the study, because we only had 67 people, we had no expectation whatsoever that we would see a significant difference between the groups on the depression outcomes. We just thought it was incredibly unlikely. And I sat with the statistician, and we did the stats, or she did the stats, and it was... You know, you don't unblind the groups until the end. We just knew it was group A and group B. And there was just this massive difference in the depression scores after three months, and we were just completely blown away.

  10. 20:27 – 24:51

    What changed in SMILES: remission rates, adherence, affordability, and replication

    1. RC

      How, how big a difference?

    2. FJ

      Well, h- to put it into a, a, I guess a, 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.

    3. RC

      So hold on. That, we, we just gotta pause there, because, you know, I'm asking you the question for the listener. I'm, I'm very familiar with the trial. Um, that is absolutely remarkable. You, you were talking about people who have got moderate or severe depression-

    4. FJ

      Mm-hmm

    5. RC

      ... who literally w- were, they were doing exactly what they were doing. If they were on treatment, I believe they stayed, they were already-

    6. FJ

      Yes, that's right

    7. RC

      ... they stayed on everything they were doing-

    8. FJ

      Mm-hmm

    9. RC

      ... but they were just split into two groups. And if you change your diet, within 12 weeks you got above a 30% remission rate in symptoms-

    10. FJ

      Mm

    11. RC

      ... of depression. That is absolutely staggering. No wonder s- you got so much attention-

    12. FJ

      Mm

    13. RC

      ... after that trial, because not only are the results amazing, the fact that you, everything you had to overcome, the skepticism, recruiting patients, all this kind of stuff, you know, and you didn't know till the end. I mean, do you remember where you were when... Do you remem-

    14. FJ

      Oh, absolutely

    15. RC

      ... wh- when, when you got the results? What, well, tell me about it. Where, what, what was going on?

    16. FJ

      Well, hilariously, the, the statistician was sitting there and she, you know, did whatever the statistician does with the magic computer, and she went, "Oh, no. There's no difference." And we sort of went, "Oh, well, that's what we expected." And then she said, "Oh, hang on. I haven't done, you know, X, Y, Z," whatever it was.

    17. RC

      Yeah.

    18. FJ

      And she went, "Hang on, hang on." And then she went back and she went, "Oh my God." [laughs] And we really just could not believe it. Um, and then of course we unblinded it and we went, "That's, that's the diet group."

    19. RC

      So-

    20. FJ

      "That's extraordinary."

    21. RC

      So initially you knew there was a big s- big, big improvement, but you didn't know yet, was it the, the social support group or the diet group? [laughs]

    22. FJ

      Yeah, that's exactly right.

    23. RC

      Oh, wow.

    24. FJ

      And then, of course, the, 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 skeptical about patients' ability to take dietary advice and act upon it, and we found that people loved this.

    25. RC

      They love it.

    26. FJ

      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.

    27. RC

      So the more you change your diet, the more you would improve.

    28. FJ

      Exactly.

    29. RC

      Wow.

    30. FJ

      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. And then lastly, and I think this is possibly the most important finding in the trial, was the economic evaluation, showing that massive cost saving, because it benefited people across the board. Now, the really cool thing is, um, a few months later, that study was more or less replicated, but in a group-based setting by the group in South Australia. They found very similar. People were able to change their diet. The degree of dietary change correlated with the degree of improvement. They saw a big difference between the groups, and it was highly, highly cost-effective. So that's two clinical trials that have shown this. So I think it's really exciting, and we just need to now get, uh, this translated into clinical practice.

  11. 24:51 – 29:34

    Practical access: budget-friendly food examples and role of dieticians

    1. RC

      So I, I recognize it's hard. But the second point is, you know, people were able to make those changes, and it was cost effective, and that is one of the biggest criticisms that gets leveled at this whole lifestyle medicine movement is, well, it's for the middle classes. You know, um, it's too expensive. Uh, low socioeconomic status is a big risk factor for these things, and of course it is, and we will touch on that. So that, that-

    2. FJ

      Yeah, absolutely

    3. RC

      ... I think that's super important. But generally speaking, do you think that it is possible to eat well without, you know, blowing your whole budget?

    4. FJ

      We, we know that it is because we did the really detailed, um, investigation of this. And I mean, you know, the sorts of things we were recommending to people were very simple. They were things like a whole wheat biscuit with a, a tin of tuna and, um, some sliced salad or, you know, a tin of beans. You can buy a tin of beans or a packet of dried beans so incredibly cheaply, and they're just brilliant.

    5. RC

      What, what sort of beans are you talking about?

    6. FJ

      So, like lentils-

    7. RC

      Right

    8. FJ

      ... or chickpeas or m- you know, any of those, any of the legumes. They're really fantastic. Super, super cheap. Tinned fish, frozen vegetables, nothing wrong with those, and really convenient. And we really focused on suggestions that were very feasible, so things that wouldn't take much time. You know, making up a big pot of stew at the end of the week in the slow cooker, which you can get really cheaply. Um, and just, you know, there's many ways that you can do it very, very inexpensively. You certainly don't have to be having organic food and, you know, organic blueberries and things like that. So I think that's a really important conversation and bit of knowledge that needs to be, uh, transmitted. But of course, one of the key issues we have is that there's so many people with vested interests, including big food, who, who really benefit from keeping the waters very muddy about what constitutes a healthy diet, and that has led people to be exceptionally confused. Now, I know that in the UK and in the US, something like 75% of junior physicians do not feel qualified to offer dietary advice to their patients, and a lot of that has got to do with the misinformation and the mixed messages that have, have come out of the diet gurus and, uh, big food as well about what is and isn't a healthy diet and what the evidence says about that. So I do agree that there's a massive challenge in clinical practice to, uh, tackle these things in the scope of a, you know, a 15-minute consultation, and it may be, um, in, in Australia, we're advocating that, um, there is a Medicare item number for people with mental disorders to be able to go and see a, a dietician, a clinical dietician.

    9. RC

      Yeah.

    10. FJ

      Because we know from the meta-analysis that we've done that if you use a clinical or a, a nutrition professional to deliver a dietary intervention, you get a far better outcome, and that's because they know not just what people should be eating, but how they might get there, how they might achieve that. So I think that that's one possible solution to the issue of, you know, um, uh, having limited time-

    11. RC

      Yeah

    12. FJ

      ... in clinical practice. You can also have shared appointments where you, you know, a clinical practitioner might see a number of patients at once with the same information, and then they've got peer group support. So there's different ways potentially of going about it.

    13. RC

      Yeah, absolutely. Uh, I just wanna highlight the point there, um, that on the, on this course that we run where we teach doctors, but it's not, it's primarily doctors, other healthcare professionals as well, we enc- ac- actively encourage referrals to nutrition professionals.

    14. FJ

      Mm.

    15. RC

      But, but I don't think that negates the need for doctors to know-

    16. FJ

      Absolutely

    17. RC

      ... how powerful these interventions are.

    18. FJ

      Mm.

    19. RC

      Because here's the thing, if we don't know about it, we're never even gonna think to refer to nu- a nutrition professional in the first place, and I'm really pleased the feedback we're getting from the doctors who've attended our course is it is increasing their referrals. You know, if they've got a, a clinical dietician nearby, great. If they've got a nutritional therapist nearby, great. Whatever, uh, you know, whatever services they have available to them, they're able to refer out. They start off in, let's say, their 10 or 15 minutes saying, "Hey, look, have you thought about diet as an approach?" And if a patient's engaged in this, they might give some preliminary advice, but also make that referral on to a nutrition professional who can actually go through that in detail. Um, so I think, I think that's a, that's a really, really good point. Uh, one, one thing I... I, I really wanna go into the, the foods that were in the SMILES trial. What foods were these participants given? And then why do you think that these foods had an impact on moods?

  12. 29:34 – 36:59

    Mediterranean-style eating, red meat findings, and the ‘diet wars’

    1. FJ

      Great question that we don't have the answers for. So, uh, we based the dietary advice on, um, the best science available, and that of course, the, the Mediterranean diet has the s- by far the strongest and the largest evidence base.

    2. RC

      And what do you mean by a Mediterranean diet?

    3. FJ

      Yeah, I know.

    4. RC

      'Cause a lot of people then say-

    5. FJ

      There's many [laughs]

    6. RC

      ... you know.

    7. FJ

      And, and, it, this is not a prescriptive diet. But it's basically a diet that is, um, much higher in plant foods, so vegetables and fruits, um, legumes, uh, that's your lentils and chickpeas, et cetera, nuts and seeds. So all these sources of dietary fiber, and we can talk about why that-

    8. RC

      Sure

    9. FJ

      ... we think that is particularly important in a little while. But also healthy fats, so these are the mono and the polyunsaturated fats from fish and olive oil, et cetera. You know, healthful forms of protein. But we also included recommendations for, um, three or four, uh, palm-sized servings of unprocessed meat per week, which is at odds with the traditional Mediterranean diet, and that was on the basis of, um, a study that I'd published where I saw very unexpectedly a very clear U-shaped relationship between- ... red meat intake and, um, depressive and anxiety disorders and even bipolar disorders in this large population-based sample of women. So women who had less than the recommended intake, which is this three to f- uh, four small serves a week, or more than the recommended intake, when we took into account their overall diet quality, they were twice as likely to have a clinical depressive or anxiety disorder.

    10. RC

      Okay, I mean, this is, this is super fascinating, especially with the growing movement to move to vegan diets-

    11. FJ

      Mm

    12. RC

      ... um, which is, you know, exploding really around the world in terms of popularity. A lot of people are doing it for, um, [lip smack] ethical reasons.

    13. FJ

      Mm-hmm.

    14. RC

      Um, and there's a lot of, uh, as you well know, a lot of controversy in what I call the, the social media diets wars. Uh, it really-

    15. FJ

      Yeah, [laughs] I call it that too. [laughs]

    16. RC

      It really highlights how, um, how complex nutritional research is because people seem to have the same paper, and there's five different interpretations, and then people write their blogs about them, and then Joe Public is like, "Well, what the hell do I do?"

    17. FJ

      [laughs]

    18. RC

      "Because I ... This expert who I respect is saying this. This expert who I respect is saying the complete opposite." And I think that, that confusion is causing big problems with patients. I s- I see that all the time.

    19. FJ

      Mm.

    20. RC

      They're just confused.

    21. FJ

      And with doctors as well. [laughs]

    22. RC

      And with doctors, exactly. And, you know, I, I'm sort of trying to keep on top of the research, and even I get confused sometimes. I think, "Well, hold on a minute. I thought that, and then now this trial is suggesting that." And it's-

    23. FJ

      Mm

    24. RC

      ... you've got to take that balanced approach. But let, let's dive into some of these foods. So red meat, right?

    25. FJ

      Mm.

    26. RC

      Is red meat, from what you have seen ... I mean, I, I mean, that's an overly simplistic question. I, I'm sort of, uh, I'm trying, I'm trying to bring out basically, do you think red meat is good for our mental health?

    27. FJ

      I have no particular opinion on it. I think our study was a really unexpected finding. It was a very clear finding, and it's sort of concordant with other epidemiological studies where you see a link between vegetarianism and poor mental health. But we just don't know whether it's a causal relationship. It could well be explained by third factors that we haven't measured or haven't accounted for. So I would not hang my hat on that. I do hear a lot of clinicians saying that they quite commonly will see young women who are menstruating, who are vegetarian, and they're really in a terrible state, and they have, um, they get a lot better when they reintroduce red meat into their diet.

    28. RC

      I have seen that many times.

    29. FJ

      Yeah.

    30. RC

      I really have. And, um, [lip smack] I guess this is one of the reasons why I'm very diet agnostic, and I have certain-

  13. 36:59 – 39:34

    Healthy vs unhealthy patterns aren’t opposites—and both matter for mental health

    1. FJ

      Absolutely. And I think that it's a really important thing though, is we don't know whether it's what people are eating or what they're not eating-

    2. RC

      Yeah

    3. FJ

      ... when they change their diet, and this is true like with the SMILES trial, we don't know if it was because they increased their vegetables and fiber, et cetera, or because they reduced their junk and processed foods. They did both at the same time. Um, but if we look at the epidemiological literature, what I think is fascinating is that healthy dietary patterns and unhealthy dietary patterns are not related to each other. They're not just the opposite of each other. There'll be lots of people who have really, particularly like kids, have lots of healthy food at home, but then they have lots of junk and processed foods when they're out and about. That is still problematic for mental health. There's other, other groups-

    4. RC

      That is so key. Say that again. That is really, really key, 'cause I think people think, "I can eat what I want, but if I have a bit of broccoli now and again, I'm being healthy."

    5. FJ

      That's right, and, and the evidence does not support that. In all of the incredibly extensive studies that we've done now, we see that healthy diet and unhealthy diet, wherever you sit on that scale, they're both independently related to mental health outcomes. So if you are having lots of healthy food, but also having lots of junk and processed foods, it's still gonna be a problem. Similarly, lots of older people will h- not be going out and having Mackers and, you know, lots of junk and processed foods, but they'll be having a very limited, kind of a white diet, whether at home or in a nursing home or what have you, and that's also problematic. So they're not just the opposite of each other, and we have to tackle both.

    6. RC

      Yeah, key, key points. In terms of the diet that your participants in the SMILES trial went on, you mentioned what those foods are, and you've also mentioned that we don't know what it was about it.

    7. FJ

      No.

    8. RC

      In my last book, The Stress Solution, there's a chapter on fiber and how that can help, you know, with the gut microbiome, and therefore stress levels. I quote some of your research. I quote some of John Cryan's research in there. What's really interesting for me, if we think about that diet, and, and I, the, I, I sort of, I think I wrote a paragraph on this. I said, "For me, whilst we're waiting for more research, there are a couple of things there which really spring out to me as that could be making a difference." You, you had fatty fish in there, I, I believe. There's fatty fish in the diet, was there? Sort of-

    9. FJ

      Yeah, fatty fish and lots and lots of olive oil as well.

    10. RC

      Yeah, so there was some Omega-3s from the fatty fish.

    11. FJ

      Mm-hmm.

    12. RC

      You've obviously got all the benefits of olive oil. So either of those independently you could, you could make a case for thinking-

    13. FJ

      Yeah

    14. RC

      ... was it that that did it?

    15. FJ

      Yeah.

    16. RC

      But then the big one for me, as well as that, was this whole point that you were encouraging a very diverse range-

    17. FJ

      Mm

    18. RC

      ... of foods.

    19. FJ

      Mm.

    20. RC

      And so let's talk a little bit about diversity of foods, and let's talk-

    21. FJ

      Mm

    22. RC

      ... a little bit about the gut microbiome and why that is so important.

  14. 39:34 – 45:18

    Gut microbiome, fiber, diversity, and emerging mechanisms

    1. FJ

      It, it's so critically important, and it's so interesting. You know, we can see that medical science is being transformed a little bit in like what, how physics was transformed when they discovered the ultra-small particles. 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. The bacteria in your gut in particular, at 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, your nuts, uh, your 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, 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 through these particular receptors. They influence gene activity. I mean, really importantly, most of what we know so far comes from animal studies, so we always have to be a little bit cautious, but there are more and more human studies, and we're doing many studies in our center that is, you know, looking at this.

    2. RC

      That's the, the Food and Mood Center.

    3. FJ

      The Food and Mood Center.

    4. RC

      Love that name.

    5. FJ

      That's right, yeah. [laughs]

    6. RC

      Absolutely love that name. Who came up with that?

    7. FJ

      Oh, well, it was [laughs] a joint effort between myself and the, the, the comms department at Deakin. [laughs]

    8. RC

      But I just, I think that's progress in itself, and in the 21st century, we actually have an institution called the Food and Mood Center.

    9. FJ

      Yeah.

    10. RC

      I think that, that's progress.

    11. FJ

      Well, it, it's unique in the world in its focus on nutritional psychiatry research, and we've got more than 20 different projects underway at the moment, many more in the planning stages. Trying to get funding for research, of course, is incredibly difficult, but we've had some traction with philanthropic funding, which has been great. But most of the studies that we're doing are looking at this diet, gut microbiome, mental health, um, triangle, because we know that the gut microbiome is so important for our immune system, for our metabolism and body weight, for our, our, the, our brain health, and right across the board, and we know this from a number of different, uh, sources of information, and there's huge amount of research that's being done a- across the world now in this field, which is wonderful 'cause 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 the, your gut health within a very short space of time, like even within days-

    12. RC

      Within days

    13. FJ

      ... by changing your diet, and that's such a powerful n- um, you know, thing to understand.

    14. RC

      So, so do you have a certain recommendation you make for people in terms of diversity?

    15. FJ

      Yeah, so what we know so far, and again, we need more studies in humans, but on the basis of some pretty good evidence in humans as well as many, many studies in animals, we know that obviously we need dietary fiber because the bugs can't do what they're supposed to do without the dietary fiber. And, you know, none of us are getting enough dietary fiber.

    16. RC

      Yeah.

    17. FJ

      Not even close. Uh, in Australia, less than half a percent of children and adolescents get their recommended intake of vegetables and legumes. It's less than half a percent. So this is not-

    18. RC

      Less than half a percent?

    19. FJ

      Yes.

    20. RC

      Wow.

    21. FJ

      This is not just an issue for those of, um, lower education or income. This is something across the board, less than 5% of adults in Australia. So we're not getting enough dietary fiber, so the bugs can't do what they're supposed to do. But polyphenols seem to be really important. These are the things that are in colorful fruits and vegetables and green tea and, and dark chocolate and things like that.

    22. RC

      And coffee for lo- there's coffee lovers out there.

    23. FJ

      Yeah.

    24. RC

      They contain polyphenols.

    25. FJ

      That's right. Yeah, yeah, and, uh, really fascinating work, again, in animals, but showing that if you, if you put one bunch of, of rodents on a normal diet, they don't necessarily gain weight, but if you put another group on a high-fat diet, of course, they, they gain a lot of weight. But if you put a third group on a high-fat diet and then supplement it with polyphenols, they only put on about half as much weight.

    26. RC

      Yeah, you mitigate it.

    27. FJ

      Yeah, so incredibly interesting research. But then your healthy fats, your mono and your polyunsaturated fats, uh, and your quality proteins. But it might also be what you're not eating that's really important in your gut health.

    28. RC

      Yeah.

    29. FJ

      Again, from animal studies, we see that, uh, emulsifiers, which are ubiquitous in processed food, seem to strip the gut lining. We see that artificial sugars seem to have a negative impact on, on the gut. 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.

    30. RC

      Yeah, it's incredible. The, the Hadza tribe, this hunter-gatherer tribe in Tanzania whose, whose lives are relatively untouched by modernity, I read that they're exposed to 2,000 different plant foods in their lifetime. I think they eat about 800 of them.

  15. 45:18 – 55:32

    Early life, pregnancy, and environment: compassion + systems change

    1. RC

      Yeah

    2. FJ

      ... illnesses. In Australia, where I am, in Melbourne, it is the food allergy capital of the world, and it's certainly one of the asthma cap- uh, capitals as well. No one really understands why, but we think it's linked to the early life gut microbiome because based on what we know so far, the early life gut microbiota plays a really key role in the development of our immune system and also our brain development. Now, we've just finished a really important study in pregnant women at the Royal Children's Hospital, looking at whether if you help women to change their diet during pregnancy, does it affect the infant microbiome? Because we, we need to make sure that the infant microbiome is optimized, we think, to ensure that that child has a strong immune system and, um, optimal brain development.

    3. RC

      Yeah, I mean, the implications of this are huge really because, you know, we, we saw stuff talking about the SMILES trial. So somebody who has got depression may start to get some benefit from changing their diet. That's incredible in itself, but, but taking that research on and talking about, and thinking about what you just said, if early life is so important, and if the, the diet of a pregnant lady is so important, you know, if we're trying to get to the root of the root of the root of a problem, yes, it's great to be able to treat people who've got a problem, but wouldn't it be great if the research builds up where we know, actually, you know what? When you're pregnant or, or, or maybe when, even pre-conceiving-

    4. FJ

      Mm

    5. RC

      ... it's important then to focus on your health and your microbiome health. The, the implications in terms of the downstream effects-

    6. FJ

      Yeah

    7. RC

      ... could be profound.

    8. FJ

      That's right, and I talk about that a lot in the book.

    9. RC

      You do.

    10. FJ

      That-

    11. RC

      It's a really nice bit

    12. FJ

      ... you know, the, the, the metabolic state, so whether parents to be are overweight or obese, whether they've got high blood glucose, all of those things seem to be very clearly linked to, um, both cognition and other developmental outcomes in children. We led the first study looking at the role, the potential role of, um, mothers' diets during pregnancy on children's emotional health. There's been many, many s- more studies since then showing that what mothers eat during pregnancy is linked to their children's emotional health, even when you take into account all sorts of other really important factors. And certainly, if you look at the animal studies, you see that if you feed pregnant rats or mice or other non-human primates, those sorts of, uh, animals, a, a junk food, Western-type diet during their pregnancy, you see all sorts of impacts on the offspring that are relevant to mental health in humans.

    13. RC

      Y- you see it in, you know, we talk about diet. Um, I, I wrote a chapter on touch in, in, when I was writing about stress, and I was looking at this research that shows that, um, pups who lick their offspring c- ... a lot when they're young, you modify their response to stress-

    14. FJ

      Mm

    15. RC

      ... for the rest of their life.

    16. FJ

      That's right.

    17. RC

      Because that, that sort of close contact with your parents at a young age almost in many ways sets your stress responsiveness for the rest of your life.

    18. FJ

      Mm.

    19. RC

      It, it's really quite incredible. But one thing, uh, Felice, I think you do beautifully well in the book is you write with real compassion, and when you talk about diets for pregnant women, you also talk about, "Wait a second, let's not feel bad about this. Let's not put blame on people." And I think it's really important when we're talking about what a pregnant mother is eating-

    20. FJ

      Mm

    21. RC

      ... because a lot of people will hear that and go, "Oh, no, you know, when, when I conceived, um, I was having McDonald's every day, and what impact has that had?" And, and I think there's a... Well, I, I'd love to explore what you think about that.

    22. FJ

      Mm.

    23. RC

      It's not about putting, making people feel bad about their choices, is it?

    24. FJ

      No, that's right. And, uh, my, my jumping-off point is always around public health and the fact that we need to make our environment supportive of healthful food choices. So in the West now, even if you go and fill up your car with petrol or anywhere you go, you are bombarded with opportunities and marketing to prompt you to consume these ultra-processed food products. Now, in the US, nearly 60% of energy intake is coming from ultra-processed food products. 60% of children alive today in the US will be obese, not just overweight, obese by the time they're 35, which is their prime child-rearing years. It's not quite as bad in the U- UK and Australia, but we're certainly getting there, and that's because the food environment supports really poor choices. We have, uh, very few limits on marketing, so big food can market, you know, um, really, uh, with impunity. These foods are very, very cheap. They're very easy to produce. They've got a very long shelf life. They're highly palatable. I mean, we are designed to want those sorts of high-fat, high-sugar foods. And they're ubiquitous. They're just everywhere. We can't escape them, so the food environment makes it very difficult to make healthful food choices. And I talk about this a lot in the book, is that it's not about individuals.

    25. RC

      Yeah.

    26. FJ

      It... You know, yes, we want to empower people to make healthful choices in their life, but it shouldn't be that hard because the environment needs to support those healthful choices.

    27. RC

      Yeah, I think you start off in the book talking about the Victorian times, don't you?

    28. FJ

      Yeah, yeah.

    29. RC

      And that, that's a nice example of this.

    30. FJ

      Well, it was s- such an interesting st- uh, it was an interesting paper

  16. 55:32 – 1:07:50

    Personal realism, 80/20 approach, whole grains, FODMAPs, and next steps for the field

    1. FJ

      Look, I'm by no means a purist, and I think it's actually really bad for your mental health to be really hung up on the-

    2. RC

      Yeah

    3. FJ

      ... details and being perfect with all your food choices. I th- I go by the 80/20 rule.

    4. RC

      Yeah.

    5. FJ

      And certainly, if 80% of my food choices are good, that's gonna put me way above the rest of the population based on what we know about how poorly people are eating. Um, you know, I had, um, popcorn on the way up today because I'm really, really jet lagged, but I also had a big vegetable soup that I got at the station. And you know-

    6. RC

      Yeah

    7. FJ

      ... I find that you can make healthy choices nowadays, which is great because even 10 years ago, you, there were no healthy-

    8. RC

      No

    9. FJ

      ... choices from takeaway. But now you've got Mexican, you've got Japanese, you often can buy really nice soups, you can get kombucha to drink in the, you know-

    10. RC

      Yeah

    11. FJ

      ... the takeaway. So things are certainly improving. Basically, my recommendation is just try and avoid the ultra-processed foods and have as much diversity and h- of whole foods as you can, and so what we call a plant predominant diet.

    12. RC

      Yeah.

    13. FJ

      I do really worry about the low carb and the high fat diets. Um, as I said, we're about to start a-

    14. RC

      For longevity or for... 'Cause in the short term, uh, uh, people are getting good results on them with things like-

    15. FJ

      That's right

    16. RC

      ... their blood sugar and, and certainly weight loss for sure.

    17. FJ

      Yeah.

    18. RC

      Uh, and some are reporting improved cognition in the short term. So is-

    19. FJ

      Mm

    20. RC

      ... your worry long term or, you know, e- expand on that.

    21. FJ

      It's, it's long term. So what we, what we see from all of the evidence is that long-term diets that are higher in complex carbohydrates and lower in animal protein and fat are linked to longevity. But in the short term, diets that are lower in carbohydrates and higher in animal protein and fat are linked to leaner body weight and more reproductive success.

    22. RC

      I, I do wanna touch on whole grains because whole grains have become quite a controversial area in, in the diet wars, and I think that's because often what we consider to be whole grains are not whole grains.

    23. FJ

      Mm.

    24. RC

      Um, so I think it's quite clear that there's pretty good research suggesting that real whole grains can have beneficial impacts on your gut microbiome and consequently on your overall health, including your moods.

    25. FJ

      Mm-hmm.

    26. RC

      Um, what do you see the problem with whole grains? Is, is it that interpretation? Is it that we're, the food industry are marketing refined grains as whole grains?

    27. FJ

      Yes. Basically, yes. And I think, you know, people in, in the US where their food system is just so broken and has been-

    28. RC

      It really is

    29. FJ

      ... for decades to the point where nobody alive today in the US remembers what normal food looks like. I mean, it really is, it's a, it's a rarity. And for them, whole grain might be a brown bread that's still highly refined and full of all sorts of things. But if you look at certainly the epidemiological data, whole grain intake is at, out of all of the food groups, the most strongly associated with improved health outcomes. If you look at the gut and what we know so far, whole grains, and here we're talking about things like oats and barley and freekeh and spelt and, and buckwheat and brown rice. So things that are true whole grains are just a really valuable source of fiber for that fermentation process of, of the gut. But they're also anti-inflammatory.

    30. RC

      Yeah.

Episode duration: 1:07:50

In the uListen app, the transcript lights up word by word as you listen. Get uListen

Transcript of episode OfVGRCVGAf8

Get more out of YouTube videos.

Read along on your phone, search it beside the video, or ask your favorite AI app what was said.

iOSAndroidClaudeChatGPTChrome