Gluten-Free Casein-Free Diet and Autism: Fact or Fad?

Introduction to Autism and the GFCF Diet

Autism, or classical autism, is the most severe form of Autism Spectrum Disorder (ASD) (National Institute of Neurological Disorders and Stroke, 2010). ASD is a group of complex neurological developmental disorders characterized by social impairments, communication difficulties, and restricted, repetitive, and stereotyped patterns of behavior. Milder forms within this spectrum include Asperger Syndrome, Rett syndrome, and unspecified childhood disintegrative disorder and pervasive developmental disorder. The spectrum occurs across all ethnic and socioeconomic classes and all age groups. Statistics indicate that 3–6 out of every 1,000 people will develop ASD, with the disorder occurring four times more frequently in males than in females (National Institute of Neurological Disorders and Stroke).

Statistics also suggest that 1 in every 110 Americans will develop autism, which is more than 90% heritable. There are pharmacological therapies for ASD, but up to 27% of parents are drawn to the promise and observed effects of the gluten-free, casein-free (GFCF) diet in reducing ASD symptoms in their children. Naturopathic doctors advocate its use as one of several complementary and alternative medicines (CAM). Autistic persons are believed to be gluten- and casein-sensitive, and these substances are thought to produce morphine-like effects that translate into the symptoms of autism. The rising popularity of the diet has motivated increased research. Recent studies suggest there is limited scientific evidence of its effectiveness; results are mixed, the diet helps some autistic persons but not all, it may lead to deficiencies in essential nutrients, and it is difficult and expensive to prepare. Some researchers consider it an outright fad treatment.

Researchers have noted that the broadening of diagnostic criteria and environmental factors explain an 8-fold increase in autism cases over the preceding decade (DeNoon, 2009). The increase was most prominent in California. Parents are also far more aware of the illness than they were a decade or more ago. Much of the autism research funding has been devoted to genetic studies and to identifying the environmental factors that make certain individuals genetically susceptible. Environmental changes under investigation include medications, reproductive technology, and everyday household substances such as soaps, shampoos, and toothpaste. Experts have expressed concern over the difficulty of testing for thousands of environmental exposures, some of which may no longer be detectable (DeNoon).

Autism is more than 90% heritable — a higher degree than nearly any other behaviorally defined neuropsychiatric disorder (Brkanac et al., 2008, p. 599). Rapidly advancing genomic technologies and large international collaborations have yielded significant insights into the molecular genetic causes of autism. Medications are currently under investigation for two single-gene disorders — fragile X syndrome and Rett syndrome — which are believed to capture many aspects of the autistic phenotype (Brkanac et al., pp. 600–603).

Present pharmacological treatment approaches to autism are largely drawn from those effective in addressing behavioral symptoms of other disorders (Brkanac et al., 2008, p. 604). Some drugs can reduce symptoms of aggression, irritability, and hyperactivity. The National Institute for Mental Health and the Research Units on Pediatric Psychopharmacology evaluated selected agents in managing behavior among autistic children. That evaluation led to the selection of risperidone as the first drug approved by the U.S. FDA for managing irritability in autism. The use of methylphenidate for both autism and ADHD symptoms was also confirmed (Brkanac et al., pp. 605–607).

Naturopathic Approach and the Rise of Dietary Interventions

Naturopathic physicians are those who uphold and practice beliefs rooted in vitalism (Atwood, 2003). Vitalism is a pre-20th-century belief that biological processes are in conflict with the physical and chemical principles of modern medicine. Naturopaths believe in the healing power of nature in treating disease. They aim to treat underlying causes rather than merely suppress symptoms — which they argue is what modern medicine does. They pursue holistic healing by boosting the immune system with herbs and homeopathic preparations. They claim knowledge in disease prevention that is unknown to, or disputed by, medical doctors, public health practitioners, nutritionists, and allied health professionals. Part of the naturopathic framework concerns the actions of toxins from synthetic medicines, allergies, imbalances of the Qi, and natural food substances such as gluten and casein (Atwood).

Naturopaths identify gluten and casein as factors behind ASD. Gluten is a natural protein found in wheat, rye, and barley, giving these grains their spongy texture (Geraghty & Marschner, 2008). Casein is another natural protein found in dairy products; it forms a gel during digestion, which accounts for the slow, sustained release of nutrients in the body. The belief is that autistic children are sensitive to these food substances, resulting in intestinal permeability — commonly called a "leaky gut." A leaky gut is thought to absorb gluten and casein before they are completely broken down. As a result, they produce large peptides that pass out of the intestines and into the bloodstream. These peptides behave as opiates in the body, and autistic children exhibit this opiate effect in their eye contact, social interactions, and behavior (Geraghty & Marschner).

Naturopathic doctors treat earaches, allergies, and medical problems using various complementary therapies intended to strengthen the body's natural life force (Atwood, 2003). Their treatments include enemas and fasting for "detoxification," hydrotherapy, homeopathy, acupuncture, chiropractic manipulation, aromatherapy, herbal remedies, rigid dietary regimens, and other "natural remedies." They also sell preparations related to these treatments to their clients at a profit (Atwood).

A licensed naturopathic physician (ND) holds a four-year, graduate-level naturopathic medical school education that covers the same basic sciences taught to a medical doctor (MD) (Atwood, 2003). However, an ND's theory and practice are not grounded in the same evidence-based knowledge accepted by the broader scientific community. The scope and quality of an ND's education does not adequately prepare them for comprehensive diagnoses and appropriate treatments. MDs contend that naturopathy should not replace conventional treatment methods, and they expect NDs to acknowledge that they do not possess either the medical training or the required scientific skepticism for the task. Instead, NDs often present themselves as primary care physicians despite having only a fraction of the primary care training that MDs receive. NDs may use homeopathy and other questionable and unproven methods to address medical conditions (Atwood).

Actress and author Jenny McCarthy described her ordeal and experience with her young son, autism, and the GFCF diet (Roberts et al., 2007). One doctor diagnosed her son Evan with epilepsy; a second said he had autism. The revelation also greatly affected her marriage. In a desperate search for solutions, she found a controversial approach on the internet in the form of a gluten-free and casein-free diet. She learned that many parents already believed that the protein content of wheat and dairy damages their children's brains. A pediatrician specializing in treating autistic children, Dr. Jerry Katzinel, said that the two substances act like morphine in autistic children, making them lethargic or giddy after consuming foods containing these substances. Jenny immediately placed her son on the diet and was amazed by the results. Evan began to speak, communicate, and make eye contact. After two and a half years of combination therapy — which included medication, daily therapy, the GFCF diet, and supplements — Evan could engage in full conversation. Despite the lack of strong evidence on the merits of the diet, parents of autistic children like Jenny stand by its benefits, while medical experts remain skeptical (Roberts et al.).

Biological Mechanism: How Gluten and Casein May Affect Autism

The mechanism of gluten toxicity is best explained through a condition called gluten-sensitive enteropathy, or celiac disease (Department of Pediatrics Staff, 2010). This is an inflammatory condition of the intestines that develops in response to small peptides from incompletely digested large gluten molecules. In celiac disease, a small peptide can cross the intestinal microvillus border. When processed by a transglutaminase enzyme, it can interact with immunological cells and produce cytotoxic inflammation. In autism, it is believed that peptides from gluten and casein cross the intestinal microvillus barrier and enter the bloodstream. They also cross the blood-brain barrier. In the brain, certain amino acid sequences of these peptides compete with natural peptides that bind to opioid receptors — G-protein receptors on the cell membrane surfaces of neurons. Binding to these receptors disturbs neuronal function and may ultimately contribute to autism (Department of Pediatrics Staff).

Dr. Paul Nash, a nutritional wellness practitioner, has argued that the body appears not to completely break down gluten and casein (Santanielli, 2008). He and other doctors who share this view believe that these substances can alter the thinking and behavior of autistic children. They draw support from laboratory experiments on animals that exhibited behaviors similar to autism and schizophrenia following exposure to these substances. Medical doctors, on the other hand, remain hesitant to accept that a change in diet can change children's behavior (Santanielli).

Dr. Bryan Jepson, a biomedical expert on autism at the Thoughtful House Center for Children in Texas, reported that 60–70% of his patients showed positive responses to the diet (Santanielli, 2008). Medical doctors typically warn parents that the diet is an expensive option offering only false hope. Nevertheless, parents continue to be drawn to practitioners like Dr. Jepson. Penni Ruben, director of Lakewinds Natural Foods, offers wheat-free, gluten-free, yeast-free, and dairy-free foods in response to customer demand, and also hosts cooking classes for parents wishing to learn how to prepare such foods. His wife, Janette, acknowledges that the diet is hard to prepare and expensive — costing $100 or more per month — but considers it a form of food therapy that can help an autistic child's body and mind function better (Santanielli).

Gluten is a problem only to those who are gluten-sensitive, such as many autistic individuals (Woeller, 2010). The substance is most commonly found in wheat, the predominant ingredient in bread, pasta, and baked goods. Hybridization has significantly raised the amount of gluten in modern wheat compared to a century ago, accompanied by a cultural preference for the doughy texture that high-gluten wheat provides (Woeller).

Gluten has already been associated with skin disorders, autoimmune disease, digestive disorders, and neurological disorders (Woeller, 2010). It promotes inflammation in the gut and in other body systems — problems that are common among autistic children. Gluten can also predispose individuals to food allergies by damaging the lining of the intestines. In a gluten-sensitive child, the finger-like projections called villi become flattened due to an inability to produce the enzymes needed for digestion. This results in malabsorption, nutrient deficiency, and food allergies. Inadequate breakdown and poor absorption of food particles intensify food allergies. Autism doctors believe this process underlies many cognitive symptoms in autistic people, including language problems, poor attention, and self-stimulatory behavior. Gluten proteins may interfere with the action of brain chemicals. Behavioral problems such as aggression, self-injury, and tantrums have also been associated with gluten sensitivity in autism (Woeller).

Autism doctors suggest that parents who suspect their child is gluten-sensitive or who notice unexplained chronic symptoms eliminate gluten from the child's meals for three to four months and observe the results (Woeller, 2010). If the child's condition improves, parents may have identified a specific sensitivity. Gluten-free grains such as rice, millet, buckwheat, and corn are available alternatives (Woeller).

Scientific Evidence: Studies For and Against the GFCF Diet

UK researchers investigated more than 30 scientific articles on the effectiveness of the GFCF diet in autistic children (Bastian, 2004). They found only one that provided reliable scientific evidence that the diet works. That particular study, however, was conducted on only 20 children aged 5–10 who had elevated levels of protein in their urine. When placed on the diet, these children exhibited reduced autistic traits. The prevailing conclusion was the need for more and larger randomized trials to support the result (Bastian).

Autistic traits examined in that research included verbal and non-verbal communication, speaking when spoken to, lack of eye contact, repetitive talk and movement, and a failure to share emotions (Bastian, 2004). The researchers noted the difficulty of removing gluten and casein proteins from children's diets, as these substances are found in wheat, most cereals, and dairy products. They also noted that children could suffer withdrawal symptoms if the substances were removed. Parents were advised to seek stronger evidence before making the difficult lifestyle change required by the diet. They were encouraged to consult resources such as Informed Health Online for accurate information (Bastian).

These researchers also performed the 2002 Cochrane Review, using the Danish Instrument for Measuring Autistic Traits, which covered social contact and ritualized behaviors (Geraghty & Marschner, 2008). A follow-up review in 2006 found no significant benefit derived from the diet in treating ASD. A more recent study found that boys aged 5–6 with ASD had significantly thinner bones than those without the disorder, and boys on casein-free diets were found to have bones twice as thin as those on minimally restricted diets. Parents were advised to carefully consider how much of their child's current intake consists of gluten- and casein-containing foods, as many essential nutrients — including protein from dairy, calcium, Vitamin D, B vitamins, and iron — would be lost. Parents who choose to adopt the diet plan should also provide their children with a multivitamin-mineral supplement and an additional calcium and Vitamin D supplement, and should consult a registered dietitian before implementation (Geraghty & Marschner).

The GFCF diet first gained widespread attention when used to treat celiac disease, a condition in which the body is unable to digest gluten properly, leading to intestinal injury (Sodergren, 2008). It gained further popularity with the emergence of lactose intolerance, food allergy, and acid reflux. However, its popularity has not been sustained at the same level when applied to autism, ADHD, and other developmental or learning disabilities. Not only are these conditions unrelated to digestion, but the treatment is also typically administered to children — some parents even place toddlers on it. In removing gluten and casein, parents also eliminate corn, soy, sugar, food dyes, and artificial additives. The central question has been how food can affect autism, which is fundamentally a neurobiological problem in the brain. Researchers at the Autism Center at Children's Hospital of Pittsburgh have explained that gluten and casein break down into morphine-like products when consumed, and that autistic individuals have inflamed intestines that cannot expel these substances effectively (Sodergren).

Director Cynthia Johnson of that Center stated that the diet helps a subgroup of children with autism, though it does not work for all of them (Sodergren, 2008). She and her team studied 36 autistic children's skills and behaviors while on the diet or on Omega-3 supplements. Implementing the diet is not simple — it eliminates chicken nuggets, macaroni and cheese, chocolate milk, and desserts, which causes many families to abandon it. Dr. Johnson formed parent support groups for families who withdrew from the diet. However, families that observed rapid changes in their children after starting the diet maintained that it works. One child was able to visit an amusement park and speak after only a few days off milk. Another child progressed from using fewer words to speaking three-word sentences within a month on the diet. Within a single day, one previously silent child began making vocalizations and showed marked improvement in alertness (Sodergren).

The diet does not appear to work for all families (Sodergren, 2008). Some families are unable to remove every trace of gluten and casein from their autistic children's food. Others report that the diet does not work at all, even those who initially saw dramatic changes. Families that travel frequently find it especially difficult to maintain the diet. Some families placed their child on the diet but discontinued it before the child entered kindergarten. A few families who had experienced positive results found that their child's behavior deteriorated once the diet was stopped. Nonetheless, most families felt it was worth trying. One mother noted that diet has a significant impact on anyone's health, making the controversial approach worth exploring (Sodergren).

Autism remains a mystery, though a combination of genetic and environmental factors is believed to be responsible (Shukla, 2010). Current approaches include educational programs, medications, and special diets. Parents are willing to try almost anything in search of a cure, but studies on the effectiveness of the GFCF diet have yielded mixed results. Not only is the diet difficult and expensive to prepare — there is also no guarantee that a child will receive all needed nutrients while on it (Shukla).

A review of electronic databases was conducted to determine the efficacy of gluten- and casein-free diets as an intervention treatment for autistic individuals (Millward et al., 2008). The databases included the Cochrane Library Issue 2 of 2007, MEDLINE from 1966 to April 2007, ERIC from 1965 to 2007, LILACS from 1982 to April 2007, and the National Research Register of 2007. The review sought all randomized controlled trials in which gluten and/or casein were removed from the diets of autistic individuals. It found that the trials did not share common outcome measures and, therefore, did not permit meta-analysis. Only three significant treatments showed positive effects of dietary intervention on overall autistic traits — specifically social isolation and overall ability to communicate and interact. The research revealed high rates of CAM therapy use for autistic children, including GFCF diets, but current evidence of efficacy was deemed poor, requiring more, larger, and better-designed randomized controlled trials (Millward et al.).

The review was prompted by rising incidence of diet use stemming from the contention that gluten and casein peptides produce excessive opioid activity in autistic individuals (Millward et al., 2008). The extensive search for evidence from randomized controlled trials found only three papers reporting on two such trials. The first trial had 10 participants and the second had 15. The first trial's results indicated that a combined gluten- and casein-free diet reduced autistic traits. The second trial yielded no significant difference in outcomes between the diet group and the control group. Neither study recorded adverse outcomes or potential harm (Millward et al.).

The research also noted that CAM therapies, including GFCF diets, are widely used by parents of autistic children, despite the lack of scientific evidence to support them as effective interventions and the absence of research into their potential harms (Millward et al.).

Many parents of autistic children want to know whether the diet actually works (WebMD, 2010). Some of these children are allergic or sensitive to gluten or casein and seek allergy confirmation. Despite negative allergy findings, many parents still opt to place their autistic children on the GFCF diet because of observed improvements in speech and behavior. The theory holds that autistic individuals process gluten and casein differently from non-autistic individuals, and that gluten and casein exacerbate autistic symptoms because the brain treats these proteins as opiate-like chemicals. As a result, autistic individuals may act in abnormal ways. Researchers have found that autistic individuals do have abnormal levels of peptides in their body fluids. However, the effectiveness of the diet remains unproven and requires substantiation from randomized clinical trials. Current data reflect a lack of scientific evidence, and no definitive conclusions about whether the diet is helpful or harmful can be drawn (WebMD).

Eliminating these proteins from food sources has also been shown to be difficult and expensive (WebMD, 2010). Many natural and healthful foods contain gluten or casein. Many stores have responded to increasing demand by offering gluten-free foods in dedicated sections. An autistic child or person on the GFCF diet should receive supplements of fiber, vitamins, and minerals to compensate for those eliminated by the diet. Casein is present not only in dairy products but also in many dairy-free and lactose-free foods, as well as many soy and dairy-like products. Calcium and Vitamin D supplements should be given to those on the casein-free diet (WebMD).

Researchers at a symposium entitled "Outrageous Developmental Disabilities Treatments" stated that there was insufficient scientific evidence to warrant the effectiveness of the GFCF diet (Busko, 2007). The symposium was part of the 115th Annual Convention of the American Psychological Association in San Francisco. The researchers noted that the incidence of autism had increased by over 200% between 1987 and 1998 alone. Treatments correspondingly grew to hundreds of different types. Parents of autistic children try an average of seven of these, according to a survey of 552 members of the Autism Society of America. Symposium chairman James Mulick attributed the rise in case numbers to better diagnoses and the broadening of the range of similar disorders. Early behavioral interventions often produce positive outcomes for autism, such as highly structured one-on-one behavioral approaches of up to 40 hours per week over many years. The expense and difficulty of obtaining such interventions could lead many parents to seek alternative forms of treatment (Busko).

Presenter Tracy Kettering reported on the more popular fad treatments for autism (Busko, 2007). Three small but well-designed studies on the combination of Vitamin B6 and magnesium found the treatment ineffective. Two studies on the GFCF diet showed no improvement in autism symptoms. Other interventions studied included secretin, holding therapy, animal therapy, and hyperbaric oxygen therapy; none of these proved effective. Dr. Mulick commented that fad treatments such as these can even be harmful. Chelation therapy, for example — involving medicines to control mercury levels in the body — resulted in the death of at least one autistic boy (Busko).

Dr. Mulick also suggested that fad treatments have become popular because parents seek them before their children's symptoms worsen (Busko, 2007). When symptoms then disappear or improve for other reasons, parents credit the fad therapy. He noted that autism studies take considerable time and expense to conduct, meaning that some current fad treatments will never be rigorously tested — making them potentially dangerous to use (Busko).