GFCF Diet – Research

How can a change of diet help a child with special needs? Many decades ago, the medical establishment viewed disorders such as autism as psychological conditions potentially caused by deficient parenting. More recently it was accepted that autism has a strong genetic basis. Currently there is a growing body of research on the biological manifestations of autism, for instance seeking to identify biomarkers for autism which would have important implication for both diagnosis and treatment (1). Children on the autistic spectrum have been found to display a range of atypical characteristics, for example in several areas of brain structure and function. Children with autism also appear to have a predisposition to certain health problems, such as gastrointestinal and bowel health disorders. Bearing in mind the atypical health profile of many children with autism – and indeed other special needs – it is perhaps less surprising that a special diet could be beneficial.

In fact, there is strong empirical evidence that the GFCF diet has been beneficial to many children. Parents of children on the autistic spectrum rate the GFCF diet very highly in comparison to other interventions. In a 2009 survey of the Autism Research Institute, 69% of parents who tried the GFCF diet with their child found responded that their child “got better” on the diet (2). Similarly, researchers from Penn State published findings in 2012 showing that a gluten free, casein free diet could lead to improvements in behavior and physiological symptoms in some children diagnosed with an autism spectrum disorder, in a study based on survey data from parents (3).

The reasons why the GFCF diet is effective are not conclusively understood and for this reason the GFCF diet is still considered controversial in some circles. The main theory behind the GFCF diet, first postulated by Dr Karl Reichelt in the 1980s, is that due to gastrointestinal issues, some children suffer damage to their intestinal tract which becomes too permeable, causing what is known as “leaky gut”. Peptides from poorly digested proteins in wheat and dairy foods are thus able to cross the leaky intestinal wall and travel through the bloodstream to the brain. Because these peptides have a chemical structure similar to opiates, it is suggested that they attach to opiate receptors in the brain, interfering with normal brain function. Dr Reichelt found higher than normal levels of the peptides derives from gluten and casein in the urine of children on the autistic spectrum, and postulated that removing the dietary sources of of the gluten and casein peptides from a child’s diet could improve the child’s symptoms.

Another theory behind the success of the GFCF diet is based on the observation that some children on the autistic spectrum have an abnormal immune response to gluten and dairy. There are various ongoing research efforts based on these and other theories and it can be hoped that the reasons why the GFCF diet can improve the well-being of some children with special needs will be better understood in the future. In the meantime, the GFCF diet has proved an invaluable tool to many families.

All of this begs the question: how can parents know whether the GFCF diet will benefit their child? The short answer is that the only way to be sure is to try the diet. However, good results are often found in children who tend to self-restrict their diets to food containing gluten and dairy. It is also possible to undergo a laboratory test that analyzes peptide levels in urine, although the test sometimes results in false negatives.


(1) Walsh, P. et al. (2011) ‘In search of biomarkers for autism: scientific, social and ethical challenges’, Nature Reviews Neuroscience 12, 603-612 (October 2011):, PDF (538KB).

(2) Autism Research Institute (2009) ‘Parent ratings of behavioral effects of biomedical interventions’, ARI Publ.34/March 2009:, PDF (95KB).

(3) Pennesi, C. and Klein, L. (2012) ‘Effectiveness of the gluten-free, casein-free diet for children diagnosed with autism spectrum disorder: Based on parental report’, Nutritional Neuroscience 2012: PDF (1.4MB); a summary of the research was also published in Science Daily.