I introduce the “re-evolutionary” premise that we should model our diet, exercise, and lifestyle behaviors after our primal ancestors from 10,000 years ago, adapting those behaviors strategically to the realities of high-tech modern life. The inexorable technological progress of civilization has diverted us from the healthy dietary habits and active, stress-balanced lifestyles that allowed primal humans to prevail under the harsh competitive pressures of evolution. However, we are almost genetically identical (in nearly all areas relevant to human health) to our hunter-gatherer ancestors, owing to the fact that evolution lost its main catalyst when the major selection pressures of starvation and predator danger (eat or get eaten!) were eliminated with the gradual advent of civilization across the globe.
Genes are much more than the narrow conventional understanding of them as fixed heritable traits (e.g., hair, skin, and eye color). Genes are the “traffic cops” that direct the function of every cell in your body at all times. Genes are activated or deactivated by the signals they receive from the environment. Drink a soda, and your genes direct the flood of insulin into your bloodstream to counteract the high glucose levels, returning you to a state of homeostasis that ensures your short-term survival. By following the Primal Blueprint laws, you can reprogram your genes in the direction of health and longevity. Even if you have strong familial genetic predispositions to disease, excess body fat, and other adverse health conditions, you can honor your Homo sapiens genes and render these dispositions virtually irrelevant.
The 10 Primal Blueprint laws are:
1. Eat Plants and Animals
2. Avoid Poisonous Things
3. Move Frequently
4. Lift Heavy Things
5. Sprint Once in a While
6. Get Plenty of Sleep
7. Play
8. Get Plenty of Sunlight
9. Avoid Stupid Mistakes
10. Use Your Brain
Nothing in biology makes sense except in the light of evolution.
—Theodosius Dobzhansky
The quote by Dobzhansky was also the title of his famous 1973 essay in which the noted evolutionary biologist and devout Russian Orthodox Christian acknowledged that, whether or not you believed in the existence of a higher power, you could not begin to understand even the simplest concepts in biology unless you accepted how evolution had worked to shape and differentiate the genes of every single one of the several million species on the planet.
Within the past hundred years, tens of thousands of anthropologists, evolutionary biologists, paleontologists, epigeneticists, and other scientists have worked diligently to piece together a fairly detailed interpretation of the environmental and behavioral factors that directly influenced our development as a species. As a result, we now have a very good picture of the conditions under which we emerged as Homo sapiens.
Some seven million years ago, hominids (our prehuman ancestors) split from apes and branched out into various new species and subspecies. Then, about 2.5 million years ago, the humanlike species Homo erectus, with its large brain, upright stature, skilled use of tools, eventual mastery of fire (around 400,000 years ago), and organized hunter-gatherer societies, began to take charge of the food chain. Over time, Homo erectus branched into various species and subspecies (Homo neanderthalensis, Homo habilis, and Homo sapiens, among others). Most researchers believe that modern Homo sapiens first appeared in East Africa around 160,000 years ago. Then, about 60,000 years ago, a very small number of Homo sapiens left Africa and began their great migration across the planet.
Recent archeological findings strongly support this “Out of Africa” theory1: that the entire human population of the planet, amazingly, can trace their origins to a small pool of intrepid Homo sapiens in East Africa. There were only an estimated 2,000 to 5,000 African humans at that time; and some scientists believe that only about 150 people crossed the Red Sea to begin the migration. Despite our disparate physical appearances today, and our layman’s misconception of race as distinct parallel tracks of ancestry, the truth is that all humans descend from a very small clan of globetrotters, making us extremely similar from a genetic perspective.
Evolving Without Evolution
When the advent of civilization freed humans from constant selection pressure (because predator danger and the threat of starvation were greatly reduced), evolution nearly ground to a halt. This means that we are nearly genetically identical to our primal ancestors, at least in relation to those aspects that dictate how we should eat, exercise, and live in order to promote the ultimate goal of evolution: to survive long enough to reproduce. Yet the essence of the Primal Blueprint is to leverage what we know of the evolutionary model far beyond the modest goal of reproducing. Our goal is to replicate as many of our ancestors’ dietary and lifestyle choices as possible to promote optimal health, peak physical and cognitive performance, and longevity.
While a slender, six-foot-four, blond, fair-skinned Scandinavian might seem highly disparate from a stout, five-foot-seven, dark-skinned Indian, these physical variations are relatively superficial from a DNA perspective. As a species, we tend to inflate the significance of differences between ethnic groups. But humans are much more alike than not, genetically speaking. For example, David Epstein’s brilliant book, The Sports Gene, references the work of Yale genetics professor Kenneth Kidd, who asserts that there is greater genetic diversity between two members of the same pygmy tribe in Africa (or any two individuals whose ancestry has been contained within the African continent since primal times) than there is among the rest of the entire human race combined!
Today’s phenotypic differences in appearance around the globe obscure the larger truth that when it comes to DNA, we are all fundamentally human. You may have heard how we share more than 98 percent of our DNA with chimps and bonobos, so you can imagine how trying to split hairs to differentiate humans is irrelevant. One implication this genetic similarity has for your health is that you don’t need to go looking for the latest fad diet that’s linked to your blood type or even your ethnicity. Rather, the blueprint for healthy living comes from our shared evolutionary history as hunter-gatherers.
This is not to say that there are no meaningful differences between individuals—obviously there are. The set of genes we receive from our parents have distinct features that predispose us to being athletic, a math genius (like my friend Big George), obese, or suffer from arthritis if we nurture such positive or negative outcomes with accordant lifestyle behaviors.
It is also true there are some relatively recent examples of genetic mutations, aka genetic drift, that make recent ancestry potentially more relevant to your healthy eating and lifestyle choices. For example, your skin pigmentation strongly influences your vitamin D health. (Our ancestors had dark skin for over a million years; researchers believe the lightening of skin color among some peoples happened perhaps 40,000 or as recently as 10,000 years ago in conjunction with colonizing the higher latitudes.) Darker-skinned people require longer sun exposure to optimize vitamin D production and are much more susceptible to vitamin D deficiency in today’s indoor-dominant lifestyle.
Another interesting example is the prevalence of lactase persistence (continuing to make the enzyme lactase, enabling one to digest lactose—the sugar in milk—throughout life) amongst those of distinct herding ancestry, such as Northern Europeans and Scandinavians. While most adults (~75 percent) across the globe become lactose intolerant after childhood, those with strong herding ancestry are nearly all (~90 percent) lactase persistent.
Thirdly, as you might discern from looking at the disparate success rates in maintaining ideal body composition despite devoted efforts, one’s ability to successfully tolerate carbohydrate ingestion without getting fat has strong genetic influences. Recent science has promoted the idea that those with more copies of the AMY1 gene (a salivary enzyme involved in the breakdown of starches) can better manage carbohydrate intake without getting fat than those with fewer copies. Some scientists cite these and other examples to argue that evolution is still occurring. At a certain point, we are just arguing semantics about the effects of population expansion, genetic drift, and modern science being increasingly able to identify variations (that were likely always there) in the human genome, versus traditional conceptualizations of evolution driven by random mutations and survival of the fittest. For now, let’s stay focused on the big picture: discovering the most important evolution-tested behaviors that promote optimal gene expression—behaviors that have not changed in 10,000 years. These are really all you need to know to achieve optimal health.
I hope you are sitting down to absorb one of the most critical—and quite possibly mind-blowing—tenets of the Primal Blueprint:
Our primal ancestors were likely stronger and healthier than we are today.
“How can this be?” you ask. It’s all about survival of the fittest. The human body is the miraculous result of millions of years of painstaking design by evolution. Through natural selection—countless small genetic mutations and adaptations in response to a hostile environment—our ancestors were able to prevail over unimaginably difficult conditions and opponents and to populate all corners of the earth.
On the other hand, the development of agriculture and civilization caused humans to become smaller and sicker, leading to a dramatic decline in life expectancy. Many anthropologists suggest that the human species reached its physical evolutionary pinnacle (in terms of average muscularity, bone density, and brain size) about 10,000 years ago. After that, we started to take it easy and get soft. Our physical decline was a natural consequence of a couple of things. First, we had already spent thousands of generations leveraging our increasingly proficient brain function to manipulate and tame the natural environment (with tools, weapons, fire, and shelter) to our advantage. Doing so made life easier and survival more likely.
The second factor is perhaps the most significant lifestyle change in the history of humanity: the gradual advent of agriculture. When humans began to domesticate and harvest wheat, rice, corn, and other crops, as well as livestock, they gained the ability to store food, divide and specialize labor, and live in close civilized quarters. This virtually eliminated the main selection pressures that had driven human evolution for 2.5 million years—the threats of starvation and predator danger. Our transition from hunter-gatherer existence to agricultural societies happened independently around the globe, becoming prominent about 7,000 years ago in modern-day Egypt. North America was one of the last areas to implement agriculture, about 4,500 years ago.2
FEELIN’ SOME PRESSURE TO EXPLAIN SELECTION PRESSURE
“Selection pressure” is the Darwinian-inspired term to describe life-or-death environmental circumstances that drive the evolution of all species. The evolutionary process we know as “survival of the fittest” might be more accurately expressed as “survival of the luckiest”—that is, survival of those who were lucky enough to be born with features that conferred a reproductive advantage. Consider the example of Darwin’s famous Galapagos finches: a bird born with a long, pointy beak (by random genetic mutation) discovered that he was better adapted to picking seeds out of cactus fruits on his island. Consequently, he enjoyed a reproductive advantage over less well-endowed finches in that habitat, and long, pointy beaks soon proliferated on that particular island. Meanwhile, short, stout beaks (better for collecting seeds off the ground) were selected for and proliferated on a different island.
The lightening of skin pigmentation to afford better vitamin D production away from the equator is an example of Darwin’s mutation and natural selection process.
Similarly, over thousands of years of human evolution, genetic mutations that promoted our survival (higher-functioning brains, explosive fast-twitch muscle fibers, etc.) appeared in the gene pool by luck through random genetic mutations in individuals and were then selected for and proliferated through reproduction. For example, as humans migrated north from the equator into the higher latitudes, getting enough sun exposure to produce ample vitamin D became a big problem with potentially fatal consequences. The first human born with lighter skin at the higher latitudes (from darker skinned parents who had emigrated there) was bestowed a significant survival advantage. Hence, the lightening of skin color spread like wildfire among humans living at higher latitudes. Conversely, unfavorable genetic mutations that compromised chances for survival and reproduction were eliminated from the gene pool with ruthless efficiency.
The idea that human DNA—the genetic “recipe” for building a healthy, lean, thriving human that resides in each of our 60 trillion cells—is almost exactly the same today as it was 10,000 years ago was first notably promoted by the work of Dr. Boyd Eaton, chief anthropologist at Emory University in Atlanta and author of The Paleolithic Prescription (1988) and a landmark paper published in the New England Journal of Medicine in 1985, “Paleolithic Nutrition.” Other researchers leading the way were the late James V. Neel, founder of the University of Michigan’s Department of Genetics, and Dr. Loren Cordain, professor of exercise physiology at Colorado State University, who was a pioneer in talking about eating in accordance with our hunter-gatherer ancestors in The Paleo Diet (2002). Today, with the evolutionary health movement exploding in popularity, more and more research is being published by anthropologists, evolutionary biologists, and genetic researchers validating the early arguments set forth by these paleo pioneers.
While our primal ancestors made the most of their genes (remember, this was not a conscious choice; the alternative was to starve or become some other creature’s dinner!), most of us today fall far short. The development of agriculture and civilization caused humans to become smaller (including in brain size) and sicker (originally due to contagious diseases, but now due mostly to vastly inferior diets, exercise, and lifestyle patterns).
Human life expectancy 10,000 years ago was about 33 years. While not too impressive by 21st-century standards, and somewhat misleading due to high rates of infant mortality at the time, primal man actually lived longer relative to his civilized descendants all the way into the early 20th century! Average life expectancy reached a low of 18 during the Bronze Age (~3300-1200 B.C., Ancient Egypt), rose only slightly to a range of 20 to 30 years through Classical Greek times (~500-300 B.C.), the Roman Empire (~0-500 A.D.), and the Middle Ages (~700-1500), and was still only between 30 and 40 years as recently as the early 20th century. Around that time, medical advancements (antibiotics, hospital and community sanitation, better infant survival, and so on) helped life expectancy skyrocket.
Life expectancy was brutal during the time of Brutus—under 30 years. Brutus lived to 43 (long enough to knock off Caesar), but Grok and his pre-civilized pals often bested that.
Fossil records show that primal humans who steered clear of fatal misfortune could routinely live six or seven decades in excellent health. The records also show a “maximum observed life span” of an astonishing 94 years!3 Among present-day hunter-gatherers (e.g., Aché, Hadza, Hiwi, and !Kung—groups with almost no modern conveniences or access to medical care), it is not uncommon to see strong, healthy folks living well into their 80s. More than a quarter of the Aché (Ah-CHAY) people of Paraguay make it to 70. Moreover, 73 percent of Ache adults die from accidents and only 17 percent from illness. Think about the extraordinary implications of hunter-gatherer longevity: with no modern medications or medical care of any kind, a massive lifelong struggle for food, clothing, and shelter, and lives completely devoid of modern comforts, primal humans (and modern humans living primally) can still live to what even we softies consider old age.
The Ultimate Human award goes to Grok, my nickname for the prototypical pre-agricultural human being.
Of course, the decline in life expectancy with the onset of civilization didn’t matter in a purely evolutionary context. As long as civilized humans made it to reproductive age and had children, they could pass their genes along to the next generation without penalty. While progressing beyond primal humans’ harsh survival of the fittest conditions is definitely a good thing, the sober reality is that today’s technological age is populated with the fattest, most sedentary humans in the history of humanity. Hence, the Ultimate Human award goes to Grok,4 my nickname for the prototypical pre-agricultural human being. Grok is a lean, smart, healthy character, the primal representative of sorts of both this book and my blog at MarksDailyApple.com.
Unlike Grok, who ruled the planet with little more than a spear and a thatched hut in his portfolio, even the most impoverished humans of the last several thousand years, extending up to the present day’s most socioeconomically stressed persons, have not really “competed” genetically. The presence of the most rudimentary modern advantages, such as the availability and storage of basic food stuffs like grains, permanent shelters, and basic defenses to nullify predator danger, all suppress the true Darwinian survival of the fittest playing field that allowed Grok to thrive.
ARE WE REALLY DEVOLVING?
You might have heard that humans are actually devolving. Proponents of this idea argue that modern lifestyles—rife with too much sugar and too little exercise, obesity, metabolic disease, and so on—are causing unfavorable genetic changes that actually make our (long-term) survival less likely, and that we are now passing those changes on to our children. So is that true? Is the evolutionary clock actually spinning backward?
For the first time in recorded history, today’s youth have a lower life expectancy than their parents.
Not exactly. True evolution in the Darwinian sense requires that genomic changes—changes to our DNA—are passed from generation to generation There is no evidence that modern lifestyles, problematic though they are, are affecting our DNA. However, something is most definitely afoot, and that something is epigenetic transgenerational inheritance.
In addition to the genome with which you are undoubtedly familiar (the DNA, organized into genes, residing in each of our cells) we also have an epigenome. The epigenome resides outside or “on top of” (the literal meaning of epi-) the DNA and is comprised of chemical tags known as epigenetic marks. These marks attach to the genome and direct the expression of the genes, turning them on or off, up or down. Whereas our genome is fixed, our epigenome is malleable; it responds to internal and external stimuli. Scientists now believe we can change our epigenome through our behaviors, and this is the very essence of the Primal Blueprint: providing the kind of input and environment for our epigenome to direct favorable gene expression to promote health and longevity.
It turns out that there are even bigger stakes than our own health and longevity, though A growing body of research shows that epigenetic changes can be passed to offspring If individuals behave in ways or are in environments that promote unfavorable gene expression—if they overeat or eat a poor diet, are highly stressed, smoke, or are exposed to high levels of lead, for example—their offspring can inherit epigenetic markers that direct unfavorable gene expression Studies have linked epigenetic inheritance to offspring’s risk of metabolic and cardiovascular disease, abnormal stress response, mental health issues, memory problems, and asthma, among others In studies on animals with short life spans and high generational turnover such as fruit flies, there are examples of these changes persisting for many generations. (Many studies of transgenerational epigenetic inheritance have been conducted with mice or other animals, but there are ones that demonstrate epigenetic inheritance in humans as well.)
What does this all mean? First, it means that humans are not devolving in a literal sense Although modern lifestyles have serious negative health consequences, the most life-threatening problems mostly arise after our reproductive years are behind us, so there is no selection pressure leading to survival of the fittest. Humans won’t be sprouting gills (this would definitely count as a change to our DNA!) any time soon unless the world floods over for thousands of years and we need to sink or swim. However, our genes can be literally “marked” for misfortune and those marks passed to offspring as a consequence of adverse lifestyle practices.
It’s becoming increasingly clear that the choices we make affect not only ourselves but our children, our grandchildren, and maybe even further down the ancestral line That’s scary stuff, but don’t get overwhelmed It also means that we have more control over our health and our children’s health than we would if genes were the be-all and end-all And if you already had children (perhaps when you weren’t as healthy as before you went primal), know that by modeling good behavior for them going forward, you are encouraging them to make choices in their own lives that direct favorable epigenetic changes. Just consider this a wake-up call and use it to motivate your own good choices in the future!
Sure, being a math whiz or a natural athlete may significantly influence your path through life and give you a competitive edge in pursuits to which you are inclined, but these genetic attributes no longer provide a survival advantage in the evolutionary sense. Candy-chomping, video-gaming slackers can reproduce just as successfully as Olympic athletes and Ph.D. candidates due to lack of selection pressure for physical or cognitive peak performance attributes in the modern world. Obviously, the elimination of ruthless selection pressure represents progress for humanity. (Consider how most of us have suffered illnesses or traumas over the course of our lives that would have killed us a century ago, let alone 1,000 or 10,000 years ago.) However, we must be vigilant not to let the advantages of modern life compromise our health (for example, by hitting the pharmacy instead of the gym to combat back pain), or worse, lead to unfavorable epigenetic transgenerational inheritance to our offspring.
The challenge is in applying the Primal Blueprint laws to modern life. How do we leverage the lessons and benefits of natural selection against the pressures of a complex modern society bent on promoting consumerism and quick fixes over the pursuit of health? How do we reprogram our ancient genes to recapture excellent health? We simply have to ask ourselves, “What would Grok do?”
In order to begin to understand the concept of “reprogramming” your genes, it will help to understand what they actually are and how they work. Each of your 50 or 60 trillion cells contains a nucleus with a complete set of DNA instructions divided into handy subsets called genes. There are approximately 20,000 different genes located on the long strands of DNA in each cell, organized into 23 pairs of chromosomes. In any given cell, only a small fraction of the total number of genes is actively involved in carrying out the main “business” of that particular type of cell. Depending on the environmental signals that cells get from their cellular environments within the body (which can be influenced by external factors), genes trigger the manufacture of specific proteins and enzymes to perform the various tasks required of them. For example, the beta cells in your pancreas manufacture insulin, but they don’t grow bigger when you lift weights. Liver cells can synthesize nutrients, but they don’t grow new bone tissue. And yet each cell has the entire “recipe” for a human residing in the DNA.
Genes are not self-determining; they do not, turn on or off by themselves, but rather they respond to signals they receive from their immediate environment.
Genes don’t know—or care—whether these environmental signals promote or compromise your health; they simply react to each stimulus in an effort to ensure your immediate survival. The most important thing to understand here is that most genes are not self-determining; they do not turn on or off by themselves, but rather they respond to signals they receive from their immediate environment. You have the power to switch on or turn off certain genes that have a profound influence on your health. You may not be able to reprogram your eyes from blue to brown, but you can certainly avoid becoming obese, even if your dad, grandpa, and brothers (who eat a grain-based, high-carbohydrate diet) all happen to be obese.
Genes Are All About Instant Gratification —How About You?
Genes are programmed to support short-term survival—that’s it. Pound those Cheetos and Dr. Pepper on the couch, and your genes direct a flood of insulin into the bloodstream to remove excess glucose that can otherwise quickly become life-threatening. If high-insulin-producing eating habits become a lifestyle pattern, your genes will fight valiantly to keep you alive every day, but you will likely accumulate inflammation and oxidation that will compromise your long-term health. Again, with selection pressure irrelevant (you won’t get eaten by a lion if you get fat), the responsibility falls entirely on you—whether you choose to promote, or compromise, long-term health with your daily lifestyle behaviors.
Granted, a strong familial genetic predisposition to carry excess body fat is indeed relevant and plays out routinely in many families over generations due to the driving force of high-insulin-producing diets. When you give your genes a different environmental experience (e.g., a primal-aligned diet that moderates insulin), your predisposition toward obesity will cease to be relevant. Ditto if you carry genes that predispose you to alcoholism but you don’t drink.
Genes actively control cell function all the time. Your overall health is primarily dependent on which genes get turned on or off in response to their immediate environment. Sprint or lift weights, and the biochemical “byproducts” from that specific activity turn on certain genes that repair and strengthen the exercised muscles. Do too much exercise, and other genes promote excessive production of catabolic (breakdown) hormones, leading to prolonged inflammation and hindered recovery. An allergic reaction represents your body’s (misdirected) genetic response to a perceived airborne or ingested threat. An autoimmune disease is often a genetic overreaction of that same system caused by pro-inflammatory foods (see Chapter 6). Type 2 diabetes typically develops after prolonged periods when your genes are trying to protect you from the dangers of eating too many processed carbohydrates.
Here’s a great example of our genes’ ability to switch on and off. In a 2009 report from the journal Cancer Research, researchers studying the link between smoking and lung cancer discovered that tobacco smoking causes hypermethylation (a complete or partial deactivation) of a single gene known as MTHFR (pronounced Mother-Fu... forget it!). MTHFR is one of many genes known to be involved with cancer and tumor growth, but among the genes included in this study, MTHFR was uniquely hypermethylated by tobacco use. This is critical because turning off MTHFR triggers global hypomethylation (systemic dysfunction) in many other genes; and global hypomethylation is known to contribute to cancer development and progression.
The idea that the environment influences whether genes are turned on or off is not a new one. In 1942, geneticist and evolutionary biologist C. H. Waddington first coined the term epigenetics to describe how genes might interact with their surroundings to create a unique individual. Today the study of epigenetics is one of the fastest growing subdisciplines of genetics. Moreover, the burgeoning field of nutrigenomics has identified hundreds of ways that nutrients (foods or supplements) impact gene expression. You may be familiar with the direct influence folic acid has on reducing neural tube birth defects, which is why all pregnant women are advised to take supplemental folic acid.
And it’s not just about vitamins and minerals. An Australian study suggested that human genes are adversely affected by just two weeks of sugar ingestion (genetic controls designed to protect the body against diabetes and heart disease are switched off as an acute reaction to eating sugar) and that prolonged poor eating can cause genetic damage that can potentially be passed through bloodlines! On an even grander scale, research shows that certain cells within the body called mesenchymal stem cells can become bone cells, fat cells, muscle cells, or even cancer cells in adults, depending upon the environmental signals they receive.
Your lifestyle can either enhance or severely undermine many aspects of your health, and can often be far more relevant than inherited predispositions to allergies, diabetes, or even more severe conditions. Not to make light of the serious genetically influenced health challenges that many face over their lifetimes, I would argue that we are all predisposed to heart disease, cancer, arthritis, and today’s other leading lifestyle-related health problems if we program our genes with diet, exercise, and behaviors that are in conflict with our genetic expectations for health and longevity.
What “Reprogram Your Genes” Really Means
Your genome (your complete set of DNA, including all genes) is set at birth. Your DNA is copied into every cell of your body. You cannot modify or reprogram your genome. Epigenetics expert Randy Jirtle, Ph.D., likens your genome to computer hardware, while your epigenome (the chemical compounds that direct your genome what to do) would be the software loaded onto the hard drive.
Your epigenome is what responds to environmental signals. You can manipulate chemical activity and gene expression by switching from Dr. Pepper to water, or by getting off the couch and hoisting some weights in the gym. We have immense power to turn some genes on and other genes off to generate optimal results. There are multiple possible versions of future you. It’s up to you to decide which version you will become. It’s up to you to make lifestyle choices that direct genes toward fat burning, muscle building, longevity, and wellness, and away from fat storing, muscle wasting, disease, and illness.
Every cell contains a complete set of genes, each with on/off switches that are largely under your control.
Obviously, you cannot grow your kids to seven feet tall simply by feeding them healthy food and making sure they get plenty of sleep; we all have profound limitations on how our genes can express our unique individual potential. For confirmation, just take a look at the physical marvels in the Olympic 100-meter dash or on an NFL or NBA roster, collections of the most physically gifted athletes on the planet. These athletes are one-in-a-million genetically, but they still embody optimal gene expression that has enabled them to realize their athletic potential. The choices they have made—the foods they’ve eaten, how they’ve trained, even how they’ve thought—have all helped them make the most of their natural-born talents to rise to the top of very competitive arenas. This is all you ought to be concerned with—making the most of your own genetic potential to enjoy a long life of excellent health and peak performance through the 10 Primal Blueprint laws.
The chapters that follow will explore the rationale behind and benefits of the 10 simple Primal Blueprint laws, and will offer practical suggestions for living accordingly. These laws represent the specific behaviors that led directly (thanks to 2.5 million years of evolution) to the genetic recipe for a healthy, lean, fit, happy human being. Almost nothing of real significance has changed in this recipe since pre-agricultural times—except the endless new ways we modern humans mismanage our genes and compromise our health.
By understanding how these behavioral “laws” shaped our genome, you can reprogram your genes to express themselves in the direction of health. And when I say “simple laws,” I really mean it. If you read just this chapter and never open the book again, you’ll have all the information you need to live a long, healthy, disease-free life. Here, then, is a brief description of the laws of living 10,000 years ago and a quick overview of how to adapt them to a healthy 21st-century lifestyle.
Plants and animals encompass everything our ancestors ate to get the protein, fats, carbohydrates, vitamins, minerals, antioxidants, phenols, fiber, water, and other nutrients necessary to sustain life, increase brain size, improve physical fitness, and support immune function. The pre-civilization human diet differs greatly from the Standard American Diet (SAD) today. Because the various diet camps passionately argue conflicting positions to a confused public, it’s essential to reflect on how profoundly important and logically sound it is to model our diets after the diets of our ancestors, whose bodies evolved to survive, reproduce, and thrive on these foods. Talk about a lengthy and severely scrutinized (as in “life or death”) scientific research protocol!
For one, primal humans across the globe ate widely varied diets due to environmental circumstances such as climate, geography, seasons, and activity level. There is no single regimented diet of narrowly defined foods that trumps all. Once you subscribe to the broad guidelines of the Primal Blueprint (eat plants and animals, avoid modern foods foreign to your genes), personal preference and self-experimentation—that is, discovering your body’s own unique responses—will be the driving force behind your food choices each day.
SHOUT OUT TO THE CRITICS AND THE MISINTERPRETERS
Many critics of primal/paleo argue that a Paleolithic diet is not easily definable and not sensible to follow since we don’t know exactly what our ancestors ate. Other naysayers misunderstand the basics of evolutionary biology and argue that our 10,000-year exposure to a high-carbohydrate diet has prompted a genetic adaptation to high carb intake. This conjecture is easily refuted by genetic science and by looking at the ever-expanding waistlines and escalating type 2 diabetes rates among modern humans. Like it or not, we remain hunter-gatherers from a genetic perspective and will continue to be so unless some new selection pressures present themselves in the future.
The arguments about the particulars of our ancestors’ eating habits distract from the most important message, which is that we know what our ancestors didn’t eat: sugars, sweetened beverages, grains, and refined vegetable oils, most importantly. Eliminating toxic modern foods is the most pressing issue to address, especially since they comprise the bulk of calories in the Standard American Diet. Dr. Cordain contends that 71 percent of SAD calories come from non-paleo foods.
I also want to clarify my original Primal Blueprint argument and the boilerplate paleo diet rationale that we should not consume modern foods because they are foreign to our hunter-gatherer genes. While this advice can’t hurt you, and will assuredly keep you away from sodas and cotton candy, it may overshadow the most important reason to avoid certain modern foods: because they are unhealthy, pure and simple, not necessarily because we have not yet adapted to consume them Throughout evolution, our ancestors came upon brand new food sources, consumed them, and were able to thrive because the foods offered good nutrition for the human body. Similarly, certain foods that were not eaten in hunter-gatherer times, such as dark chocolate and high-fat dairy products, offer genuine health benefits and have few or no health drawbacks.
We should avoid certain modern foods because they are unhealthy, not necessarily because we have not yet genetically to consume them.
When the hardcore paleo message advises against consuming grains, for example, because they weren’t around 10,000 years ago and we haven’t had time to adapt to them, this might obscure the more critical point that grains are unhealthy to ingest, period. The high carbohydrate content of grains contributes to wildly excessive insulin production and associated health problems like chronic inflammation and excess body fat. Furthermore, the protein molecules contained in grains (gluten and other lectins) damage the human intestinal tract. Humans are genetically adapted to digest carbohydrates (remember, all forms of carbs get converted into glucose upon ingestion), so the problem is one of quantity, concentration, and source when it comes to our modern carbohydrate consumption. It takes a lot of Grok’s wild berries to equal the sugar content of a Jamba Juice smoothie!
So, while it helps to model our dietary and exercise habits after the behaviors of our ancestors, we can make adjustments and allowances for modern life and still be healthy, even if it means eating or doing modern stuff like working out with a BowFlex machine instead of hunting wild game. And we should still avoid poisonous berries or mushrooms, even if they were around 10,000 years ago!
Another notable aspect of our ancestors’ diets was that they ate sporadically—mostly due to inconsistent availability of food. (Not a big issue in the developed world these days, eh?) Consequently, we became well-adapted to store caloric energy (in the form of body fat, along with a little bit of muscle and liver glycogen) and burn it when dietary calories were scarce. You may be disturbed about possessing the genetic trait to store extra food calories efficiently as fat. However, by simply eating the right kinds of foods, you can leverage this “savings and withdrawal” mechanism to your advantage, thereby maintaining ideal body-fat reserves and stabilizing daily appetite and energy levels. Hint. It’s mostly about moderating the wildly excessive insulin production resulting from the SAD.
Focus on consuming quality sources of animal protein (local, pasture-raised, or organic sources of meat, fowl, fish, and eggs), an assortment of colorful vegetables and fresh, in-season fruits, and healthy sources of fat (animal fats, avocados, butter, coconut products, nuts and seeds, olives and olive oil). Realize that a significant amount of conventional wisdom about healthy eating is marketing fodder that grossly distorts the fundamental truth—which is that humans thrive on natural plant and animal foods—or that relies on ploys to support the dogma of flawed, manipulated research. For example, strategies such as eating at particular times (three squares or six small meals a day), combining or rotating specific food types at meals, structuring your meals according to pre-programmed phases or stages, eating foods supposedly aligned with your blood type, striving for specific macronutrient ratios, or keeping score of your portions and weekly treat allowances are all gimmicks that have no credibility in the context of evolutionary biology.
Furthermore, regimented programs are virtually impossible to enjoy and stick to over the long term because they cause eating, which should be enjoyable and gratifying, to be imbued with stress and anxiety. We humans thrive on eating a diverse array of natural foods that satisfy and nourish us, and we are designed to eat at times and in amounts and varieties that fluctuate according to personal preference, environmental circumstances, activity levels, stress levels, and many other factors. I suggest you enjoy eating as one of the pleasures of life and reject most everything you’ve ever heard about when and how much you should eat. Instead, eat when you are hungry and finish eating when you feel satisfied. Realize that primal foods are intrinsically the most delicious, because they satisfy your cravings and distinct tastes, stabilize mood and energy levels, and promote health and wellbeing.
The ability of humans to exploit almost every corner of the earth was partly predicated on consuming vastly different types of plant and animal life. Primal humans developed a keen sense of smell and taste, along with liver, kidney, and stomach function, to adapt to new food sources and avoid succumbing to poisonous plants that they encountered routinely when foraging and settling new areas. For example, the sweet tooth we have today is probably an evolved response to an almost universal truth in the plant world that anything sweet is safe to eat. Furthermore, gorging on sweet foods and being able to store that excess caloric intake as fat was an evolved response for surviving harsh winters with diminished food availability.
While we have little risk of ingesting poisonous plants on walkabouts today, the number of toxic agents in our food supply is worse than ever. By toxic, I mean human-made substances that disturb the normal, healthy function of your body when ingested. The big offenders, including sugars and sodas, chemically altered fats, and heavily processed, packaged, fried, and preserved foods, are obvious. It’s not a stretch to directly compare the poisonous berries of Grok’s day with much of the stuff shelved at eye level in your local supermarket.
The more insidious dietary “poisons” are the grain products that form the foundation of the SAD (wheat products like bread, crackers, muffins, pancakes, tortillas, waffles, etc., as well as pasta, breakfast cereals, rice, and corn, and also cultivated grains like oats, barley, rye, and amaranth). These global dietary staples are generally inappropriate for human consumption because our digestive systems (and our genes) are traumatized by unfamiliar protein structures that can damage the intestinal tract, causing systemic inflammation and autoimmune reactions.
Both simple and complex carbs get converted into glucose—albeit, at differing rates—once they enter the body. Ingesting grains (yep, even whole grains, as we’ll discuss in detail in Chapter 6), legumes (beans, lentils, peanuts, peas, and soy products), and other processed carbohydrates cause blood glucose levels to spike. (We use the accurate term “blood glucose” to convey what is often referred to as “blood sugar.”) This spike is a shock to your genes, which are adapted to a much lower total carbohydrate intake, as well as to more complex carbohydrates that are natural, more fibrous, and much slower burning, like sweet potatoes and other starchy tubers.
When you shock your system with a glucose bomb after a well-intentioned trip to the muffin shop or smoothie bar, your pancreas rushes to the rescue by pumping out the requisite amount of insulin. After all, excess blood glucose is toxic and can quickly become life threatening, as diabetics who don’t get their insulin shots on schedule can attest. While insulin is an important hormone that also delivers nutrients to muscle, liver, and fat cells for storage, there is a balance that must be carefully maintained in order to remain healthy. Modern eating habits abuse this extremely delicate hormonal process by stimulating chronic excessive insulin production. If I had to pick a one-liner to summarize the number one health problem facing modern society—the gateway to type 2 diabetes, obesity, heart disease, and cancer—“chronic excessive insulin production” is it.
The flood of insulin from your pancreas to counter a medium Jamba Juice Lime Colada Fruit Refresher (91 grams of carbs—you’ll learn the scale to which this amount of carb intake affects your health in upcoming chapters) causes glucose to be removed so rapidly and effectively over the next hour or two that it can result in a “sugar crash.” This familiar mental drain (because the brain relies heavily on glucose for fuel) and physical lethargy is followed by a strong craving for more high-carbohydrate food as a quick fix. Thus goes the vicious cycle of the ill-advised carbohydrate bomb causing a temporary high, an excessive insulin response causing a low, and cravings for more carbs to bring you back up, creating a daily energy and mood roller coaster that all starts with that All-American high-carbohydrate breakfast.
Since insulin’s job is to transport nutrients out of the bloodstream and into the muscle, liver, and fat-cell storage depots, its excessive presence in the bloodstream inhibits the release of stored body fat for use as energy. This is especially true in the context of our modern lifestyles that are overabundant in food and deficient in physical movement, a combo that reduces insulin sensitivity. This means your cells become less responsive to the signals of insulin, so your pancreas must pump even more into the bloodstream to do the same amount of work.
When insulin is high, insulin’s counter regulatory hormone glucagon is usually low. Glucagon accesses carbs, protein, and fat from your body’s storage depots (muscle, liver, fat cells) and delivers them into the bloodstream for use as energy, so low glucagon means you are not able to use your stored energy efficiently. If you don’t have energy in your bloodstream, your brain says, “Eat now! And make it something sweet so we can burn it immediately.” The mobilization of stored body fat has been humans’ preferred energy source (and weight-control device) for a couple of million years, and now we brazenly bypass that whole process with a grain- and sugar-laden diet. It’s as simple as this: you cannot reduce body fat on a diet that stimulates chronically high insulin levels and low insulin sensitivity—period.
But the weight-loss frustrations associated with carbohydrate-induced insulin overload are just part of the story. The more critical reason to avoid these foods is that overstressing your insulin response system with years of eating a Standard American Diet can lead directly to devastating general system failure in the form of insulin resistance (a pathological inability of cells to respond to insulin), type 2 diabetes, obesity, cardiovascular disease (thanks to vascular inflammation, oxidative damage, and other insulin-related troubles we will learn more about later), and diet-related cancers. Furthermore, Chapter 6 will explain in detail that even whole grains (brown rice, whole wheat bread, etc.) are not particularly healthy, because they contain anti-nutrients that promote inflammation and hamper digestion and immune function (even if they have slightly more nutritional value than refined “white” grain products). Finally, a grain-based diet displaces the far more nutritious plants and animals as potential caloric centerpieces in your diet, and can lead to assorted dental problems that, as we learned in the “Are We Really Devolving?” sidebar, can be passed onto your offspring.
If Wisdom Teeth Are So Smart, Why Isn’t There Any Room for Them?
Human teeth, jaws, and faces have shrunk since primal times. Researchers believe this is due to a complex interplay between gene expression and epigenetic (environmental) influences. Because so much of today’s food is “soft”—heavily processed, calorically dense (e.g., grains, sugars, sweetened beverages, and vegetable oils providing a huge percentage of total calories), we no longer need the robust chewing mechanism that we did to chew the tough foods throughout evolution. Furthermore, the nutrient-deficient modern diet is directly associated with assorted dental problems. For example, half of all Americans require their wisdom teeth to be removed. We are hard wired to express the genes that develop wider mouths, a full set of teeth, and an extremely strong and active jaw, but we suppress these genes because we don’t need them to sip apple juice from a baby bottle, and we carry on from there into a modern dietary pattern.
Dr. Mike Mew, a London orthodontist, estimates that modern humans use the masticatory system at only about 3 to 5percent of the level that our primal ancestors did! This has led to an atrophy that has been passed to offspring for the hundreds of generations since the advent of civilization. This insight is a centerpiece of the pioneering research of Dr. Weston A. Price in the early 1900s. (You might be familiar with the Weston A. Price Foundation that does respected research, education, and activism today.) One study of Aboriginals who rapidly transitioned into a modern diet revealed elders with excellent teeth and facial structure and youth with full-blown modern soft-food-driven problems. The study abstract proposed that “the rapidity of the transition is proportional to the rapidity of urbanizational change.”
Grok spent several hours each day moving about at what today’s exercise physiologists might describe as a very low-level aerobic pace. He hunted, gathered, foraged, wandered, scouted, migrated, climbed, and crawled. This low-level activity prompted his genes to build a stronger capillary (blood vessel) network to provide oxygen and fuel to each muscle cell and readily convert stored fat into energy. (Fat is the main fuel used for low-level aerobic activity.) His daily movement also helped develop strong bones, joints, and connective tissue.
What Grok did not do was go for extended periods of time without moving, something that (as we’ll soon learn in more detail) causes a host of metabolic and cognitive problems. Grok also didn’t engage in a chronic pattern of sustained moderate-to-difficult-intensity efforts like today’s devoted fitness enthusiasts tend to do. This counterintuitive behavior would have depleted his precious muscle and liver glycogen stores and generated system-wide fatigue, leaving him vulnerable to a predator, starvation, or some other misfortune. (Plantar fasciitis anyone? Bowing out of hunting duties for six weeks probably wouldn’t play too well in the clan, you know?) You may have heard the recently popularized sentiment that humans were “born to run?” More accurately, we were born with the genetic ability to perform magnificent feats of endurance now and then (with plenty of downtime in between), sprint for our lives on those rare occasions when we faced such danger, and to walk and generally move about extensively every single day. When we decide to train in chronic patterns to prepare for a 26.2-mile marathon races, this can put our health in peril.
Today most of us are either too sedentary or we conduct workouts that are too stressful and misaligned with our primal genetic requirements for optimum health. The exercise gospel for decades has been to pursue a consistent routine of aerobic exercise whether it be jogging, cycling, cardio machines, group classes, or any other sustained effort. The message was that this effort would supposedly lead to more energy, better health, and weight control. However, too many lengthy workouts at heart rates beyond a comfortable aerobic, fat-burning intensity (a pace where you can converse easily and feel absolutely no strain on your muscles or oxygen supply) can put you at risk of exhaustion, burnout, injury, and illness. The high-carbohydrate diet on which most athletes rely to fuel these workouts day in and day out only adds to the problem. At the extreme—such as with the overtrained marathon runner or ironman triathlete—a commitment to fitness can actually accelerate the aging process and elevate the risk of heart disease.
Overexercising is a common scenario—consider how modern athletes display such strong focus, dedication, and willpower to push through signs of fatigue. Our bodies are simply not adapted to benefit from chronic aerobic exercise at even mildly uncomfortable heart rates. Neither are they designed to slog through exhausting circuits on resistance machines several days a week. The mild-to-severe difficulty of these chronic cardio or chronic strength workouts overtaxes the stress response (commonly referred to as the fight or flight response) in your body, specifically from your HPA (hypothalamic-pituitary-adrenal) axis. Here, your pituitary gland tells your adrenal glands to release cortisol and other adaptive hormones into your bloodstream. Cortisol is a powerful hormone that is critical to a variety of physical functions and energy production. The spike of cortisol (and other feel-good hormones like dopamine, serotonin, epinephrine, and norepinephrine) triggered by a stressful exercise session (or other high-stimulation life event) increases respiration, heart rate, blood circulation, and mental focus, and even converts muscle tissue into glucose for quick energy.
This is a great example of how we abuse a system that was designed to ensure short-term survival, such as when Grok faced a predator. Even today, the fight or flight response is highly desirable and effective in the face of true danger or peak performance stimuli, such as an Olympic sprinter crouching in the starting blocks or an emergency worker summoning superhuman strength for a rescue effort. Unfortunately, when the stress response is triggered repeatedly (by the constant hectic pace of modern life, by a demanding boss, or by overly stressful workouts), your stress response mechanisms eventually wear out, and you produce lower-than-normal levels of cortisol and other hormones critical to many aspects of everyday health. Thyroid hormones and testosterone also become dysregulated from prolonged stress, resulting in fatigue, loss of lean muscle tissue, a suppressed immune system, and the general condition best described as burnout.
What our genes truly crave is frequent movement at a slow, comfortable pace: walking, hiking, easy cycling, or other light aerobic activities at heart rates not to exceed “180 minus your age” in beats per minute (details on this formula, championed by Dr. Phil Maffetone, in Chapter 7). These efforts are far less taxing than the typical huffing and puffing, struggling and suffering exertion level that we’ve been conditioned to think leads to cardiovascular fitness. In addition to structured low-level cardio workouts, it’s imperative to find ways to move more often every day—taking five-minute movement breaks from your work desk, parking at the farthest edge of the parking lot instead of always trolling for the closest space, taking the stairs instead of the elevator. Finally, complementary activities in the realm of mobility and flexibility are also encouraged under the “Move Frequently” law—things like Pilates, yoga, tai chi, gymnastics, dancing, and dynamic rolling, stretching, and physical therapy work. Try as you might, it’s difficult to escape the ubiquitous sedentary influences in modern life, so moving your body in assorted different ways can make a big difference in your over health and fitness.
Grok’s life demanded frequent bursts of intense physical effort—returning gathered items (firewood, shelter supplies, tool materials, and animal carcasses) to camp, climbing rocks and trees to scout and forage, and arranging boulders and logs to build shelter. The biochemical signals triggered by these brief but intense muscle contractions prompted improvements and adaptations in muscle tone, size, and power.
Today, conducting brief, intense workouts of full-body, functional movements (squats, pushups, pull-ups, etc.) helps you develop and maintain lean muscle mass, optimize your fat metabolism, increase bone density, prevent injuries, and enjoy balanced hormone and blood glucose levels. When it comes to lifting heavy things, there is no magic formula for the perfect workout. The specifics of the workout are less important than honoring the principles of making your workouts brief, intense, and functional. You may enjoy CrossFit, working with heavy weights in the gym, doing a machine circuit, or bending BowFlex rods at home. You can also just haul off sets of pushups, pull-ups, squats, and planks (aka the four Primal Essential Movements; see Chapter 7 for more details, or search YouTube for “Primal Essential Movements”).
Conduct your strength-training sessions regularly, but without excessive regimentation, and always align them with your energy levels. This will produce results superior to a routine of going to the gym too often for workouts that last too long. The latter is a recipe for fatigue and undesirable gene expression due to excessive sympathetic nervous system activation (i.e., the fight or flight response), and the associated cortisol overproduction, that results from these overly stressful sessions. You can enjoy excellent benefits doing just a couple of brief, intense sessions per week—lasting as little as 10 minutes and no more than 30 minutes—with minimal risk of overstress.
In a primal world where danger lurked around every corner, Grok’s ability to run was a strong indicator of whether he would live long enough to pass down those superior genes to the next generation. Grok’s occasional life-or-death sprints triggered a cascade of hormones into the bloodstream that allowed him to build the fast-twitch muscle and central nervous system resiliency to go a little faster the next time.
Today, brief, all-out sprints help increase energy levels, improve athletic performance, and minimize the effects of aging by promoting the release of testosterone, human growth hormone, and other “adaptive” (generating a health, fitness, or survival benefit) hormones into the bloodstream. Once every 7 to 10 days, when energy and motivation levels are high, choose a simple, brief sprint workout and go all out! Novices can choose low-impact options (e.g., stationary bike) and work up to actual running sprints.
An effective sprint workout could mean no more than a few minutes warmup at low intensity, some drills to promote good technique, and a series of four to five efforts lasting between 10 and 20 seconds. All told, that’s only a couple minutes of max intensity performance—plenty to stimulate the hormonal adaptations that can skyrocket your fitness levels in a short time, make your mind and body more resilient for all manner of less intense exercise performance, and put the finishing touches on your transition into a fat-burning beast. Why does a little go such a long way? Well, all-out sprints require an effort level as high as 30 MET (Metabolic Equivalent of Task—30 times more metabolic activity than is required at rest). This is an extremely shocking (in a good way!) metabolic event that sends a powerful signal to your genes to upregulate fat metabolism, build or tone lean muscle, enhance mitochondrial function, and generally delay the aging process according to the “use it or lose it” maxim.
Our ancestors’ activity and sleep patterns were strongly calibrated on a hormonal level by sunrise and sunset. Days started early (Grok actually caught the worm... and ate it!), and after the sun went down, it was safest to huddle together and rest. Furthermore, hunter-gatherers required plenty of downtime to repair and rejuvenate from their active lifestyles.
Today, with life exponentially more hectic and chronically stressful than at any other time in human history, adequate sleep and restoration are widely neglected. Adequate sleep promotes the release of important hormones that support immune and endocrine function, refreshes cognitive function and solidifies learning, optimizes tissue repair, and plays a major role in regulating appetite and metabolizing fat. Excess artificial light and digital stimulation after dark, along with ingestible toxins (e.g., sugar, alcohol, and prescription and over-the-counter medications), and, of course, the ubiquitous alarm clock that delivers a high-stress start to the day, all undermine healthy sleep patterns.
For optimal sleep, it’s critical to minimize your exposure to artificial light after dark, to create calm, relaxing transitions into sleep time (and mellow morning routines too), and to obtain sufficient hours of sleep such that you wake up naturally (no alarm). Go to sleep at the same time each night after a tranquil, deliberate wind down—no TV, laptop, tablet or smartphone screens, no heavy exercise, and no big meals or any other high stimulation in the final couple of hours before sleep. Make sure you allow yourself enough time in bed that you are able to wake naturally, near sunrise, feeling refreshed.
You may have heard the popular maxim that eight hours per night represents an ideal amount of sleep. While this is certainly a reasonable recommendation (especially if you habitually obtain less than that!), your sleep needs are highly individualized and subject to numerous variables such as your geography and time of year (more sleep is needed when days are shorter; less during long summer days), genetic profile, exercise routine, work demands, and other life factors.
Don’t be afraid to take naps when your afternoon energy levels wane. The world will not miss you while you grab a few quick winks, and science proves that you will quickly restore the optimum balance of brain chemicals to increase productivity when you get back to your day. Even a 20-minute siesta can make you feel wonderfully refreshed and can also significantly improve your cognitive performance when you are deficient in nighttime sleep.
As you pursue health and balance in the digital age, always keep in the back of your mind the reality that for millions of years, humans awakened and went to sleep in accordance with the rising and setting of the sun. The moment you flip open that laptop to catch up on emails in the evening, you introduce one of the most destructive genetic offenses in modern life: artificial light after dark. Chronic exposure to excess light and digital stimulation after dark ranks right up there with the consumption of heavily processed junk food as a major disruptor of health.
For millions of years, human sleep/wake cycles were directly connected to the rising and setting of the sun. Today, we traffic in excess artificial light and digital stimulation after dark, compromising the natural hormonal processes that facilitate ideal sleep patterns. Engaging in calm, quiet, dark, mellow evenings with minimal light and screen use will help recalibrate the hormonal processes that optimize sleep.
Our ancestors spent hours every day involved in various forms of social interaction not related to their core responsibilities of securing food and shelter and caring for their young. Studies of modern hunter-gatherers, such as the !Kung Bushmen of the Kalahari Desert in Africa, reveal that they generally work far fewer hours and have more leisure time than the average 40-hour-plus modern clock puncher. Anthropologist Marshall Sahlins’s popular theory of the “original affluent society” argues that hunter-gatherers are able to achieve affluence—meaning a comfortable existence in which one’s needs and wants are met—by desiring little. This enables them to satisfy their every need and desire relatively easily by doing the work of normal daily life. This is much different from the consumerism-tainted definition of affluence—being “rich” in material possessions and outward displays of wealth—with which we are most familiar.
For Grok and his clan, once the day’s catch was complete, or the roots, shoots, nuts, and berries had been gathered, it was time to play. Youngsters might have chased each other around and wrestled, vying for a place higher up in the tribe’s social strata. Primal humans might also have practiced throwing spears or rocks for accuracy, chased small animals just for sport, or spent time hanging out and grooming each other. The net effect of their play was to support familial and community bonding, unwind from the stresses and dangers of primal life, and to experiment, problem-solve, and process “what-if” scenarios that helped promote daily survival. Through play, our ancestors were able to increase their skills and experience free from the usual life-or-death stakes of real-life challenges.
Today play is a four-letter word, a fond memory from childhood, something we are too busy to even consider. After I published the first edition of The Primal Blueprint, one reader remarked to me, “I understand play is important, but I get to the park with my kids and realize that I don’t even know how to play.” Insufficient play is another major disconnect in modern life, causing reduced productivity, increased stress, and accelerated aging. Stuart Brown, author of Play: How It Shapes the Brain, Opens the Imagination, and Invigorates the Soul and one of the world’s leading experts on play, calls play a “profound biological process.” He explains that play, across the span of a lifetime, promotes the development and maintenance of a “cognitively fluid mind.”
Cognitive fluidity—being able to go with the flow, think outside the box, process what-if scenarios, and react quickly and effectively to changes in our environment—is believed by anthropologists to represent one of the most profound breakthroughs in human evolution. This breakthrough in brain function, probably emerging 60,000 years ago, meant that humans’ brains could link knowledge from different domains. The way humans understood and approached the world became both more flexible and more expansive. This enabled more creative use of technology, better transfer of knowledge between generations, and a resultant spike in human longevity. Cognitive fluidity is still essential today, helping us adapt and thrive in a complex, high-tech society. When we get stuck in patterns of overwork and overstress, we lose that important connection with our creative, intuitive, playful selves. Our work suffers and so does our happiness.
I recommend that you take some time every day to unplug from the office or daily chores and have some unstructured fun. Even a few minutes here and there makes a big difference. Particularly if you have children, you can model that play is a lifetime endeavor—and learn a few things from them while you’re at it. Besides being fun, socially redeeming, and cognitively stimulating, play offers biochemical benefits in the form of endorphins released into the bloodstream, and it provides a healthy balance to the excessive stimulation thrust upon us in the digital age. If you are at a loss for how to start, I provide a few suggestions in a Chapter 8 sidebar.
Cavemen and women didn’t spend their days inside caves; they were mostly outdoors pursuing various survival and leisure endeavors. Regular sun exposure allowed Grok to manufacture plenty of vitamin D (technically a precursor hormone, not a vitamin), which is critical to healthy cell function and cancer prevention. Adequate vitamin D is nearly impossible to obtain from diet alone; we must manufacture it internally via the exposure of large skin surface areas to sufficient amounts of sunlight during daily and seasonal periods of peak solar intensity. Developing and maintaining a slight tan during the summer months is a good sign that you are making and storing enough vitamin D to thrive all year long.
Our original Homo sapiens ancestors coming of age in East Africa had no problem getting sufficient vitamin D and even developed dark skin pigmentation and thick hair to prevent overexposure. The importance of vitamin D is confirmed by the remarkable and relatively rapid evolutionary adaptation of the lightening of skin pigmentation among populations who colonized ever farther away from the equator. The straight truth is that humans would not have survived in Europe and other less sun-kissed locales without lighter skin to enable more efficient vitamin D synthesis from sun exposure (and/or eating large quantities of oily, cold-water fish—the only dietary source of vitamin D worth mentioning).
Today, getting plenty of sunlight—and hence vitamin D—is nowhere near a given, what with our penchant for spending much of our time in confined spaces such as cars, offices, and homes, and obsessively lathering up with sunscreen when we do venture out under the big, bad sun. Many modern citizens also happen to live at latitudes discordant with their ancestral genetics, putting darker-skinned residents of higher-latitude locales at significant risk for vitamin D deficiency. Experts believe a variety of serious health problems result from these relatively abrupt changes in human lifestyle. (Sound familiar from our discussion of how the advent of agriculture compromised the healthy hunter-gatherer?)
To ensure adequate, healthy levels of vitamin D, you must make a concerted effort to spend ample time outdoors, exposing large skin surface areas to direct sunlight that’s strong enough to generate a tan. You can also take supplemental vitamin D to bolster your levels when sun exposure is compromised. In today’s indoor-dominant lifestyle, it is essential to adopt a progressive attitude about sun exposure instead of kowtowing to the distorted and oversimplified conventional wisdom that sun exposure increases cancer risk. On the contrary, science strongly suggests that lack of sun exposure is a leading risk factor for melanoma and other cancers. Obviously, you never want to burn, as this increases the risk of carcinoma (the less serious form of skin cancer) and also melanoma. And because you are looking to expose maximum skin surface area, screening your face and neck won’t materially compromise vitamin D production, but it will protect you from overexposure and carcinoma risk.
Besides the critical vitamin D requirement, sunlight also has a powerful mood-elevating effect that can enhance productivity and interpersonal relations. Taking time to enjoy direct sunlight, fresh air, and open spaces (perhaps during your daily moderate exercise sessions) balances the health- and mood-compromising effects of spending long periods of time confined in homes, offices, and cars, with their artificial light and stale air.
Our ancestors required a keen sense of observation and self-preservation to avoid danger. They were always scanning, smelling, and listening to their surroundings, ever aware of potential trouble from saber-toothed tigers, falling rocks, poisonous snakes, or even a twisted ankle from a careless step. Keen vigilance and risk management were premium skills honed to perfection every day. Even minor mistakes could prove disastrous, such as scraping a knee on a rock and dying from an ensuing infection gone unchecked.
Today, vicious tigers are no longer a life-threatening safety concern, but we humans carelessly find ways to invite pain and suffering of a different nature into our lives. (Can you say multitasking?) Buckle your seat belt; don’t drink and drive, nor text and drive. Be prepared and vigilant when you go backpacking in the wilderness or descend a steep hill on your 15-pound racing bike, not to mention when using a blowtorch, chain saw, or tile cutter. Devote a little more attention and energy to risk management day-to-day so you can enjoy a long, happy life and pass on your own superior genes to the next generation.
I would also argue that with all the knowledge about genetics and healthy living we have today, making a less-than-stellar commitment to healthy eating, exercise, sleep, and lifestyle might be considered a stupid mistake! Thanks to the hard work of our ancestors ancient and recent, we humans in today’s developed world enjoy a level of luxury, convenience, and physical ease unimaginable throughout human history. Living in a world of freedom and abundant choice, we can do what we wish with our health without the immediate penalty our ancestors faced.
Our ancestors did not have the luxury of skimping on sleep and getting lost while out foraging because their attentional systems were suffering, or of getting too fat to outrun the predator that was chasing them. The Primal Blueprint is about making informed choices and understanding the health consequences of your choices at the genetic level. I’m not here to judge what’s right or wrong for you—even when it comes to stupid mistakes! But there are surely ways to have fun and be happy that do not involve becoming a victim of the modern “sick care” system, for example. Or, in my case, suffering through an athletic training regimen that compromised my health and enjoyment of life. Which leads me to the final law....
It wasn’t so long ago that Homo sapiens shared the planet with other hominid species. Yet, today we humans are the only ones left standing. (Pun intended.) Scientists attribute our survival not to our big brains per se (other hominids—notably the Neanderthals—had big brains, too), but to the fact that the human brain had a greater capacity for complex thought. Humans’ superior capabilities for language, abstract thought, and other higher-level cognition ultimately gave us the edge in terms of adapting to an ever-changing world. And as early Homo sapiens used their brains to develop better tools and hunting strategies, as well as to communicate, socialize, and organize with other humans, the human brain continued to grow.
The rapid increase in the size of the human brain over just a few thousand generations was the combined result of optimum dietary choices (including high levels of healthy protein and saturated and omega-3 fats—see Law #1) and a continued reliance on complex thought—working the brain just like a muscle. The best proof of our impressive evolution in brain function is the fact that hunter-gatherers around the world developed language, tools, and superior hunting methods independently.
While you might argue that we use our minds plenty to navigate and make a buck in today’s world, the reality is that many of us are stuck in unfulfilling or tedious jobs, or are otherwise disconnected from continued intellectual challenge and stimulation. Numerous studies of general intelligence identify curiosity as one of the most profound intelligence markers. Opportunities for intellectual stimulation are everywhere in daily life. Commit to some personal challenges, such as learning a new language, playing a musical instrument, or taking an evening college class. Research indicates that the risk of devastating mental conditions including depression, dementia, and Alzheimer’s can be reduced by keeping your brain active as well as your body.
[My] greatest error has been not allowing sufficient weight to the direct action of the environments [upon evolution], i.e., food, climate, etc., independently of natural selection.
—Charles Darwin
LEARN THEM, KNOW THEM, LIVE THEM!
Aside from—ahem—the reproductive act, I challenge you to name any other significant behavior that shaped our genes and currently plays a critical role in our health and wellbeing. Could it really be this simple? Could the prevention of and cure for obesity, diabetes, heart disease, physical decline, most cancers, and the generally overstressed existence of the modern human be contained in our genes? While you may be able to find detractors who extract bits and pieces of this blueprint and offer up a critical view, the premise is unassailable: our genes are suited for a hunter-gatherer existence, because that is how we Homo sapiens have spent 99-plus percent of our time on Earth.
The same genes that turn against you and promote heart disease, diabetes, atherosclerosis, high blood pressure, high cholesterol, arthritis, and most other degenerative diseases can also be reprogrammed to unlock a leaner, fitter, more energetic body, a substantially slowed aging process, and a reduced risk of illness, injury, and burnout. The secret is to do the right thing: choose behaviors that promote desirable gene expression and avoid those that promote negative outcomes.
The secret is to do the right thing: choose behaviors that promote desirable gene expression and avoid those that promote negative outcomes.
That statement alone—do the right thing—is no revelation. The revelation here is how easy, natural, and fun the lifestyle and behaviors are that will help you build your ideal body. Now you can enjoy delicious, nutrient-dense foods that foster health and effortless weight management by optimizing fat metabolism. Now you have permission to back off from exhausting workouts and regimented schedules and instead enjoy an active lifestyle with regular low-intensity aerobic movement accompanied by brief, intense strength and sprint workouts. You can even lounge in the sun or take a nap in the name of health!
You will notice the benefits of the Primal Blueprint lifestyle laws in a matter of days, not weeks or months. Your genes are active all the time, either helping you build, regenerate, and maintain homeostasis or unintentionally tearing you down. It’s all based on the environmental signals you provide them through your most recent meal, workout, play session, sleep session, and so forth. As we reflect on the legacy of our ancestors and the tribulations they faced to bestow good genetic fortune upon us today, it’s clear that the Primal Blueprint is not about being perfect. It’s about trending in the right direction, being aware of environmental hazards like junk foods or too much screen time at night, and doing the best you can under the circumstances you face each day.
Unfortunately, as you will read in Chapter 2, modern society on the whole is not doing a great job of honoring the legacy of our ancestors. So we’ll go back to the beginning and learn more about Grok, contrast him sharply with his modern day antithesis, Ken Korg, and build the knowledge base and momentum to reconnect with our ancient genetic requirements for health.
1. Evolution: The Homo sapiens evolutionary timeline began seven million years ago when hominids split from apes. The smart, upright, humanlike Homo erectus appeared 400,000 years ago. Around 160,000 years ago, the first Homo sapiens appeared in East Africa. Sixty thousand years ago, a small group of humans—perhaps as few as 150 individuals—ventured out to colonize the globe.
2. Grok: Survival of the fittest drove 2.5 million years of evolution and created the ultimate human being... 10,000 years ago! Grok is the nickname for our primal human role model who was bigger, stronger (on average versus modern humans—really!), and in many respects healthier than us. Soon after Grok’s time, the advent of agriculture across the globe eliminated the main selection pressures on humans: starvation and predator danger. Civilization effectively resulted in a slowing of our evolution, and we have gone soft as a consequence. However, because our DNA is nearly identical to Grok’s, we can adapt his evolutionary-based behaviors into our 21st-century lifestyle to pursue optimum health.
3. Genes: Your health depends upon how genes respond to signals in their immediate environment. Genes are traffic cops that direct the function of every cell in the body at all times. They respond to environmental stimuli and promote homeostasis and short-term survival. Genes don’t know or care how behaviors affect long-term health. (It’s up to you to care!)
4. Primal Blueprint Laws 1 and 2—Diet: Eat plants and animals! Avoid processed foods (sugary foods and beverages, grains, refined high polyunsaturated vegetable/seed oils, partially hydrogenated oils, and interesterified fats). Grains, while a global food staple long believed to be healthy, stimulate an excessive release of insulin and are less nutritious than vegetables, fruit, nuts, seeds, and animal foods. A diet emphasizing grains, even whole grains, inhibits fat metabolism and paves the way for serious disease.
5. Primal Blueprint Laws 3, 4, and 5—Exercise: Move frequently (increase general everyday movement with movement breaks, along with walking, jogging, or hiking sessions—but avoid excessive medium-to-high-intensity “chronic” cardio). Lift heavy things (conduct regular functional, full-body strength-training sessions that are brief and intense). Perform occasional all-out, short-duration sprints to stimulate growth hormone release, build muscle, turbo-charge fat metabolism, and delay the aging process.
6. Primal Blueprint Laws 6, 7, 8, 9, and 10—Lifestyle: Get plenty of sleep (mainly by minimizing artificial light and digital stimulation after dark). Find time in your busy schedule for unstructured play (relieves stress and improves emotional and mental wellbeing). Get plenty of sunlight (stimulates production of vitamin D and helps balance the negative effects of spending excessive time confined indoors). Avoid stupid mistakes by remaining vigilant and managing risk expertly when navigating potential modern hazards like texting and driving. Use your brain for creative pursuits that balance the often repetitive or intellectually rote elements of daily life.
7. Blueprint for Success: The Primal Blueprint laws are simple and intuitive, unlike many elements of conventional wisdom that suggest you have to struggle, suffer, and deprive yourself to attain your fitness and weight-loss goals. You will notice the benefits of Primal Blueprint living immediately—more even energy levels, better immune function, more enjoyable eating and exercising—as your genes direct your cells to function optimally at every moment.
1 Origin of Man: The “Out of Africa” theory is also known as the Recent Single-Origin Hypothesis (RSOH), Replacement Hypothesis, or Recent African Origin (RAO) model. The theory, originally proposed by Charles Darwin in his Descent of Man, modernized by Christopher Stringer and Peter Andrews, and strongly supported by recent studies of mitochondrial DNA, says that anatomically modern humans evolved solely in Africa between 200,000 (first appearance of anatomically modern humans) and 100,000 years ago, with some Homo sapiens leaving Africa 60,000 years ago and replacing all earlier hominid populations including Homo neanderthalensis and Homo erectus.
2 Origin of Agriculture: Dr. Jared Diamond, evolutionary biologist, physiologist, and Pulitzer Prize-winning professor of geography at UCLA, is the author of Guns, Germs and Steel: The Fates of Human Societies that discusses the advent of agriculture and its effects on civilization and human health. Chapter 5 of Guns, Germs, and Steel details agriculture’s origin (including which crops were cultivated) in several locations around the globe. The Emergence of Agriculture by Bruce Smith also details the great transition of humanity from a hunter-gatherer lifestyle to agriculture and thus civilization.
Guns, Germs and Steel and Richard Manning’s Against the Grain detail the negative aspects of humankind’s shift to agriculture, blaming it for large-scale disease, imperialism, colonialism, slavery, and an inexorable progression to global warfare. All this thanks to the abuse of “free time” resulting from the specialization of labor and the pursuit of power over resources, humans, and geography—goals that were previously irrelevant in the largely egalitarian hunter-gatherer societies.
3 Primal Human Life Span: The estimate of “maximum life span potential” from Homo sapiens 15,000 years ago is 94 years; this is actually higher than the prediction for modern humans, whose corresponding figure is 91 years! This material comes from the work of Dr. Richard G. Cutler, molecular gerontologist and longevity expert, who has produced more than 100 papers on the subject. Dr. Cutler was a research chemist at the Gerontology Research Center at the National Institute on Aging at the National Institutes of Health for 19 years. Dr. Cutler’s estimate is derived from laboratory analysis of skeletal material, with particular emphasis on the ratio of body weight-to-brain-size. Other factors involved in making accurate life-span calculations are age-of-sexual-maturation-to-life-span ratio (a 5:1 ratio is common among humans) and rates of caloric intake and expenditure. (Of course, we know that modern humans can and do live longer than 91 years; this formula merely provides an estimate to predict relative maximum life span potential among different hominid species based on their physical characteristics, and primal humans beat us modern folk. This reinforces the notion that our relative longevity is due to technological advances, not to increasing physical robustness.)
4 Grok: In Chapter 2 we talk about Grok as the patriarch of a primal family, who happens to have a wife named Grokella. However, in the interest of inclusivity and ease of reading throughout the book in general, you can view Grok as a non-gender-specific archetype for the primal ancestor(s) whom we aspire to emulate in lifestyle behaviors. For example, “Grok never ate sugar, and neither should you.”
