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The Gluten and Casein Free Diet


A Dietary Approach for the Treatment of Autism


Allyson Giangiulio




Autism: Background Information


Autism is a developmental disability which is usually first diagnosed in children between the ages of one and three. Autism is thought to affect over 1.5 million people in the U.S. alone and is rising at a rate of 10-17 percent per year. It is the third most common developmental disorder. It is more common than childhood cancer, and occurs in 1 out of every 500 births. It is more pervasive in boys, for reasons which are unknown, and occurs in a ratio of 5 boys for every girl (, ( Autism is characterized by social and communication skills impairment. Autism is a spectrum disorder and thus occurs within a wide range of severity. While there are behaviors common to autism, the amount, combination, and severity of these behaviors can be manifested in a number of ways depending on the severity of the disability. Some common characteristics of autism are: little or no eye contact, lack of affection, unresponsive to own name, difficulty learning language, little or no verbal communication, repetition of words, using hands instead of verbal communication, rocking, spinning of objects, no interest in other kids, repetitive play for long periods of time, resistance to change, aggression toward self or others, no real fear, either more or less sensitivity with all five senses. (, (



While the cause is still unknown, it is thought that Autism results from brain abnormalities. It is not clear whether these abnormalities result from genetic, medical, environmental, or pregnancy problems. It is known, however, that autism is not a psychological disorder, but instead is something that children are either born with or born with the potential to develop.


There is no known or proven cure for autism, however there are many experimental treatments currently being practiced, including special education interventions, treatments targeting behavior and communication, as well as medical, and dietary approaches. One such dietary approach has been gaining a great deal of attention over the last few years. The gluten and casein free diet while still largely experimental, and has not yet been accepted by the medical community. However anecdotal reports and new research indicate that the gluten and casein free can have a large impact on the behavior and overall quality of life of people with autism. The diet has caused a lot of attention especially in the United Kingdom and the United States. Evidence is still largely anecdotal, however it appears as though restricting the diet of an autistic person can have the potential to reduce the symptoms of autism and in some cases “cure” the disability (, (



The Gluten and Casein Free Diet: How it Works

The gluten and casein free diet works by eliminating the foods that contain the proteins of gluten and casein which act as opiates in the central nervous systems of people with autism (


Gluten and Casein

Gluten and casein are similar proteins which are found in food products. Gluten is found mostly in wheat, oat, rye, barley, spelt, kamut, tritacale, and semolina, and other grass foods. It can also be found in other grains, food starches, flavorings, artificial colorings, malt, and some vinegar. Casein is a protein found in milk and milk products such as yogurt, cheese, ice cream, butter, some margarine. Casein is also sometimes added to other food products which do not contain milk. It is thought that these proteins work as a sort of toxin in the bodies of some children and thus cause autism. (


‘Leaky Gut’

This toxicity occurs due to a ‘leaky gut’ common to autistics. The term ‘leaky gut’ refers to small holes in the intestinal tract through which proteins such as gluten and casein could probably leak. The cause of such a leaky gut is unknown; however, it is thought that it might be caused by genetic or environmental toxins combined with a trigger of some sort. Possible triggers may be a virus, a vaccine, yeast infection, or a reduction in phenol sulfur transferase, which lines and protects the intestinal tract. It is theorized that some people with autism cannot completely digest these gluten and casein proteins, and in fact, autistics are found to have higher levels of these proteins than an average healthy person. When gluten and casein are not completely digested, they act like opiates (opium or other narcotics) in a person’s body. In addition, because of the ‘leaky gut’ the proteins are able to leak out into the bloodstream and into the brain. This would explain the seemingly distorted perceptions, behaviors, and responses of autistic children. In fact, they may be manifesting characteristics of being on an opiate drug- like substance. In addition to this it has also been found that there is a chemical compound called dermorphin in autistics. Dermorphin is a drug like chemical which causes greater hallucinations than LSD. Therefore, being autistic may be very similar to being on heavy drugs. It is thus thought that removing foods which contain casein and gluten from an autistic’s diet will remedy most if not all of the autistic characteristics, as it will remove the drug like substances in their body and brain (, (


Support for this theory comes from the gluten and casein peptide levels being found in children’s urine. This theory would also explain why children with autism develop normally during the first year of life. Children are not usually diagnosed with autism until they are at least 1 year of age. It isn’t until around this age that children typically begin consuming diets which contain gluten and casein. 



Does It Really Work 


Support and Evidence Found Online


 It is thus thought that removing foods which contain casein and gluten from an autistic’s diet will remedy most if not all of the autistic characteristics. And in fact, this is what largely has been found as indicated by online sources. Most of the evidence of the diet’s effectiveness is anecdotal and thus not scientific. However, those anecdotes of parents who have put their autistic child on the diet claim that it not only remedies some of the autistic symptoms, but in some cases even “cures” their child. It is important to note, however, that some families have found no positive results with the diet. Though, not every autistic is found to have elevated levels of the proteins and levels of opiate like substances. Most of the anecdotal evidence found online does indicate at least some improvement. Parents and caregivers have been implementing the gluten/casein free diet for over twenty years; however, because there was little to no scientific research on the diet years ago, it has been slow to catch on, and only has done so through word of mouth. The treatment has not yet been accepted by the medical community, and thus doctors do not typically recommend the diet. However, this diet as a form of treatment has gotten much attention in the past few years, and there are now a number of studies and research projects done and being done on the effectiveness of removing casein and gluten in order to improve the conditions of autistics (  The GFCF diet is now quickly becoming noticed and more accepted by the medical community. 



Support and Evidence found in Professional and Scientific Journals: A Literature Review


While the gluten and casein free diet is still not accepted by the medical community, there have been a number of studies which support the claim that the diet can be used to treat autism. One review indicates that there had been published studies on the diet dating back twelve years prior to their study in 2001. The researchers claim that of those studies, only one did not report positive results from the GFCF diet (Knivsberg, Reichelt , Nodland 2001). More recent studies over the past few years indicate similar results. Knivsberg et al. more recently performed a single blind control study with randomized diet and control groups. It was found that those children on the GFCF diet developed significantly better than those not on the diet (Knivsberg, Reichelt, Hoien, Nodland ,2002).


There have also been some studies on the specific short and long term effects of the diet. One study monitored children on the gluten free diet over 5 months. They found improvements in behavior over this time; however they did not see a reduction of peptide levels in the urine (Whiteley, Rodgers, Savory, Shattock, 1999). Another study found that the urine and peptide levels were normal after one year of being on the diet, and that the children’s behavior and skills had improved. When the children were tested four years after they had begun the diet, they were still found to be improving (Knivsberg, Reichelt, Nodland, Hoien, 1995). A study by Lucarelli et al. indicates that the removal of even one type of problem food, in this case milk, can have a positive impact. When milk (which contains casein) was removed from the diet of infants with autism, the infants exhibited noticeable behavioral improvement within 8 weeks of the onset of the diet (Lucarelli, Frediani, Zingoni, 1995). On the contrary, a lack of support for the diet was found in a study done by Sponheim. Seven children with autism were tested to see if they benefited from the gluten and casein diet. It was found that there were no improvements in behavior when the children were placed on the diet for 6 months. In addition, they found the diet to further socially isolate the children and their families (Sponheim, 1991).


Evidence for the opiate theory of gluten and casein can also be found in the literature. One study tested the urine of children who had improved on the GFCF diet and found that there was a decrease in the peptides in the children. They thus concluded that opiate like peptides are from the diet.  Another study found that parents report that their children have “withdrawal” like symptoms when placed on the gluten and casein diet (Whitely, Rogers, Shattock, 2000). Contrary to these studies, however, a review done by Cocchi in 1996 argues against the theory of opiods being the cause of autistic symptoms. After a review of previous literature, it was found that not all children respond to the GFCF diet. It is thus argued that opiods might play a secondary role and may be linked to the “stress of the illness”, but that they are not connected strongly enough to autistic symptoms to indicate a causal link (Cocchi, 1996)


In addition to the scientific support for the diet, one study was performed to test whether children on the GFCF diet were getting enough nutrients on such a restricted diet. Results indicate that those children on the diet are no less healthy than individuals not on the diet, and that they are not lacking any nutrients. In fact, it was found that those children on the diet consumed more fruit and vegetables than those children not on the diet. Further, the kids in the non-diet group were below the Lower Reference Nutrient Intake for more nutrients than the kids who were on the diet. No significant differences were found between the groups (Cornish, 2002).


Overall, most of the scientific literature which can be found (there are a number of studies in different languages) indicates that there is an overwhelming support for the GFCF diet as a treatment to reduce autistic symptoms. There are a few researchers which seem to dominate the literature and research on this topic. Some of the most influential include Dohan, Reichelt, Shattock, Cade ( . It is important to note, however, that most of the studies have extremely small sample sizes. There are many single case studies; and most of the studies of larger samples seem to have fewer than 50 subjects (including healthy controls). Therefore, it is hard to generalize findings across the autistic population.


Is the Gluten and Casein Diet Right For Every Child?


Testing for Gluten and Casein Peptides

Gluten and casein digestive problems may not be the reason for a child’s autism. In fact, not all autistics have been found to have opiates in their urine. There are tests that parents can have done in order to see if there are opiate peptides in the child’s urine. However, caution is advised when choosing to test a child. There have been reported incidents of false tests. Sometimes tests do not reveal signs of the peptides. Some families have been made aware of extremely high levels of the opiates only after testing was performed by a second lab. Most online sources report that the best test is to try the gluten and casein free diet (



Parents’ Evaluations and Warnings

Some parents argue that the GFCF diet is an inexpensive, harmless approach, and that it is compatible with any other form of treatment. In addition the effects are immediate and there are no known negative effects. Other parents and sources note that implementing the diet can be a somewhat complex and daunting task. It can be especially hard to learn about the contents of foods, especially those with hidden gluten and casein ingredients, and even the contents of one’s own ingredients. Certain food products must be purchased and often are more costly than more common foods. One must also adopt new recipes and sources for cooking. Much research must be done, and sites claim it is necessary to buy informational books as well as special gluten/casein free cookbooks.  It can also be difficult at times to get skeptical relatives, teachers, and other caregivers to strictly abide to the rules of the diet when the child is in their care. Any slip up can have negative effects and cause autistic characteristics to return. It is also important to note that even though children show improvements very quickly often times the children appear to get worse for a period of time as well. Behavioral problems and physical problems such as fever, diarrhea, and vomiting have been reported, especially when the diet is implemented suddenly. This may be due to a sort of withdrawal effect, similar to that of drug addicts. Thus, the sites promoting the GFCF diet advise that foods be removed gradually (  Even with the gradual removal of foods parents should expect immediate noticeable improvements for a few days followed by a period of regression. This hard period is said to pass within a week for younger children and within three weeks for older children and adults.  Even those parents who warn that implementing the diet can be a daunting task, though, also claim that it is worth any hardships for the benefits it provides for their child and their family.



Works Cited


Cocchi, Renato. (1996). On gluten free and casein free diet in autism and the opiods’ excess theory: Another perspective. Italian Journal of Intellective Impairment, 9, 139-152.


Cornish, E. (2002). Gluten and casein free diets in autism: A study of the effects on food choice and nutrition. Journal of Human Nutrition and Diuretics, 15, 261.


Knivsberg, A.M., Reichelt, K.L., Nodland, M., Hoien, T. (1995) Autistic syndromes and diet. A four year follow-up study. Scandinavian Journal of Education Research, 39, 223-236.


Knivsberg, A.M., Reichelt, K.L., Nodland, M. (2001). Reports on dietary intervention in autistic disorders. Nutritional Nueroscience,4,25-37.


Knivsberg, AM., Reichelt, K.L., Hoien, T. Nodland, M. (2002) A randomized, controlled study of dietary intervention in autistic syndromes. Nutritional Nueroscience, 5, 251-61.



Lucarelli, S., Frediani, T., Zingoni, A.M. (1995). Food allergy and infantile autism. Panminerva Medicine, 37, 137-41.


Sponheim, E. (1991). [Gluten-free diet in infantile autism. A therapeutic trial] [Article in Norwegian] Tidsskr Nor Laegeforen, 111, 704-7



Whiteley, P., Rodgers, J., Savory, D., Shattock, P. (1999) A gluten-free diet as an intervention for autism and associated spectrum disorders: Preliminary findings. Autism, 3, 45-65.


Whiteley, P., Rogers, J., Shattock, P. (2000). MMR and autism. Autism, 4, 207-211.





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