“I don’t think it is possible to overemphasize just how important mismatch diseases are”

Dan Lieberman, The Story of the Human Body

Key Points

Collectively, compromises in the biological foundation of the brain is the single largest constraint on human intelligence.

Every species has a habitat, or range of environmental conditions to which its best adapted, which we can refer to as its “ancestral” environment.

Mismatches between an animal’s present and ancestral environment strain its capacity to maintain homeostasis. Depending on its degree and duration, that mismatch can result in dysfunction, disease, or death.

This concept of mismatch is the best framing device for understanding the foundations of health and wellness, and for understanding the key drivers of chronic disease, including degenerative conditions of the nervous system.

And minimizing mismatch is first priority in optimizing the biological foundation of our intelligence, and protecting the integrity of the brain over the course of our lives.


Gorillas Beat Anxiety & Heart Disease With Diet
Dan Lieberman’s “The Story of the Human Body
The Migraine Miracle Book
Success Stories applying a mismatch framework to migraine:
Harnessing the Power of Story
From “Living On Pills” To Migraine Freedom
An Incredible Journey from “Rock Bottom”
A “Stunning” Transformation
Success story excerpts from Facebook & Amazon
Physicians for Ancestral Health
The Physicians for Ancestral Health podcast
Migraines as the Hypothalamic Distress Signal” – Ancestral Health Symposium Presentation



About a decade ago, a disturbing trend was observed amongst gorillas kept in captivity. The male gorillas, especially, were suffering from alarmingly high rates of heart disease. Around 70% of gorillas kept in zoos were thought to be suffering from it. A marked contrast to their wild counterparts and whom heart disease wasn’t a problem.

At the Cleveland zoo Ultrasound scans showed that there two male gorillas were also afflicted with the condition. In addition, they also exhibited other concerning behaviors not seen in gorillas in the wild. They regurgitated their food up to four times an hour. They plucked the hairs from their skin and ate them. These behaviors thought to be a manifestation of anxiety were also common amongst gorillas in captivity.

Researchers at Case Western Reserve decided to try and experiment. Instead of feeding the gorillas there gorilla biscuits, scientifically engineered gorilla food packed with energy and vitamins, they instead decided just to feed them what gorillas ate in the wild, the biscuits were out and in it’s place were dandelion greens, lettuces, green beans, alfalfa hay. Not as tasty as the biscuits, but the same sort of thing wild gorillas eat. So what happened next? Their health improve markedly. The gorillas lost about 65 pounds, they stopped obsessively regurgitating their food, and they stopped plucking and eating their hairs.

So I opened this episode with the tail of the gorillas at the Cleveland zoo and now I’m going to tell you a similar tale of another great ape. Only this time the ape is me. So almost a decade ago now, I made some major changes to my own diet and lifestyle. I didn’t do so in an effort to solve any particular problem like being overweight, rather I did it because I’d come to a fundamental reconceptualization of the foundations of health and wellness.

So after I’d realized that my notions about what constituted a healthy diet and lifestyle had never really been critically examined despite the fact that I was a practicing physician, but rather inherited from conventional wisdom I decided to try to remedy that. That critical examination led to the discovery that many of the ideas that I thought were the basics of human health were wrong.

And while maintaining good health and function was always important to me, in particular, doing what I could to prevent the common chronic diseases that I commonly saw as a position, I would have never characterized myself as a health enthusiast.

It’s something I’d much rather set and forget then continually obsess over. I thought that I had the basics down and I didn’t feel like there was going to be much of a return on efforts beyond that. At the time, I wasn’t aware of having any particular diet or lifestyle related problem that was in need of solving, but I’d come to understand that the foundational ideas that I’ve integrated into my set and forget strategy were wrong, which drove my desire to change my behaviors, to bring them in line with this renewed understanding.

So this was done in part to reduce cognitive dissonance as well as an effort to afford myself the best chances of a life well lived. As it turns out, those changes led to all sorts of remarkable and unexpected things which were in and of themselves, a powerful validation of those ideas and a refutation of much of the conventional wisdom I’d previously been abiding by. Those changes included that loss of about 15 to 20 pounds of fat from my mid section over the course of about six weeks.

And along with it, a returned to the pant size I had as a senior in high school, a size I remained at this day at the age of 43. The impact on my energy levels were astounding. Prior to making these changes, I’d come home from a full day of seeing patients exhausted, making the task of ushering my kids through their evening routines at times feel Herculean and I had the typical swings in energy and alertness around mealtimes that I’m sure many are familiar with.

The ravenous hunger prior to meals followed by the post-meal sleepiness, most notably in the early afternoon after lunch, all of that evaporated entirely in a matter of weeks. The swings, and energy, and alertness were gone. The evening family routine no longer felt like a chore and moreover I now had the energy to actively engage my kids in play at night. This also profoundly effected cognition, specifically with marked improvement in my ability to sustain clearheaded focus for extended periods.

That allowed me to start using my evening and morning times to work on developing projects that had long been on the back burner. In addition, my skin cleared up, lingering aches and pains in my joints, some of which stemmed from old injuries, resolved, my digestion improved, my reflux went away, the morning congestion that I had attributed to allergies was gone. All in all multiple issues which I, like so many others, had attributed to a natural part of being a human and of getting older.

All of these problems that I didn’t even know I had were solved by these changes. But the most remarkable thing was about six to eight weeks into this, I noticed something else shocking. I’d had no headaches. Now, from a personal perspective, this was a revelation. I’ve had migraines since adolescence. They’d steadily worsened as an adult and had become a persistent feature in my life for years.

So going from that state, from them being a continuous presence, to nothing is life changing and the experience seemed miraculous. Professionally, this was humbling and ironic. As you know, I’m a neurologist and migraines are one of the prime areas of expertise for a neurologist. The typical neurologist sees more patients for this condition than any other. I’d spent countless hours researching them out of both personal and professional interest and had worked with many thousands of patients.

Needless to say, up until that point, I had been utilizing every bit of my academic and practical expertise on myself. I had the best that modern medicine had to offer available to me, and yet, here I just inadvertently stumbled upon a way to end them entirely, a way that modern medicine was entirely ignorant of. That was orders of magnitude more effective than anything it had to offer.

Like I said, this was humbling and ironic. I began using this approach with patients in achieving similar results. I wrote a book on this subject in 2013 titled the Migraine Miracle, created additional online resources and an online community and I’ve been spreading this approach far and wide. It has since transformed many lives around the world as it did mine and like me, many of those folks had suffered for decades with chronic migraines, oftentimes daily in spite of the best modern medicine had to offer.

So at this point you may be wondering what were the changes I made and what prompted them? Ultimately, the answer to that stems from the mental model of this episode, mismatch. It’s no secret that the nature of human life has changed in profound ways over the past 10,000 years. The general time when we moved from being wild hunter-gatherers to building civilizations, a transition made possible by farming as we no longer had to chase after our food.

Human like animals or hominids have been on this planet evolving for about two and a half million years and our species, homo sapiens, for about 300,000 and so for almost all of that time we were leading lives as hunter-gatherers. And from a health standpoint, farming hit our species very hard as evidenced by the archeological record. What seemed like a good idea turned out to be a very bad one at least if you were an average human living between 10,000 years ago to about 150 years ago.

Because after the transition to farming, humans died earlier and were sicker while they were alive. It’s really only been in the past 100 years that we’ve recovered from this, at least with respect to lifespan in comparison to our pre civilized ancestors. And that’s thanks largely to improvements in infant mortality, sanitation, and our ability through technology to keep sick people alive for longer.

And of course, the pace of change has only continued to accelerate since the agricultural revolution, especially over the past century in the industrial and information ages. Yet, while evolutionary forces for adapting to a changing environment are extraordinarily powerful, we, oh, the wonder that is our brain to that process much of that power stems from the very long time scales those processes have operated for.

In evolutionary time, 10,000 years is very fast and yes, while some adaptations have occurred in the human genome during that timeframe, perhaps the most widely known being lactase persistence or the continued expression of the enzyme required to digest milk sugars beyond infancy and adaptation believed to have occurred about 7,500 years ago in dairy farmers in central Europe.

But by and large, the overwhelming majority of our genome is still adapted and finely calibrated to the environment of a wild hunter-gatherer human. And certainly there’s been nowhere near enough time to adapt to the major changes brought about by technology over the past century. And furthermore, that very same technology has also removed the selection pressures that would drive those adaptations.

This basic principle is true of every animal on the planet from the cockroach to the dodo bird. Every species has a particular set of environmental conditions that it’s best adapted to. The thermo regulation mechanisms of a polar bear work quite well in the Arctic, but are a major liability in the African desert. And on some level we all recognize this. We recognize that there’s dog food, cat food, fish food and so on even if we don’t stop to think about the forces that shape those different dietary needs.

And we recognize that feeding an animal, a food it isn’t suited for, will lead to sickness; dogs, and cats, and fish, and horses, and zebras all have different food processing machinery, a reflection largely of the habitats their species has been evolving in as well as the constraints of their evolutionary lineage.

Yet we’ve largely failed and applying this same straightforward logic to ourselves, likely in part from the fact that we’re only born into the world we know, so it’s natural to think the world we find ourselves in is our natural habitat. We don’t know anything different, so this habitat, this environment, and the way we feel living in it is our normal, and yet it’s difficult to overstate the health consequences of this oversight, which have been catastrophic.

I’d strongly urge any human listening right now to read Dan Lieberman’s book, the story of the human body, if they haven’t already. In that book, Dr Lieberman, Paleo anthropologist and chairman of the Department of Evolutionary Biology at Harvard, tells the story of how our body and brain has changed over time since the last common ancestor we shared with the chimps. The book provides an overview of the contours of human evolution over the past two and a half million years and the forces that have shaped the adaptations we currently possess.

And his motivation for doing so is largely to illustrate the mismatch between the environment or habitat that drove those adaptations of our body and brain that we still possess and the habitat or environment that our body and brain now finds itself in. He’s trying to sound the alarm that addressing those mismatches is central to both preventing chronic disease and achieving health and wellbeing.

As he says, “This book argues that our society’s general failure to think about human evolution is a major reason we fail to prevent preventable diseases.” And I think that’s the kind and charitable way to put it. Others might say that this is the greatest blunder in the history of medicine. Virtually all of the chronic diseases that we, physicians, routinely see now: diabetes, obesity, heart disease, stroke, dementia, Alzheimer’s, cancers, chronic pain, anxiety, depression, arthritis, virtually all of these are ultimately the result of a mismatch between the diet and lifestyle of our hunter-gatherer ancestors and our current diet and lifestyle, diseases that up until a little more than a century ago were medical oddities.

These aren’t diseases of aging or of genes, they are the result of accumulated stress on regulatory systems driven by environmental mismatch. They are diseases that are also conspicuously absent in the diverse set of indigenous hunter-gatherer populations whose health has been studied in several instances quite systematically, diseases that also consistently emerge once those indigenous peoples are assimilated into modern society, modern diets, and lifestyles.

And of course, if we simply combine an understanding of evolutionary science with the story of the human species over the past 10,000 years, this is all an entirely predictable and unsurprising consequence. Combine a habitat that is increasingly discordant with our evolutionary paths with a therapeutic paradigm that overlooks the fundamental pathogenetic mechanism and you end up with a massive public health catastrophe. It’s the same story of the gorilla, where problems and behaviors not seen in the wild emerge in habitats and environments, which of course includes diet, to which that animal has not adapted. Whether it’s heart disease, food, regurgitation, picking hairs or migraine headaches, it’s fundamentally a result of mismatch.

As a physician, I find this simultaneously maddening and inspiring. On the one hand, we’ve missed the obvious with catastrophic consequences. On the other hand, it provides a clear path for getting out of the mess we are in, a path for us as individuals to get our biological house in order and a path for us collectively to make major headway in the problems we face with human health as a society. And it also explains how we found ourselves going so far off the rails when it comes to our public discourse about human nutrition, where it’s possible to find studies to support just about any contention about diet and health, something that could not be said about fields like physics and chemistry.

Over the past half century or more, we’ve been trying to cobble together an understanding of the requirements for health and wellness. In the grand scheme of things, this is still a fairly novel concept and a new field. While people have been interested in their own wellbeing, as long as there have been people, there really hasn’t been a systematic scientific way of understanding that through the lens of biology.

And much of this research has been in the field of nutrition, a field that currently more often finds itself as the punchline of a joke rather than the source of truth and knowledge. We’ve witnessed a continuous barrage of conflicting advice of one recommendation making headlines one week and an entirely contradictory one the next. And the average Joe or Jill is left with virtually no bedrock truths he or she can rely on. People joke that they might as well eat anything because if they’re telling you it’s bad for you today, then there’ll be telling you it’s good for you tomorrow and that it’s largely a result of how we’ve been trying to acquire knowledge in that realm.

The majority of it, specifically the research that has guided the nutritional recommendations that have emerged from bodies of authority, much of that research has been in the realm of nutritional epidemiology from large scale population studies to try to tease out associations or correlations between various factors and their connection to health outcomes.

I’m not going to dig into the finer points of this kind of research, but the take home message here is that this sort of thing is supposed to be a starting point, a place to generate hypotheses that can be tested rather than an end in and of itself. And so one big reason for the general lack of clarity in this area is because it’s been treated not as a vehicle for generating testable hypotheses, but as an end in and of itself and in many cases a device for supporting pet theories.

And the other big reason is because the field began without any guiding foundational principles. No ground truths, that we could then build a scaffolding of knowledge. This entire area of research is really just asking, what are the environmental conditions most likely to promote health and wellbeing? And the obvious place to start from are the range of environmental conditions to which our genome is best adapted.

We owe almost all the advances in biology in the past century to evolutionary theory. It is the foundation of modern biology and the obvious starting point for framing the environmental conditions needed for human wellness. Just as it’s the obvious starting point for framing the conditions needed for the health of any other animal, like those poor gorillas who were made sick with gorilla biscuits and when we describe it like in the opening story.

This all seems incredibly obvious, saying that you should feed a gorilla gorilla food seems to go without saying, animals should live in a manner appropriate for their species otherwise they’ll get sick, and that the habitat or environment that’s most likely to lead to health is the one that’s most evolutionarily concordant. This is true of gorillas. This is true of polar bears. It’s true of cockroaches and it’s true of humans. And that’s not a remotely controversial thing to say.

That is our ground truth, that the diet and lifestyle to which our species is best adapted should be the foundation of health. And then if we elect to deviate from that basic template, we must provide evidence that our deviation is clearly superior, evidence far stronger than epidemiological associations. And as I’ve already discussed, simply applying this basic framework for both wellness care and the diseases of civilization has already proven to be revolutionary for myself and the many other providers who are doing so. I’m confident that were everyone to implement these principles tomorrow, we’d solve our most intractable problems in health care.

As Dr Lieberman states in the book, a large percentage of the medical conditions that afflict human beings today are evolutionary mismatches because they are caused or aggravated by modern lifestyles that are out of sync with our body’s ancient biology. And this of course includes the majority of conditions that can impact the brain, most notably stroke and neurodegenerative disorders like Alzheimer’s. Both of which have multiple lines of evidence indicating that they are mismatched diseases.

I mentioned in the opening episode that I went into a career in medicine and neurology in large part because of the perceived promise of an impending revolution in medical therapy, especially when it came to some of the most devastating conditions that impact the brain. It’s been nearly two decades now, and not only have those revolutionary treatments not materialized, there hasn’t even been incremental improvement precisely because we’ve overlooked the fundamental drivers of those conditions. Being tasked with the responsibility of healing and alleviating suffering and having virtually nothing to offer is a frustrating and demoralizing position to occupy. But by the same token, now having a clear path out of that position is exhilarating.

So because this relates to diet, lifestyle, and nutrition; areas that have somehow reached a level of contagiousness on par with politics and religion, the signal to noise has become depressingly low, even amongst many academics. So I’ll say a brief word about how this model of mismatch has been misconstrued and misrepresented. And I think the best way to frame these misconceptions and misrepresentations is in the difference between a principle and the application of that principle.

What’s important to understand is that this concept of mismatch is a framing device or a governing principle for understanding the basic foundations of human health and for understanding the root cause of diseases of civilization or lifestyle. It’s a place to begin understanding the foundations of human health and wellness from first principles and it’s a foundation that can then be refined through the tools and methods of western medicine and science.

But it flows as a direct logical extension of the most rock solid principle in the field of biology. And the critiques of this area, almost exclusively been at the application of this framing device or principle rather than the underlying principle itself. In the same way that someone might hold up a failing public school as an argument against public education in general, critics of the ancestral health movement have attacked specific applications of it rather than the underlying principle, which is again a grounded in the bedrock ideas of modern biology.

If I miscalculate the area of a rectangle, I don’t hold that up as evidence that the formula is wrong. And the same is true here, rejecting this idea of mismatch as a framing device for health and wellness requires rejecting the theory of evolution. Other critics have resorted to the straw man approach claiming that proponents of this perspective are arguing for something they aren’t, like saying that we should reject all of modern life and go back to living in caves or that it’s presenting our pre civilized life is some sort of utopian past.

None of that is remotely accurate. Again, the argument here is that we are most likely to thrive in the environmental conditions we’re best adapted to, which we can refer to as our ancestral environment. And that chronic disease is driven by mismatches between that environment and our present one. Now there are some who feel threatened by the principal because its implications undermine some long held beliefs and claims including things like dietary fat is the cause of heart disease and so on. And there are also some very deep pockets that don’t like the implications either. But this is too important issue to let it fall prey to our lesser instincts because the cost of doing so is just too high.

So there are at least two very important ways in which this mental model of mismatch applies to the themes of this intelligence unshackled project of understanding how to optimize human brain health and function and realize the potential of human intelligence. And the first mental model of hardware and software, I mentioned that the biological foundation of our intelligence is compromised in multiple ways and that compromise arises directly or primarily from mismatches.

And so simply understanding the role of mismatch and adjusting for it can produce profound improvements in the biological function of the brain, ones that far exceed anything that modern medicine can currently offer. After realizing that we already had the solution to many of the problems we face in medicine right in front of us, that we already possess the therapeutic tools to achieve the transformations I’d expected to occur in the medical clinic in my career, I spent the next several years reconfiguring my professional life so that I could work on getting these ideas out there.

This is the single biggest impediment to optimizing brain health and function, and the single biggest risk to its integrity over the longterm, and arguably the most significant way in which human potential is presently constrained. It’s a problem that’s so pervasive it’s become normalized. As I outlined in my own story, all of the changes that occurred as a result of trying to minimize mismatch were entirely unexpected because I, like most other modern humans, had normalized the experience of living in a mismatch world and now having experienced what the implementation of these principles can do and having now been able to use them to deliver transformative treatments to migrainers that weren’t possible inside of the conventional healthcare system, I want everyone to get to experience the same thing; to experience what being a human is supposed to feel like.

As I’ve already said, minimizing mismatch is priority one for anyone interested in improving cognitive function in protecting against neurodegeneration. It isn’t some fancy smart drug or neurotropic. It isn’t a $300 supplement. It isn’t an advanced brain stimulation device. It’s that basic template, which once it’s in place can then be refined further using the tools and methods of science and Western medicine. So in effect, we have two significant mismatches of concern.

The first is between our modern and ancestral habitat, which is driving the pathogenesis of the diseases of civilization and compromising the biological foundation of our intelligence. And the second mismatch is between our modern healthcare system and the chronic diseases that we now see so commonly. Our system was designed to treat acute single variable illness and this remains at strength and is where all of the major therapeutic advances have come in modern medicine.

It is still ill-fitted to treat chronic multifactorial diseases of civilization, oftentimes making them worse. And we shouldn’t expect our system to solve problems it wasn’t designed for. Implementation of this approach must occur outside of the traditional insurance based healthcare system. And the other important way that this model of mismatch relates to the themes of this podcast is in understanding our own behavior.

We’ve already reviewed how much of our behavior is subterranean or walled off from conscious access that we often don’t know why we do the things we do, even though we can still provide a convincing narrative to ourselves and that includes behaviors and cognitive biases; ways of interpreting phenomenon that are themselves adaptations from our evolutionary history; things that in our ancestral environment were advantageous, but which now can undermine our goals and can lead us to act in ways that are at odds with our values. And so this concept of mismatch is also invaluable for constructing a robust and complete model of human behavior.

So it’s hard for me to overstate just how much promise I think there is in this approach of combining the concept of mismatch with the tools, technology, and methods of science in Western medicine. Not by using technologies to prolong lives of sickness and suffering, which any physician can attest is essentially what we do, but by combining modern medical technologies to refine and approach guided by this concept of mismatch.

And this solution while simple, isn’t easy. We’ve spent the last 10,000 years advancing our civilization without being mindful of the idea of mismatch and spent decades spinning our wheels in the realm of medical therapeutic research because of our ignorance of this crucial concept. So there’s much that needs to change and much that needs to be created to support this effort, but that effort is already underway and as I said, it’s one that’s going to take place outside of the conventional healthcare system, which is as it should be.

And the results of these early efforts are already incredibly promising. I’ve already mentioned how transformative this has been with migraine and the reach of that effort continues to accelerate. So we will continue to dig much deeper into this topic of minimizing mismatch and how to optimize the biological foundation of our intelligence. That’ll include conversations with my colleague and collaborator, Dr Tami Wood. Dr Wood and I are also co-hosts of the Physicians for ancestral health podcast.

And Physicians for Ancestral Health is an organization of physicians trying to promote these principles that we care so deeply about. Dr Wood is also the chief scientific officer for nourish balance thrive, an organization for whom I’m also the consulting neurologist. And they’ve been implementing this new paradigm for health and wellness for the past several years now, focused primarily on using it to optimize the health and performance of elite athletes from around the world and are really creating a fantastic model of this new synthetic paradigm.

All right, so that concludes this episode of the Intelligence Unshackled podcast. Again, if you enjoy the podcast, it’d be great if you left a rating or review on iTunes. Also, as a reminder, the first ever brain fitness challenge for members of the Brain Joe Collective is underway, but there’s still plenty of time to get involved. And that initial challenge, as I’ve mentioned in prior episodes, is learning how to play the Ukulele and doing so not only to reap the pleasures that come from learning a musical instrument, but also to help grow a really large brain.

So you can learn more about that and the collective by going to elitecognition.com/fitness. Also as a reminder, you can find the show notes for this episode, which will include links to things that I mentioned, like this story about the gorillas along with Dan Lieberman’s book, the story of the human body, by going to elitecognition.com. Clicking on the podcast tab you’ll also find full transcripts for this and all of the prior podcasts as well as a summary of key points that I create for each episode. Thanks so much for listening and I will see you in the next episode.

Episode 9: Mismatch