The Paleo Diet Read online

  Nutritional science is not static. What we once believed to be true ten years ago is invariably replaced by fresh knowledge based on better experiments, more comprehensive data, and a newer understanding of how our bodies work. When I first wrote The Paleo Diet, a great deal of the dietary advice I offered was cutting edge—so much so, that it was looked on with skepticism by scientists and the public at large. Here’s a perfect example. One 2002 online review of The Paleo Diet read, “Claims of improving diseases from diabetes to acne to polycystic ovary disease may be a little overstated.” I feel vindicated knowing that the original dietary recommendations I made for type 2 diabetes, acne, and polycystic ovary syndrome have been confirmed by hundreds of scientific experiments.

  Especially gratifying are a series of epidemiological experiments from Dr. Walter Willett and colleagues at the Harvard School of Public Health that linked milk consumption and the occurrence of acne. Even more convincing evidence for the diet-acne link comes from Dr. Neil Mann’s research group at the Royal Melbourne Institute of Technology, where acne patients were actually fed high-protein, low-glycemic-load diets and reported significant improvement in their symptoms.

  Anytime a diet/health book survives eight years, the hindsight rule (hindsight is 20/20) surely has to come into play. Indeed it did with this book, as reflected by my current updates and edits to the original volume. The elegance of The Paleo Diet concept is that the essential idea (the evolutionary basis for optimal human nutrition) is fundamentally sound and will never change; as Boyd Eaton, the godfather of Paleolithic nutrition commented, “The science behind Paleolithic Nutrition is indisputable; however, we will continually hone the concept as newer information accumulates.”

  So, what’s new in this edition, and what are the noteworthy changes?

  The first revision involves recommended oils. We are now down to only four: olive oil, flaxseed oil, walnut oil, and avocado oil. I no longer can recommend canola oil at all, and the only oil I believe should be used for cooking is olive oil. My friend and noted nutritionist Robert Crayhon always said to “let the data speak for itself,” and I believe his words ring true. The rationale for these new recommendations is solely based on new facts that have emerged. You can find this updated information in this revised edition.

  Another shift is that I have softened my stance on the saturated fat issue as more and more data become available, including information from my recent evolutionary paper on the topic.

  Finally, as scientists begin to unravel the mystery of autoimmune diseases, it is becoming apparent that multiple nutritional elements of the Paleo Diet may protect us from these one hundred or more illnesses that afflict nearly 10 percent of the U.S. population.

  All of this information, along with the tweaks needed to bring The Paleo Diet up to date in 2010, is to be found within this edition. I’ve also just published a new book, The Paleo Diet Cookbook, which contains more than 150 Paleo recipes. I owe a debt of gratitude to each and every Paleo Diet supporter for making this concept known to the world.

  Acknowledgments

  I am the storyteller, but the tale I tell would not have been possible without the dedication and lifework of countless scientists from many diverse fields. I am particularly indebted to my friend and colleague S. Boyd Eaton for enlightening me with his seminal New England Journal of Medicine article “Paleolithic Nutrition” and then for generously recognizing me in the midst of a sea of faces. I have had countless hours of discussion (both on and off the electronic ether) regarding diet, disease, and anthropology with many notable scientists, physicians, and interested lay scholars. Without their encouragement, passion, knowledge, and enthusiasm, I suspect that this book would not have been written. Thank you, Boyd Eaton, Jennie Brand Miller, Neil Mann, Andy Sinclair, Mike and Mary Dan Eades, Artemis Simopoulous, Bruce Watkins, Dean Esmay, Ward Nicholson, Don Wiss, Ben Balzer, Clark Spencer Larsen, Mike Richards, John Speth, Norman Salem, Joe Hibbeln, Stephen Cunnane, Kim Hill, Craig Stanford, Robert Crayhon, Robert Gotshall, Joe Friel, Kevin Davy, Lynn Toohey, David Jenkins, David Lugwig, Soren Toubro, George Williams, Luisa Raijman, Michael Crawford, Staffan Lindeberg, Ray Audette, Wolfgang Lutz, Ann Magennis, Art DeVany, Ashton Embry, Bill DiVale, Pat Gray, Char-lie Robbins, Irvin Liener, Nicolai Worm, Tony Sebastian, Robert Heaney, Stewart Truswell, and Pam Keagy. Finally, many thanks to my agents, Carol Mann and Channa Taub, for working indefatigably to get this book off the ground, and to my editor, Tom Miller, for his commitment to and enthusiasm for the Paleo Diet as a book concept.

  PART ONE

  Understanding the Paleo Diet

  Introduction

  This book represents the culmination of my lifelong interest in the link between diet and health, and of my fascination with anthropology and human origins. Although these scientific disciplines may at first appear to be unrelated, they are intimately connected. Our origins—the very beginnings of the human species—can be traced to pivotal changes in the diet of our early ancestors that made possible the evolution of our large, metabolically active brains. The Agricultural Revolution and the adoption of cereal grains as staple foods allowed us to abandon forever our previous hunter-gatherer lifestyle and caused the Earth’s population to balloon and develop into the vast industrial-technological society in which we live today.

  The problem, as you will see in this book, is that we are genetically adapted to eat what the hunter-gatherers ate. Many of our health problems today are the direct result of what we do—and do not—eat. This book will show you where we went wrong—how the standard American diet and even today’s so-called healthy diets wreak havoc with our Paleolithic (Old Stone Age) constitutions. It will also show you how you can lose weight and regain health and well-being by eating the way our hunter-gatherer ancestors ate—the diet that nature intended.

  The reason for this book is very simple: the Paleo Diet is the one and only diet that ideally fits our genetic makeup. Just 333 generations ago—and for 2.5 million years before that—every human being on Earth ate this way. It is the diet to which all of us are ideally suited and the lifetime nutritional plan that will normalize your weight and improve your health. I didn’t design this diet—nature did. This diet has been built into our genes.

  More than twenty years ago, I read a book that endorsed vegetarian dieting titled Are You Confused? I suspect that this title pretty much sums up how many of us feel about the conflicting breakthroughs and mixed messages we hear every day from scientific and medical authorities on what we should and shouldn’t eat to lose weight and be healthy.

  But here’s the good news. Over the last twenty-five years, scientists and physicians worldwide have begun to agree on the fundamental principle underlying optimal nutrition—thanks in part to my colleague Dr. S. Boyd Eaton of Emory University in Atlanta. In 1985, Dr. Eaton published a revolutionary scientific paper called “Paleolithic Nutrition” in the prestigious New England Journal of Medicine suggesting that the ideal diet was to be found in the nutritional practices of our Stone Age ancestors. Although a few physicians, scientists, and anthropologists had been aware of this concept, it was Dr. Eaton’s writings that brought this idea to center stage.

  Dr. Eaton applied the most fundamental and pervasive idea of all biology and medicine—the theory of evolution by natural selection—to diet and health. His premise was simple: our genes determine our nutritional needs. And our genes were shaped by the selective pressures of our Paleolithic environment, including the foods our ancient ancestors ate.

  Many modern foods are at odds with our genetic makeup—which, as we’ll discuss in the book, is basically the same as that of our Paleolithic ancestors—and this is the cause of many of our modern diseases. By restoring the food types that we are genetically programmed to eat, we can not only lose weight, but also restore our health and well-being.

  I have studied diet and health for the past three decades and have devoted the last twenty years to studying the Paleo Diet concept. I have been fortunate enough to w
ork with Dr. Eaton to refine this groundbreaking idea and explore a wealth of new evidence. Together with many of the world’s top nutritional scientists and anthropologists, I have been able to determine the dietary practices of our hunter-gatherer ancestors. Understanding what they ate is essential for understanding what we should eat today to improve our health and promote weight loss. Our research has been published in the top nutritional journals in the world.

  It’s all here for you in this book—all the dietary knowledge and wisdom that my research team and I have gleaned from our distant ancestors who lived in the days before agriculture. Part One explains what our Paleolithic ancestors ate, the basics of the Paleo Diet, and how civilization has made us stray from our original diet, bringing us ill health and obesity. Part Two shows how you can lose weight and how much you can lose, and also how the Paleo Diet can prevent and heal disease. Part Three spells out everything you need to know to follow the Paleo Diet—including meal plans for the three levels of the diet and more than 100 delicious Paleo recipes. That’s the best part of the Paleo Diet—you’ll eat well, feel great, and lose weight! The book ends with a complete list of scientific references that back up all of this information.

  How Our Healthy Way of Life Went Wrong

  The Agricultural Revolution began 10,000 years ago—just a drop in the bucket compared to the 2.5 million years that human beings have lived on Earth. Until that time—just 333 generations ago—everyone on the planet ate lean meats, fresh fruits, and vegetables. For most of us, it’s been fewer than 200 generations since our ancestors abandoned the old lifestyle and turned to agriculture. If you happen to be an Eskimo or a Native American, it’s been barely four to six generations. Except for perhaps a half-dozen tiny tribes in South America and a few on the Andaman Islands in the Bay of Bengal, pure hunter-gatherers have vanished from the face of the Earth. When these few remaining tribes become Westernized during the next decade or so, this ancient way of life—which allowed our species to thrive, grow, and mature—will come to an end.

  This loss of humanity’s original way of life matters a great deal. Why? Look at us. We’re a mess. We eat too much, we eat the wrong foods, and we’re fat. Incredibly, more Americans are overweight than aren’t: 68 percent of all American men over age twenty-five, and 64 percent of women over age twenty-five are either overweight or obese. And it’s killing us. The leading cause of death in the United States—responsible for 35 percent of all deaths or 1 of every 2.8 deaths—is heart and blood vessel disease. Seventy-three million Americans have high blood pressure; 34 million have high cholesterol levels, and 17 million have type 2 diabetes. It’s not a pretty picture.

  Most people don’t realize just how healthy our Paleolithic ancestors were. They were lean, fit, and generally free from heart disease and the other ailments that plague Western countries. Yet many people assume that Stone Age people had it rough, that their lives were “poor, nasty, brutish, and short,” as Thomas Hobbes wrote in The Leviathan.

  But the historical and anthropological record simply does not support this line of reasoning. Almost without exception, descriptions of hunter-gatherers by early European explorers and adventurers showed these people to be healthy, fit, strong, and vivacious. These same characteristics can be yours when you follow the dietary and exercise principles I have laid out in the Paleo Diet.

  I have examined thousands of early-nineteenth and twentieth-century photographs of hunter-gatherers. They invariably show indigenous people to be lean, muscular, and fit. The few medical studies of hunter-gatherers who managed to survive into the twentieth century also confirm earlier written accounts by explorers and frontiersmen. No matter where they lived—in the polar regions of Canada, the deserts of Australia, or the rain forests of Brazil—the medical records were identical. These people were free from signs and symptoms of the chronic diseases that currently plague us. And they were lean and physically fit. The medical evidence shows that their body fat, aerobic fitness, blood cholesterol, blood pressure, and insulin metabolism were always superior to those of the average modern couch potato. In most cases, these values were equivalent to those of modern-day, healthy, trained athletes.

  High blood pressure (hypertension) is the most prevalent risk factor for heart disease in the United States. It’s almost unheard of in indigenous populations. The Yanomamo Indians of northern Brazil and southern Venezuela, to whom salt was unknown in the late 1960s and early 1970s, were absolutely free from hypertension. Their blood pressure didn’t increase with age and remained remarkably low by today’s standards. Amazingly, scientific studies of Greenland Eskimos by Drs. Hans Bang and Jørn Dyerberg from Aalborg Hospital in Aalborg, Denmark, showed that despite a diet containing more than 60 percent animal food, not one death from heart disease—or even a single heart attack—occurred in 2,600 Eskimos from 1968 to 1978. This death rate from heart disease is one of the lowest ever reported in the medical literature. For a similar group of 2,600 people in the United States during a ten-year period, the expected number of deaths from heart disease would be about twenty-five.

  When you put into practice the nutritional guidelines of the Paleo Diet, you will be getting the same protection from heart disease that the Eskimos had. You will also become lean and fit, like your ancient ancestors. This is your birthright. By going backward in time with your diet, you will actually be moving forward. You’ll be combining the ancient dietary wisdom with all of the health advantages that modern medicine has to offer. You will reap the best of both worlds.

  1

  Not Just Another Low-Carb Diet

  What’s the diet craze this week? You name it, there’s a book selling it—and people buying it, hoping for a “magic bullet” to help them shed excess pounds. But how can everybody be right? More to the point, is anybody right? What are we supposed to eat? How can we lose weight, keep it off—and not feel hungry all the time? What’s the best diet for our health and well-being?

  For more than thirty years, as an avid researcher of health, nutrition, and fitness, I have been working to answer these questions. I started this quest because I wanted to get past all the hype, confusion, and political posturing swirling around dietary opinion. I was looking for facts: the simple, unadulterated truth. The answer, I found, was hidden back in time—way back, with ancient humans who survived by hunting wild animals and fish and gathering wild fruits and vegetables. These people were known as “hunter-gatherers,” and my research team and I published our analysis of what many of them (more than 200 separate societies) ate in The American Journal of Clinical Nutrition. We were astonished at the diversity of their diet. We were also amazed at what they did not eat—which we’ll get to in a minute and which may surprise you.

  Health Secrets of Our Ancestors

  What do Paleolithic people have to do with us? Actually, quite a lot: DNA evidence shows that basic human physiology has changed little in 40,000 years. Literally, we are Stone Agers living in the Space Age; our dietary needs are the same as theirs. Our genes are well adapted to a world in which all the food eaten daily had to be hunted, fished, or gathered from the natural environment—a world that no longer exists. Nature determined what our bodies needed thousands of years before civilization developed, before people started farming and raising domesticated livestock.

  In other words, built into our genes is a blueprint for optimal nutrition—a plan that spells out the foods that make us healthy, lean, and fit. Whether you believe the architect of that blueprint is God, or God acting through evolution by natural selection, or by evolution alone, the end result is still the same: We need to give our bodies the foods we were originally designed to eat.

  Your car is designed to run on gasoline. When you put diesel fuel into its tank, the results are disastrous for the engine. The same principle is true for us: We are designed to run best on the wild plant and animal foods that all human beings gathered and hunted just 333 generations ago. The staples of today’s diet—cereals, dairy products, refined sugars, fat
ty meats, and salted, processed foods—are like diesel fuel to our bodies’ metabolic machinery. These foods clog our engines, make us fat, and cause disease and ill health.

  Sadly, with all of our progress, we have strayed from the path designed for us by nature. For instance:• Paleolithic people ate no dairy food. Imagine how difficult it would be to milk a wild animal, even if you could somehow manage to catch one.

  • Paleolithic people hardly ever ate cereal grains. This sounds shocking to us today, but for most ancient people, grains were considered starvation food at best.

  • Paleolithic people didn’t salt their food.

  • The only refined sugar Paleolithic people ate was honey, when they were lucky enough to find it.

  • Wild, lean animal foods dominated Paleolithic diets, so their protein intake was quite high by modern standards, while their carbohydrate consumption was much lower.

  • Virtually all of the carbohydrates Paleolithic people ate came from nonstarchy wild fruits and vegetables. Consequently, their carbohydrate intake was much lower and their fiber intake much higher than those obtained by eating the typical modern diet.