No group of DISEASES is more insidious than autoimmune diseases. They are difficult to treat, and progressive loss of physical and mental func- tion is a common outcome. Unlike heart disease, cancer, obesity and Type 2 diabetes, with autoimmune diseases the body systematically at· tacks itself. The afflicted patient is almost guaranteed to lose. A quarter million people in the u.s. are diagnosed with one of the forty separate autoimmune diseases each year.I. 2 Women are 2.7 times more likely to be afflicted than are men. About 3% of Americans (one in every thirty-one people) have an autoimmune disease, a staggering total of 8.5 million people; some people put the total at as many as 12-13 million people.3 The more common of these diseases are listed in Chart 9.1.2 The first nine comprise 97% of all autoimmune disease cases. 2 The most studied are multiple sclerosis (MS), rheumatoid arthritis, lupus, Type 1 diabetes and rheumatic heart disease.2 These are also the primary autoimmune diseases that have been studied in reference to diet. Others not listed in Chart 9.1 include inflammatory bowel disease,4 Crohn's disease,4 rheumatic heart disease3 and (possibly) Parkinson's disease. s Each disease name may sound very different, but as one recent re- view points out,2 " .. .it is important to consider ... these disorders as a group." They show similar clinical backgrounds,3.6. 7 they sometimes occur in the same person and they are often found in the same popula- tions.2 MS and Type 1 diabetes, for example, have "near(ly) identical
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ethnic and geographic distribution."8 Autoimmune diseases in general become more common the greater the distance from the equator. This phenomenon has been known since 1922.9 MS, for example, is over a hundred times more prevalent in the far north than at the equator.10 Because of some of these common features, it is not too far-fetched to think of the autoimmune diseases as one grand disease living in dif- ferent places in the body and taking on different names. We refer in this way to cancer, which is specifically named depending on what part of the body it resides in. All autoimmune diseases are the result of one group of mechanisms gone awry, much like cancer. In this case, the mechanism is the immune system mistakenly attacking cells in its own body. Whether it is the pan- creas as in Type 1 diabetes, the myelin sheath as in MS or joint tissues as in arthritis, all autoimmune diseases involve an immune system that has revolted. It is an internal mutiny of the worst kind, one in which our body becomes its own worst enemy. IMMUNITY FROM INVADERS The immune system is astonishingly complex. I often hear people speaking about this system as if it were an identifiable organ like a lung. Nothing could be further from the truth. It is a system, not an organ. In essence, our immune system is like a military network designed to de- fend against foreign invaders. The "soldiers" of this network are the white blood cells, which are comprised of many different sub-groups, each having its own mission. These sub-groups are analogous to a navy, army, air force and marines, with each group of specialists doing highly specialized work. The "recruitment center" for the system is in the marrow of our bones. The marrow is responsible for generating specialized cells called stem cells. Some of these cells are released into circulation for use elsewhere in the body; these are called B-cells (for bone). Other cells formed in the bone marrow remain immature, or unspecialized, until they travel to the thymus (an organ in the chest cavity just above the heart) where they become specialized; these are called T-cells (for thymus). These "soldier" cells, along with other specialized cells, team up to create intricate defense plans. They meet at major intersections around the body, including the spleen (just inside the left lower rib cage) and the lymph nodes. These meeting points are like command and control centers, where the "soldier cells" rearrange themselves into teams to attack foreign invaders. These cells are remarkably adaptable when they form their teams. They are able to respond to different circumstances and different for- eign substances, even those they have never before seen. The immune response to these strangers is an incredibly creative process. It is one of the true wonders of nature. The foreign invaders are protein molecules called antigens. These foreign cells can be a bacterium or a virus looking to corrupt the body's integrity So when our immune system notices these foreign cells, or antigens, it destroys them. Each of these foreign antigens has a sepa- rate identity, which is determined by the sequence of amino acids that comprises its proteins. It is analogous to each and every person having a different face. Because numerous amino acids are available for creating proteins, there are infinite varieties of distinctive "faces. " To counter these antigens, our immune system must customize its defense to each attack. It does this by creating a "mirror image" pro- tein for each attacker. The mirror image is able to fit perfectly onto the antigen and destroy it. Essentially, the immune system creates a mold for each face it encounters. Every time it sees that face after the initial encounter, it uses the custom-made mold to "capture" the invader and destroy it. The mold may be a B-cell antibody or a T-cell-based receptor protein. Remembering each defense against each invader is what immuniza- tion is all about. An initial exposure to chicken pox, for example, is a difficult battle, but the second time you encounter that virus you will know exactly how to deal with it, and the war will be shorter, less pain- ful and much more successful. You may not even get sick. IMMUNITY FROM OURSELVES Even though this system is a wonder of nature when it is defending the body against foreign proteins, it is also capable of attacking the same tissues that it is designed to protect. This self-destructive process is common to all autoimmune diseases. It is as if the body were to commit suicide. One of the fundamental mechanisms for this self-destructive behav- ior is called molecular mimicry. It so happens that some of the foreign invaders that our soldier cells seek out to destroy look the same as our own cells. The immune system "molds" that fit these invaders also fit our own cells. The immune system then destroys, under some circum- stances, everything that fits the mold, including our own cells. This is an extremely complex self-destructive process involving many different strategies on the part of the immune system, all of which share the same fatal flaw of not being able to distinguish "foreign" invader proteins from the proteins of our own body. What does all of this have to do with what we eat? It so happens that the antigens that trick our bodies into attacking our own cells may be in food. During the process of digestion, for example, some proteins slip into our bloodstream from the intestine without being fully broken down into their amino acid parts. The remnants of undigested proteins are treated as foreign invaders by our immune system, which sets about making molds to destroy them and sets into motion the self-destructive autoimmune process. One of the foods that supply many of the foreign proteins that mimic our own body proteins is cow's milk. Most of the time, our immune system is quite smart. Just like an army arranges for safeguards against friendly fire, the immune system has safeguards to stop itself from at- tacking the body it's supposed to protect. Even though an invading antigen looks just like one of the cells in our own body, the system can still distinguish our own cells from the invading antigen. In fact, the im- mune system may use our own cells to practice making molds against the invader antigen without actually destroying the friendly cell. This is analogous to training camps in preparations for war. When our immune system is working properly, we can use the cells in our body that look like the antigens as a training exercise, without destroying them, to prepare our soldier cells to repulse the invading antigens. It is one more examplel of the exceptional elegance of nature's ability to regulate itself. The immune system uses a very delicate process to decide which pro- teins should be attacked and which should be left alone.ll The way this process, which is incredibly complex, breaks down with autoimmune diseases is not yet understood. We just know that the immune system loses its ability to differentiate between the body's cells and the invading antigen, and instead of using the body's cells for "training," it destroys them along with the invaders. TYPE 1 DIABETES In the case of Type 1 diabetes, the immune system attacks the pancreas cells responsible for producing insulin. This devastating, incurable disease strikes children, creating a painful and difficult experience for young families. What most people don't know, though, is that there is strong evidence that this disease is linked to diet and, more specifically, to dairy products. The ability of cow's milk protein to initiate Type 1 diabetes12- 14 is well documented. The possible initiation of this disease goes like this: • A baby is not nursed long enough and is fed cow's milk protein, perhaps in an infant formula. • The milk reaches the small intestine, where it is digested down to its amino acid parts. • For some infants, cow's milk is not fully digested, and small amino acid chains or fragments of the original protein remain in the in- testine. • These incompletely digested protein fragments may be absorbed into the blood. • The immune system recognizes these fragments as foreign invad- ers and goes about destroying them. • Unfortunately, some of the fragments look exactly the same as the cells of the pancreas that are responsible for making insulin. • The immune system loses its ability to distinguish between the cow's milk protein fragments and the pancreatic cells, and destroys them both, thereby eliminating the child's ability to produce insu- lin. • The infant becomes a Type 1 diabetic, and remains so for the rest of his or her life. This process boils down to a truly remarkable statement: cow~ milk may cause one of the most devastating diseases that can befall a child. For obvious reasons, this is one of the most contentious issues in nutrition today. One of the more remarkable reports on this cow's milk effect was published over a decade ago, in 1992, in the New England Journal of Medicine.12 The researchers, from Finland, obtained blood from Type 1 diabetic children, aged four to twelve years. Then they measured the levels of antibodies that had formed in the blood against an incomplete- ly digested protein of cow's milk called bovine serum albumin (BSA). They did the same process with non-diabetic children and compared the two groups (remember, an antibody is the mirror image, or "mold," of a foreign antigen) . Children who had antibodies to cow's milk protein must have previously consumed cow's milk. It also means that undi- gested protein fragments of the cow's milk proteins had to have entered the infant's circulation in order to cause the formation of antibodies in the first place. The researchers discovered something truly remarkable. Of the 142 diabetic children measured, every Single one had antibody levels higher than 3.55. Of the seventy-nine normal children measured, every single one had antibody levels less than 3.55. There is absolutely no overlap between antibodies of healthy and diabetic children. All of the diabetic children had levels of cow's milk antibodies that were higher than those of all of the non-diabetic chil- dren. This implies two things: children with more antibodies consumed more cow's milk, and second, increased antibodies may cause Type 1 diabetes. These results sent shock waves through the research community. It was the complete separation of antibody responses that made this study so remarkable. This study,12 and others even earlier,15-17 initiated an ava- lanche of additional studies over the next several years that continue to this day.13. 18.19 Several studies have since investigated this effect of cow's milk on BSA antibody levels. All but one showed that cow's milk increases BSA antibodies in Type 1 diabetic children,18 although the responses were quite variable in their magnitude. Over the past decade, scientists have investigated far more than just the BSA antibodies, and a more complete picture is coming into view. Very briefly, it goes something like this13, 19: infants or very young children of a certain genetic background,2o,21 who are weaned from the breast too early22 onto cow's milk and who, perhaps, become infected with a virus that may corrupt the gut immune system,l9 are likely to have a high risk for Type 1 diabetes. A study in Chile23 considered the first two factors, cow's milk and genes. Genetically susceptible children weaned too early onto cow's milk-based formula had a risk of Type 1 di- abetes that was 13.1 times greater than children who did not have these genes and who were breast-fed for at least three months (thus minimiz- ing their exposure to cow's milk). Another study in the U.S. showed that genetically susceptible children fed cow's milk as infants had a risk of disease that was 11.3 times greater than children who did not have these genes and who were breast-fed for at least three months.24 This eleven to thirteen times greater risk is incredibly large (1,000-1,200%!); any- thing over three to four times is usually considered very important. To put this in perspective, smokers have approximately ten times greater risk of getting lung cancer (still less than the eleven to thirteen times risk here) and people with high blood pressure and cholesterol have a 2.5-3.0 times greater risk of heart disease (Chart 9.2) .18 So how much of the eleven to thirteen times increased risk of Type 1 diabetes is due to early exposure to cow's milk, and how much is due
