How to Keep Your Brain Sharp As You Age — The One Habit to Start Tomorrow

The full transcript of this episode is below. Lightly edited for readability.

Kelly: Welcome to Wellness Simplified. I’m Kelly Nicholls, and this show is for busy people who care deeply about their health but are drowning in conflicting advice and don’t know where to focus. Every episode, we simplify one area of health — one habit, one simple experiment, one clear next step that will actually fit into your life. Together, let’s optimise our health one simple step at a time.

If keeping your mind sharp as you age is a priority for you, this episode is for you. Today I’m talking to Dr. Michael Elstein. Michael is a Sydney-based integrative doctor, author, and someone who has spent decades looking at what actually protects the brain as we age. What I love about this conversation is how practical it is. We’re not talking about expensive interventions or complicated protocols — we’re looking at the things that are free, simple, and backed by evidence. We get into the key nutrients your brain actually needs, the link between your immune system and your brain, why sleep is so much more powerful than most of us give it credit for, the role of exercise and which type, and how to keep challenging your brain as you age. And of course, we end with the one habit Michael says you can start tomorrow. If you’ve ever worried about your memory, your sharpness, or what your brain is going to look like in twenty years, this one’s worth listening to. Let’s get into it.

Hi, Michael. Thank you so much for joining us — I really appreciate it. I have a deep personal interest in long-term cognitive health and preventing cognitive decline. It’s something that’s affected my family, so it’s a very strong personal interest, and I can’t wait to have this chat. Before we jump in, I always like to let listeners get a sense of our guests. How do you start your day? How do you set yourself up each morning?

Dr. Elstein: I often go to work early in the morning, so I don’t always have time to do a lot beforehand. But because I catch public transport, the one thing I make sure I do every day is take a lot of immune-boosting nutrients — I want to protect myself and not get sick. As we get older we’re a bit more vulnerable, especially on the bus, with everybody coughing and sneezing. I think I’m the only one wearing a mask, which is a bit frightening. So a strong immune system is very important to me. And the immune system is connected with the brain — every part of the body is interconnected. So if I’m looking after my immune system and protecting myself now, I’m hopefully not going to get sick. On days where I have time, I also do some yoga and get outside in the sun, because the sun is very important for regulating melatonin — a hormone we make at night that helps us sleep and is also brain-protective. Getting some sun in the morning turns on the body’s natural production of melatonin. And the yoga’s enjoyable to do outside in the sun, so you get the benefit of both.

Kelly: That’s great, because it’s practical. We’re busy people — my audience are busy people — so it’s whatever you can do inside your busy life. I’d love to dig into a couple of things. First, the morning sunlight, because that’s crucial. Is it true you want to get it as early as possible — ideally the first thing you do?

Dr. Elstein: I don’t think the time matters that much. I just think we need some morning sunlight before nine. You don’t have to leap out of bed and bathe in the sun’s rays. But a lot of us get in the car, drive to work, park in the office — no sunlight exposure at all. So we need to make sure we get some, even if it’s not at the crack of dawn. You need about six to ten minutes of sunlight, but it doesn’t have to be the moment the sun rises.

Kelly: I love that. Six to ten minutes — that’s so easy. You make a cup of tea, you chat to your kids, you just shift it outside. Now, you mentioned the supplements you take to avoid getting ill, and the importance of the immune system — you’ve written an entire book about it. Even though that’s not exactly today’s topic, what are some of the supplements you think are really important for immunity?

Dr. Elstein: One of the most important is zinc. A lot of people aren’t getting enough, because zinc is found in red meat and oysters — and we tend to encourage people not to eat too much red meat, and nobody eats many oysters. You can also get it from nuts and seeds. I also take vitamin C, which is important for the immune system, and herbs like echinacea and andrographis. People have heard of echinacea, but andrographis is another good immune herb. I take them every day. It’s important as we get older and our immune system weakens — don’t wait until you’re sick and then rely on antibiotics.

Kelly: Andrographis — I’ve never heard of that. How do you spell it?

Dr. Elstein: A-N-D-R-O-G-R-A-P-H-I-S. There’s a company called Bioceuticals with a product called Armour Force — it contains andrographis and echinacea and other immune-boosting ingredients. I take two of those a day, so it’s all in one tablet.

Kelly: Beautiful. So today we’re talking specifically about brain health. In your own life, what are some of the key habits you personally integrate for brain health?

Dr. Elstein: I’m 72 now, so I’m especially attached to looking after my brain — memory decline gets scarier as we age. I’ve noticed some things I used to remember easily, like the names of celebrities, I don’t have the same easy access to. So I make sure I’m eating a healthy diet, because diet is so important for the brain. We need enough protein, which is vital, and good fats. I’m actually a vegetarian, and vegetarians can run into trouble getting enough protein, so I make sure I have a protein smoothie. I take fish oil capsules in the morning, and I use olive oil with my meals and eat avocado — other good fats. There are other important nutrients too. Magnesium is one — it’s found in greens, vegetables and nuts, but a lot of my patients simply aren’t getting enough, and it helps the brain to relax. Another is vitamin B12. Vegetarians often don’t get enough because it’s found in eggs, meat and fish, so I take a B12 supplement. And I measure these things regularly — anyone wanting to look after their brain needs to know whether they’re getting enough protein, fat, magnesium and B12. Sometimes that means a blood test.

Kelly: I agree on the healthy fats. I did an Omega Index test — I don’t know if you do that with your patients — and my levels were off. Since taking higher-dose omega supplements, I’ve really noticed a difference in my sharpness and less brain fog. Do you do that test?

Dr. Elstein: Yes. You can do a blood test for the Omega Index, but not through conventional laboratories — most doctors don’t know about it. You can get it done through a lab in Melbourne. We need to make sure we’re getting omega-3. Some of us eat fish but a lot don’t — you need two or three serves a week — and you want to be careful about mercury, so choose smaller fish rather than the larger ones. Alongside that, you should test the other nutrients too.

Kelly: And what are the key markers you test?

Dr. Elstein: Anyone who wants to know how their brain is functioning needs to check they’re getting enough protein — you can do a blood test for that, though a lot of doctors don’t even ask what people are eating. You can also test vitamin B12, magnesium and zinc. Then you need to know whether you’re eating the right foods for you — some people have food intolerances they don’t know about, like gluten or dairy, or lactose intolerance, and there are tests for those. Then you look at things that can harm the brain. You want your sugar metabolism to be optimal. High blood sugar — which you might not know you have — switches on inflammation, and brain inflammation is very silent. Most people won’t know they have it without a blood test. There’s also a chemical called homocysteine. We all make it the moment we eat protein, but too much increases inflammation, which can damage the brain. You measure homocysteine alongside your B12, because B12 is the vitamin that keeps homocysteine in check.

Kelly: And some people have a particular sensitivity to homocysteine?

Dr. Elstein: Some people have high homocysteine because they’re not getting enough B12. Others have a gene that compromises their ability to use B12 to lower it. So a brain-ageing assessment should look at homocysteine together with B12 levels. If your homocysteine is high but your B12 looks reasonable, you do a gene test — it’s called the MTHFR gene.

Kelly: And if people have that gene, they just need a methylated form of B12?

Dr. Elstein: Exactly. If you have the MTHFR gene, you need to take activated — methylated — B12, so that it can effectively lower homocysteine even with that gene.

Kelly: Let’s take a step back. At what age does cognitive decline actually start? People assume it’s an older-age thing. And is it different for men and women?

Dr. Elstein: It can start subtly in our thirties and forties — things like processing speed, or how quickly we grasp things, might decline a little. But those changes are usually subtle and not very noticeable. When you get to sixty and beyond, memory changes become more obvious. We all undergo some memory loss as we age — that’s inevitable; you don’t have the memory of a thirty-year-old in your sixties. It becomes a problem when the loss is significant enough to affect daily life — people notice you forgetting, you’re remembering less than others your age, it’s affecting your work, you have trouble making sentences or finding words. That’s when it’s more concerning.

Kelly: So for people in their forties or fifties — to what extent is this preventable?

Dr. Elstein: At that stage, when things are subtle, you do the foundational things: a healthy diet with enough protein and fats, all the minerals your brain needs like magnesium and zinc, and the vitamins like B12. But you also need to exercise — it’s really important for the brain, and I don’t think people realise how much. People think of exercise as being about a better body, but it enhances your cognitive processes too. That includes aerobic exercise, but also resistance training — lifting weights switches on chemicals that increase neuroplasticity, which is forming new brain connections.

Kelly: Could you explain the mechanism as simply as possible — how does lifting weights or doing cardio actually improve the brain?

Dr. Elstein: You’re increasing blood supply to the brain. And when you engage your muscles, they send chemicals to the brain that enhance its function. Exercise — both aerobic and weight training — switches on a substance called brain-derived neurotrophic factor, or BDNF, which encourages new connections between nerve cells. Weight training in particular also increases a growth-promoting hormone called IGF-1, which encourages new brain cells to grow. So all of this causes chemical changes in the brain that improve cognitive function without you even realising it while you’re in the gym.

Kelly: A good body and a good brain — two for one. And sleep is really important. How does poor sleep affect cognition, short and long term?

Dr. Elstein: When we sleep, we produce melatonin, which is a very powerful antioxidant — antioxidants protect the brain against free radicals that can be damaging in excess. Melatonin also has powerful anti-inflammatory effects, so we’re hosing down inflammation. And when we get good sleep, the brain clears chemical poisons and toxins that, if they accumulate, can set us up for dementia. So during sleep we get rid of this chemical garbage — and if we don’t sleep, it builds up and harms the brain. It’s very important to clear the brain of these things through regular sleep.

Kelly: When you talk to patients about optimising sleep specifically for the brain, what do you recommend — beyond the morning sunlight you mentioned?

Dr. Elstein: We need to turn off our exposure to blue light at night — screens, phones, computers, television. In old times we didn’t have all this artificial light. We start producing melatonin around ten o’clock, so we should switch off devices around nine or nine-thirty; if we expose ourselves to artificial light after that, we switch off the brain’s natural rhythm of making melatonin and compromise our sleep. Also, keep your extremities warm — warm hands and feet. The warmer your extremities, the more your core and your brain can cool off, and your brain needs to be cool to sleep. Warm hands and feet draw blood to the extremities, which cools the brain and tells it it’s time to switch off. If your brain is heated up and your hands and feet are cold, it’s much harder for the brain to deactivate.

Kelly: I’ve never heard it explained like that — I hate cold feet, but I’ve never linked it to the brain. Fascinating. You mentioned melatonin — for people who struggle to sleep, do you ever recommend supplementing it?

Dr. Elstein: I do. I take melatonin most nights. As we get older, our bodies produce less of it, so a supplement can help. It’s much better than a sleeping pill — sleeping pills can be addictive and leave you with hangovers, and they just shut the brain off artificially rather than protecting it. So if someone isn’t making enough melatonin and they struggle with insomnia, melatonin together with natural remedies is what I prefer over Valium, benzodiazepines or other sleeping tablets.

Kelly: My partner fits this bucket — a very overactive mind, hard to switch off at night. What other supplements help people like that?

Dr. Elstein: There’s a herbal remedy called Redormin Forte — R-E-D-O-R-M-I-N Forte — that contains valerian and other herbs that help with sleep. Magnesium is one of the minerals that helps the brain relax, so it’s worth optimising your magnesium levels, sometimes with a supplement. And if you want to switch off the stress hormone cortisol — which people often have too much of — that matters too. We naturally produce cortisol in the morning to get us out of bed, but you don’t want it high at night. If you’re very active late in the evening, you may have too much. A natural way to lower it is a supplement called phosphatidylserine.

Kelly: Do you recommend particular brands, and do you take it at night?

Dr. Elstein: Yes, at night. There’s an Australian company called Orthoplex with a product called Phospholipid Complex. I’m also looking at one on my desk from Life Extension, an American company — it’s called Cognitex Elite. It has a lot of brain-supportive ingredients: sage, which is very good for brain health; blueberry, which has been researched for helping prevent dementia and enhancing cognitive function; phosphatidylserine; and another brain-boosting compound called uridine. So there’s a lot in it. But as I said, magnesium and the natural herbal sleep remedies together with melatonin are key.

Kelly: We’ll put all these links in the show notes. You’ve also written about the importance of social connection for the brain. People hear about it for longevity, but maybe not specifically for the brain — what does the research actually say?

Dr. Elstein: It comes back to neuroplasticity — switching on new nerve connections. The more positive connections we make, the more we’re looking after the brain. We want our interactions to be nurturing rather than adversarial. Positive social connection actually encourages neuroplasticity — so you don’t have to learn the violin or French to switch it on. Social connection at least every week, not being isolated, seeing friends, being part of committees and bigger organisations where you interact with people outside your immediate circle — all of that switches on neuroplasticity. And the converse has been shown: in people who are isolated, the brain actually shrinks. The hippocampus, which is intimately connected with memory, shrinks with isolation — which is a terrible thing. So social isolation is a major risk. We need to stay regularly connected with the people we love, and with associates and friends too.

Kelly: I love that — it’s something enjoyable you can do, maybe alongside learning a language or an instrument. Or do those things with a friend — double the points.

Dr. Elstein: Yes. Dancing would be a perfect way.

Kelly: You’re speaking my language, Michael — I love dancing. So it’s boosting my brain.

Dr. Elstein: It is.

Kelly: Why is dancing so good for the brain — is it the cross-body connection?

Dr. Elstein: I think it’s a combination. It gets you doing things that are a little bit difficult, which switches on neuroplasticity. And there’s the social connection with your partner — the intimacy and the hormones that get switched on by that connection. All of it is brain-protective.

Kelly: Let’s go a little deeper into neuroplasticity. Is that capacity something we have throughout life, or does it decline with age — and if it does, can we reverse it?

Dr. Elstein: Children and babies have a huge amount of neuroplasticity — that’s why they can pick up languages so easily at one or two. That level is much harder to access as we get older, so it’s harder to learn a language at sixty or seventy. But the ability to make new brain connections is something we keep throughout life. You can always challenge your brain to do new things. You might be much slower than a toddler, but you always have the capacity to encourage neuroplasticity by doing things that are slightly difficult. There was an item on television recently about a 104-year-old man in America who started pottery at ninety-four — he’s top of his class, interacting with others, still making pottery as a centenarian. I see people on Gardening Australia — a wonderful ABC show — who are in their eighties, active gardeners, feeling vibrant physically and mentally because they’re staying engaged. They may be chronologically old, but they’re not biologically old, because they’re constantly stimulating their biology.

Kelly: So learning new things, connecting with people, keeping the brain active. People can fall into a rut — same routine every day. You’re saying challenge that, try new things.

Dr. Elstein: Absolutely, and it’s a challenge, because we’re creatures of habit — it’s comfortable, and it’s hard to step out of that comfort zone.

Kelly: Even doing the same things in a different way helps, I’ve read — small things like brushing your teeth with the other hand.

Dr. Elstein: Yes. I shave with my other hand as much as I can, brush my teeth with my other hand, comb my hair with it. Standing on one leg is also good for you — if you can brush your teeth or shave while balancing on one leg without falling over, that’s good for the brain. Stand on one leg as long as you can.

Kelly: Everyone’s heard it — stand on one leg, do things with the other hand, and don’t blame Michael or me if you cut yourself shaving. I’ll be brushing my teeth with my left hand tonight. Let’s talk about inflammation, because it’s increasingly linked to cognitive decline and dementia. What drives it?

Dr. Elstein: Inflammation is the turning on of chemicals in your body that can be harmful, especially to the brain. So make sure you’re eating foods that suit you — if you’re eating foods you react to, like gluten or dairy, that can switch on inflammation that accumulates and harms the brain over time. You won’t notice it, because it’s a slow build-up. Poorly controlled blood sugar is another driver — if you’re overweight, your blood sugar may be high without you knowing, and high blood sugar increases inflammation. So you need a test that looks at your sugar metabolism, even if you’re not overweight. Homocysteine, when it’s too high, also leads to inflammation. And the gut is intimately connected with the brain — an imbalance of germs, which we call dysbiosis, can increase inflammation and harm the brain. If you have a lot of bloating, gas and abdominal discomfort, it could mean dysbiosis. And alcohol is a huge brain poison.

Kelly: What do you recommend on alcohol?

Dr. Elstein: Excess alcohol is usually defined as more than ten drinks a week, and a lot of people are well over that — more than two a day. That can be harmful for the brain and switch on inflammation. People need to be careful, because alcohol is so embedded in our culture as a social lubricant. I had a patient recently who was having a bottle a day and felt fine, but his liver blood tests were abnormal — you don’t feel a damaged liver, but over time it’s extremely harmful. I don’t drink any alcohol at all, but you don’t want more than one or maximum two drinks a day, and even that can add up to more than ten a week.

Kelly: I also drink very little. Finally — there’s a lot out there on brain-training apps and platforms. How useful are they, and do you recommend any?

Dr. Elstein: I don’t, really. I tried one of these brain-training programs and it just seemed designed to hook you into subscribing — they give you an exercise, set you up, and want you paying monthly. There’s research showing these exercises mostly just make you good at that particular exercise. So I don’t think they’ll do as much as the other things we can do for the brain — a healthy diet, the right nutrients, exercise, social connection, staying engaged with your work or some function that keeps you active, rather than retiring and doing nothing. All of those will look after your brain probably more than brain training.

Kelly: You also offer a corporate brain-power program. What’s in that?

Dr. Elstein: We used to run it alongside a psychologist. A very important part is the assessment — a medical and blood-test assessment to see whether you’re getting all the nutrients your brain needs, checking your sugar metabolism, your homocysteine, your cholesterol, your B12 — and then correcting whatever you’re deficient in, and whichever foods aren’t ideal for your brain. Together with that, the exercise side, both aerobic and anaerobic. And the psychologist did mindfulness training and meditation, because being taught to be mindful and to meditate is very good for the brain.

Kelly: We didn’t touch on the role of stress — thank you for the reminder. Can you talk about that?

Dr. Elstein: When you have excessive, unrelenting stress, you switch on cortisol, and too much of that hormone can be harmful to the brain. Mindfulness, meditation, sleeping well, and switching cortisol off at night — when you don’t want much of it — can all help prevent that harm. One way to find out if you have too much cortisol is a test — a blood test, or even a saliva test, which is probably more accurate, especially at night, since you’re not going to have a blood test at ten o’clock at home. It’s not routinely embraced by conventional practitioners, but it’s one way to find out. And we’ve talked about ways to lower it — meditation and mindfulness are natural ways, without any supplement. Exercise is another good way to lower cortisol naturally.

Kelly: And I love that so much of what we’ve discussed is easy and not expensive. There’s a lot of noise about the fancy, costly things, but most of this is simple and accessible.

Dr. Elstein: A hundred percent. Getting out in the sun won’t cost you much. Neither will exercise — you don’t need an expensive membership to enjoy regular exercise.

Kelly: Michael, this has been amazing — you’ve covered so much. Every episode I like to bring it right down and meet people where they are: what’s the one habit? If listeners could only do one thing, where should they start?

Dr. Elstein: It’s really two things. The simple one, obviously, is getting some sun in the morning — that’s an easy thing to do. The more involved one, if you want to look after your brain more effectively and you’re concerned about it, is to have a test — go and find a doctor who looks at all those things, the hormones and nutrients and diet, to see whether you’re getting everything your brain needs to work optimally.

Kelly: So start with something simple you can do tomorrow — six to ten minutes of sunlight as early as you can, definitely before nine, to set your melatonin. There’s no barrier to that. Then, when you’re able, look for a doctor who runs a thorough brain panel. And we’ll put the key tests you’ve mentioned in the show notes, because it helps to walk into your doctor knowing what you’re looking for.

Dr. Elstein: That’s great.

Kelly: Thank you so much for your time. You’ve written a lot of books and have plenty of resources on your website — could you tell everyone where to find you and how you help people?

Dr. Elstein: Yes. My website is eternalhealth.org — eternal, as in forever. There you’ll find all the books I’ve written; they’re available on Amazon, including my book on the immune system and books on brain ageing — all under the book section, all available as ebooks. My practice details are there too, so if you Google eternalhealth.org or my name, you’ll find my practice. I also have a monthly newsletter people can subscribe to.

Kelly: Thank you again. They were really practical, simple things, and I hope listeners try them out. I’ll definitely be making a conscious effort to get that morning sunlight — and as I say in the intro, I always share how I’m going on socials, and I hope you do the same. If you can find a practitioner, and you’re in Sydney, you could see Michael and get that basic panel done — because it all starts with knowing where you are. Then you’ll know the exact steps to take based on your own data. Thank you again, Michael.

Dr. Elstein: Thanks so much for having me — I really enjoyed it.

Kelly: Now it’s your turn. Take what you’ve learned today and put it into action. Try the habit, run the experiment, and actually track how you go. I’ll be doing it right alongside you and sharing on socials, so come find me there — links are in the show notes. Tell me what’s working, what isn’t, and what questions are coming up. I genuinely want to know. If today’s episode helped, share it with someone who needs it. And if you haven’t already, hit subscribe so we can keep optimising our health together — one simple step at a time. Take care, and I’ll see you next week.