(Ivanhoe Newswire) – Eliminating gluten and casein from the diets of children with autism had no impact on behavior, sleep or bowel patterns, according to a new study.

The University of Rochester researchers took pains to ensure participants received adequate nutrients, as children on gluten-free, casein-free diets may receive inadequate amounts of vitamin D, calcium, iron and high quality protein. They also controlled for other interventions to ensure all observed changes were due to dietary alterations.

Although no improvements were demonstrated, the researchers acknowledged that some subgroups of children, particularly those with significant gastrointestinal (GI) symptoms, might receive some benefit from dietary changes.

"It would have been wonderful for children with autism and their families if we found that the GFCF diet could really help, but this small study didn't show significant benefits," principal investigator Susan Hyman, M.D., associate professor of Pediatrics at Golisano Children's Hospital at the University of Rochester Medical Center (URMC) was quoted as saying.

"However, the study didn't include children with significant gastrointestinal disease. It's possible those children and other specific groups might see a benefit."

In response to widespread parent-reported benefits, URMC initiated the trial in 2003 to scientifically evaluate the effects of the gluten-free and casein-free diet, which eliminates wheat, rye, barley and milk proteins.

Hyman's study enrolled 22 children between 2 ½ and 5 ½ years old. Fourteen children completed the 18-week intervention. The families strictly adhered to a gluten-free and casein-free diet and participated in early intensive behavioral intervention throughout the study. Children were screened for iron and vitamin D deficiency, milk and wheat allergies and celiac disease. The children's diets were carefully monitored to make sure they were getting enough vitamin D, iron, calcium, protein and other nutrients.

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 snacks were carefully engineered to look, taste and feel the same.

Parents, teachers and a research assistant filled out standardized surveys about the child's behavior the day before they received the snack, at two hours and 24 hours after the snack. If the child's behavior was unusual at the scheduled snack time, the snack would be postponed until the child was back to baseline. Parents kept a 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.

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 and subsequent effect of challenges with these substances in a group of children getting early intensive behavioral intervention.

"This is really just the tip of the iceberg,” said Hyman. “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."