The Paleo Diet (9 page)

The health picture got worse over the years with the arrival of salt, fatty cheeses, and butter. Our ancestors learned to ferment grains, make beer, and eventually distill spirits. Selective breeding—and the innovation of feeding grain to livestock—steadily produced fatter pigs, cows, and sheep. Most meat wasn’t eaten fresh—fewer people hunted—but instead was pickled, salted, or smoked. Fruits and vegetables became luxuries—rare seasonal additions to the monotony of cereal and starch.

More recently—just 200 years ago—the Industrial Revolution brought refined sugar, canned foods, and refined white flour to the average family’s table. Food was processed in earnest by the mid-twentieth century with the invention of trans-fatty acids, margarine, shortening, and combinations of these fats mixed with sugar, salt, other starches, high omega 6 vegetable oils, high-fructose corn syrup, and countless additives, preservatives, coloring agents, and emulsifiers.

Imagine a Paleolithic human confronted with a Twinkie or even a pizza. He or she wouldn’t even recognize these modern-day treats as food.

In many ways, the 1950s were a simpler time. Part of the mind-set then seemed to be to find simple solutions for complicated problems. In the early 1950s, when scientists were unraveling the links between diet and heart disease, they found that
saturated fat
(the kind found in butter, cheese, and fatty meats) raised total blood cholesterol; it also raised the LDL (the bad kind) cholesterol level and increased the risk of heart disease. More recent research has shown that not all saturated fats raise total and LDL cholesterol. Stearic acid actually lowers blood cholesterol similar to the way that monounsaturated fats do. Unfortunately, red meat became the scapegoat; all of a sudden, it was the chief artery clogger and cause of heart attacks. Even many nutritionists and physicians jumped to the conclusion that red meat was an unhealthy food that promoted heart disease and bowel cancer.

The food industry responded to the message that saturated fats were bad by creating all sorts of “healthy alternatives”—highly polyunsaturated vegetable oils (corn, safflower, sunflower, and cottonseed, to name a few). They also gave us all kinds of products made from these oils, such as margarines, shortening, spreads, and dressings. And almost overnight, these vegetable oils and their spin-offs were incorporated into virtually all processed foods and baked goods.

Unfortunately, as we now know, this was a very bad move. The indiscriminate infusion of vegetable oils into the American diet gave us far too many omega 6 polyunsaturated fats at the expense of the good omega 3 polyunsaturated fats. And the increased use of margarine and spreads caused the widespread introduction of still another kind of fat, called “trans-fatty acids,” into our meals and snacks.

The next plan the nutritional masterminds came up with—like the anti-red meat campaign, it was not well thought out and was inadequately tested before being put into practice—was to replace saturated fats with carbohydrates, primarily starchy carbohydrates, like those found in bread, potatoes, and cereals. By the early 1990s, this recommendation had become so entrenched that it was the official policy of the USDA. The bedrock of our national Food Pyramid is its base—six to eleven servings of cereal grains. We now know, from scientific studies examining something called the “glycemic index” of certain foods, that this is six to eleven servings too many.

Part of the confusion here is that all carbohydrates are not created equal. Some of them are good for us. But others promote ill health and disease, and this brings us to the glycemic index. Good carbohydrates have a low glycemic index. This means they cause a minimal or slow rise in our blood glucose (sugar) level. The “glycemic load” is the glycemic index of a food times its carbohydrate content. It is this high-glycemic load that elevates blood insulin levels in many people. High-glycemic carbohydrates cause large and rapid rises in blood glucose and have been implicated in a wide variety of chronic diseases—adult-onset diabetes, high blood pressure, heart disease, obesity, elevated blood uric acid levels, elevated blood triglycerides (the building blocks of fat, which float around in the bloodstream), elevated small-dense LDL cholesterol, and reduced HDL cholesterol. This cluster of diseases is known to cardiologists as metabolic syndrome. Regrettably, the architects of the Food Pyramid did not distinguish between high- and low-glycemic carbohydrates when they started this carbomania.

Let’s see how our modern way of eating has deviated from the Seven Keys to nutrition I laid out in chapter 2, and how this has affected our health.

Protein makes up 15 percent of the calories that most Americans (and people in other Western countries) eat every day. But it should be much higher—between 19 and 35 percent—to give us more energy and help us burn off extra calories. Look at the numbers: For every 100 calories, cereals average only about 12 percent protein—compared to 83 percent protein for game meats. Legumes like lentils, peas, and beans average 27 percent protein.

As for dairy products, the phenomenon of the “milk cow” (or goat or sheep) happened roughly 9,000 years ago. Milk contains 21 percent protein, cheese averages 28 percent protein, and butter has absolutely no protein—but a lot of fat.

The bottom line: Most of us are getting only half of the protein we need.
Why is this bad? As I’ll discuss in the next three chapters, a low protein intake contributes to weight gain and a high blood cholesterol level and increases your risk of many chronic diseases.

The USDA Food Pyramid is based on carbohydrates; we’re a nation of starch and sugar eaters. Carbohydrates make up about half of the typical Western diet—a considerable difference from the Paleo Diet. For our ancient ancestors, carbohydrates accounted for 22 to 40 percent of the daily calories—but these were good carbohydrates, from wild fruits and vegetables. These low-glycemic foods—which don’t cause blood sugar to spike—are digested and absorbed slowly.

With nonstarchy fruits and vegetables, it’s very hard to get more than about 35 percent of your calories as carbohydrates. For example: There are 26 calories in the average tomato. To get 35 percent of your daily calories as carbohydrates from tomatoes only, you’d have to eat thirty tomatoes. And this is why, with the Paleo Diet, you can indulge yourself by eating all the nonstarchy fruits and vegetables you want. When you eat the right foods, getting too many carbohydrates—or eating too many high-glycemic carbohydrates, which can cause a dangerous rise in your blood sugar and insulin levels—is simply not something you have to worry about. The average carbohydrate content of fruits is only about 13 percent per 100 grams, about 4 percent for nonstarchy vegetables—and zero for lean meats, fish, and seafood. In stark contrast, the average carbohydrate content of cereal grains is 72 percent per 100 grams.

Why are many carbohydrates bad? Many whole grains and legumes don’t have a lot of vitamins and minerals. They’re poor dietary sources of these important nutrients. So a diet that’s tilted too heavily toward grains and legumes—at the expense of lean meats, fruits, and vegetables—can lead to vitamin and mineral deficiencies. This is why so many of our breads and cereals are fortified with extra nutrients. Food shouldn’t need to be supplemented with vitamins, and if you’re getting the right balance of lean meats, fruits, and vegetables, neither should you.

Worse, cereal grains and legumes even contain “antinutrients”—chemicals that actually
prevent
your body from absorbing the proper nutrients and can damage the gastrointestinal and immune systems. Too many grains and legumes can disrupt the acid balance in the kidneys as well, and can contribute to the loss of muscle mass and bone mineral content with aging.

Finally, if you eat more carbohydrates, you’re eating less protein. Protein is the dieter’s friend: it reduces your appetite and increases your metabolism—and this translates rapidly into weight loss.

One of the great dietary myths in the Western world is that whole grains and legumes are healthful. The truth is that these foods are marginal at best. But what about the “health-food” breads? At best, they’re
less bad
than the overprocessed, super-refined white breads you could be buying. But they’re still not part of the Paleo Diet. Formerly (before “progress” brought refined milling technology to bread making), almost all cereal grains either were eaten whole or were so crudely milled that nearly the entire grain—bran, germ, and fiber—remained intact, and flour was much less refined than the kind we buy today. Our great-greatgrandparents ate cracked wheat breads and baked goods with a moderate glycemic index—which meant a more moderate rise in blood sugar level.

Does this mean that whole grains are good for you? Not necessarily. It just means that an extra bad characteristic—a high glycemic index—wasn’t incorporated into them yet. That unfortunate addition happened about 130 years ago, when steel roller mills came on the flour-making scene. They smashed all the fiber out of the grains and left the wimpy white, high-glycemic powder most of us think of as flour. Today, almost all baked goods made with this stuff frequently cause the blood sugar level to rise excessively.

Even “whole wheat” bread made from flour ground by these steel roller mills does the same thing to your blood sugar, because the flour particle size is uniformly small—so it’s virtually no different from white flour. About 80 percent of all the cereal products Americans eat—as they follow the directions of the USDA Food Pyramid—come from refined white flour with a high glycemic index.

Our Paleolithic ancestors loved honey. But it was a rare treat, because it was only available seasonally and in limited quantities (and they had to outmaneuver bees to get it). So for the most part, refined sugars—another source of carbohydrates—simply were not part of humanity’s diet for 2.5 million years. In fact, until about the last 200 years or so, they weren’t part of anybody’s diet.

Sugar is another of those side effects of technological “progress,” and its rise to prominence in our daily life has been rapid. In England in 1815, the average person used about 15 pounds of table sugar a year; in 1970, the average person used 120 pounds. How much sugar do you buy a year? Do you buy another 5-pound bag every time you go to the grocery store? You’re not alone.

Yet sugar, like refined cereal grains, is not good for us. Sure, it causes cavities—most of us hear that message every time we go to the dentist. But it’s also becoming evident that sugar poses more serious health problems. It promotes insulin resistance and metabolic syndrome diseases almost as much as high-glycemic breads and starchy potatoes do.

The chemical name for table sugar is “sucrose.” Although sucrose has nearly the same high glycemic index (65) as white bread (70), it has two additional characteristics that make it particularly harmful for insulin metabolism. First, it is 100 percent carbohydrate, meaning that its glycemic load is very high.

Second, when your body digests sucrose, it is broken down into two simple sugars—high-glycemic glucose (with a glycemic index of 97) and low-glycemic fructose (with a glycemic index of 23). Scientists used to think that fructose was not harmful because of its low glycemic index. But recent laboratory studies by Dr. Mike Pagliassotti and colleagues at Arizona State University have revealed that fructose is actually the main culprit in table sugar that causes insulin resistance. Dr. Pagliassotti’s findings were bolstered by research at the University of Lausanne Medical School in Switzerland, by Dr. Luc Tappy and colleagues, showing that fructose can cause insulin resistance in humans. Insulin resistance, in turn, often promotes obesity and chronic metabolic syndrome diseases, including hypertension, heart disease, and diabetes.

The steady increase in table sugar use was an unfortunate development in the carbohydrate content of our diet. But in the 1970s, the food-processing industry made a discovery: high-fructose corn syrup could save them a lot of money. Because fructose is so much sweeter than sucrose, less of it is needed to sweeten any processed food. Today corn syrup is the food-processing industry’s sweetener of choice. Imagine the financial incentive here: with fructose, millions of tons of sugar are saved each year.

What does this mean to average Americans? It means we are getting grossly disproportionate amounts of sweetener in our diets. There are about
10 teaspoons of high-fructose corn syrup in a single 12-ounce can of soda.
The average American now eats 66 pounds of corn syrup a year, plus 64 pounds of sucrose, and an appalling total of 131 pounds of refined sugars. When you begin the Paleo Diet and gradually wean yourself off processed foods, your daily sugar intake will drastically shrink—and, better still, the sugar you get will come from healthful fruits and vegetables.

Fiber intake began to go down the day our ancient ancestors started harvesting cereal grains. How can this be? Don’t whole grains equal fiber? When our doctors tell us to add more fiber to our diet, don’t they mean for us to eat more oatmeal? The truth is that calorie for calorie, whole grains can’t hold a candle to fruits and vegetables. Fruits on average contain
almost twice as much
fiber as whole grains. Compared to whole grains, nonstarchy vegetables have
eight times more fiber.
Sugars have absolutely no fiber.

And yet we know that dietary fiber is absolutely essential for good health. Not having enough fiber raises our risk of developing scores of diseases and health problems. A comprehensive medical text edited by Drs. Hugh Trowell, Denis Burkitt, and Kenneth Heaton has implicated low dietary fiber in the following diseases and health problems: constipation, diverticulitis, colon cancer, appendicitis, Crohn’s disease, ulcerative colitis, irritable bowel syndrome, duodenal ulcer, hiatal hernia, gastroesophageal reflux, obesity, type 2 diabetes, gallstones, high blood cholesterol, varicose veins, hemorrhoids, deep vein thrombosis, and kidney stones.