Preface

I think it’s important to give you a history of the Paleo Diet concept. The Paleo Diet and Paleo in general have recently become very hot topics. These ideas have become household words in the last few years; however, it hasn’t always been this way. On the next page is a graph from Google Trends for the words “Paleo Diet.”

It’s clear from this graph that the Paleo Diet was unknown to all but dedicated fans until three years ago. Fortunately, I’ve been in the middle of this worldwide movement nearly from its beginnings.

Last October, I approached my sixtieth birthday with some trepidation. I was part of the 1960s generation whose mantra was not to trust anyone over thirty, and now I’m twice that age. As I look back over my life, I can pinpoint a few key events that led me to discover and appreciate the Paleo Diet.

I came of age as a track and field athlete at the University of Nevada, Reno, in the late 1960s and the early 1970s, and I was always interested in diet, fitness, and athletic performance. Later as lifeguards at Lake Tahoe, my friends and I read all of the now-classic vegetarian diet and health books such as Francis Moore Lappé’s Diet for a Small Planet, Paivo Airola’s Are You Confused? and Dick Gregory’s Natural Diet for Folks Who Eat, among others. I attended a Dick Gregory lecture in Seattle and got to shake the famous comedian’s hand. My lifeguard friends and I experimented with vegan diets, fasting, and all kinds of vitamins and supplements. Almost everyone seemed to own a juicer.

Google Trends Search for “Paleo Diet”

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Each summer, instead of shying away from the sun and using sunscreens, we all tried to get the deepest tans possible. We swam in Tahoe’s icy, invigorating, nonchlorinated waters, and decades before Vibram Five Fingers and Nike Frees (shoes that mimic bare feet) were the rage, we ran barefoot in the sand along Sand Harbor’s pristine shoreline. Those twenty memorable summers as a lifeguard at Tahoe heightened my awareness of the outdoor, natural world, sunshine, health, fitness, and diet.

I completed my Ph.D. in exercise physiology at the University of Utah in the spring of 1981 and was promptly hired as an assistant professor in the Department of Health and Exercise Science at Colorado State University. For the first five to ten years of my career, my research focused mainly on how diet and exercise affected fitness and athletic performance. I still hadn’t encountered Paleo, but I read widely and had a considerable interest in anthropology.

In the spring of 1987, I happened upon Boyd Eaton, M.D.’s now-classic scientific paper “Paleolithic Nutrition: A Consideration of Its Nature and Current Implications,” which had been published two years earlier in the prestigious New England Journal of Medicine. This article made a lasting impression on me; it was the single factor that caused me to focus my research interests on ancestral human diets from that point forward.

One of the surprising points that Dr. Eaton made in a subsequent paper was that cereal grains were rarely or never consumed by pre-agricultural hunter-gatherers.

In the days and months after reading Boyd’s groundbreaking paper, I became engrossed in studying ancestral human diets, and I voraciously read everything I could about the topic. At first, I simply filed all of the scientific papers and documents into a single file folder I labeled “Paleolithic Nutrition.” Early on, I realized that this strategy wouldn’t work because of the enormous volume and diversity of topics that materialized.

As I read more and more, patterns began to emerge. Stone Age people did not drink milk or consume dairy products. So I created a file folder labeled “Dairy.” They also didn’t eat cereal grains, as Dr. Eaton pointed out, so I created a single file folder called “Cereal Grains.” Just like the single folder I had originally created for “Paleolithic Nutrition,” it soon became apparent that the topic of cereal grains and their potential for adversely affecting health was an enormous topic that ultimately would require a huge number of file folders.

Eating Paleo

As my lifeguarding days drew to a close in 1991, my wife, Lorrie, and I began to eat Paleo. During the course of the next seven or eight years, I collected more than twenty-five thousand scientific papers and filled five large filing cabinets—each with hundreds of categories dealing with all aspects of the Paleo Diet and the Paleo lifestyle. In 1994, I mustered enough courage to telephone (no one used e-mail then) the man who was responsible for my collection of articles on anything and everything related to Paleo. Dr. Eaton is a true gentleman and a scholar in every sense of the word. We spoke for almost an hour on that first telephone call. He gave me one of the greatest compliments of my life at the end of the conversation when he said, “It sounds to me like you know more about this than I do.”

Boyd and I eventually met in 1995, and two years later he invited me to speak with him at an international conference on fitness and diet organized by Dr. Artemis Simopoulos in Athens, Greece. Artemis was a wonderful hostess for the conference, and during my two-week stay in Greece, we had many conversations about diet and health. I mentioned that I had written a partially completed manuscript on the nutritional shortcomings of cereal grains. About a year later, she asked me if I could complete the paper and submit it for publication in a scientific journal she edited. I did, and the paper “Cereal Grains: Humanity’s Double Edged Sword,” published in 1999, launched my academic career in Paleo nutrition.

The Paleo Diet concept is now taken seriously in the scientific world, thanks in part to Boyd Eaton’s pioneering work. There is no doubt in my mind that without Dr. Eaton’s influential 1985 New England Journal of Medicine paper, Paleo would continue to be an obscure word known mainly to anthropologists and would not have become a household term now recognized by millions. The Paleo Diet and the Paleo lifestyle are clearly much larger than either my writings or Boyd Eaton’s. Hundreds, if not thousands, of scientists, physicians, and people from all walks of life are responsible for creating this incredibly powerful idea, full of the wisdom of the ages, that can be used to bring order to your dietary, health, and lifestyle questions and issues.

Some of the key players who came before Dr. Eaton in the Paleo Diet and lifestyle world bear mention. Charles Darwin’s Origins of the Species was published in 1859 and started it all. It still amazes me that the most powerful idea in biology—evolution via natural selection—generally had not been applied to nutritional thought until 126 years later, with Dr. Eaton’s classic paper. Theodosius Dobzhansky, a well-known Russian evolutionary biologist, said, “Nothing in biology makes sense, except under the light of evolution.” Indeed, his statement could easily be reworked to “Nothing in nutrition makes sense except under the light of evolution.” This quote could be applied to a multitude of lifestyle issues, which I discuss later in this book.

One way that we can look at how and where the Paleo Diet and Paleo lifestyle concepts arose would be to examine the contributions of a few of the key players who came both before and after Dr. Eaton’s landmark paper. Charles Darwin started it all, but a number of other noteworthy people recognized the value of ancestral dietary patterns decades before the publication of Boyd’s article.

Perhaps the first book about non-Western diets and disease to receive attention was Weston Price’s Nutrition and Physical Degeneration, A Comparison of Primitive and Modern Diets and Their Effects, published in 1939. Dr. Price, an American dentist, extensively traveled the world in the 1920s and the 1930s and made detailed observations about diet and health in numerous non-Westernized populations, including Amazon Indians, Alaskan Eskimos, Australian Aborigines, Canadian Indians, Polynesians, and African tribal populations, among many others. His book is a treasure and contains hundreds of photographs of non-Westernized people in excellent health taken in an era when modern processed foods were not universally available. Dr. Price noted that wherever and whenever modern diets were adopted by non-Westernized cultures, their health declined. His statement was just as true then as it is today.

An intriguing aspect of early books such as Dr. Price’s is that frequently the diet/health observations were correct, but the underlying mechanisms about how diet and lifestyle specifically affected health were either unknown or poorly understood. In the early part of the twentieth century, before population-wide vaccination programs existed, tuberculosis remained a major public health problem responsible for millions of deaths worldwide. In his book, Dr. Price noted that in Europe, sunbathing was being effectively used to treat tuberculosis. At the time and even decades later, these kinds of observations were commonly ridiculed by the “best medical minds” because they seemed ludicrous and had no known physiological basis.

Let’s fast-forward sixty-five years and look at this 1930s observation from a modern perspective. Discoveries made in the last four or five years show that sunlight exposure might be one of the best strategies to prevent or cure tuberculosis infections. When you sunbathe, ultraviolet radiation from the sun causes vitamin D to be produced in your skin. The more sun you get, the more vitamin D is produced. Blood concentrations of vitamin D regulate the synthesis of a recently identified substance called cathelicidin, which turns out to be one of the most potent bacteria-killing peptides that our bodies produce. Cathelicidin shows specific killing activity against bacteria that cause tuberculosis, and indeed studies confirm that vitamin D insufficiency is a risk factor for tuberculosis. Most of us have been vaccinated against tuberculosis, so we really don’t need to worry about it, but, as I show you in this book, sunlight and vitamin D are good medicine for all of us.

Although Dr. Price’s book was advanced for its time, the evolutionary basis for optimal nutrition and a healthy lifestyle still lay decades in the future. Other early popular books touching on ancestral diets and health include Arnold DeVries’s Primitive Man and His Food (1952), Walter Voegtlin’s The Stone Age Diet (1975), Leon Chaitow’s Stone Age Diet (1987), and Boyd Eaton’s The Paleolithic Prescription (1988). All of these books are out of print, and, except for Boyd’s, the books faded into obscurity because they didn’t have the bigger picture right—without the evolutionary template correctly in place, they were incomplete and inconclusive.

Prior to the publication of Boyd’s 1985 paper, a few scientists had independently recognized the evolutionary underpinnings for healthful diets and lifestyles, but their work was published in obscure scientific journals that received little or no attention. I list most of these articles in the extensive reference section at the end of the book.

After publication of Boyd Eaton’s influential paper in the New England Journal of Medicine, a number of events ultimately set the stage for the worldwide recognition of the Paleo Diet, as well as the evolutionary basis for modern-day Paleo lifestyles.

The Paleo Diet and Darwinian Medicine

The foundation of the Paleo Diet concept is a recently recognized discipline called Darwinian medicine. Following in the footsteps of Boyd’s landmark paper came the revolutionary 1991 scientific publication in the Quarterly Review of Biology by Drs. George Williams and Randy Neese, “The Dawn of Darwinian Medicine.” This was the first scientific publication addressing how our ancestral evolutionary experience affects the manner in which we view and treat modern diseases. Although this paper is almost twenty years old, its message is finally being filtered down to many physicians, their patients, and the public.

Here’s a quote: “Human biology is designed for Stone Age conditions. Modern environments may cause many diseases . . . [and evolutionary medicine] provides new insights into the causes of medical disorders.” Cough, fever, vomiting, diarrhea, fatigue, pain, nausea, and anxiety, for instance, are widespread medical problems. Many orthodox physicians focus on relieving short-term distress by prescribing drugs to block these responses. Darwinian medicine would say these responses are not necessarily harmful but rather signify the body’s effort to remedy a problem. In most situations, coughing when you are sick is a natural and healthy response because it helps purge disease-causing microbes from your throat and lungs. Similarly, fever increases your body temperature, which helps destroy pathogens that have infected your body. Medications that suppress coughs and block fever may relieve symptoms but actually prolong the illness.

Obviously, certain extreme situations necessitate a balanced approach between our bodies’ evolutionary responses to disease and modern medicine. For example, blocking fever can prevent febrile seizures, and stopping vomiting can prevent severe dehydration.

The bottom line: We need to balance our hunter-gatherer genetic legacy with the best technology of our modern world. In The Paleo Answer, I show you how the majority of chronic health problems we suffer from today can be traced to our modern world and its discordance with the ancient world for which our bodies are genetically adapted.

Having been a faculty member at a major research university for the past thirty years, I can tell you that your personal experience with the Paleo Diet and a dollar will buy you no more than one cup of coffee in the scientific community. No matter how much weight you have dropped on the Paleo Diet, no matter how much your blood chemistry has improved or how much better you feel, the medical and scientific community will, by and large, not listen to you. What the academic community of science and medicine require is not your personal anecdotal evidence, but rather experimental evidence based upon one of the following four scientific methods: animal studies, tissue or organ studies, epidemiological (population) studies, or randomized, controlled human trials.

When The Paleo Diet came out in 2002, thousands of indirect experimental studies had already supported its general principles in promoting weight loss, improving overall health, and curing disease:

By 2002, thousands of scientific papers had independently verified that certain individual aspects of the Paleo Diet normalized body weight and improved health and well-being. But at that time, not a single study had yet examined all of the combined nutritional characteristics of the Paleo Diet. Was a diet high in animal protein, omega 3 fats, monounsaturated fats, vitamins, minerals, phytochemicals, and fiber and low in salt, refined sugars, cereal grains, dairy products, vegetable oils, and processed foods healthy? Was it more healthful than the officially sanctioned USDA MyPyramid, which was renamed MyPlate in June of 2011 (both MyPyramid and MyPlate base their recommendations upon the 2010 Dietary Guidelines for Americans), or even the highly touted Mediterranean diet? The direct scientific answers to these questions had yet to be answered.

Fortunately, in the past five years a number of scientists have dared to test contemporary versions of humanity’s original diet against supposedly “healthful diets.” One of the key figures behind this groundbreaking research is my friend and colleague Dr. Staffan Lindeberg, M.D., Ph.D., from Lund University in Sweden.

Staffan became interested in the Paleo Diet almost twenty years ago through his medical studies of the Kitavans, a non-Westernized group of 2,250 people living on remote islands near Papua New Guinea. The Kitavans obtain virtually all of their food from either the land or the sea and have little contact with the modern world. Common Western foods such as cereals, dairy, refined sugars, vegetable oils, and processed foods are nearly absent from their diets. These people represent the epitome of health compared to the average citizen living in the Western world. No one is overweight, and heart disease and stroke are extremely rare. High blood pressure and type 2 diabetes are nonexistent, and acne is not present among their children or teenagers. I doubt that you could round up a random group of two thousand Western people anywhere on the planet without encountering high rates of all of these diseases.

In the late 1990s, I first began to correspond with Dr. Lindeberg. We soon discovered that we had read almost all of the same scientific papers and were interested in most of the same diet/health topics.

Paleo Clues from the Outback

One study that stood out to both of us was an extraordinary experiment performed by Dr. Kerin O’Dea and published in the journal Diabetes in 1984. In this study, Dr. O’Dea gathered together ten middle-aged Australian Aborigines who had been born in the Outback. They had lived their early days primarily as hunter-gatherers until they had no choice but to finally settle into a rural community with access to Western goods. All ten subjects eventually became overweight and developed type 2 diabetes as they adopted Western sedentary lifestyles in the community of Mowwanjum in the northern Kimberley region of western Australia. Inherent in their upbringing, however, was the knowledge to live and survive in this seemingly desolate land without any of the trappings of the modern world.

Dr. O’Dea requested that these ten middle-aged subjects revert to their former lives as hunter-gatherers for a seven-week period. All agreed and traveled back into the isolated land from which they originated. Their daily sustenance came only from native foods that could be foraged, hunted, or gathered. Instead of white bread, corn, sugar, powdered milk, and canned foods, they began to eat the traditional fresh foods of their ancestral past: kangaroos, birds, crocodiles, turtles, shellfish, yams, figs, yabbies (freshwater crayfish), freshwater bream, and bush honey. At the experiment’s conclusion, the results were spectacular: the average weight loss in the group was 16.5 pounds; blood cholesterol dropped by 12 percent, and triglycerides were reduced by a whopping 72 percent. Insulin and glucose metabolism became normal, and their diabetes effectively disappeared.

Dr. Lindeberg and I both realized that this type of experiment would probably never be repeated, simply because the hunter-gather lifestyle is nearly extinct and because very few contemporary people have the knowledge or skills to live entirely off the land. Yet we both had the same vision. This experiment should be conducted in a slightly different manner but not with Westernized, former hunter-gatherers. Why not take a group of typically unhealthy Westerners and put them on commonly available contemporary foods that mimic the nutritional characteristics of hunter-gatherer diets? We knew that this experiment was precisely what Dr. Eaton had in mind with his inspirational paper.

It took nearly twenty-two years for Dr. Eaton’s dream of an experimental modern-day Paleo Diet to come true, but it finally happened with the publication of a paper by Dr. Lindeberg’s research group in 2007. Staffan followed this publication with two additional papers in 2009 and 2010. Good ideas catch on, and two other independent research groups around the world followed suit with similar results—the first in 2008 by Dr. Osterdahl in Sweden and the next in 2009 by my colleague Lynda Frassetto, M.D., from the University of California San Francisco School of Medicine. Although science may move slowly, it eventually does move forward as old ideas are replaced with new and better thoughts and information.

I can assure you that the Paleo Diet, a fundamental diet and lifestyle concept based on evolutionary biology and scientific research, is not a fad and will not fade away.