Why 90% of Alzheimer's cases are preventable | Drs. Ayesha and Dean Sherzai

25:58I think we might be jumping ahead of ourselves, but the London taxi driver study. I was just thinking about that. We've been married for a while. Yes. And you know, the concept that most people think that you have to do this during your youth and very early in life to create that bank account that Dean was describing, but it can actually, your brain can create more connections at any age. One of the examples is the London taxi driver study, phenomenal study where they compared London taxi drivers to bus drivers. And apparently, to become a taxi driver, this is the pre-GPS time. You know, the candidates had to go through this arduous testing technique or mechanism called the knowledge.

26:45They had to learn the names of the streets and the locations. And, you know, I don't know if you've lived in London or you are from London, but it's pretty intense and it's very chaotic. And so to memorize the different elements takes a long time and it takes some effort. So they looked at the brains of those who went through this testing versus the brains of bus drivers who had a specific route and they didn't really have to memorize anything. And at the end of that particular study, they found that taxi drivers had actually grown their brain. They'd grown their brain. Particularly the part of the brain that is responsible for encoding memory called the hippocampus, while those of the bus drivers didn't.

27:27And these were individuals who were over the age of 50. And that in itself is an example of how dynamic the brain is. And obviously they did neuropsychological testing or memory testing them as well. And they scored higher as far as their memories are concerned. That's extraordinary. So really your brain, you can build this and this matters. I'd love to go back to this topic that you just picked up, Dean, earlier about saying that these four contributing factors, I think you said inflammation, oxidation, so problems with fat and problems with sugar. Yes. Could you help me to understand a little bit more about how that is driving this?

28:03Yeah. So a lot of times people say Alzheimer's is type 3 diabetes. But when we look at the data downstream, there seems to be lots of other pathways that can lead to this trauma that then accumulates into amyloid later and then accumulates into the disease. You can come to it from diabetes or prediabetes. We did a study in Haines, which is a nationwide study. We looked at it and it was published a few years ago. Looked at prediabetics and not prediabetics in their 70s, prediabetics in their 50s. and even they had lower cognitive state. And other studies have shown that as well. People who have pre-diabetes, which means their blood sugar levels are higher than normal, actually their brain is like influenced by that in a bad way.

28:48Yeah, I mean, we have to be careful not to overstate that because different conditions, different people, how well you can control that and the level and how well you control your pre-diabetes and diabetes matters. Just because you have diabetes, that doesn't mean you're going to develop dementia. In fact, if it's treated well, If it's controlled, well, not at all. So uncontrolled prediabetes and diabetes does influence cognition over time. Same thing with lipid. There's a lot of data on LDL and cholesterol, specifically LDL, and many, many studies. And Aisha will tell you all these studies that show that people with high LDL, even in midlife and even earlier, have much greater risk of dementia later on.

29:30So that's a different pathway, right, LDL. Sometimes it's both of them. And sometimes people have both that. And then people who have a chronic inflammation have the same thing. So those are the four pathways that can either separately or together, which often with metabolic diseases, they often happen together, can contribute to enough damage, enough abnormal systems and protein production that can later manifest into either vascular dementia or Alzheimer's dementia. What's the lifestyle? What are people doing that are contributing to these different factors that you're describing causing this risk?

30:07So in studies, especially the types of studies that look at large groups of people over a long period of time, have shown us that there are a number of factors that matter, and especially their existence throughout the span of our lives can either increase or reduce the risk of developing Alzheimer's disease. The Lancet magazine, so it's a well-known medical journal, and they come up with a consensus report every three to four years. And recently, just a few months ago, they created this beautiful picture of the risk factors during childhood, midlife, and late life. And they have listed a number of different factors.

30:52And Dean and I have, you know, kind of made it easy for our patients to remember these factors. So we've created this acronym called neuro, N-E-U-R-O, self-serving because we're neurologists. But, you know, N stands for nutrition, E, exercise, U, unwind or stress management, R is restorative sleep, and O is optimizing cognitive activities or building cognitive resilience. And under each of them, so for example, in nutrition, we have lipid metabolism, LDL cholesterol that is, you know, contributed or affected by the kind of foods that we eat. Smoking comes under that as well. Alcohol comes under that as well.

31:29So all of these factors play a very, very important role in either reducing or increasing our risk factor for Alzheimer's disease. And we talk a lot across this show, I think, about how sort of modern Western lifestyles have had a lot of unintended negative consequences. And so we talk a lot, obviously, about nutrition here, impact on microbiome, impact on sort of the rest of our health. And I think everybody here listening to this show sort of knows, well, you know, if you eat the wrong sort of diet, then it increases your risk of a heart attack and, or indeed getting diabetes. I think a lot of people will be more surprised that it's linked to something like Alzheimer's.

32:08If we just take this back to sort of simple aspects of lifestyle, like what are the aspects of lifestyle? If you were going to try and explain to, you know, my son or my daughter, like that actually matter for Alzheimer's, what do they need to worry about? So the organ that's most affected is brain. This little three pound organ, which is 2 % of your body's weight, consumes 25 % of your body's energy. 25%. 25%. It's amazing. At any moment. At any moment. And it also is the most vascular organ in the body. It has more arteries and veins than any other organ in the body. if you connect all the arteries and arterioles and capillaries end to end, it's 400 miles.

32:52There's a picture, people can actually search for this. They've denuded, they've gotten rid of all the other tissue and all they've left behind is the vasculature. And then you look at it and you say, how come there's room for anything else? There's room for about 87 billion neurons, one quadrillion connections. So it's really well-compacted system. So anything that affects vasculature. You were worried about the vasculature. Well, guess what? Most vascular organ is the brain. Metabolic, 25 % of your energy. Oxygenation, 50 % of oxygen at times. So it's the organ that's going to be most affected by all the metabolic things that affect everything else.

33:27Absolutely. So when you're thinking about your exercise or your nutrition or any of the rest of these things in your health, anything you're thinking about that might affect your heart or any of the rest of it, you're saying it's also directly affecting your brain, maybe even more so. Much more so. Yeah. People always think that the brain, you know, just the organ that's above your neck is somehow disconnected from the rest of your body. And it's not. If we think of everything that affects our gut, our heart, our kidney, our skin affects our brain as well, I think it will make more sense. And we, Dean and I, you say that it actually, your brain gets affected most by anything you do.

34:04So the kind of foods that you eat, the kind of people that you surround yourself with, the kind of activities, movements that you choose to partake in, all of these impact your brain health significantly. The reason we say that 90 % and we haven't seen that because we don't really optimally do all those things, which is optimally eat, optimally exercise, optimally stress manage. And we'll talk about stress and its effect, its profound effect. Optimally sleep, the only cleanse, the only cleanse is sleep and water. We will describe the process of what happens during sleep. It's literally the most efficient city cleaning mechanism you could ever imagine.

34:47And then mental activity, challenging your brain to keep these billions and trillions of connections connected and making more connections in your 60s, 70s and beyond. If everybody does that optimally, you're not going to avoid for a great majority. We want to be responsible. There are those that are genetically driven. We talked about 3%. We even pushed the edge all the way to 10%. So for about 90%, but that means optimal. But here's the good news. And Aisha did a study in California teacher study, the largest population, 133 ,000 people. She won the youngest researcher award for this. But the study showed that it's not all or none.

35:25Every positive move you make incrementally helps the brain. Whether it's small changes in nutrition, small changes in movement, small changes in stress management, Small changes in sleep where you get those four to five cycles of sleep, deep restorative sleep, you will make profound changes. So this is an empowering message and it doesn't rely on some gimmicks. Aisha, earlier you mentioned the neuro plan, but can you remind us what is it and who should follow it? It stands for nutrition, exercise, unwind or stress management, restorative sleep and optimizing cognitive activity. And these are based on evidence-based lifestyle intervention and lifestyle factors that improve brain health and prevent cognitive decline on Alzheimer's disease.

36:16Amazing. And who should be following them? Everyone, whether you're 9 or 99. So N, nutrition. Very important. And I think you know this more than anybody else. And you do such a fantastic job in this podcast empowering people about nutrition. So in the realm of neurology and neuroscience, we have a tremendous body of evidence showing that the types of food that people choose directly impacts their brain health. And it can prevent devastating diseases like stroke and Parkinson's disease and Alzheimer's disease and other types of dementia, particularly vascular dementia. And when you look at the different dietary patterns, it's essentially a variation of the same theme.

36:57Diets that are high in plant-based foods, fruits, vegetables, whole grains, legumes, nuts and seeds, and sources of polyunsaturated fatty acids, they tend to do very well. So that could be a mind diet, a Mediterranean diet, a DASH diet. It could be any cultural diet that highlights the importance of foods that are high in polyphenols, that are high in fiber, good fats, which is polyunsaturated fatty acids. And they're low in processed foods, in refined carbohydrates, in sources of saturated fats, which are the type of fats that can increase your LDL cholesterol and can potentially harm the brain.

37:37And the numbers are incredible. For example, there was a study that was conducted in Rush University in Chicago here in the United States. Dr. Martha Morris, she was the lead researcher, the late Dr. Martha Morris. And she looked at adherence to the MIND diets. The MIND diet is a hybrid diet. It stands for Mediterranean Dash Intervention for Neurodegenerative Delay. Thank goodness for the acronym MIND. The Mediterranean Dash Combination. And when you look at the diet, it's not a cultural diet per se. It's essentially a scoring system. When people adhere to the MIND diet, they get a high score for consuming green leafy vegetables, cruciferous vegetables, other vegetables, fruits, specifically strawberries and blueberries that are high in polyphenols and flavanols.

38:26When they consume whole grains, when they have less refined carbohydrates such as white bread or added sugar to foods, when they consume nuts, seeds, which are great sources of polyunsaturated fatty acids and omega fats. When they consume extra virgin olive oil, which could potentially have high polyphenols and mono and polyunsaturated fatty acids, they get a high score. And sources of omega-3 fatty acids, which are found in fatty fish or flax seeds, chia seeds, hemp seeds. And they get a low score when they consume a lot of red meat, a lot of high-fat dairy products, which may be higher in saturated fats, and if they consume too much alcohol.

39:04So that is essentially the concept that you find in all of these dietary patterns. And in this population, when they adhere to the MIND diet, they reduce their risk of developing Alzheimer's disease by 53%. And even moderate adherence reduce the risk by 37%. And in my study, in the California teacher study, same thing. We looked at the Mediterranean diet and we looked at the scoring system. And the beautiful thing was it was not an all or none phenomenon. Every small incremental change towards that positive outcome, say, for example, adding a cup of green leafy vegetables or switching a donut for some fruits, it actually made a huge difference.

39:45And I think that's pretty empowering for people to know that you don't have to jump into it wholeheartedly. You can start by simply changing a few things moving forward. I'd love to ask a question that I think quite a lot of our listeners will have right now. So a lot of listeners to this podcast are also Zoe members. And so that means that they're using our app, they've used a test kit to then get this personalized advice. And that advice was built really to optimize overall health. And so it's very much focused on gut health. It's very similar to a lot of the advice you're talking about with a Mediterranean diet.

40:19It doesn't have a particular focus on trying to be like a brain specific diet. It's like it's reducing inflammation, all of these sorts of things. And I think what they're going to be interested in listening to this is, is there anything different and specific that you would be recommending for somebody who's worrying about dementia? Or given what you were saying about how sort of the brain is just even more affected by what's happening everywhere else, is this sort of like the best brain diet is like the same as the best overall health diet? Yeah. I mean, just for transparency, we're whole food plant-based ourselves.

40:52We don't push that aggressively than others because we think that you can achieve brain health in many other ways. In most cases, it's the same. It's the same diet, whether it's for heart, for everything else. A couple of things to be aware of at this point. I mean, as I said earlier, I love the concept of to the best of our knowledge today. The three elements that are important for brain, B12, make sure that your B12 levels are normal or on the higher side, vitamin D and omega-3. We just did two reviews, two comprehensive reviews, one on omega-3 and the developing brain and omega-3 on the aging brain.

41:28And in both of them, there seems to be trends towards needing omega-3, being extra aware of omega-3 because omega-3 has that much effect. It's the only fat that the body doesn't make. Well, omega-6 as well, but in the Western diet, you don't have to worry about omega-6. In fact, we have excess of omega-6. So omega-3 is very, very important. DHA for the brain in particular makes up more than 50 % of brain's volume. So it's critically important and we don't make it. So we have to kind of be aware of it. So that's basically, whether you get it from fish or in our cases and other people's cases, they can get it for chia, flaxseed or supplements.

42:03And that's basically it. The acronym is SMASH. Salmon, mackerel, anchovies, sardines and herring. The fatty fish. But it's not the fish. The fish gets it from the algae. So it's the omega-3 in particular. There's no uniqueness beyond that. So that's important to kind of know where are you going to get your omega-3 and be aware of it and get it. And we just did a conversation with a world-renowned lipidologist and omega-3 expert who said that even people who are just taking it from chia and flaxseed, if they're extra aware of it, they should be fine. Yes, if they have healthy livers and if they're eating a healthier diet, that we should be able to convert ALA into EPA and DHA, which is important for brain health.

42:49And also being aware of omega-6 because there seems to be a competition with enzymes. So lowering your omega-6, which is processed foods, right? And making sure that alcohol does not affect the liver to the extent that it's going to affect the transition. So that's basically it. Am I allowed like a glass of red wine a few times a week? What does the brain doctor say about that? That's interesting. That's a funny thing. So I think we've a pretty big following on social media and I've never been lambasted more than when I said the amount of alcohol that's good for your brain is zero. But does that mean that I never drink alcohol?

43:23I do, you know, once a month, once a couple of times, if there's a glass of wine, I sip it. But I say that I will never create science for my hypocrisy. So once in a while, it's not gonna damage at all, but it's the chronic use of alcohol that's going to affect the brain. Some of the intermediary factors that are important that are affected by diet and that in turn affects brain health and Alzheimer's risk is LDL cholesterol. And I'm very, very aware of that fact. And it's almost become a jingle. Wherever I go and there's a one minute, if you could just tell me one thing that I need to do for my brain health, what would it be?

44:01And my answer is usually, keep an eye on your LDL cholesterol. It was recently added by the Lancet Committee for Dementia Prevention as one of the major risk factors for dementia in midlife. And so because we know that there is almost a direct relationship between saturated fat consumption, LDL, it's important to keep that under the radar and address it as much as possible. So my conclusion is I can go to my dad and tell him what I tell him all the time, but he doesn't listen to me anyway, which is that sort of changing your nutrition, moving towards the sort of diet that, you know, we probably talk about on this podcast all the time.

44:38Yes. Can have a profound impact on your risk of dementia. That is very evidence-based and yes, absolutely true. He still won't listen to me, but at least I can say that. Could we move on? So I think we are on N. And so I guess the next one must be E. E, exercise. Exercise is tremendously important. Both Aisha and I have degrees in nutrition. She's also a culinary chef and she knew the importance of nutrition. She was doing her fellowship at Columbia University in New York. In the mornings, she would be in a fellowship in the ICU. and at night she would take cooking classes because realizing that that's how important it is to teach people how to eat healthy, but also tasty, right?

45:18So the taste is important. Oh, very important. But recently we realized that exercise is as important, if not more. Let's say as important so that we don't create a competition between the nutritionist and the exercise people now. But exercise is tremendously, probably more important for the brain. Again, I think we're being selfish because we're neurologists, but it's extremely important. It actually grows the brain. So we say that nutrition and stress management and sleep create the environment for the brain to thrive. But the two elements of neuro that grow the brain is exercise and mental activity or optimize.

45:55Do you know someone who's worrying about keeping their brain healthy as they age? And they might not know that keeping your brain healthy starts in your 40s. Why not share this episode with them right now and show them how simple lifestyle changes can protect their brain and allow them to enjoy many more healthy years. I'm sure they'll thank you. So I think most listeners will be, like the nutrition makes sense. I understand why that's affecting my brain. It's really obvious. But the exercise seems really, I can't think of any exercise my trainer has made me do where I'm like stretching my brain, my biceps and my legs.

46:33So could you help us to understand? Have you ever done leg exercises? Yes. Yes. So leg exercises in one study showed that they compared MCI patients pre-dementia. Okay. And it was a really, really well done, robust study. Yes. One arm was told to do leg exercises. The cases. Yes, cases. And the other arm was stretching. Not that stretching is bad, but in this case, it's compared to the two. They didn't really do any resistance training. No resistance training. Exercise reduced the chance of progression from MCI to dementia by more than 35%. So how could it do that? Multiple ways. One is we know that people who exercise increase this hormone called BDNF, brain-derived neurotrophic factor, which is basically, if fertilizer is powerful for plants, BDNF is a thousand times more powerful for the brain.

47:23That's how important it is. But it's not just BDNF, it's GDNF and VGF as well. VGF is vascular. Remember that the brain is the most vascular organ and there are hormones that keep the brain vasculature healthy and growing. So VGNF grows with exercise and GDNF is glial cells, which is the protective cells. So it directly affects the infrastructure and the hormones and the chemicals and the building blocks of the brain every time you exercise. It's not like a muscle. I'm not directly stretching my brain during the exercise. But when I'm doing this exercise, it's then creating these hormones and other chemicals that are going into my brain and they're having these really beneficial impact.

48:06Profound benefit. Which is, it reminds me of many of the conversations we have talking about the microbiome and this understanding now that the food we eat is affecting these microbes that are then creating these chemicals that go to the brain. But am I stretching this or there's an analogy here? 100%. Yeah, that's through microbiome. But this is directly, every time you exercise, especially leg strength, it has direct effect on the brain. Can I ask, because you just mentioned leg strength. So is there particular types of exercise that are better for the brain? So, yes. It seems that for a long period of time, we thought that walking and running, which is phenomenal.

48:42Walking is amazing. Running is great if people want to do it. But building muscle specifically makes a huge difference. And because we have the largest groups of muscles in our legs below our belt, activating those muscles can create more of these growth hormones that Dean was talking about, specifically brain-derived neurotrophic factor. So doing things like squats and lunges. And sometimes we joke and say, we say bigger legs, bigger brain. That could be a title for a really nice book. But really focusing on our glutes and our hamstrings and our quads is incredibly healthy for the brain. And it also prevents falls.

49:22And as we grow older, our balance and our mobility gets affected. And the number one reason why a lot of our elderly community members end up in the emergency room is because of imbalance and falls. And by strengthening our legs, we actually reduce the risk of falls as well. So it has so many different benefits from multiple angles. That's amazing. I never heard that before about, and I'm going to be discussing that with my son as well as a teenager. So he's really gone into the gym. Don't skip leg day. Exactly. But I feel that he feels that for the full aesthetic, maybe the legs doesn't have quite the same impact.

49:56And so now I'm going to tell him like, well, you've got to still care about the legs. I think that at his age, worrying about dementia is very, very low on the list of concerns. One other element to add is frailty. A new study shows that the one variable that determines length of life is frailty. And frailty, the main determinant of frailty is leg strength. So in many ways, I think people focusing on leg strength in a responsible way, you don't have to, You're not going to be a bodybuilder. So don't do squats with weights on your shoulder, things of that nature. And people have knee issues and back issues.

50:31Taking all of that into consideration, creating a program that builds your legs is probably the most effective thing you can do for your longevity and your brain health. Isha, I'd love to move on to the next one, which I think is going to be you. Yes. So you, unwind or stress management is critical. We're learning more and more about it. And we know that when people are under a lot of stress or if they are chronic worriers, which I think is such a ubiquitous condition, we're worrying about things and we're constantly inundated with information. And we never really were trained to deal with it.

51:09We're never trained in school to deal with stress. It's not something that is a part and parcel of our life, and we're just assumed to live in it and just brush it aside and not even complain about it. But we now know that when people have either adversities early in life or when they go through periods in life that are difficult to manage, whether it's loss of a loved one, loss of a job, divorce, family issues, all of that can impact our brain. There is a cycle, it's called a pituitary hypothalamic adrenal axis, which essentially translates as how you feel affects you physically. So when we experience stress and adversity, our body starts secreting specific neurochemicals and hormones that can be damaging, specifically adrenaline and cortisol.

52:02You're saying that this stress really is a real physical effect on my brain? And they've done studies in individuals who've been through stressful life situations or people who have immigrated from one country to another or who have tremendous anxiety as just a habit of being in that stressful situation. And they have realized that the chronic secretion of cortisol and adrenaline affects the different parts of the brain and it shrinks the brain. People who have been stressed for a long period of time have smaller brains. It shrinks your brain. It shrinks the brain. And specifically the part of the brain, the hippocampus, which is responsible basically for memory, but it has a lot of other responsibilities as well.

52:43It is very sensitive to the level of cortisol and adrenaline in our body and it shrinks. And therefore people have difficulty memorizing things or paying attention or even solve their problems, make a good decision about things. So globally, it affects our cognition and specifically, it really, really impacts our memory. And if this is continued over time, it can result in Alzheimer's disease. And so that seems like a very dark subject, but the good side, the positive side of it is it can be managed. And stress management in itself is a whole conversation that we could probably spend a lot of time on.

53:21But it starts with perception, identifying bad stressors in our life. And especially in this, you know, fast paced life that we live in, we're not able to actually identify our stressors very well. And so identifying bad stresses and differentiating them from our good stresses, the kind of stresses or activities that we bring on ourselves to help us grow, to be better versions of ourselves, whether it's going to school or doing a podcast with you or, you know. Hopefully not too stressful an experience. So just having cameras and a microphone in front of you, you feel responsible. You want to make sure that you bring out the best to the audience so that it's helpful.

53:59These kind of activities are ones that grow the brain, that really puts a purpose with an activity rather than something that's dark. So not all stress is a bad thing. It's actually the opposite. There's good stress and bad stress. And we want people to actually increase their good stress. Remember, that's the part that challenges the brain continuously. sleep. And the way you differentiate those is bad stress is the kind of activities that are not driven by your purpose, that don't have clear timelines or clear direction. And that sense of uncertainty and lack of purpose actually creates this indolent feeling that translates through the limbic hypothalamic pituitary pathway, chronic adrenaline cortisol overload, which then also affects inflammation, by the way.

54:44So this is absolute plenty of data that shows this repeatedly. Now, the other side is good stress that's purpose-driven, has somewhat of a clear direction, somewhat of clear timelines when you achieve it. All these books about dopamine, that's what that is. Dopamine is not the joy hormone. Dopamine is not the success. It's the anticipation hormone because the moment you have the climax, it's not at the climax, it's not the dopamine just No, at the climax, dopamine actually drops. Dopamine is the anticipation of building of that tension. In this case, knowledge, challenge, taking on things that have somewhat of a clear direction.

55:24You know you're gonna achieve it. That's a direct timeline. And the anticipation builds dopamine, which has a direction with happiness, also grows the brain. This is the beauty of separating good stress from bad stress. So the secret comes to the language you have in you. What does the R stand for? So R is restorative sleep, and it is so important. I think we've said all of these elements are really important, but sleep is one of the newest member of the family. For a long time, we took pride in not sleeping enough and just, you know, existing on fumes. Who are talking about it? How in order did we actually function when we were residents in the hospital on such little sleep?

56:01But sleep is probably the most dynamic and active stage of our brain. And, you know, even though we're knocked out and we're unconscious, the brain is awake and it reorganizes itself and it cleanses itself. To summarize what happens in the brain during sleep, two very important things happen. The first thing that happens is we have a very elegant cleansing system, a janitorial system, if you should say, that gets activated when we go through the deeper stages of sleep. So when you look at the sleep architecture, you have wakefulness, and then you have REM, and then stage one, two, and three. During the stages, the third stages is when we have the microglia, which are these cells that are responsible for cleaning the brain, gets activated.

56:47And then we have a glymphatic system, which is a system of lymph fluid that flows through the brain. Imagine your brain being a building or a city, and you have these janitorial teams that go into the building, and they start collecting all the trash and the garbage, and they clean the floors and the walls. That's exactly what happens during the deeper stages of sleep. But it only gets affected when we actually go there. And when people don't necessarily go there, how does that happen? Say, for example, if they don't get enough sleep or if they have had too much caffeine or if they have had too much alcohol or if they have some sleep disorder like sleep apnea, restless leg syndrome that doesn't let them to go through the deeper stages of sleep, that cleansing doesn't happen.

57:28Or they've flown in like eight hours of time zones for this conversation the night before. Yes, but hopefully the conversation is going to build a lot of resilience and going to negate the impact of sleep. You know, it's a comprehensive system. But I need to have that deep sleep. So it's not just any sleep that does this cleansing. You need to get into this sort of deep sleep. Seven to eight hours of it, of deep sleep. And so that is then when the brain, which is obviously on all the time when I'm thinking, presumably. Yes. It's sort of like, almost like it's switched. This is sort of somehow sort of switched off and therefore it can be cleaned out.

57:59Absolutely. And then the second thing that happens, your memories get organized. Initially, it seems like a chaotic group of just messy words altogether. But when we go through the deeper stages of sleep, it gets organized in the right file folder cabinet. So it's easier for the individual to retrieve it later on. Wonderful. I think we have one more, which I think is the O, if I've got that right. Yes. The Optimize we touched on a bit earlier, which is about mental activity. Challenge your brain. Any activity is great. Even, you know, simple games like Sudoku or even though I usually attack Sudoku, but the Sudoku or crossword puzzles are great.

58:34And we did a meta-analysis in 2019. Yes. And looked at all the data and looked at what works. All activities work, but complex behaviors are better. Complex behaviors are real-life activities that engage multiple domains of brain. For example, learning a musical instrument, learning how to dance, learning a new language, using that language in public or with others, running a group, running a podcast. Activities that push you, that challenge you, that are ever-changing, you have to adapt to it, but also involve multiple domains. When you're learning a musical instrument, guitar in my case, Aisha's an amazing singer.

59:12I'm a terrible guitar player. But when I'm playing guitar, I'm learning, I'm reading the notes. That's your left parietal lobe, the language centers, Wernicke's and Broca's. You're processing, it's your frontal lobe. You're visually processing, it's your occipital lobe. You're being dexterous, it's your cerebellum and your motor cortex. You're being creative, it's your parietal lobe. You're emotionally involved. For my listeners, it's bad emotions. For me, it's good emotions. So it's all of the brain being challenged and pushed around novelty, around the next level, learning new things. That's what makes the connections.

59:45And optimize is critically important. No matter how old you are, no matter what you've been doing, please get engaged. Not in one thing. If all you're doing is crocheting, it's great. It's good. But add two or three other activities that are a little more diverse. Taking a class online, learning how to dance. These diversity of actions involves multiple domains of brain, which grow the brain powerfully. Thank you both so much. And I love that you've offered so many tips that our listeners could actually start implementing tomorrow, right? Like many of these are things that you could change immediately.

1:00:20I'd like to try and do a quick summary, and please correct me if I've got any of this wrong. So the thing I start with is this amazing thing you said that like 90 % of Alzheimer cases you believe could potentially be prevented with the right change in lifestyle. So it just transforms this from being this sort of almost like this death sentence in front of you, which is, as I said, very much how I sort of brought up this idea that actually for the vast majority of people, you could change your behavior and mean this didn't happen. You also explained that today, once you have Alzheimer's, it can't be reversed.

1:00:50That's not currently possible with the medicine we have, but it takes decades and decades. So actually, although we think about this as being an old person's disease, actually, you're saying it's really in middle age, it's all already starting to happen because your brain is sort of struggling to clear these deposits. But therefore, if you make the changes now, little by little, you can sort of push this off. I'm thinking about this idea that you sort of build up this capability. Therefore, whatever age our listener is right now, they can be doing things right now that are sort of building up their capabilities.

1:01:20And you sort of talked about this reserve, right, of potential with this brilliant acronym, neuro. So I'm going to try and see if I can remember what was in there. So N was about nutrition. So we're very pleased to hear that you started with nutrition. That makes you a great guest on this show. And interestingly, you talked about this mind study that I think you said like a 53 % reduction of Alzheimer's with a diet that looked, you know, very similar to sort of the Mediterranean diet, sort of gut health friendly diet that we tend to talk about a lot on this show. You know, if you're gonna pick out one specific area of food that you really focused on maybe about the brain, I took away sort of omega-3 as this thing you were saying in particular, and we've talked about it on the show a number of times.

1:02:04My colleague, Dr. Sarah Berry is like focused on fats and you can get that from fatty fish, which is often called oily fish in the UK. So that's a good one to learn. Supplement if necessary, but actually you're saying even just with a really healthy diet, you should probably be getting this. Then talked about exercise. And amazingly, exercise is really important for your brain, even though it's not a muscle. And you said that basically these hormones that are created by the exercise you're doing is actually having this amazing sort of impact on your growth. And not all exercises are equal. So if you focus on your legs, because that's your biggest muscles, and you're doing sort of squats or lunges, that's where you'd like really particularly suggest to somebody focus on that.

1:02:45And amazingly, you're not just going to be making yourself healthier because of exercise, you're directly going to be supporting your brain. We talked about stress. There is such a thing as good stress, but there's also definitely bad stress, sort of chronic stress. This is real. You know, I wish I could tell my grandparents this, it's too late, but it is real. It actually shrinks your brain. So you can actually measure that. But there are things you can do about that. And we didn't have a chance to get into that on this podcast. then you talked about restorative sleep and amazingly if you can get into this deep sleep basically you know all the cleaners come out and they clear away everything so it's really important to be having that deep sleep and enough sleep so my flying backwards and forwards to the states is probably not ideal for that reason on top of everything else and then finally talked about optimize and this was like i guess the challenge in your brain that if you are doing hard things You talked about this amazing London taxi driver study that they learn all the roads in London in their 50s and their brain actually gets bigger.

1:03:46It's not just whether or not you studied when you were a kid. You're saying there's behaviors now that can really make a difference. And you want to be doing things that are complex. You're saying Sudoku or Crossword is okay. But actually, like the more that it's sort of challenging you and different, the more that you're going to learn. And if you do all of these things together, like, does that get me to the 90 %? Presumably it does, yes. We can't say individually at the individual level, at the population level. Absolutely. I think that the cumulative effect of this is so powerful for the brain that it will definitely avoid dementia.

1:04:17But more importantly, you'll be able to live resilient, powerful, you know, empowered, mentally, cognitively empowered lives. Wonderful. Thank you so much. I enjoyed it very much. I can see that we didn't manage to pick up on some of these areas. So I hope we can get you back in the future. Oh, we would love to. Thank you so much for having us. It was fun. Now, if you listen to the show regularly, you already believe that changing how you eat can transform your health, but you can only do so much with general advice from a weekly podcast. If you want to feel much better now and be on the path to live many more healthy years, you need something more.

1:04:52And that's why more than 100 ,000 members trust Zoe each day to help them make the smartest food choices. Combining our world-leading science with your Zoe test results, Zoe is your daily companion to better health for life. So how does it work? Zoe Membership starts with at-home testing to understand your unique body. Then Zoe's app is your health coach, using weekly check-ins and daily guidance to help you shift your food choices to steadily improve your health. I rely on Zoe's advice every day, and truly it has transformed how I feel. Will you give Zoe a try? The first step is easy. Take our free quiz to find out what Zoe membership could do for you Simply go to zoe.com slash podcast Where as a podcast listener, you'll get 10 % off As always, I'm your host, Jonathan Wolfe Zoe Science and Nutrition is produced by Julie Pinero, Sam Durham, and Richard Willen The Zoe Science and Nutrition podcast is not medical advice And if you have any medical concerns, please consult your doctor See you next time

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