Hey folks! I think I’ve mentioned that my 2nd book, Wired To Eat is available for pre-order and will be released March 21. I’m excited (and a bit nervous!) to hear what y’all think of the book. I put a lot of work and thought into the project and it is a bit of a beast. It’s about 400 pages (which is beefier than the publisher really wanted) but I was hard pressed to get the story told in a way that was much more concise. As it is, we had to cut quite a bit of material and some of it is pretty good, so I’ll occasionally drop some of that on the blog and social media. This post is material that appeared early in the book, laying some basic foundations about how rapidly our world has changed in the past 10,000 years. In the book I make a case that the Four Pillars of Health (Sleep/photoperiod, food, movement, community) are critical, non-negotiable elements of human health. I make the case that although there has clearly been genetic change in humans since the Paleolithic (lactase persistence and sickle cell anemia are but two examples) that change may be inadequate to allow us to be healthy when we are exposed to modern hyper-palatable foods, altered sleep schedule, inadequate exercise and a paucity of social interactions. There is some indication these problems are reaching such a fever pitch that metabolic issues may be delaying or altering puberty in teenagers. That’s a pretty big deal. Many of the folks who dismiss the paleo diet or ancestral health concept and who cite the genetic changes like those I mentioned may find themselves in a bit of a moral and intellectual pickle. For natural selection to occur, you either need something that makes one adaptation highly beneficial, thus conferring a survival advantage, and/or you need a stress that is so profound that you cull members of the species before they can reproduce. It is not unlikely that one could select a breed of humans that can survive on junkfood, altered sleep cycles, little exercise and a non-tribal social network. but to get that “beneficial adaptation” we need folks to be so sick that they cannot generally reproduce. Only the folks who can handle this new world will make the reproductive cut. Along the way to that dystopian future, we have a massive amount of death and illness, to say nothing of staggering medical and societal costs. Dealing ineffectually with diabestiy related issues has, for the past few decades, produced an exponential increase in medical costs:
The “real world” does not tolerate exponential growth well. Not for long. While certain medical and health experts dismiss the potential inherent in the Ancestral Health template, the Western world is goose-stepping towards a number of intractable situations. In general, to fix a problem, one needs to understand the mechanism of causation. Without this understanding one is operating with at best luck, but luck is scarce when the process of dealing with a problem has a fundamentally flawed orientation. This is the story of our current approach to chronic degenerative disease. Symptoms are suppressed, which inevitably leads to worse problems. Without an understanding of the significance of an overly rapid pace of change (The Discordance Theory) all that we can hope for is reactionary symptom chasing. We will ultimately adapt to this situation. We will see either cultural adaption in that we adopt something approximating an Ancestral Health perspective (running in parallel with a modern technologically rich world) or the adaptation will be foisted upon us, and at staggering cost. It is as yet unclear which route we will take.
My purpose in life is to help as many people as possible and to that end I’m reasonably convinced that we need to both understand and implement the concepts implicit in the Discordance Theory. For the folks who dismiss the Ancestral Health model I’m going to start demanding a viable alternative. The current model is not working, “everything in moderation” is not working. To the degree we can get buy-in with something that looks a bit like the ancestral template, one which considers sleep, food, movement and community in a synergistic fashion, that stuff works. As you read through this piece I’m sharing today think about the implications of a rate of change that may be too rapid for us to properly adapt to. Next week we will look at an organism that was formerly an opportunistic omnivore (like us) that embarked on a new strategy for survival. For this critter, things are not going so well as the need for species specific change in this case is not yet at a level in which the organism can truly thrive. Bonus points for the folks who guess which critter I’m talking about!
Sleep, Light and circadian rhythm.
Every organism on earth with a reasonably complex central nervous system undergoes a process that looks like what we’d call sleep. Even plants who lack any type of central nervous system follow a circadian rhythm with periods of greater and lesser activity. No one really knows why we need sleep but given that nature has had billions of years to develop a work-around it appears sleep is a pretty important process. An organism is never more vulnerable than while sleeping, so the cost benefit story of sleep is clearly quite compelling. What we do know about sleep is that it appears to play a critical role in growth, repair, and cleansing. It is during sleep that toxins accumulated in the brain during daily activity are removed. It is in deep sleep that damage to our tissues from exercise and normal wear and tear are repaired. When we consider pre-industrial societies we notice that these people tend to sleep much more than folks in Westernized societies. Recent research indicates disordered or inadequate sleep can dramatically increase our propensity for diabetes, autoimmunity, neurodegenerative disease and certain cancers. Another significant change related to sleep is the amount and timing of light we are exposed to. Even on a cloudy day the light intensity we might be exposed to outside is significantly greater than indoor light. Conversely, in the evening we tend to be exposed to light levels much higher than we would have seen in the ancestral environment. In essence, we see neither the highs nor lows in light intensity which govern our circadian rhythm, sleep, and health.
Food — Simple might be better
Non-westernized cultures tend to consume relatively simple, wholesome meals which although tasty, are in stark contrast to the hyper-palatable foods which typify the modern junk-food centric meals which are so common today. Palatability refers to how tasty something is. A rock is generally “not that tasty” ie- it’s a low palatability item. Chocolate ice cream with toffee chunks and salted almond sprinkles…well, that’s pretty damn palatable! We will talk a lot about what exactly palatability is and how it can derail our eating in Chapter 2. It’s a reasonably intuitive concept but has received little attention in mainstream nutrition circles. In general, whole, unprocessed foods tend to be if not low in palatability (grass fed steak and sweet potatoes cooked in olive oil and rosemary are damn tasty) then “appropriate” in palatability, relative to junk food, for which there is no “off” switch. Whole, unprocessed, tasty foods can also be described another way: they are highly satiating. They make us feel full, but not in a bloated, “OMG, did I just get thrown out of an all you can eat buffet” sort of way. Lean meats, seafood, fruits and vegetables tend to be highly satiating and it’s remarkably tough to overeat these foods. As amazing as modern cuisine is it has a downside in that our meals tend to have a remarkable spread in flavors, textures and scents. Add to this the fact that refining certain foods (milling grains to make flour) makes them more palatable and we have a very tough situation to navigate. The folks who tell us to “just eat less” are largely correct that yes, we generally need to reduce our calories to lose weight and reverse many of the health conditions overeating can cause, but what is missed is that telling folks to “just have a little chocolate ice cream with toffee chunks and salted almonds” is great in theory, but almost a guarantee of failure.
In addition to the amounts and types of foods changing rapidly in recent years, how and when we consume these foods has also changed. Most organisms on the planet experience periods of “feast and fast” and this is certainly true of humans up until recent times. The term “fasting” is usually associated with woo-woo topics like “detoxification” and “cleanses.” I’m not talking about that. What I’m talking about is the notion that throughout most of our past humans had a decent amount of variability in how often and how much they ate. The “norm” was not three square meals per day, with snacks every 45 min, mixed liberally with sugary coffee drinks. Although a contentious topic, it is likely that our genetics are expecting bouts of both feast and famine. In this program I’m not going to suggest that you starve yourself, but part of the program entails training your metabolism to not need food the way an emphysemic needs an oxygen bottle.
Most critters (people included) display some amount of movement or activity. Even plants tend to shift leaves to track with the sun, although we’d be hard pressed to call that “exercise.” Until quite recently humans moved to survive. We had to gather food, firewood, and water while shifting encampments based on weather and the season. Anthropologists have estimated that hunter gatherers walked 6-10 miles most days in the course of their daily lives. This may seem like a lot but modern cultures who do not rely on cars for their primary transportation frequently hit these levels through the course of their day. Exercise, although not strictly essential to life, does appear to improve the quality of the life we live. Modern, sedentary living has reduced our activity dramatically. Where once we routinely walked miles (while also running, jumping, carrying and climbing) many of us now walk less than a half mile every day as we shuffle from house to car to office.
Humans are social animals. We appear to have evolved in small groups and this process has literally altered our genetics to “expect” certain amounts and types of interaction with not just other people, but the natural world around us. Social isolation is recognized as a huge stressor and appears to be a key piece of addictive behavior, including overeating.
Another facet of community that has largely been overlooked until quite recently involves the trillions of microorganisms which live in, on and around us. These microbes appear to be critical in everything from plants extracting nutrients via their root systems to human health. The development of antibiotics, refined foods, cesarian sections and hyper-clean environments appear to have altered the bacteria which play a critical role in our health.
These are the broad brushstrokes of the factors governing our health and waistlines, let’s look at each of these topics from the perspective of a timeline so we can gain an appreciation for the scope and rate of change in each of these areas.
10,000 years ago
Most people shifted from a foraging or hunter gatherer life-way to a settled, agricultural approach. This GENERALLY meant a reduced variety of foods (until very recently) and a host of ailments are well documented with this transition. Living in close proximity to larger numbers of people as well as animals appears to have posed a significant immune challenge for our early agricultural ancestors. Reliance on starchy, low-nutrient foods such as grains also appears to have posed a significant challenge with regards to growth and nutrient deficiencies. From the perspective of sleep and circadian rhythm we still tended to go to bed not long after the sun went down and got up when the sun came up. In general, we got a lot of sleep and downtime. Although the shift from small groups to villages and cities was clearly a significant cultural shift, people still had the advantage of extended families and tight social units. Social isolation and loneliness were a few thousand years in the future. Given the lack of antibiotics and other hygiene practices it is unlikely our gut biome was negatively altered by the shift to agriculture, but the exposure to infectious agents as well as malnutrition from an unvaried diet appears to have been quite tough on the folks living through this time.
200 years ago
Most people began a shift from working on farms which required significant amounts of physical labor, to factory and urban life that was a bit less strenuous. Gas lighting was limited to the large urban centers, so the amount of additional “day time” people could experience via artificial light was not remarkably different than 10,000 years earlier. Although many aspects of culture had changed relative to our foraging ancestors, sleep was not that different than 10,000 or even 100,000 years earlier. In general, food variety appears to have increased around this time, which began to unwind some of the deficiency diseases common in earlier times. Social networks and extended families continued to be relatively strong as although mobility allowed people to follow work opportunities, people tended to move the whole family vs the fragmentation we see today.
100 years ago
Thomas Edison (and a number of other folks around the world) invented a long lasting, electrically powered, incandescent light bulb. This made lighting relatively cheap, ubiquitous and democratized a number of things like learning and entertainment. Where only the wealthy could previously afford significant amounts of artificial light, now almost everyone could partake of this miracle. This opened up whole new ways of doing business and dramatically changed industry. Factories could run all night, the concept of shift work was born, and human innovation exploded. As good as all this was for most of humanity, we began sleeping less — and this set the stage for one of the most profound changes in human history. Antibiotics were only a few decades in the future and although these wonder drugs would save millions of lives, the unintended impact on our gut microbes (and health) would not be well appreciated until the beginning of the 21st century.
30 years ago
The explosion of microprocessors and innovation ushered in the internet, 24/7 commerce and dozens, then hundreds, then thousands of cable TV channels. If we wanted entertainment, education or distraction, it was only a dial-up phone connection away (or the smart phone in your pocket now.) We work much more and sleep much less than we did even in the 1980’s, about 2.5 hrs less on average for most Americans. This change in not only sleep but also our constant exposure to artificial light (which affects every body system you care to consider) is perhaps the most profound change humanity has experienced. I’d ALMOST say that sleep and circadian rhythm are more important than proper nutrition. The only caveat I’d put on that is that if you are a shift worker, a new parent or in a similar situation in which your sleep is continually disturbed, keeping an eye on your food may be much more doable — it’s likely not feasible to quit your job as an ER nurse or Cop and there’s no way but through for the folks in the new parent category. As we will see in subsequent chapters, our food system began to rapidly change, shifting us away from largely traditional, home cooked meals to grab-n-go options as well as an avalanche of processed junk foods. Our gut microbiota likely underwent a profound change due to antibiotic use, modern medical procedures and an increasing focus on products like hand sanitizers and antimicrobial soaps. It’s worth noting that changes in the gut tract strongly with increasing rates of obesity, cardiovascular disease and neurodegeneration. In a later chapter we will explore how alterations in the gut can play into these conditions. On a social level the past 30 years have seen the most profound changes in all of human history. Our highly mobile, information based society has been a boon for work opportunities but an unintended consequence has been a profound increase in social isolation, particularly in the elderly. Although epidemiological in nature, studies have indicated that inadequate social connectivity increases early death potential as much as a pack a day smoking habit.
My Second book, Wired To Eat is available for pre-order everywhere books are sold and will be released March 21.
Eirik Garnas says
“… we need to both understand and implement the concepts implicit in the Discordance Theory. For the folks who dismiss the Ancestral Health model I’m going to start demanding a viable alternative. The current model is not working, “everything in moderation” is not working.”
Spot on, Robb!
The thing I think eludes a lot of people is that natural selection doesn’t select for health, but rather for reproductive success. Often, the two are linked, but not always. E.g., some chronic diseases develop primarily late in life and have little impact on the reproductive success of the organism in question.
This is critical to remember when talking about diet/lifestyle-related genetic adaptations, for example in the context of lactase persistence.
People who carry lactase-persistence alleles are able to consume milk and other lactose-containing dairy foods without experiencing gastrointestinal distress, but that doesn’t necessarily mean that it’s healthy for them to do so. The weight of the evidence suggests that it’s not (at least if large quantities are consumed). This is something those people who bring up recent genetic adaptations as a way to dismiss the ancestral health model don’t seem to understand.
Guillaume Lacerte says
Critter: Panda. Seems like a bamboo diet for an omnivore isn’t so great for fertility. 😀