Autism used to be considered a rare disorder. Just fifteen years ago, the incidence was approximately I in 5,000. Now the rates are closer to I in 200. This means that doctors who treated patients for years without seeing an autistic child may now have several in their practice. It also means that some young doctors are finding out that their own children are on the autistic spectrum. Many of these physician-parents are pioneering new therapies and accepting new ideas. And since their own children are affected, they are seeking the same miraculous cure as the rest of us.

Perhaps this is the reason that many doctors are finally listening to scientists and parents who insist that dietary changes really are helping children with autism. The information has been available for a long time, though it is only in the last five years that a large percentage of parents began hearing about it shortly after receiving diagnoses.

At first, it may seem odd that removing specific foods would help people with developmental disabilities. The clues, however, have been there all along. Chronic constipation and diarrhea are common in autistic spectrum children. Sadly, these symptoms were often simply dismissed as part of the autistic disorder and rarely, if ever, were the underlying causes thoroughly investigated. Not even the fact that celiac disease is fairly common in the relatives of autistic children led to a closer look at intestinal health.

As early as 1979, researcher Jaak Panksapp noted the similarity between characteristics of autistic children and the effects of endorphins ( naturally occurring substances) and opiate drugs. Intrigued by Panksepp's observation, Norwegian physician and DAN! pioneer Karl Reichelt recalled previously published work suggesting that diet could be implicated in some cases of schizophrenia. He set out to look for evidence of opioids in autistic children, choosing to study urine samples that could be collected with minimal disruption to his young subjects. He found very elevated urinary peptides in his subjects.

Reichelt's work was later replicated by Paul Shattock in England and then by American Robert Cade. These findings led to the "opioid excess theory" of autism. In short, the theory holds that a metabolic defect leads to the incomplete breakdown of gluten and casein proteins. Proteins are composed of amino acid chains; in the normal course of digestion, the proteins are broken down into their constituent amino acids. At some point during this process, short chains of amino acids remain. These chains are known as peptides.

It has long been known that gluten and casein have opioid characteristics if incompletely digested, and the fact that autistic children often have "leaky guts" (through which incompletely digested proteins could pass to the blood) lends further support to the theory. Undigested peptides that cross from the intestine to the blood will be, for the most part, dumped into the urine, and that is where scientists have found them.

Some peptides will cross into the central nervous system, according to the theory , and affect the brain by mimicking neurotransmitters (the chemicals that deliver messages between nerve cells by sending or inhibiting nerve impulses. ) It is now known that everyone has some level of peptide in the gut, but far greater numbers of peptides are found in the urine of people on the autistic spectrum. This means there is likely a concomitant increase in the number that reaches the central nervous system. The increased permeability (leakiness) of the gut worsens the problem.

Recently, pediatric gastroenterologists in England and the United States have begun studying the GI problems in autistic children. They acknowledge what many parents have known for years -- gastrointestinal illness plays an important part in the cause and expression of autism. Autistic spectrum individuals also frequently have complex immunological abnormalities along with their other symptoms. In the last few years, British gastroenterologists have pointed out several commonalities in patients with liver disease and a subtype of autism in which regression follows a period of normal development. In both these conditions, abnormalities in opioid biochemistry are common, and this lends further support to the theory that opioid peptides are involved.

Fortunately, there are many doctors and researchers attempting to find the primary problems that underlie this baffling and devastating disorder. In the meantime, there is little doubt that removing gluten and casein from the diet is helpful for a large percentage of those who have tried it.

It is hoped that in the near future these questions will be resolved. For now, however, these researchers have one thing in common: all recommend that gluten and casein be removed from the diet of autistic spectrum children. Until we know with certainty why these proteins are not digested fully, removing them from the diet remains the only way to prevent further damage.

Despite the mounting evidence, many physicians still dismiss dietary intervention in the treatment of autism. Some suggest that "diet won't hurt," but they do not encourage dietary trials. Others continue to discourage parents from trying a gluten-free and casein- free (GF/CF) diet. Some parents are made to feel that removing milk is tantamount to child abuse. The fact that a large percentage of the world's population does not consume milk once babyhood has passed is ignored.

Some children who were diagnosed with autism and began the diet before the age of two have lost their labels and no longer require special education. For children who started the diet at a later age, recovery is probably out of reach. Even so, dramatic improvement has been achieved after implementing a GF /CF diet. Parents around the world have reported significant changes in bowel function, behavior, attention, language and sociability once gluten and casein have cleared the system.

For a large number of autistic spectrum children. the diet seems to be a critical piece of the puzzle. For others, the results might be less dramatic. In a minority of cases, diet does not help at all. Screening usually shows vitamin. mineral and amino acid deficiencies in this population.  Spectrum children typically eat terribly unbalanced diets, often accepting fewer than five foods. We must improve their nutritional state if we are to see good results from any biological intervention. Amazingly, these notoriously picky eaters often will increase the number and type of foods they eat once gluten and casein have been removed.

The search for answers continues, but for now removing gluten and casein from the diet remains one of the safest, least invasive interventions available. Whether or not the diet will need to be life-long is still unclear. If scientists have correctly pinpointed the enzyme that is deficient, it may be possible to "fix" this problem in the future using supplementation or even gene therapy. If the metabolic problem is merely a symptom of a greater immunological dysfunction, it may be that the immune system can be healed.

Elaine Gottschall, BA, MSc

Two Views: Mother and Scientist

A Mother's View:

From 1952 to 1960, there seemed to be no answers to the series of health problems facing our child. There were periods of severe diarrhea, severe constipation, spontaneous nosebleeds, night-time seizures, failure to thrive, and, finally, the diagnosis of ulcerative colitis. The years of treatment with prednisone and sulfonamides, plus innumerable other medical approaches, had been unsuccessful and surgery seemed imminent. The prospect of the removal of an eight year old child's colon can be described, as one Mother said when faced with the same prospect, "'it was like every black cloud ever created was hovering over us." And then, it happened! An acquaintance pointed us to the office of Dr. Sidney Valentine Haas, a specialist practicing pediatrics in New York City. Ninety-two year old Dr. Haas placed our child on the Specific Carbohydrate Diet and within days, the neurological symptoms went, never to return, the colitis symptoms were completely gone in one year. She began to thrive leaving all the previous problems behind and making up for lost time.

How could a simple diet cure an "incurable disease?" The mystery haunted me and launched me on a "treasure hunt" through academia for the next 12 years.

A Scientist's View:

The pieces of the puzzle began falling into place during the process of integrating old and new findings in the science of digestion, immunology, nutritional biochemistry, microbiology, cellular biology , and histology.

Even as this odyssey progressed, discoveries were rapidly being reported in the medical literature. It became apparent that in those suffering with intestinal problems there is injury to the intestinal surface, specifically, to the digestive enzymes residing on the intestinal cells. This prevents the completion of digestion of most carbohydrates and some protein and, therefore, these undigested foods provide excess nutrition for the unseen world of intestinal microbes. Result: they overpopulate. Their increase in numbers results in an increase in fermentation. This results in: ( I) the production of an excess of short chain organic acids (thus lowering the pH of the colon); (2) an increase in the production of metabolic byproducts of fermentation as well as bacterial toxins; and (3) a possible mutation of some harmless bacteria into pathological forms.

Additionally, excess mucus production on the surface of the intestinal cells prevents further digestion and absorption of carbohydrates. The Specific Carbohydrate Diet, developed by Dr. Sidney v. Haas, provides an intervention to this vicious cycle by depriving intestinal microbes of their energy source while providing excellent nutrition to the patient. By providing a diet that contains predominantly "predigested" carbohydrates, the individual with an intestinal problem can be maximally nourished without over-stimulation of the intestinal microbial population.

Slides show biopsies taken from children, all with chronic diarrhea, (including soy-protein, milk protein, and gluten sensitivities). It can be seen that the intestinal mucosa has an increase in mucus covering in which colonies of microorganisms are found. There is increased cell shedding and turnover, damage to the intestinal microvilli, partial and complete villous atrophy, and resulting carbohydrate intolerance.

To summarize, the continual, indiscriminate feeding of indigestible, and, thereby, unabsorbable carbohydrates to individuals with chronic diarrhea ( with various diagnoses) can only perpetuate and exacerbate the problems.

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The Specific Carbohydrate Diet entered the world of autism through "the back door" -the intestinal tract. And what may have first appeared to be "the back door," via the digestive system, is rapidly becoming one of the most scientifically researched areas in determining what may be one of the underlying causes of many autism spectrum disorders.3 Because the Specific Carbohydrate Diet's goal is to heal the intestinal tract and to rid it of bacterial and fungal overgrowth, it is proving to be a very successful dietary intervention in treating many autistic children and leading them back to a life of normalcy.

Studies have revealed that eventually more than four hundred bacterial species live together in the human colon.4 The stomach and most of the small intestine does not normally harbor more than a sparse population of microbial flora. However, the number of microbes normally increases at the lowest part of the small intestinal, the ileum, because of its close proximity to the microbial-rich colon.

In the healthy intestinal tract, intestinal microbes appear to live in a state of balance; an overabundance of one type seems to be inhibited by the activities of other types. This competition between microbes prevents anyone type from overwhelming the body with its waste products or toxins. Another important protective factor which works to maintain the sparse bacterial population of the stomach and upper small intestine is the high acidity of the stomach' s hydrochloric acid in which microbes cannot usually survive. In addition, normal peristalsis (waves of involuntary muscular contractions) sweeps many microbes out of the intestine to be lost in the feces, thereby, decreasing their numbers.

However, bacterial overgrowth in the stomach and small intestine can and does increase in our children's ' intestines for various reasons among which are the following:

Coleman and Blass, in 1985, in The Journal of Developmental Disorders reported the first evidence that autism might be linked to carbohydrate digestion.22 These researchers reported that the syndrome of D-Iactic acidosis (D-Iactic acid is a byproduct of bacterial fermentation (the process by which microbes get energy from carbohydrates) was present in autistic children. Their work was based on reports of the 1970's and 1980's showing that undigested carbohydrates were being changed by bacterial action in the intestine to a substance, D-Iactic acid. High amounts of D-Iactic acid in the bloodstream have been found to cause bizarre behavioral symptoms. Among these symptoms were aggressiveness, sudden disorientation, blurred vision, blunted judgment, abusive behavior, slurred speech, staggering gait, rolling of the eyeballs, confusion, and delirium. The attacks lasted between 36 -60 hours. Using the most sophisticated methods of analysis, it was found that carbohydrates were not being digested or absorbed (in these cases, surgery had severely limited digestive capacity) and intestinal bacteria were, therefore, being flooded with a surplus of carbohydrates which were being fermented in the remaining intact intestinal tract. As a result, a waste product of bacterial fermentation, D-Iactic acid, was being produced in abnormally large amounts. It is currently thought that this acid, along with other toxic products produced by intestinal microbes, is entering the brain and "poisoning" the brain cells. It has been noted that this same type of malabsorption and the resulting production of D-Iactic acid occurs not only when there has been surgical shortening of the intestine but in other gastrointestinal disorders as well. 23

We are faced, then, with intestinal malfunctioning which involves microbial populations which have been altered in number, in kind, or both. The normal contractions (peristalsis) of the intestinal muscles are not able to remove them, they appear to be tenacious. Indeed, there is evidence that intestinal microbes will not cause disease unless they develop methods of adhering to the gut wall. Antibiotic therapy is of limited usefulness and has side effects if continued too long.

A sensible and harmless form of warfare on the aberrant population of intestinal microbes is to manipulate their energy (food) supply through diet. Most intestinal microbes require carbohydrates for energy 24 and the Specific Carbohydrate severely limits the availability of carbohydrates. By depriving intestinal microbes of their energy source, their numbers gradually decrease along with the waste products and toxins they produce.

In a healthy intestinal tract, the intestinal columnar cells form a barrier preventing contents of the gut lumen from entering the bloodstream until these contents (mainly undigested food) are thoroughly broken down by digestive enzymes. The columnar cells stand like "gatekeepers," tightly joined by desmosomes, in a Velcro-like fashion, preventing antigenic substances (such as incompletely digested proteins and bacterial toxins) from entering the underlying tissues of the intestinal mucosa, as well as the bloodstream, from passing through. However, it is believed that this tight barrier function is disru~ted by various agents among which are infectious agents such as bacteria, viruses, and protozoa. 5

It is thought by this author that if the bacterial overgrowth is corrected through diet, these leaky junctions will revert to normalcy thereby preventing the entrance of antigenic substances which trigger the adaptive immune system in abnormal ways.

It has also been suggested by recently published reports that bacterial toxins produced in the intestine can result in sensitivities to certain dietary protein.27,28 The researchers ask the question: "can the body's innate immune system, by reacting to the toxins of certain bacterial cell walls, cause the sensitivities to proteins such as casein and gluten?" The explanation for this interaction between bacterial overgrowth/toxins and the production of cytokines and antibodies, initiators of the inflammatory response is that there are two immune systems -the innate immune system and the adaptive immune system and that the innate immune system triggers the adaptive immune system.

Light microscopy, as well as enzyme assays (in vitro studies), .do not always demonstrate mucosal damage in the small intestine -mucosal damage that prevents the digestion of disaccharides and their ability to be transported into the bloodstream rather than to remain in the gut to over nourish intestinal flora.

Research has shown that in children diagnosed with chronic nonspecific diarrhea, gluten- sensitive enteropathy, milk protein-sensitive enteropathy, soy protein-sensitive enteropathy, protracted diarrhea of infancy, Giardiasis, cystic fibrosis, and Crohn' s disease there is marked damage to the mucosal surface of the small intestine bearing the disaccharidase enzymes. 28 This indicates that carbohydrate digestion cannot proceed normally in infants and children with these diagnosis and, very possibly, autism/digestive disturbances.

In spite of the fact that measurements of disaccharidase activities were normal in most mucosal specimens, oral tolerance tests with lactose and sucrose were always abnormal because of the decrease of mucosal digestive enzymes. Additionally, using the scanning electron microscope, it was apparent that there was colonization of the surface of the mucosa with a variety of microorganisms -often acknowledged in children with the contaminated small bowel seen in chronic non specific diarrhea.

The continual, indiscriminate feeding of indigestible, and, thereby, unabsorbable carbohydrates to individuals with chronic diarrhea can only perpetuate and exacerbate the problems.

1. Go, V.L. W. and W.H.J. Summerskill. 1971. Digestion, maldigestion, and the gastrointestinal hormones. American Journal ofClinical Nutrition. 24:160-167.

2. Gee, S. 1888. On the coeliac aflliction. St. Bartholomew Hospital Report 24: 17.

3. Ashwood, P., S.H. Murch, A. Anthony., A. A. Pellicer, F. Torrente, M.A. Thomson, J.A. Walker-Smith, and A.J. Wakefield. 2003. Intestinal lymphocyte populations in children with regressive autism: Evidence for extensive

mucosal immunopathology. Journal of Clinical Immunology 23(6):504-517.

4. Moore, W.E.C. and L. V. Holdeman. 1975. Discussion of current bacteriological investigations of the relationships between intestinal flora, diet, and colon cancer. Cancer Research 35:3418- 3420.

5. Plotkin, G.R. and K.J. Isselbacher. 1964. Secondary disaccharidase deficiency in adult celiac disease (non tropical sprue) and other malabsorption states. New England Journal ofMedicine. 271:1033-1037

6. Gracey, M.S. 1981. Nutrition, bacteria and the gut. British Medical Bulletin 37:71-75.

7. McEvoy, A., J. Dutton, and 0. F. W. James. 1983. Bacterial contamination of the small intestine is an important cause of occult malabsorption in the elderly. British Medical journal 287:789-793.

8. Dubos, R. 1962. The Unseen World. The Rockefeller Institute Press, New York.

9. Moog, F. 1981. The lining of the small intestine. Scientific American 245:154-176.

10. Prinsloo, J.G., W. Wittmann, H. Kruger, E. Freier. 1971. Lactose absorption and mucosal disaccharidases in convalescent pellagra and kwashiorkor children. Archives of Diseases of Childhood 46:474-478

II. Campos, J.V,M., U.F. Neto, F.R.S. Patricio, J. Wehba, A.A. Carvalho, and M. Shiner. 1979. Jejunal mucosa in marasmic children. Clinical, pathological, and fine structural evaluation of the effect of protein-energy malnutrition and environmental contamination. American Journal of Clinical Nutrition. 32:1575- 1591.

12. Lee, P.C. 2984. Transient carbohydrate malabsorption and intolerance in diarrhea disease of infancy. In Chronic Diarrhea of Children. Ed. E. Lebenthal. Nestle, Vevey/Raven Press, New York.

13. Poley, J. R. 1984. Ultrastructural topography of small bowel mucosa in chronic diarrhea in infants and children: Investigations with the scanning electron microscope. In Chronic Diarrhea in Children. Ed. E. Lebenthal. Nestle, Vevey/Raven Press, New York.

14. Dvorak, A.M., A.B. Connell, and G. R. Dickersin. 1979. Crohn's disease: A scanning electron microscopic study. Human Pathology 10:165-177. 18. Lee, P.C. 2984. Transient carbohydrate malabsorption and intolerance in diarrhea disease ofinfancy. In Chronic Diarrhea of Children. Ed. E. Lebentha1. Nestle, Vevey/Raven Press, New York.

15. Stephen, A.M. 1985. Effect of food on the intestinal microflora. In Food and the Gut. Eds. J.O. Hunter and V .A. Jones. Bai1here Tindall, London.

16. Stolbetg, L., R. Rolfe, N. Git1in, J. Merritt, L. Mann, Jr., J. Linder, and S. Finegold. 1982. D- lactic acidosis due to abnormal flora. The New England Journal ofMedicine 306: 1344-1348.

17. Perlmutter, D.H., J. T. Boyle, J.M. Campos, J.M Egler, and J.B. Watkins, 1983. D-lactic acidosis in children: an unusual metabolic complication of small bowel resection. The Journal of Pediatrics l02:234-23

18. Haan, E., G. Brown, A. Bankier, D. Mitchell, S. Hunt, J. Blakey, and G. Barnes. 1985. Severe illness caused by the products of bacterial metabolism in a child with a short gut. European Journal ofPediatrics 144:63-65.

19. Traube, M., J. Bock, and J.L. Boyer. 1982. D-lactic acidosis after jenunoileal bypass. The New England Journal of Medicine 307: 1027.

20. Mayne, A.J., D.J. Handy, MA. Preece, R.H. George, and I. W. Booth. 1990. Dietary management of D-lactic acidosis in short bowel syndrome. Archives of Diseases of Childhood 65:229-231.

21. Thurn, J.R., G.L. Pierpont, C. w. Ludvigsen, and J.H. Eckfeldt. 1985. D-Iactate encephalopathy. The American Journal ofMedicine 79:717-721.

22. Coleman, M. andJ.P. Blass. 1985. Autism and lactic acidosis. Journal of Autism and Developmental Disorders. 15:1-8.Four patients are described who have two coexistent syndromes: the behavioral syndrome of autism and the biochemical syndrome of lactic acidosis. One of the four patients also had hyperuricemia and hyperuricosuria. These patients raise the possibility that one subgroup of the autism syndrome may be associated with inborn errors of

carbohydrate metabolism. 23. Thurn, J.R., G.L. Pierpont, C. W Ludvigsen, and J.H. Eckfeldt. 1985. D-Iactate encephalopathy. The American Journal ofMedicine 79:717721

23. Salyers, A.A. 1979. Energy sources of major intestinal fermentative anaerobes. American Journal ofClinical Nutrition 32:158-163.

24. Lim, S.G. et al. 1993. Intestinal permeability and function in patients infected with human immunodeficiency virus. A comparison with coeliac disease. Scandinavian Journal of Gastroenterology 28:573-580.

25. Jyonouchi, H, S. Sun, and N. Itokazu. 2002. Innate immunity associated with inflammatory responses and cytokine production against common dietary proteins in patients with autism spectrum disorder. Neuropsychobiology 46:76-84.

26. illevitch, R.J. and P.S. Tobias. 1999. Recognition of gram-negative bacteria and endotoxin by the innate immune system. Current Opinions Immunology .11: 19-22.

27. Poley, J.R. 1984. illtrastructural topography of small bowel mucosa in chronic diarrhea in infants and children: Investigations with the scanning electron microscope. In Chronic Diarrhea in Children. Ed. E. Lebenthal. Nestle, Vevey/Raven Press, New York.