In The Politics of Autism, I write:
The conventional wisdom is that any kind of treatment is likely to be less effective as the child gets older, so parents of autistic children usually believe that they are working against the clock. They will not be satisfied with the ambiguities surrounding ABA, nor will they want to wait for some future research finding that might slightly increase its effectiveness. They want results now. Because there are no scientifically-validated drugs for the core symptoms of autism, they look outside the boundaries of mainstream medicine and FDA approval. Studies have found that anywhere from 28 to 54 percent of autistic children receive “complementary and alternative medicine” (CAM), and these numbers probably understate CAM usage.
Parents of children with autism often try diet changes or supplements to ease symptoms of the disorder, but a new review concludes there's no solid evidence that any work.
After analyzing 19 clinical trials, researchers found little proof that dietary tactics -- from gluten-free foods to fish oil supplements -- helped children with autism spectrum disorders (ASDs).
Some studies showed positive effects, while others found nothing, the researchers said. Overall, the trials were too small and short-term to draw conclusions one way or the other.
"Even though we don't have clear evidence documenting safety and efficacy, many -- if not most -- families of children with ASDs try different diets and nutritional supplements at some point in time," said senior researcher Zachary Warren.
Parents often feel there is at least no harm in trying, according to Warren, an associate professor of pediatrics, psychiatry and special education at Vanderbilt University in Nashville.
But, "that's not always a safe assumption," he said.
"For example, some nutritional supplements can actually cause harm in high doses," Warren noted.
He recommended that parents talk to their doctor before changing their child's diet or adding supplements.
From Pediatrics, the abstract:
Nutritional and Dietary Interventions for Autism Spectrum Disorder: A Systematic Review
Nila Sathe, Jeffrey C. Andrews, Melissa L. McPheeters, Zachary E. Warren
CONTEXT: Children with autism spectrum disorder (ASD) frequently use special diets or receive nutritional supplements to treat ASD symptoms.
OBJECTIVES: Our objective was to evaluate the effectiveness and safety of dietary interventions or nutritional supplements in ASD.
DATA SOURCES: Databases, including Medline and PsycINFO.
STUDY SELECTION: Two investigators independently screened studies against predetermined criteria.
DATA EXTRACTION: One investigator extracted data with review by a second investigator. Investigators independently assessed the risk of bias and strength of evidence (SOE) (ie, confidence in the estimate of effects).
RESULTS: Nineteen randomized controlled trials (RCTs), 4 with a low risk of bias, evaluated supplements or variations of the gluten/casein-free diet and other dietary approaches. Populations, interventions, and outcomes varied. Ω-3 supplementation did not affect challenging behaviors and was associated with minimal harms (low SOE). Two RCTs of different digestive enzymes reported mixed effects on symptom severity (insufficient SOE). Studies of other supplements (methyl B12, levocarnitine) reported some improvements in symptom severity (insufficient SOE). Studies evaluating gluten/casein-free diets reported some parent-rated improvements in communication and challenging behaviors; however, data were inadequate to make conclusions about the body of evidence (insufficient SOE). Studies of gluten- or casein-containing challenge foods reported no effects on behavior or gastrointestinal symptoms with challenge foods (insufficient SOE); 1 RCT reported no effects of camel’s milk on ASD severity (insufficient SOE). Harms were disparate.
LIMITATIONS: Studies were small and short-term, and there were few fully categorized populations or concomitant interventions.
CONCLUSIONS: There is little evidence to support the use of nutritional supplements or dietary therapies for children with ASD.