Popular Autism Diet Does Not Demonstrate Behavioral Improvement

[Guest guest]

Popular Autism Diet Does Not Demonstrate Behavioral Improvement

ScienceDaily (May 20, 2010) — A popular belief that specific dietary changes can

improve the symptoms of children with autism was not supported by a tightly

controlled University of Rochester study, which found that eliminating gluten

and casein from the diets of children with autism had no impact on their

behavior, sleep or bowel patterns.

The study is the most controlled diet research in autism to date. The

researchers took on the difficult yet crucial task of ensuring participants

received needed nutrients, as children on gluten-free, casein-free diets may eat

inadequate amounts of vitamin D, calcium, iron and high quality protein. Unlike

previous studies, they also controlled for other interventions, such as what

type of behavioral treatments children received, to ensure all observed changes

were due to dietary alterations. Past studies did not control for such factors.

And 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, " said Hyman, M.D., associate professor of Pediatrics

at Golisano Children's Hospital at the University of Rochester Medical Center

(URMC) and principal investigator of the study which will be presented on May 22

at the International Meeting for Autism Research in Philadelphia. " 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. Parent observation

has played an important role in earlier treatment discoveries in children with

autism, such as melatonin's benefits for sleep.

Hyman's study enrolled 22 children between 2 ½- and 5 ½-years-old. Fourteen

children completed the intervention, which was planned for 18 weeks for each

family. The families had to strictly adhere to a gluten-free and casein-free

diet and participate in early intensive behavioral intervention throughout the

study. Children were screened for iron and vitamin D deficiency, milk and wheat

allergies and celiac disease. One child was excluded because of a positive test

for celiac disease and one was excluded for iron deficiency. Other volunteers

who were excluded were unable to adhere to the study requirements. The

children's diets were carefully monitored throughout the study 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

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. "

This study was funded by the NIH's National Institutes of Mental Health Studies

to Advance Autism Treatment Research and National Center for Research Resources

(NCRR).