After at least four weeks on the strict diet, the children were challenged with either gluten, casein, both or placebo in randomized order. They were given a snack once weekly with either 20 grams of wheat flour, 23 grams of non fat dried milk, both, or neither until every child received each snack three times. The type of snack was given in randomized order and presented so that no one observing - including the family, child, research staff and therapy team - knew what it contained. The snacks were carefully engineered to look, taste and feel the same, which was an exercise in innovative cooking. In addition, the nutrition staff worked closely with the families to make a snack that met their child's preferences. Casein was disguised in pudding, yogurt or smoothies and gluten in banana bread, brownies, or cookies depending on the child's food preferences.

Parents, teachers and a research assistant filled out standardized surveys about the child's behavior the day before they received the snack, at two and 24 hours after the snack. (If the child's behavior wasn't usual at the scheduled snack time, the snack would be postponed until the child was back to baseline.) In addition, the parents kept a standard diary of food intake, sleep and bowel habits. Social interaction and language were evaluated through videotaped scoring of a standardized play session with a research assistant.

Following the gluten and casein snacks, study participants had no change in attention, activity, sleep or frequency or quality of bowel habits. Children demonstrated a small increase in social language and interest in interaction after the challenges with gluten or casein on the Ritvo Freeman Real Life Rating Scale; however, it did not reach statistical significance. That means because of the small difference and the small number of participants in the study, the finding may be due to chance alone.

The investigators note that this study was not designed to look at more restrictive diets or the effect of nutritional supplements on behavior. This study was designed to look at the effects of the removal of gluten and casein from the diet of children with autism (without celiac disease) and subsequent effect of challenges with these substances in a group of children getting early intensive behavioral intervention.

Hyman said, "This is really just the tip of the iceberg. There are many possible effects of diet including over- and under-nutrition, on behavior in children with ASD that need to be scientifically investigated so families can make informed decisions about the therapies they choose for their children."

Source: University of Rochester Medical Center