The Challenge of Systems Thinking and the Failures of Reductionism


Welcome to Better Brain Fitness, hosted by doctors Josh Turknett and Tommy Wood. In this podcast, we will explore the frontiers of how to keep our brain fit and healthy so that we can perform at our best and do the things we love for as long as possible. Let’s go. All right welcome again to the Better Brain Fitness podcast. I am joined today again by my illustrious cohost, doctor tommy Wood hello Tommy, Hello okay so Tommy is going to be fielding today’s question and asking it as well. It I believe comes off of maybe one or two of his most recent podcast appearances, is always prolific on the circuit and has been on Greg Potter’s new podcast and it was also recently on Peter Atia’s podcast The Drive we’ll put links to those episodes in our show notes, but tell me, why don’t you read us the question that arose from some of those appearances? I’ve created an amalgamated question or an amalgamated area that I think that we should, we should talk about a little bit based on some comments from reels on Instagram so I do a 2 hour interview and then somebody takes a twenty second right.

01:27 : And then that gets posted on Instagram and people react to that. Yeah, people react to that and that’s fine that’s what it’s there for. Absolutely that’s great. But you sort of miss some of the context around it and all these other things so this is relevant to two points, although maybe even another one that that’s come from our own podcasts so I’ll give you the three that kind of made me think about this.

01:56 : The first is that in the podcast of Peter Tia, I proposed our demand model, talked about the work that we do and how we think about the brain, and one person commented that this is complete rubbish because they know somebody who was a golfer and they developed dementia or they know fit and active people who developed dementia therefore the model must be wrong. And then there was a conversation that I had with Greg. He asked me about female hormones, particularly estrogen and the menopause transition this is some important work related to dementia risk as women are at greater risk for Alzheimer’s disease and work by researchers such as Lisa Moscone have shown very nicely that hormone levels around and after menopause are important for dementia risk.

02:50 : And then quite understandably, some people ask about their own risk, if they’ve had hysterectomies or some other things where they maybe can’t get hormone replacement therapy or that you know other factors that play into that it’s very nice to talk about the risks, but then people want to know how that applies to them and that makes sense. And then we’ve had some discussions with people about levels of you know, alcohol intake from our own podcast and some people, you know, we presented evidence that said you know a couple drinks a week is probably fine more than that risk starts to increase.

03:26 : Then of course is the anecdote of the French who drink wine every day and what about that and so all the what all these things make me think of is this idea that as we tend to do as a species as a as a group, as neuroscientists and neurologists thinking about a disease, we end up in this sort of single factor reductionism where one thing which gets presented as a risk factor an important part of a network of things that are related to brain health.

04:01 : You can come up with an anecdote that says, well you’re wrong because I saw this happen and the opposite of what you expect occurred and that’s kind of what I wanted to have pick your brains on today, hear your thoughts about it. When we present our model, I think we say quite clearly that demand is the critical driving factor. But in order to respond to that demand, there were a whole bunch of things that feed into that related to physical activity and physical fitness, cardiovascular health, hormone levels, other trophic factors, other exposures, sleep.

04:38 : So there’s all these things that feed into that and you had a very nice quote that I will quote before I have you give you a response, which is that lifestyle basically sets up how your brain responds to skills and challenge and you can have multiple factors that support this process. And I think importantly, in my view, there’s redundancy in the system just because one thing is or is a present and we know that the human brain isn’t is inherently resilient. So you know if you can’t optimize one thing or improve one thing, that’s fine if you’re taking care of all the other potential factors so that’s kind of how I think about it but I wanted to hear your thoughts yeah so there are a lot of things in those comments like biases and mindsets that as you alluded to that we oftentimes go back to that have made it challenging us for us to get at the truth of these things and one of the biggest is the challenge of thinking about multifactorial causes coupled with our desire to want to find a single smoking gun for things, right i mean there’s they’re like we’re cognitively biased towards doing that, but there are also plenty of incentives in the world to drive us towards wanting to find single factors.

06:03 : And you know even that’s not even including sort of the fact that multiple factors have immersion properties. So that you know, not only is it difficult to tease out, you know many different things interacting because you get exponential effects, but you also have emergent phenomenon where what’s happening can’t be explained by any single thing, right. It’s like I was thinking about this yesterday about, you know, popcorn, right? Buttered popcorn. Each of those individual ingredients is terrible. Salt on its own is particularly terrible. Butter, depending on who you ask, not so hot.

06:43 : And plain popcorn is just not, you know, but you put them all together and they’re incredible and then would it be reasonable to ask which ingredient was responsible for your experience of pleasure, right in popcorn, if you add them together individually, it should be terrible, right but yeah, it’s not so it’s an emergent property that’s dependent on none of the things and yet that’s kind of the way we’ve done science in a lot of these things and we are complex systems we know we have emergent properties.

07:12 : We know that it’s that our results are always going to be contingent on contacts and the impact of the entire system. Yet we keep asking well which factor is it, you know is it the salt, is it the butter and then how these things relate to each other, how these factors relate to each other in our model as we talked about so we have the driving need for demands, right we’ve we established the case in the paper i think it’s abundantly clear in biology that our repair and recovery systems are driven by activity or driven by demand that’s what you know and that’s what up regulates them so that’s why inactivity is so, is so harmful, which you know at face value you wouldn’t necessarily think that to be true, right.

07:54 : If you want to keep a painting in good shape, you tuck it away and protect it and don’t let anything touch it but it’s completely the opposite and biological systems. So if you want to drive repair and recovery and growth, then you know you have to have activity, whether it’s physical activity or cognitive activity, that is the stimulus that’s what says Okay, we need, we need these capabilities, let’s do everything we can to maintain them. But that alone, right if you just having that signal by itself isn’t enough, right you need the raw materials, you need time and you need, you know, nothing else in the system that’s mucking up your ability to respond to that stimulus, right.

08:35 : So yeah, the way I was saying it is that our lifestyle then, you know, determines the return we get on our on our efforts, right, whether it’s physical or cognitive. And they perform this sort of mutually reinforcing, you know, virtuous cycle where the greater your stimulus, right, the greater your demand, the more potential, you know, headroom you can add in the system. But likewise, the more you support those repair and recovery mechanisms, the more you’ll actually you’ll make that gaining capability of the greater you can respond to that particular stimulus.

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09:40 : All right, now back to the show and the fit golfer thing again. You know, that’s just one piece and there’s nothing there also saying that individual is engaging in any kind of sort of new stimulus, which is a critical factor in this model, right? Yeah, maintaining fitness is great but one of the challenges that we talked about in the paper is the fact that we experienced this dramatic drop in cognitive stimulation over the course of our lifespan, partly because childhood is so demanding from the perspective of the brain and nervous system and so how do we deal with that and you know, novel, novel, complex learning is part of that.

10:22 : And no guarantee that the fit golfer is doing any of that of course. Yeah this is part of the issue with having to react to an Instagram reel that’s, you know, a minute and duration at most. But, you know, this also gets to another thing that I’ve talked about a lot we talked about is our need to kind of rethink entirely how we try to answer these questions about human health.

10:49 : Since everything is contingent upon context, and since it’s the collective effect of an entire, you know, biological system, everything going on, acting together, that always is going to drive outcomes. And because it’s nonsensical to ask in a system like that, what’s the impact of any single factor in isolation. So we had to do research pretty different than what we’re doing right now, especially if we want to make a meaningful progress in the realm of empirical research on the prevention and treatment of chronic disease and you know age-related decline and deterioration.

11:25 : I think most of the progress that we’ve made in that regard has been kind of on the theoretical side with things like an ancestral health and thinking from an evolutionary standpoint. So that means, you know, shifting from these single factor population studies, whether that’s retrospective or prospective, since those really can’t get at the get us closer to the truth since they can’t evaluate context. And instead, you know, develop research tools and systems for evaluating multifactorial interventions over time in a single person. And in order for that kind of research to be applicable outside of a given person, what we really need to evaluate are the algorithms themselves for how, you know, our process, for deciding how to do what we do in a single person rather than the specific intervention since those are always going to be context dependent and every single individual is a unique complex system so it’s a it’s a challenge but I think that’s why you know that fundamentally is why we haven’t made much progress in therapeutics empirically in the last few decades so that was a long winded answer from where I where you started but it was great and you end well you ended up summer which is that we can’t the research is terrible and we need to fix it and that’s a whole other kettle of fish that we can dive into another day so I was, I was going to try and nail you down on a practical takeaway.

12:56 : So we sort of wrap this up which is so imagine if people listen to us and some of them try to take to heart what we would recommend and enact them that for themselves because they’re interested in their, in their brains, right. That’s kind of why we’re here. And so in a scenario where you had a patient and one of these critical factors was missing for them and it was not something that they could address. And I’ll take the example that we’ve had recently which is somebody’s had, so they’ve had a full hysterectomy, A frectomy and they so they’re in surgical menopause and they cannot have hormone replacement therapy for medical reasons so that’s we that’s just something that’s not going to be available to them and they’re going to be concerned because this is 1 factor that’s this important for response to learning or maintaining health that isn’t available to them.

13:53 : How would you counsel them around all the other things that they may be important and you’re not sort of being hyper focused on one area, right so the good side about the fact that there is no single factor that matters is that no single factor is going to determine your outcome. Related to that, there are likely many different combinations of lifestyles or ways of living that would lead to the outcome we want.

14:24 : You know, and many of those likely can include not, you know, having a hysterectomy, right so there’s nothing about it that determines a negative outcome, right? It also isn’t going to change how you’re going to go about doing, you know, whatever you’re going to do about it, right? You’re going to enact the same sort of plan of action either way, because there’s nothing necessary or nor sufficient to drive an a negative outcome. Then just there’s not much value in dwelling on that particular factor being present or absent.

15:00 : So then it’s just a matter of focusing on the things that we do know that work, right i mean, there’s a infinite number of things that we could focus on that don’t get us to where we want to go, right? But we also have a huge number of things that we know of that do take us to where we want to go. The approach it would be adding as many of those as we can over time.

15:24 : And ultimately I think the central point of the demand coupling model is how critical maintaining the stimulus is and then supporting it with lifestyle. And I don’t think there’s any reason to believe that, you know, if you had a hysterectomy or any other single factor that’s lifestyle related that you can’t support those adaptations without those things. Yeah, I completely agree and I think one of the downsides of providing information to two people is that you can generate stress around these factors and that’s sort of an unintended consequence you think you’re providing good information but for some individuals if they cannot act or access a certain thing you add a stressor And so that’s you know thinking around how the other things that can be done.

16:23 : And also remembering that when we talk about outcomes and health and anything in biology it’s all probabilities. So all statistics and the vast majority of statistics that are done something called frequent statistics even if you do other types of statistics, essentially you’re talking about an increase or decrease in the probability of something happening and there’s almost nothing where probability is 100 % and that’s certainly not the case in any of the factors that support brain health or response to skills or challenge yes, your probability may shift slightly in One Direction but you can probably offset that even more so in the in a positive direction with all the other things that we talked about at the same time so it’s just remembering that nothing in biology is black and white for all the reasons that you’ve mentioned and therefore you can focus on the things that you can change and that’s where I would really recommend people look, because there is so much resilience in the system if we allow that to be the case.

17:29 : A good example of this is from a recent episode where you discussed perhaps a bit of exposure to cannabis during your teenage years which the research would indicate may have some negative impact on cognition. And yet here you are doing relatively well with your brain health and cognitive function so yes, as a single factor may tip the scales a little in that direction like there are plenty of things you can do to tip the scales in the other direction which I believe you’ve clearly have done so again, yeah, it’s in it again reinforces where we started with this is the dangers of isolating any one single factor and thinking that is the thing that matters or that it’s, you know, it can’t be compensated for or whatever.

18:17 : It does tie into the need to do other types of research because it may well be that in your particular context having a hysterectomy actually makes no difference whatsoever if it’s all context dependent we don’t know if it’s applicable in your particular situation these are all population based data on a single factor, you know, ignoring the role of context so take these sorts of things with the large grain of salt, yeah, that’s a great point. Everything again, similarly in statistics in these kinds of studies is averages, right, And averages across the population so there’s the almost any individual, there’s a whole number of things that they can change that will have a positive impact and then the net effect is going to be beneficial, right? Yep so just focus on the things that help and implement those.

19:08 : That’s kind of like the way to deal with this ultimately, I think. All right good question brings up a lot of important topics and if you guys have any questions related to the preceding conversation or anything else around brain health cognitive function, send it our way All right i think that’s it for this episode and we will see you guys next time thanks, Tommy. Thank you. Thanks so much for listening to Better Brain Fitness. If you’d like to support our efforts and help us spread the word about this all important topic, you can share this podcast with someone else you think might like it.