Limitless with Chris Hemsworth is now streaming on Disney+ and ahead of its launch, we were able to sit down with a number of experts to talk about their incredible work with the one-and-only God of Thunder and how he pushed himself further than ever before.
We were able to catch up with Dr. Sharon Sha, a doctor and clinical associate professor, and associate vice chair of clinical research neurology and neurological sciences for Stanford Center for Memory Disorders, who helped Chris combat his mind’s aging process in the episode, "Memory."
She tasked Hemsworth to go off-grid into the wilderness without a GPS or map and tune into nature to navigate through the wild to stir up some of his most precious memories and she tells me all about their time together and what we can all do to improve our own brain health.
**It should be noted that we spoke with Sha prior to Hemsworth revealing to Vanity Fair that he had learned during production that his genetic makeup includes two copies of the gene APOE4, which makes him eight to ten times more susceptible to Alzheimer’s disease.**
Check out the full video interview below and please remember to SUBSCRIBE to my channel!
ROHAN: After working with Chris, what did you learn about him throughout the process and his commitment to aging more gracefully?
SHARON: Well, you know, yeah, he's sort of like, as we all know, this big A-list celebrity, and I know that he works out a lot and, that's about all I knew, besides just watching all the movies that he's that he's been in, but to understand that he's a producer on this series, and he's really committed to making himself healthier, and then, educating others about it was really fascinating for me, but also really heartwarming, as someone who really believes in the health and science behind this. So, the fact that he's committed and wants to educate others was just amazing.
ROHAN: Chris and I are both in our 30s, he's 39 and I'm 31, but what are some early signs that we could maybe see in our 30s that could help us potentially avoid dementia and Alzheimer's disease as we grow older?
SHARON: Yeah, I mean, this is a fantastic question. So, I think one thing that most people don't know about Alzheimer's disease and a lot of these other related dementias, is that the pathology or the proteins that build up in the brain, that cause these diseases can occur decades, before we even have any clinical symptoms. So, if we think about Alzheimer's disease causing memory loss, the pathology of amyloid proteins and tau proteins that build up in our brain can occur 15 to 20 years before any symptoms of memory loss begin.
So, I would not expect you, Rohan, or Chris to have any memory problems now in your 30s, and me in my 40s, I wouldn't expect that to occur, but what we can do now is so important, and that's the nature of the episode is keeping healthy and how do we keep our brain healthy? With exercise, eating healthy, sleeping well, stimulating our brains, socializing, those are all factors that diminish that risk of developing Alzheimer's disease future in life and other degenerative diseases.
ROHAN: We're living in this age where we're all constantly glued to screens, whether it be computers or phones. In your research, are you already seeing how that may be affecting us long-term? Or is the jury still out since we're all collectively the first generation dealing with it?
SHARON: Oh, yeah, you know the answer to that. Yeah, exactly. I'm of this Gen X situation, when cell phones were invented in my 20s, and so we don't have that long term data, to see how detrimental or how helpful it is, for our brains and our bodies. There's mixed data, and we actually tackle this in the episode, that there are some benefits to the technology that we have, but we also recognize that are some factors that can affect our attention, and multitasking abilities with the technology that's available.
So, I think that it's really important that the data is still emerging, but we should probably take breaks and do the things that we know are important for our brains. So, to be on screens all day, we should take a break. If we're having trouble concentrating, maybe you've been getting paged and texted and all those things too much, and we just gotta go outside. Go for a walk.
ROHAN: We've all heard about brain fog the past few years, which is seemingly brought on by an increased level of stress - how are these outside factors affecting our memories?
SHARON: Yeah, I mean, I think there hasn't been as much rigorous data about looking at stress specifically, and its risk association with developing Alzheimer's disease and dementia, but for sure, we clearly think that it's associated, and because of that, right, because we know we have stress that can affect our physiological responses, increased heart rate, high blood pressure, people can get ulcers, all of those factors can increase the risk for developing Alzheimer's disease.
Age is the biggest risk factor, but we can see vascular risk factors as other risk factors including high blood pressure, high cholesterol, all those things. So, if we are spending more time stressed out, eating chocolate chip cookies like I did during the pandemic, to eat my feelings, that's not going to be good for our brain health. So, we do have to remind ourselves that what we do know is helpful and healthy, even if the data isn't there yet.
ROHAN: In terms of improving our nutrition, are there any foods or dietary changes that we could add to our diets that would maybe help improve long-term memory?
SHARON: Yeah, I know, I mean, I think we all are looking for that miracle drug or that one miracle food. You know, my mom used to watch a TV show with a doctor and say, ‘he said, blueberries are healthy, or what about that supplement that's available.’ But that's the easy way out, and that's actually not been proven, any of those fad that we see - coconut oil, curcumin or tumeric - there's no one food. Unfortunately, it really is that overhaul, but it's common sense.
So, it's this Mediterranean heart healthy diet, that's been the most studied, but Rohan, I'm gonna guess that Mediterranean diets not in your cultural background, because it's not in mine either, and so what I usually say to my patients is that you don't have to overhaul completely, but let's think about what may be healthy in that type of diet. If I told my dad, you can't eat rice, there's no way he would survive, but we would say is look at the lean proteins, less fried food, more vegetables, and every culture has that type of diet, we just need to really lean into that type of food and nutrition.
ROHAN: Ah, yeah, my mom is the same. She always wants us eating more almonds.
SHARON: Tell her it's a balance, right? So, you can have some almonds, but it's not like only almonds, if you only ate almonds, you wouldn't get all the other nutrition you needed.
ROHAN: What are you seeing with this new generation of young adults and fluctuating dopamine levels, especially in terms of addicts or recovering addicts? How do these fluctuating levels maybe affect memory and is it something recoverable?
SHARON: Yeah, those are not the type of patients that I see, but in general, I think we would think that people who are on the recovery process or people who have had addiction, whether it's opiates, or other drugs, we need time to deal with the fact that there's an addiction process happening, and that's a disease in and of itself, and all of those factors, whether it's the drugs themselves, or the addiction may have cognitive consequences, and supporting all of those aspects of it for their brain health and journey for recovery is important.
ROHAN: When my grandfather passed away a few years ago, he was experiencing dementia beforehand, but he would also have these moments of lucidity where he would remember something from decades ago, like from when I was a kid. What sort of explains that phenomenon when elderly people experiencing dementia or Alzheimer's can recall something like that?
SHARON: Yeah, so most likely, that's related to Alzheimer's disease, but this can happen in a lot of various dementias, too, and, in specifically, Alzheimer's disease, we see memory loss as the forefront of the symptoms, and usually we see new memories are harder to form, because the memory structures, the hippocampus aren't forming those new memories, but when you were little, and when he was younger, and his hippocampus was working well, those memories were forged and sent somewhere else, and so it's really tapping into that, that he could access and everybody has good days and bad days.
So, it may have been that's a good day where he was able to really access that old memory, and what I usually suggest to patients and families is to bring out that old stuff, bring out the old photo albums, because that's a part that he remembers well. Bring out the old songs from his youth, that music, that'll really encourage him and kind of trigger those old memories and in particular, emotions can really help access those old memories a lot better.
So, anything that's sort of traumatic in our lives, like 9/11, or something really happy in our lives, they have this emotional tag, probably from the amygdala, that helps hit that hippocampus, you can tag it better. So, it's really helpful to use that access to kind of help support people and feel confident and oriented.
ROHAN: What about people experiencing depression or maybe people that don't even know they're experiencing it - how does depression affect memory loss and what are maybe some long-term consequences?
SHARON: Yeah, so I'm going to take about think about that in two ways. One, in and of itself, a lot of mood disorders like depression, anxiety, irritability, in and of itself, they can have cognitive consequences. So, imagine if you're really worried about this interview today, you may be distracted and not really focused at hand. So, you might notice attention problems, multitasking problems that we call executive function problems. So, in and of itself, these mood disorders can cause cognitive problems.
So, then we we say, you know, let's treat that whatever the underlying cause may be, you're thinking about medications, cognitive behavioral therapy, or meditation wellness techniques, but then in relation to dementia, we see a high percentage of association with mood disorders as well, we don't fully understand that it can predate the cognitive symptoms it can co occur or it could be as a consequence, as well, we see this in strokes, we see other sort of trauma, any sort of degeneration of the brain can cause these mood disorders, and again, what I usually say is that it can exacerbate the underlying cognitive concerns with executive dysfunction. So, we want to try to treat that to see if we can help improve symptoms that can be treatable.
ROHAN: When we're younger, it's a lot easier to read something once and remember it, but as we age, it seems like sitting down to study can be a taller order. What is the difference between retaining a memory versus learning a new skill? And, how can we improve our habits, so that we can continue learning as we get older?
SHARON: Yeah, I mean, I think, obviously, our ability to learn information, our cognitive processes change as we age, and so unfortunately, you might be past your peak, even in your young 30s right now, and I'm clearly crossing my peak in terms of say, memory, retention, processing speed, and all that, but it's a very slow decline and our actual content of knowledge remains the same for quite many years. So, it may be that you need to inspire yourself with different types of activities.
Maybe it's not rote memorization, but if there's something that has an interactive component, or if it has a motor skill component, they may be more beneficial, more exciting, more stimulating, really, when I suggest to someone keep your brain stimulated, or keep yourself intellectually stimulated, you don't need to go learn another language, do something that you enjoy that you've always found fascinating and that'll inspire you even further.
ROHAN: Chris obviously has a great memory, having to remember all those epic lines for his job. What kind of conversations did you have with him about how he can utilize what he's learned and take it back to his job?
SHARON: Yeah, well, a few things. As you mentioned, he has a lot of lines to remember? So, I was curious and I asked him, how do you remember your lines, because for a lot of us, we don't have to memorize a lot of information all at once for our job, and he said that he uses the emotional content to help him remember the lines.
For all of us, I think, for us to remind ourselves, how do we remember information? Or how can it be meaningful for us? And it's usually the emotions or the excitement about it, and so I use that sort of to guide him to say, to keep our brain healthy, what's important to you? Or why would you want to keep your brain healthy? And not only, is it because he himself wants to stay healthy, but for his family, his wife, his kids, it's important to him to not only stay healthy, and we remind or we discussed the routines that he could have.
So, he always already has a good healthy diet, he already has an exercise regimen, but to remind him, it's not about just the looks for the exercise, it's for the brain, and other aspects. Sleep is another important one that I think he has more difficulty with. So, we've talked about ways to destress, so that sleep can be improved.
ROHAN: Since our memory naturally declines over time, is there any exercise routine that can maybe slow down that process? Would you recommend more endurance training or quicker interval-type training?
SHARON: So, there's so much research about this. It's so exciting, actually, that there's so much research. One study that I like to quote is now 10 years old, but in older adults, but this can apply to younger people like yourself, the researchers took two groups of people, one that did no exercise, and another group that did exercise on a treadmill like 30 minutes, a few times a week, and measured their hippocampal volume, that memory center and did cognitive tasks, and after a year, the non- exercisers had a shrinking of the hippocampus about 1% and that’s sort of normal aging, and then, the exercise group actually gained 1% and did better on memory tasks.
So, there are multiple studies similar to this where aerobic exercise is beneficial, but there are mixed studies about whether say weight training and other types of exercise can be just as good or even better. So, what I usually tell patients is that, let's think about what you enjoy and make a mix of it too. So, if you really enjoy walking, just make it brisk enough, but if you can do some other types of activity that can include cognitive stimulation and social stimulation, like dance or learning a new skill, like Pickleball is the new fad right now, then do all of that, but in typically, what we've seen is that study after study, aerobic exercise has been the most beneficial or consistently repeated.
ROHAN: Since Chris is pretty advanced physically, especially compared to the average human, did you notice that his memory was maybe a bit advanced? Or would you say he was about where you expected?
SHARON: Yeah, I mean, I didn't formally test his memory. So, I'm sorry, spoiler there, I didn't formally test his memory, we know that he has to have a good one to be able to do well in his job, but I think because he's already so young and healthy, we wouldn't expect there to be difficulties.
What we were talking about mainly is how do we keep this going for his future life and how to maintain and that may be the - I think, the takeaway for all of us, if we're not noticing problems now, let's not wait until we get problems to take care of ourselves.
We don't want to wait until we're 60-70 like you were asking earlier. Let's do it now. And that can even start in our childhood to think about healthy habits, whether it's diet or exercise, or taking breaks from screen time, et cetera, you want to keep that in maintaining, because prevention is the best way than trying to sort of be reactive and treat something that may not have a fix.
ROHAN: Back to diet, I imagine stress eating can't help us. How does eating more sugar and salty foods and developing bad eating habits young affect our long-term memory?
SHARON: Yeah, I mean, I think in general, what I was saying about the Mediterranean heart healthy diet, we can't say it's just the one thing in it, that's helpful, but having that balance, so it's not too much salt, you know, maybe a little salt, okay, it's not too much of high fat food, maybe a little bit of the healthier oils are in moderation.
Doing what I did, by having a chocolate chip cookie every night, after the kids are in bed during the pandemic is not what we need to do, but on occasion, we can have a little treat. Similar to what I was saying about the Mediterranean heart health, diet, alcohol is not good for the brain, and a lot of us thought that, hey, red wine is good for our heart, but it isn't necessarily good for our brain. So, having that sort of taking it for special occasions, whether it's high salt, or high fat, or your dessert or your alcohol, taking everything in moderation is important.
ROHAN: We've all experienced this COVID-19 pandemic for the past two years, and it really feels like everyone has been experiencing this collective phenomenon where all of these pandemic years feel like a big blur. What have you learned about this shared experience and the effect that it's causing?
SHARON: Yeah, I mean, my sense, and I think there's probably going to be more emerging literature about this is this sort of like trauma that we all experienced, right? I think we're learning more about, say, long COVID or cognitive effects of actually developing COVID, but not everybody developed COVID, but we all experienced this great, sudden global pandemic, where we had to isolate and we know how important socialization is. So, the isolation, the sudden change, probably the trauma and anxiety that we experienced was affecting our cognitive function, and more likely that anxiety and heightened anxiety so that we felt like there's this fog and not be able to process a lot of this information. I don't know a lot of the data that's emerged, but I'm sure there's going to be more as time goes by.
ROHAN: When something is harder to remember, how does attaching some sort of emotion to that memory maybe help it become easier to recall decades in the future?
SHARON: Yeah, I mean, I think proactively if we're trying to remember information - I'm changing your question - but proactively, if we’re trying to remember something, if you can tag it with an emotion or people use memory palaces. If you have a lot of content to remember, so for example, if you're not familiar with a memory palaces, it’s sort of like, imagine you're walking through a castle or palace or something, and you can imagine the first doorway if the first thing you had remember was, say it's a lot of playing cards, the red hearts, like seven of hearts or something like that, then you can maybe imagine seven people behind that door.
So, you tag it with something that's familiar. So, proactively, it's much easier to remember if you have some content behind it, and similar to say why it might be hard to remember people's names, it doesn't have a semantic association or clear meaning. So, but for past memories, that might be hard, that we have to keep reminding ourselves through repetition, maybe better, or trying to, again, tag some emotion so that you can remember it in the future.
ROHAN: Circling back to screen time, could spending more time outdoors or away from work maybe help our ability to retain information and improve our long-term memory health?
SHARON: I mean, I think, if we were taking more time to say walk outside, there have been studies that look at nature, and memory retention, also looking at nature, and its association with decreased taxing on our attention, so such that when we take that break, and take a walk in the park, then we're able to focus better, and then also, creatively, we can increase our cognitive processes, so being constantly on and that technology may then conversely be detrimental to the attention and memory storage. So, I would say, yeah, if you could go have a picnic, reading a book, that would be fantastic.
ROHAN: What are maybe a few things you would recommend to people that want to join Chris and get started on this journey to improve their longevity and long-term memory health?
SHARON: I mean, okay, so I'm going to take that question in two different ways. One, I'm always going to say my top three are exercise, exercise, exercise, and we talked about that and that, the diet like the heart healthy Mediterranean diet, sleeping well and cognitively, stimulate yourself socialize, but the first step, so you can say, yeah, I want to exercise more, the first thing to do is probably just make it a routine. So, if right now you're doing zero exercise, saying I'll do it tomorrow, like it's always January 1st, people sign up for the gym membership, but let's just start with something small that is manageable.
So, if you can say, let's build into my routine, whatever is best for you. At lunchtime, go for a walk, or add it to the end of your day or before you go to work or something. Start with 15 minutes, 20 minutes, and then you build up to it, and then if your body gets used to that every day, it's so much easier to maintain. So, start with those small baby steps, and that's again, same thing with the diet. Same thing with a social interaction, whatever it is that you feel like you need to augment, build that into the daily routine, and then everything will fall through.
What if you could combat aging and discover the full potential of the human body? Global movie star Chris Hemsworth explores this revolutionary idea in the new National Geographic original series, “Limitless with Chris Hemsworth,” created by Darren Aronofsky and hailing from his production company Protozoa Pictures and Jane Root’s Nutopia. Entertaining, immersive and life-changing, “Limitless” rewrites the rulebook on living better for longer. Coming to Disney+ November 16.