The GF/CF Diet for Autism

By Lisa Lewis, Ph.D

Used with permission from

Not long ago, I questioned something my doctor was about to do because it seemed unnecessary. He gave a wry smile and replied, “At Johns Hopkins I learned not to let common sense stand in the way of medical dogma.”

My doctor was, of course, being facetious. Unfortunately, many doctors actually do fail to let their own observations and logic override what is the accepted and standard medical paradigm in which they were trained.

Historically, this tendency has had devastating effects on the families of children diagnosed with autism. For the first twenty years after this complex disorder was described, it was attributed to bad mothering. It was not until the mid-sixties that psychiatrists finally loosened their grip on the diagnosis and acknowledged that the disorder has biological and not psychological origins. The blame was shifted from “refrigerator mothers” to an unknown genetic defect buried deep in the biochemistry of the brain.

This is now the accepted medical dogma, and the current medical paradigm suggests no possibility for improvement, let alone recovery. But, fortunately, this dismal “no hope” view is changing – ever so slowly. The long overdue shift corresponds with the explosion in the number of cases of autism diagnosed all over the country.

Autism used to be considered a rare disorder. When our son, Sam, was diagnosed in 1991, the incidence was approximately 1 in 5,000. Now the rates are closer to 1 in 500. This means that doctors who treated patients for years with-out 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 avail-able 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.

The Addicted Child
As early as 1979, researcher Jaak Panksepp noted the similarity between characteristics of autistic children and the effects of endorphins (naturally occurring substances) and opiate drugs (see sidebar). Intrigued by Panksepp’s observation, Norwegian physician 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.

Not only did Reichelt find very elevated urinary peptides, his work was later replicated by Paul Shattock in England and then by American Robert Cade. Reichelt began recommending the removal of gluten and casein from the diets of these children as early as 1981. Shattock and his colleagues at England’s University of Sunderland wrote extensively on their findings throughout the 1990’s, and in 2000 American Robert Cade published similar findings in the United States.

These findings led to the “opioid excess theory” of autism. 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 bro-ken 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. 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 peptides 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.

In 1998, a researcher at Johnson & Johnson decided to see if he, too, could find the elevated urinary peptides. The father of an autistic child who recovered after restricting dietary protein intake, Alan Friedman was using equipment far more sensitive than previous researchers could access in their university-funded laboratories. In addition to verifying the presence of opioid peptides in the urine of autistic children, Friedman also found another extremely unusual compound. Identified as dermorphin, this chemical is a hallucinogenic far more powerful than LSD. No wonder so many autistic children seem as if they are on a ‘bad trip!’

Friedman theorized that an impaired or insufficient production of a particular protein might be the cause for underlying metabolic defects found in these kids. This protein, dipeptidyl peptidase IV, has many functions in the body. It is involved in the immune system because it signals lymphocytes to reproduce themselves. It is the protein that breaks down opioids. It has been suggested that the mercury preservatives found in several required childhood vaccinations have inhibited the enzyme.

Tummy Troubles
Recently, several pediatric gastroenterologists in England have begun a serious study of 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. Just this year, these 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 is common, and this lends further support to the theory that opioid peptides are involved.

Fortunately, there are 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.

In 2001, Dr. Ted Kniker from the San Antonio Autistic Treatment Center began a small study (n=28.) Because his subjects were in residential treatment, he was able to control their dietary intake. Kniker and the study team collected baseline data that included medical histories and urine peptide profiles. The Autism Treatment Evaluation Checklist was filled out for each subject, and behavioral information was collected. During the first phase of the experiment, milk and dairy and grain products were eliminated from the diet for three months. After three months, data collection was repeated. Dr. Kniker explained that ten of the 28 participants changed dramatically. Five others deteriorated, but Kniker explained that “the deterioration experienced…may be explained if the removal of these foods unmasked negative effects of other foods that they may not ordinarily consume.” Because dietary responders are so often allergic to other foods, this is not a very surprising finding.

Kniker is continuing his study, and other studies of dietary intervention are also underway. It is generally accepted that the younger the child when intervention is started, the more dramatic the result. It is therefore encouraging to note that Kniker saw dramatic results in so many of his subjects, none of whom were small children.

While this research supports the importance of the link between behavior and bowel dysfunction, it is still impossible to know whether the bowel problems are a primary cause of autistic traits or symptomatic of a broader immunological dysfunction. We do know that removal of gluten and casein often leads to formed stools in children who have had chronic diarrhea for one or more years. For many parents, relief of this symptom alone makes the diet worth the trouble.

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.

Where Are We Now?
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 percent-age 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. For now, our children join the ranks of celiacs and other gluten-intolerant people and do their best while “living without.”

The Yeast Connection
As if the situation were not complicated enough, it turns out that many people with autism are infected with Candida albicans. Why? The gut has a living environment, or flora, of microorganisms. Yeast is but one organism that lives in the gut. A healthy immune system keeps the various organisms in balance, but an infection occurs when the balance is thrown off and the yeast population dominates other flora residents.

This can happen any time the immune system is depressed, either through ill-ness or because a person is taking antibiotic medication for a bacterial infection. A person may be genetically predisposed to improper immune responses, and there is also evidence that the immune system is being damaged by an environmental toxin. For whatever reason, any time a bacteria, fungus or parasite dominates the intestinal flora, “gut dysbiosis” results.

According to chemist William Shaw, the waste products excreted by excessive yeast may be absorbed from the gut and wreak havoc on the brain by mimicking neurotransmitters. Further, yeast infections can damage the muccosal lining of the gut and lead to increased permeability. Of even greater concern is the ease with which yeast can become systemic and perhaps increase the permeability of the blood brain barrier.

When yeast is a problem, the diet must be restricted even further. In addition to removing gluten and casein, all sources of sugar must be avoided, because yeast feeds on sugar. Fermented and potentially moldy foods must also be restricted. Often a non-systemic antifungal medication, such as Nystatin, is used, but for extremely persistent yeast infections, doctors often must prescribe stronger medications.

Fortunately, yeast infections can usually be cleared up within a few months. Many children on the autistic spectrum have shown great improvement in bowel and behavioral symptoms once yeast infections are cured.

Autistic or Addicted?
Autistic children have many traits in common with people addicted to opioid drugs, including:

Self absorption – being in one’s own world

Inappropriate affect – giggling, crying for no reason

Stereotyped behavior – rocking, “stimming” – slang for certain behaviors that include hand flap-ping, finger movement, vocalizations or other actions that are used repetitively for soothing or self-stimulation.

Bizarre preoccupations

Gastrointestinal problems

Insensitivity to pain
When addicts go off drugs, withdrawal can be intense and includes physical symptoms and well as emotional pain.

Parents often report similar withdrawal when children go off gluten and casein. Behavioral regressions can be severe, as can physical symptoms. Parents have reported fevers, diarrhea and vomiting when the children have gone “cold turkey.” For this reason, it’s advisable to remove the foods gradually over a period of a few weeks. Even with a gradual removal of these proteins, parents often report an immediate improvement for a few days, followed by a very difficult period. In very young children, the negative effects usually pass within a week. For older children and adults, withdrawal can last from ten days to three

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