“The past is our definition. We may strive, with good reason, to escape it, or to escape what is bad in it, but we will escape it only by adding something better to it.”

—Wendell Berry

What do yoga mats, flip-flops, and Subway buns have in common? Until very recently, the chemical azodicarbonamide. In 2016 the sandwich giant, along with several other fast-food chains, made headlines when they announced (quietly) that they would remove this “dough conditioner” from their breads. There’s no doubt this is good news for their customers, since azodicarbonamide has been linked to asthma and cancer, but it begs the question, what on earth was it doing there in the first place? One might ask the same about countless other chemicals that show up in our food. Indeed, the additives, preservatives, artificial flavorings, and various other compounds that comprise the ingredient lists of today’s processed foods can make one’s head spin—a veritable chemistry set in every box, bottle, breast, bun, wing, fry, flake, and Happy Meal. It’s enough to make anyone long for a simpler time when food was, well, food.

And many do. In response to growing awareness of the excesses of industrialized food, more and more people are searching for an alternative. Some look back a few hundred years before modern food-distribution systems brought the world’s bounty to our doorsteps. Some harken back to a pretechnological era when the pace of life was less frenzied. Some decry the modern trend of urbanization and return to the land. Natural and organic foods; locavore; slow food; farm to table—all of these are movements born of food culture’s nostalgia for its lost past and many legitimate concerns about today’s industrial food systems. But some take that sentiment to a whole different level, and go Paleo.

Michael Pollan likes to say, “Don’t consume anything that your great-grandmother wouldn’t recognize as food.” Paleo, one of today’s most popular diet trends, sees that basic concept and raises Pollan a few hundred millennia. It says, don’t eat anything that a caveman wouldn’t recognize as food.

Paleo stands for Paleolithic Diet, a concept that emerged in the 1970s, gained traction in the 1980s thanks to S. Boyd Eaton and Melvin Konner’s paper of the same name, and was popularized in the early twenty-first century by best-selling author Loren Cordain and a rapidly growing tribe of adherents. While for some, going Paleo can include many behaviors that may reflect a Paleolithic lifestyle—like running for short intense bursts (akin to escaping predators), squatting rather than sitting to defecate (you can even buy a special toilet accessory called a Squatty Potty), or (for the more extreme) giving blood regularly to approximate the occasional wounds our ancestors must have suffered—it is generally seen as an approach to eating, and for our purposes we’ll leave the other lifestyle behaviors aside and focus on the dietary recommendations.

The basic premise of the Paleo diet, as Cordain puts it, is that “Nature determined what our bodies needed thousands of years before civilization developed, before people started farming and raising domesticated livestock.”1 Paleo advocates believe that our bodies have not significantly changed since the Paleolithic era, otherwise known as the Stone Age or the prehistoric era, which began about 2.6 million years ago. This was the era in which hominids lived as hunter-gatherers and began to use basic stone tools. Anatomically modern humans arrived on the scene during this period, around two hundred thousand years ago. The end of the Paleolithic era is marked by the full-scale adoption of agriculture, and the beginning of more complex human settlements, around ten to twelve thousand years ago.

Modern Paleo diets vary a great deal among practitioners. In general, however, they focus on foods like lean grass-fed meat or wild-caught fish (that approximate what we might have hunted or caught) and fruits, vegetables, seeds, and nuts (that approximate what might have been gathered). They eschew foods that they see as being born out of agriculture, like grains, legumes, and starchy vegetables, and they reject most highly processed foods, particularly refined carbohydrates (though, curiously, not certain vegetable oils). They also are suspicious of dairy foods, arguing that only a relatively small percentage of the human population has adapted to tolerate these in more recent history.

Paleo diets are close cousins of the low-carb, high-protein diets discussed in the previous chapter. However, they deserve to be considered on their own terms, both nutritionally and philosophically. Nutritionally, there are certainly some things to like about the Paleo approach—and some overlaps with the Whole Foods Diet—but there are some causes for concern as well. Philosophically, there are some questions that bear closer scrutiny. Even if we knew exactly what our Paleolithic ancestors ate (and we don’t), even if Paleo devotees were right in all their claims about our past (and they aren’t), and even if we could eat exactly the same type of food as our ancestors (and we can’t), there are still serious questions about whether it is the ideal diet for humans today.

The Upsides of Paleo

There are many things to like about the Paleo diet. First and foremost, unlike many food fads of the last few decades, Paleo is resolutely focused on real, whole foods, which are beneficial for health. We have seen again and again the evidence that highly processed foods—sweetened cereals; oily, salty snacks; sugary candy and baked goods; calorie-packed sodas—are not doing any health favors. In fact, Paleo has made one of the two central tenets of the Whole Foods Diet its own—eat whole foods instead of processed foods. Undoubtedly, this is one reason many people feel so much better and lose weight when they adopt a Paleo diet, especially at first. Suddenly they cut out most processed foods from their diet—and if they’re anywhere close to the average American, those could account for up to 70% of their previous food choices. Instead they eat primarily real food, maybe for the first time in their lives. It’s not surprising that they experience a dramatic difference in health and well-being.

What are those processed foods being replaced with? In part, a larger percentage of animal foods, in the form of eggs, fish, meat, and even organ meats—a concerning direction that we’ll discuss in a moment. However, people who adopt a Paleo diet are also encouraged to follow another central tenet of the Whole Foods Diet, and increase their consumption of fruits and vegetables—another reason, no doubt, that people often report positive results when they make the transition. Cut out processed foods and eat more fruits and vegetables—that’s a good foundation for any diet.

A third positive about Paleo is its cautious approach toward dairy foods. Dr. Cordain accurately states that “we are the only species on the planet to consume another animal’s milk throughout our adult lives. Humans don’t have a nutritional requirement for the milk of another species, nor do any other mammals.”2 If you choose to include dairy in your Whole Foods Diet, we recommend doing so in limited quantities. Most Americans consume far too much dairy, and Paleo offers a healthy corrective to this tendency.

The Downsides of Paleo

For all its benefits, in the form of real foods and healthy fruits and veggies, Paleo’s downsides are concerning. They start with its conviction that animal foods—in the form of meat, fish, and eggs—should play a central role in one’s diet. We have already laid out the serious long-term health concerns raised by an overreliance on animal foods, and the chronic diseases that are associated with such diets (see here). A whole foods, plant-based diet need not be vegan or vegetarian, but relying on meat and other animal foods to fill up more than 50% of one’s calories, as some in the Paleo camp suggest, is not an evidence-based health choice. Most Americans eat far too much meat already.

Paleo advocates rightly emphasize choosing lean, pastured meats and wild-caught seafood over today’s factory-farmed, feedlot fare, pumped full of corn, antibiotics, and hormones. And many warn against processed meats, pointing out that cavemen certainly did not eat lunch meats, hot dogs, and salami—a category of foods recently designated as carcinogenic by the World Health Organization. However, too many adherents unfortunately seem to consider Paleo simply synonymous with meat, and consider their new “evolved” diet a meal ticket to unlimited bacon.

Another problem with eating too much meat and other animal foods is that they tend to crowd out other good things from our diet. Healthy plant foods suddenly become less important when you build a food culture around meat. Even though fruits and vegetables may play a significant role on the plates of some Paleo adherents, they seem to be an afterthought for too many. With the Whole Foods Diet, we take the opposite approach. Some occasional pastured meat or wild-caught fish may have a place on your plate, but it should never be so prominent that it takes space away from whole plant foods.

The other significant downside of Paleo diets is what they leave off the plate altogether: whole grains, starchy vegetables, and beans and other legumes. These foods are rejected primarily because of the idea that they were not part of the human diet before the advent of agriculture, although some of the common low-carb concerns about their healthfulness tend to creep into Paleo literature as well, along with the tendency to not distinguish between whole and processed carbohydrates.

Putting aside for a moment the question about whether humans evolved to eat these foods back in the Stone Age, it seems nonsensical to ignore the wealth of evidence about how well these foods serve the health and longevity of modern humans. Remember, whole grains are correlated with a reduced risk of death from all causes,3 and starchy vegetables have played a starring role in the diets of many civilizations. As for legumes, one recent study identified them as “the most important dietary predictor of survival in older people of different ethnicities,”⁴ and the daily consumption of these protein- and fiber-packed foods was one of the most significant common denominators among the Blue Zones. In 2007 the American Institute for Cancer Research conducted the most comprehensive analysis of diet and cancer ever performed, and concluded that we should eat whole grains and/or legumes with every meal.⁵ Paleo’s strange demonization of beans and other legumes is the biggest head-scratcher of all from a health perspective.

Ask a Paleo proponent to justify this prohibition on the grounds of health, and he or she will likely say that beans and other legumes contain “antinutrients”—including phytic acid or phytate, which can reduce micronutrient absorption, and lectins, which have been shown in animal studies to impair growth, damage the small intestine, interfere with the pancreas, and destroy skeletal muscle. However, while this sounds ominous, the argument doesn’t really hold up under closer scrutiny. Soaking beans overnight and discarding the water before cooking takes care of these issues, as does cooking lentils.

From a health standpoint, then, Paleo diets score high for their focus on real foods instead of processed foods, the embrace of fruits and vegetables, and the caution over dairy, but they overemphasize meat and other animal foods and unnecessarily eliminate healthy whole grains, starchy vegetables, and legumes. If you feel drawn to this dietary philosophy but want to avoid its downsides, we’ll offer recommendations for a Whole Foodie variation on the Paleo diet in a moment. First, let’s take a closer look at some of the thinking behind this sometimes positive yet sometimes puzzling dietary trend.

Evolution and the “Natural” Human Diet

Looking back into the evolutionary past can certainly provide valuable data in the quest to find the optimum diet for our present and future. However, the idea that a particular slice of that past holds the secret to the “natural” diet is questionable. Different historical times may have produced different climates, environmental challenges, or selection pressures that pushed diets in different directions. Historically, the human diet has been one of change, adaption, and survival—not optimization. We are a constant work in progress, evolutionarily speaking, and it’s a mistake to think that some particular point in human or hominid history represents a moment of perfect adaptation to our environment or maximum evolutionary fitness. As evolutionary biologist Marlene Zuk writes in her well-argued book Paleofantasy: What Evolution Really Tells Us about Sex, Diet, and How We Live, “The notion that humans got to a point in evolutionary history when their bodies were somehow in sync with the environment, and that sometime later we went astray from those roots—whether because of the advent of agriculture, the invention of the bow and arrow, or the availability of the hamburger—reflects a misunderstanding of evolution.”6

Zuk suggests that rather than arbitrarily choosing one period, we need to look at the overall thirty million years of primate history. The three million years of the Paleolithic era is only a brief period compared with the long journey of our primate past. Some speculate that if there were a “natural” diet, it would be closer to the leaves, seeds, flowers, nuts, and fruits consumed for much of the twenty million years of hominid development. Another argument can be made that we would find the “natural” diet in the example of our closest genetic cousins, the chimpanzees, bonobos, and gorillas, who eat diets that are between 95% and 100% plant foods.

Even if it were true that the Paleolithic era is in fact the dietary gold mine that adherents like to think, there are respected researchers who take issue with the popular Paleo conclusions about what constituted the diet of the time. For starters, as archaeological geneticist Christina Warinner, PhD, says, “There is no one Paleo diet. There are many, many Paleo diets.” Coastal dwellers may have eaten more fish; northern hunter-gatherers in more extreme climates likely ate more meat and animal fats; temperate inhabitants surely ate more fresh fruits and vegetables, and so on. “When we speak about Paleolithic diets,” Warinner emphasizes, “it’s very important to speak of them in the plural.”7

Researchers have also questioned another central tenet of Paleo: the predominance of meat. No doubt our ancestors did eat meat when they could hunt and kill it, but it seems unlikely that they ever relied on it to the degree that modern Paleo dieters do. As some have suggested, perhaps the label hunter-gatherers should be turned around—gatherer-hunters would be more accurate. Yes, prehistoric man gets some of the glory for occasionally bringing down big game, but prehistoric woman was most likely the more important food provider, gathering fruits, seeds, nuts, vegetables, tubers, and all kinds of prehistoric plant foods that played the more important role in the everyday Paleolithic diet.

Anthropologist Nathaniel J. Dominy is one of many researchers and anthropologists who poke holes in the idea that hunted meat played such a central role in Stone Age diets. His research has focused around a particular gene that helps code for amylase, a protein in saliva that breaks down starches into glucose. Other primates besides humans don’t have this gene, and it makes Dominy suspect that it is part of what allowed us to take the extraordinary evolutionary leap forward known as the “brain’s big bang” and make the journey from our hominid past to Homo sapiens sapiens (something Paleo theorists tend to attribute to an increase in meat consumption). After all, Dominy argues, our brain’s preferred fuel is glucose. He suggests that humans are not really carnivores but “starchivores,” relying on starches to obtain the necessary nutrients for their developing brains: “I would say a mixture of plant foods with a large amount of starch coming from tubers and seeds—that’s the fundamental component of the human diet.”8

This, of course, calls into question another central tenet of the Paleo philosophy—the rejection of starches. Evolutionary biologist Karen Hardy has also argued that starchy vegetables and tubers like yams, squashes, and potatoes played a critical role in the development of the bigger brains that distinguish humans from their predecessors. “The regular consumption of starchy plant foods offers a coherent explanation for the provision of energy to the developing brain during the Late Pliocene and Early Pleistocene,” she writes. This idea is backed up by recent evidence that cooking began much earlier than previously believed—as far back as 1.8 million years ago.⁹ Other researchers have argued that even grains like wheat and barley played a key role in the human diet long before they were farmed. Evidence has also been found that Neanderthals ate wild varieties of peas and fava beans, contradicting the Paleo claims about legumes.¹⁰ In general, there is plenty of evidence that hominids evolved a largely plant-based eating style, with some animal foods being supplemental, though the proportions over hundreds of thousands of years were probably varied and oft-changing.

It’s important to remember that for most of our history, getting enough calories was the primary preoccupation. Even one of the originators of Paleo, Melvin Konner, acknowledged in a 2016 article that rather than being extreme carnivores, both Neanderthals and early humans were “diet opportunists.” In other words, they ate whatever they could get their hands on in order to stay alive. But merely because we can and once did eat something to survive does not mean we should eat tons of it today if we want to thrive. Interestingly, in that same article, Konner distanced himself from contemporary iterations of the diet, comparing his errant creation to Frankenstein’s monster.¹¹

Konner also backtracked on the argument, advanced in his and Eaton’s original paper and repeated by Cordain and others, that the last ten thousand years since the birth of agriculture have not been enough time for our bodies to adapt to digest the more recent foods in our contemporary diets. Science has moved forward since then, and he acknowledges that “in 1985 scientists believed that few genetic changes had occurred since we were all hunting and gathering, say 10,000 years ago. Now we know that lots of genes have changed.”12

These are just a sampling of the many cogent critiques of Paleo’s science. Even if all of these were to be dismissed, the Paleo reading of history turned out to be true, and adherents’ conclusions about its significance were borne out, there is still one major problem with the modern Paleo diet: However much we might want to eat like cavemen and cavewomen, we can’t.

Let’s imagine, for a moment, that we were to take the Paleo philosophy to its extreme and hunt our own meats—they would bear very little resemblance to the lean, wild venison or boar our ancestors would have eaten. The same is true of fruits and vegetables—the ones we eat today have been vastly altered from their wild precursors. In truth, almost all the foods we consume have been transformed over the course of history, and few if any resemble what might have been eaten in the Paleolithic era. Furthermore, modern Paleo dieters seem to overlook the fact that the range of foods available to them from all corners of the world is a far cry from the localized menu of any nomadic hunter-gatherer.

If You’re a Whole Foodie… and Paleo

Despite the questionable evolutionary claims made by Paleo advocates, let’s not forget the positive principles that their diet continues to promote. Cutting out processed food can only be good. Eating lots of fruits and vegetables and some nuts will extend our lives and protect against disease. Some lean meats and fish can be part of a healthy diet. When seen in this way, the Paleo diet is, as Yale’s David Katz writes, “eminently reasonable, and no doubt a vast improvement over the typical American diet.” However, he cautions, “When the Paleo Diet label is used to justify a diet of sausages and bacon cheeseburgers, the concept has wandered well off the reservation.”13

If the Paleo ethos appeals to you, we’d suggest a few adaptions that will make it fit the Whole Foodie philosophy—which might also make it more accurate to the historical diet of our ancestors. Eat lots of fresh vegetables and fruits, and let them fill up the majority of your plate. It’s fine to eat some lean meat, fish, and eggs, but keep these to 10% or less of total calories. If you choose to shun grains, at least consider eating starchy root vegetables like yams, squash, sweet potatoes, pumpkin, and potatoes. In place of some meat, make space on your plate for beans and other legumes, as it seems the cavemen probably did too.

Do Humans Need to Eat Animal Foods?

Clearly we don’t agree with the Paleo conviction that human beings need large quantities of animal protein to survive and thrive. But do we need any at all? Or would we be better off eating 100% plants?

Throughout these pages we have been recommending a 90+% plant-based diet, which means up to 10% of calories can come from animal foods—meat, fish, dairy products, eggs, and so on. We do this not as a concession or a compromise, but because we feel that the evidence, from a health perspective, does not clearly show that a 100% plant-based (or vegan) diet is a better choice. Yes, there are studies showing that people on a vegan or vegetarian diet fare far better than people on the Standard American Diet, with its emphasis on highly processed foods and animal foods. We know that heavy animal product consumption is associated with higher rates of mortality.14 And, as we shared in chapters 5 and 6, diets with little or no animal products have been shown to reverse heart disease and diabetes. But no study has yet compared people who eat a 100% plant-based whole foods diet with those who include up to 10% animal products. We would love to see such a study conducted.

In today’s world, unlike cavemen, most of us do not eat to simply survive. We have the luxury of considering many factors as we choose what to eat, with health being only one of them. We can choose, for ethical reasons, to eat 100% plant-based foods, and by eating skillfully we can do so without compromising health, particularly if we avoid highly processed foods. Once again, we as authors have all made this choice, but we try not to let our ethical convictions cloud our objectivity when it comes to what the science shows.

One question we asked ourselves, when considering whether to recommend a 90+% plant-based or 100% plant-based diet, from a health perspective, is this: Why are there no examples in the historical record of a tribe, culture, or civilization who ate 100% plant-based foods? Once again, it seems highly probable that a mostly plant-based omnivorous diet is the one humans have evolved eating and is the one we are best adapted to biologically, and we know that our nearest primate genetic cousins, the chimpanzees and bonobos, are approximately 95% plant-based eaters. Of course history is only a guide, and the fact that neither our evolutionary nor our cultural past includes veganism does not constitute the final word on the optimum diet today.

Among the Blue Zones—the areas in the world where people live the longest, healthiest lives (see chapter 4)—only a small subset of one community (the Loma Linda Adventists) was considered vegan. In the Adventist Health Studies, those who included small amounts of animal products in their diets all had similar health outcomes. All other Blue Zone populations got some percentage of their calories from animal foods—generally a small percentage (10% on average, according to Buettner’s meta-analysis).

The best nutritional arguments in favor of the 100% plant-based diet come from those who have successfully used such diets to reverse heart disease and diabetes. Dr. Esselstyn’s heart disease prevention program removed all animal products from patients’ diets (although he initially allowed some low-fat dairy), as did Dr. Barnard’s diabetes reversal diet, while Dr. Ornish’s program allowed only egg whites and nonfat dairy in small amounts. The results are compelling, and if you are trying to reverse heart disease or diabetes, you may well want to consider adopting a similar diet.

However, despite the fact that these diets are effective at reversing disease, their long-term health impacts over decades remain to be seen. Veganism is a new dietary approach (the term was invented only in 1944; the practice entered the counterculture in the 1960s and ’70s and has become mainstream only in the past couple of decades) and we haven’t yet had time to study its long-term effects.

Today’s growing vegan movement is a grand experiment, with millions of people eating a diet that is unprecedented in human history. We can measure its positive results on the welfare of animals, on greater environmental sustainability, and on short-term disease reversal, but from the perspective of long-term health, the jury is still out on whether it is superior. Therefore, based on our best reading of the evidence available, we recommend a whole foods, 90+% plant-based diet. To more skillfully optimize your health potential, we recommend that you make the Essential Eight whole food groups part of your regular diet (see chapter 10) as well as consider our supplementation recommendations (see here).

Evolution Continues

“We are Stone Agers living in the Space Age,” Cordain once claimed. There is truth in this perspective, but falsehood as well. No doubt most of our physiology and instincts were fashioned in the distant past. But we are not cavemen. Cavemen didn’t build civilizations or develop complex cultures, nor did they study nutrition with the lens of science. We are part Stone Age and part Space Age. Evolution connects us to our distant past and it points us toward our fast-approaching future.

Ultimately, we must deal with life conditions of our own time. We can learn from our past, but we cannot go back. We will never be Paleo again. History moves in one direction. At its best the Paleo movement has taken up the honorable fight to combat the problems of our modern industrialized processed food system, and return to putting real, whole foods on our plates. At its worst it has simply demonized healthy food choices in the name of an imagined past.

With the possible exception of a few historical cultures, many of them born of geographical necessity, humanity has never consumed the degree of animal foods that we currently do in the developed world. Paleo, for all its strengths, has changed nothing about that questionable health experiment, and, in fact, has given it ideological cover. It places the blame for chronic diseases on a series of scapegoat foods and perpetuates America’s ongoing fascination with high-protein diets and overreliance on meats. Meanwhile, as we’ve seen, all the healthiest and longest-lived peoples in the world consume animal foods in limited amounts. It is our conviction that we will not fully address America’s chronic disease nightmare, nor reach our true health potential, until both the tenets of the Whole Foods Diet are practiced: eating whole foods and eating mostly plants.

A whole foods, largely plant-based diet is the optimum diet today, and it is also the likely diet, when it was possible, of our hunter-gatherer ancestors. A typical person living in Paleolithic times might have enjoyed an occasional fish, or hunted down a deer or even bigger game, but his day-to-day food choices would likely have been a variety of different plants—and lots of them!

One area in which we have a significant advantage over cavemen is in our ability to consciously reflect on, reimagine, and reinvent our diet. We are not confined to the overwhelming necessities of immediate survival, and we have the evolutionary privilege of being able to carefully examine our relationship to our food and choose the best path forward. Our Space Age cognition has some degree of freedom from Stone Age instincts. For example, we may crave fat, salt, and sugar, but we do not need to gorge on hamburgers, fries, and milkshakes all day long. We can recognize our biological predilections, work with our instincts, choose better foods, and even rewire our taste buds (as we will explore in chapter 11). It’s important to remember that just because we are drawn to certain foods doesn’t mean they are the foods we should be eating.

The future is coming fast. Our diets will likely change, and our methods of producing food may change as well—hopefully for the better. The best we can do is learn from the missteps of the twentieth century and not let our food systems get ahead of clearheaded science and good nutrition. There is much we still don’t understand about food, but we have more than enough knowledge to live happily and healthily—for a much longer time than our Paleolithic ancestors could have dreamed of.

A Whole Foodie does his or her best to integrate the Stone Age, the Space Age, and our own age. We can learn from the past without romanticizing it, integrate the best of the present without falling prey to its pathologies, and look toward a technologically enhanced future without adopting it blindly. We can follow the best evidence where we have it, and make informed and reasonable decisions where we do not. We can recognize the strengths of approaches like Paleo while not falling prey to its idiosyncratic ideology.

We can, in other words, evolve.

WHOLE FOODIE TAKEAWAYS

• The upside of the Paleo diet is the emphasis on real food—along with the encouragement to eat fruits and vegetables and reduce dairy consumption.

• The downside of the Paleo diet is the overemphasis on meat—While you don’t have to go vegan on the Whole Foods Diet, we do recommend keeping animal foods to 10% or less to avoid the negative health outcomes consistently associated with meat-heavy diets.

• There is no convincing reason, evolutionary or otherwise, to avoid beans and whole grains—they are some of the healthiest foods on the planet.

CHAPTER 8

The Caveman Cometh

Promises and Pitfalls of the Paleo Diet