The Paleo Diet (15 page)

Of the four major acid-producing foods, three—grains, cheeses, and salt—were eaten rarely or never by our Paleolithic ancestors. Instead, they ate huge amounts (by modern standards) of alkaline fruits and vegetables, which buffered the acid from their meat-rich diets.

Many chronic diseases prevalent in Western countries develop because of a dietary acid-base imbalance. These include:

The realization that such diverse problems could be linked to acid-base imbalance is fairly recent. Not so long ago, scientists connected many of these illnesses to too much sodium, or salt. But the chemical recipe for salt has two ingredients—sodium and chloride. And as I discussed earlier, it’s the chloride part of salt that makes it acidic—not the sodium. Chloride may also be more to blame than sodium as a dietary cause of high blood pressure.

Earlier, I talked about salt’s interplay with calcium in the body: people who eat a lot of salt excrete more calcium in their urine than do people who avoid salt. In turn, this calcium loss contributes to bone loss and osteoporosis, because the acidic chloride in salt must be buffered in the kidneys by alkaline base—and the body’s largest reservoir of alkaline base is the calcium in our bones. When we eat salty potato chips or a pepperoni pizza, we are leaching calcium from our bones. When we do it over the course of a lifetime, we may well develop osteoporosis.

But salt is not just bad for the bones. Although it has not been shown to cause asthma or exercise-induced asthma, it can aggravate both conditions. Studies in humans and animals have shown that salt can constrict the muscles surrounding the small airways in the lung. My research team demonstrated that salt (both the sodium and the chloride components) increases the severity of exercise-induced asthma. We also showed that low-salt diets can reduce many symptoms of exercise-induced asthma.

Maybe you don’t salt your food. Good for you—but you should be aware that despite your good intentions, there’s probably more salt in your diet than you think. The average American eats 10 to 12 grams of salt every day. Almost 80 percent of this comes from processed foods—even those considered healthful. Two slices of whole-wheat bread, for instance, give you 1.5 grams of salt. So automatically there’s salt in any sandwich you make—even before you add salty meats like ham, salami, or bologna.

A high-salt diet increases your risk of kidney stones, stroke, and stomach cancer.

It also impairs sleep—this is one of the least-recognized benefits of low-salt diets. When you cut the salt out of your diet, you will sleep better almost immediately. Low-salt diets also have been shown to reduce motion and air sickness.

Many other foods are acidic and able to disrupt the body’s acid-base balance. Every time you eat cereals, peanuts, peanut butter, bread, muffins, cheese, sandwiches, pizza, doughnuts, cookies—basically, any processed food—you are overloading your body with dietary acid. Unless you balance these foods with healthful alkaline fruits and vegetables, you will be out of acid-base balance—and at increased risk for many chronic diseases.

Another crucial chemical balance in the body is that of potassium and sodium. Paleo diets contained about ten times as much potassium as sodium. The average American eats about five times as much sodium as potassium every day. The beauty of the Paleo Diet is that it swiftly returns your body to humanity’s original high intake of potassium and low intake of sodium.

Fiber is absolutely essential to your health—and at least thirteen illnesses can result when you don’t get enough fiber in your diet. Some of the most common digestive diseases that develop when you eat the standard American diet with its overload of refined grains, sugars, dairy, and processed foods are:

The Paleo Diet is naturally high in fiber because of its abundance of fruits and vegetables—about three to five times as much fiber each day as there is in the average American diet.

Some people worry that lean meat-based diets are constipating. This is not true. Meat, fish, and seafood are not constipating at all. The famous Arctic explorer Vilhjalmur Stefansson spent years mapping and exploring the Far North at the turn of the twentieth century. During his expeditions on dogsleds, he frequently lived off the land for more than a year at a time. He and his men were entirely dependent on the all-animal food diet that could be obtained from hunting and fishing. Amazingly, he reported in his journal that men who had suffered from constipation on their former rations of flour, corn biscuits, rice, and breads were almost completely cured of their problem within a week of adopting the all-meat (high in protein, but with enough fat to avoid the risk of protein toxicity) menu of the Eskimos.

Years later, when Stefansson returned to civilization, he and another explorer were put on an all-meat diet for an entire year, under controlled hospital conditions, by the most respected scientists and physicians of the day. The clinical evaluations at the end of the year showed bowel function to be normal. Just like Stefansson and the Eskimos, you will not suffer from constipation when lean meat, fish, and seafood dominate your diet. In fact, you will find that most of your digestive problems will disappear.

As with every other disease of civilization, it is not the soluble fiber from fruits and vegetables that will reduce your digestive problems, but rather the entire diet. Dairy products, cereals, and yeast have been implicated time and again in the development of Crohn’s disease, an inflammatory disease of the gastrointestinal tract. Elemental diets (special liquid formulas without dairy, cereal, or yeast proteins) are the first line of defense physicians use in treating these patients. Amazingly, almost 80 percent of patients achieve complete remission while on elemental diets with absolutely no drug therapy. But there is a big problem here: hardly anyone can stay on a liquid diet forever. What would you rather do, drink a liquid diet or eat humanity’s real foods—fruits, veggies, and lean meats?

One of our most powerful therapies to calm down the inflammation of both Crohn’s disease and ulcerative colitis (an inflammatory disease of the colon) is to prescribe fish oil capsules—an excellent source of omega 3 fats. Once again, we find that multiple elements in humanity’s original diet complement one another to eliminate or prevent chronic illness. And it is our deviation from the three simple foods (fruits, vegetables, and lean meats) we are genetically adapted to eat that invariably causes us trouble and ill health.

Omega 3 fats are powerful weapons in other wars as well. Perhaps because of their anti-inflammatory properties, they may prevent cancer from developing. They are also extremely effective in calming down virtually all inflammatory diseases—illnesses that end in “itis,” such as rheumatoid arthritis, ulcerative colitis, and gingivitis. These amazingly healthful fats can even reduce symptoms of certain autoimmune diseases: the combination of supplementing your diet with omega 3 fats and eliminating grains, dairy foods, legumes, potatoes, and yeast may substantially reduce the severity of symptoms of these diseases.

Autoimmune diseases such as rheumatoid arthritis, multiple sclerosis, and type 1 (juvenile) diabetes develop when the body’s immune system can’t tell the difference between its own tissues and those of foreign invaders. The result: the body attacks itself. The type of disease depends on the nature of the body’s assault: When the immune system invades and destroys nerve tissue, multiple sclerosis and other neurological diseases develop. When the pancreas is the target, type 1 diabetes occurs. When joint tissues are attacked and destroyed, the result is rheumatoid arthritis.

All autoimmune diseases develop because of interactions between the genes and one or more environmental factors, such as a viral or bacterial infection or exposure to a certain food. No one knows exactly how viruses, bacteria, and foods can spark the disease in genetically susceptible people, but research from our laboratory increasingly implicates recently introduced Neolithic foods such as grains, legumes, dairy foods, potatoes, and other members of the nightshade family.

Many environmental agents have been suspected in the development of autoimmune diseases. But only one of these types has proved capable of causing a disease. Cereal grains—such as wheat, rye, barley, and oats—are responsible for celiac disease and dermatitis herpetiformis. In celiac disease, the immune system attacks and destroys cells in the intestine, leading to diarrhea and many nutritional problems. In dermatitis herpetiformis, the skin is attacked.

Withdrawal of all gluten-containing cereals causes complete remission of both diseases. Cereal grains, dairy products, and legumes are suspected in other autoimmune diseases, such as type 1 diabetes, multiple sclerosis, and rheumatoid arthritis. To date, no dietary intervention studies have been conducted to see whether Paleo diets—free of grains, dairy products, and legumes—can reduce the symptoms of these diseases. However, anecdotal reports from Canada show improvement in symptoms of multiple sclerosis patients following the Paleo Diet.

My research group and I have published a paper in the
British Journal of Nutrition
describing our theory that dairy foods, grains, legumes, and yeast may be partly to blame for rheumatoid arthritis and other autoimmune diseases in genetically susceptible people. Legumes and grains contain substances called lectins. These substances are proteins that plants have evolved to ward off insect predators. Lectins can bind with almost any tissue in our bodies and wreak havoc—if they can enter the body, that is.

Normally, when we eat food, all proteins are broken down into basic amino acid building blocks and then absorbed in the small intestine. Lectins are different. They are not digested and broken down; instead, they attach themselves to cells in our intestines, where nutrient absorption takes place. The lectins in wheat (WGA), kidney beans (PHA), soybeans (SBA), and peanuts (PNA) are known to increase intestinal permeability and allow partially digested food proteins and remnants of resident gut bacteria to spill into the bloodstream. (Alcohol and hot chili peppers also increase intestinal permeability.) Usually, special immune cells immediately gobble up these wayward bacteria and food proteins. But lectins are cellular Trojan horses. They make the intestines easier to penetrate, and they impair the immune system’s ability to fight off food and bacterial fragments that leak into the bloodstream.

Surprisingly, we have found that many common gut bacteria fragments are made up of the same molecular building blocks as those found in certain immune system proteins and in the tissues under attack by the immune system. This matchup—of gut bacteria or food protein, immune system protein, and body tissue protein—may confuse the immune system, causing it to attack the body’s own tissues. A number of research groups worldwide have found that milk, grain, legume, and nightshade proteins can also trick the immune system into attacking the body’s own tissues by this process of molecular mimicry.

If you have an autoimmune disease, there is no guarantee that diet will cure it or even reduce your symptoms, but there is virtually no risk, and there are many other great benefits from the Paleo Diet that will improve your health.

One of the least known benefits of grain-free diets is their ability to improve mental well-being. My colleague Dr. Klaus Lorenz of Colorado State University has extensively studied how cereals may influence the development and progression of schizophrenia. In a wide-ranging review study, Dr. Lorenz concluded that in “populations eating little or no wheat, rye and barley, the prevalence of schizophrenia is quite low.” Dr. Lorenz’s analysis included the clinical studies by Dr. F. Curtis Dohan of the Eastern Pennsylvania Psychiatric Institute. In studies spanning almost twenty-five years, Dr. Dohan reported time and again that the symptoms of schizophrenia were reduced in patients on grain-and dairy-free diets but worsened when these foods were returned to the diet. Exactly why cereals may alter mood and mental well-being is not entirely clear. But several studies have shown that when wheat is digested, it contains a narcoticlike substance that may affect certain areas in the brain that influence behavior. Similar substances called “casomorphins” have been isolated from cow’s milk; however, no one knows whether they can alter mood or behavior.

My colleague Joe Hibbeln at the National Institutes of Health has demonstrated that omega 3 fats may be effective in reducing depression, hostility, schizophrenia, and other mental disorders. His finding was confirmed in a four-month study of thirty manic-depressive patients by Dr. Andrew Stoll of the Brigham and Women’s Hospital in Boston. Dr. Stoll used medicine’s most powerful study tool, a double-blind, placebo-controlled trial, to compare the efficacy of omega 3 fats versus olive oil for treatment of manic-depressive illness. According to Dr. Stoll and his colleagues, “for nearly every outcome measure, the omega 3 fatty acid group performed better than the placebo group.” This work lends credence to a number of recent studies demonstrating that the symptoms of depression are much lower in people who eat a lot of fish (an excellent source of omega 3 fats).