GFCF Diet

1.  Introduction

The gluten-free, casein-free, GFCF diet is probably the most anecdotally supported treatment for autism. One yahoo support group for the diet has over 9000 members. Suprisingly, there is still no peer-reviewed double-blind evidence of effectiveness. A non-blinded study of only four children found a favorable effect on autistic symptoms. and the only published, double-blinded study suggests no effect.

2.  Theory behind the GFCF diet

Karl Ludvig Reichelt in Norway, and Paul Shattock in the UK proposed that children with autism were reacting to externally supplied (exogenous) opioid compounds, that were metabolized from gluten and casein, the proteins in wheat and milk. They performed analysis on the urine of autistic children, and appeared to find gliadorphin and casomorphin peptides. These peptides were thought to be due to incomplete breakdown of gluten and casein, and were entering the blood stream via a "leaky gut", travelling to the brain where they resulted in an opioid effect on the autistic person, exacerbating autistic symptoms.

Unfortunately, more recent and detailed chemical analysis of the urine samples showed that no opioid peptides were in fact present. Moreover, another compound urinary indolyl-3-acryloylglycine which was also thought to be implicated in autism, has been found at the same levels in the urine of autistic children and controls, suggesting that this compound is not important in autism either. Despite the lack of scientific evidence, the belief in these peptides persists today.

3.  Other possible reasons for the GFCF diet to be beneficial

In practice, the diet is actually milk-free and wheat-free. Since milk and wheat are two of the most common food allergens, it seems feasible that some children would benefit simply from the removal of an substance to which they had an undiagnosed allergy. In addition, lactose intolerance is a very common condition, for which symptoms include nausea, cramps, bloating, gas, and diarrhea. The GFCF diet would ameliorate these symptoms for children with lactose intolerance (diagnosed or undiagnosed). When a child is on a GFCF diet, they usually eat fewer processed foods, as these tend to have either milk or wheat in them. In this case, the child may benefit from removing food additives, dyes and trans fats from their diet. Finally many children with autism are reported to eat a very restricted diet. A GFCF diet may introduce them to a bigger variety of foods, and thus provide a better nutritional balance.

Research by Dr. Jyonouchi suggests a relationship between cytokine production in response to certain dietary food proteins (found in cow's milk, wheat, and soy) non-allergic immune sensitivity, and GI symptoms in some children with ASD.