Dietary interventions for autism spectrum disorder: A meta-analysis

Fraguas D, Díaz-Caneja CM, Pina-Camacho L, Moreno C, Durán-Cutilla M, Ayora M, González-Vioque E, de Matteis M, Hendren RL, Arango C, Parellada M. Dietary Interventions for Autism Spectrum Disorder: A Meta-analysis. Pediatrics. 2019 Nov;144(5).

CONTEXT: Dietary interventions such as restrictive diets or supplements are common treatments for young people with autism spectrum disorder (ASD). Evidence for the efficacy of these interventions is still controversial.

OBJECTIVE: To assess the efficacy of specific dietary interventions on symptoms, functions, and clinical domains in subjects with ASD by using a meta-analytic approach.

DATA SOURCES: Ovid Medline, PsycINFO, Embase databases.

STUDY SELECTION: We selected placebo-controlled, double-blind, randomized clinical trials assessing the efficacy of dietary interventions in ASD published from database inception through September 2017.

DATA EXTRACTION: Outcome variables were subsumed under 4 clinical domains and 17 symptoms and/or functions groups. Hedges’ adjusted g values were used as estimates of the effect size of each dietary intervention relative to placebo.

RESULTS: In this meta-analysis, we examined 27 double-blind, randomized clinical trials, including 1028 patients with ASD: 542 in the intervention arms and 486 in the placebo arms. Participant-weighted average age was 7.1 years. Participant-weighted average intervention duration was 10.6 weeks. Dietary supplementation (including omega-3, vitamin supplementation, and/or other supplementation), omega-3 supplementation, and vitamin supplementation were more efficacious than the placebo at improving several symptoms, functions, and clinical domains. Effect sizes were small (mean Hedges’ g for significant analyses was 0.31), with low statistical heterogeneity and low risk of publication bias.

LIMITATIONS: Methodologic heterogeneity among the studies in terms of the intervention, clinical measures and outcomes, and sample characteristics.

CONCLUSIONS: This meta-analysis does not support nonspecific dietary interventions as treatment of ASD but suggests a potential role for some specific dietary interventions in the management of some symptoms, functions, and clinical domains in patients with ASD.

Courtesy of:  https://www.mdlinx.com/journal-summaries/dietary-interventions-asd-autism-spectrum-disorder/2019/11/07/7584074?spec=neurology

From the paper

Meta-analyses revealed the following:

Dietary supplementation (omega-3, vitamin supplementation, and/or other supplementation) was more effective than placebo in treating the following symptoms and/or functions groups: anxiety and/or affect, autistic general psychopathology, behavioral problems and impulsivity, global severity, hyperactivity and irritability, language (general), and social-autistic and stereotypies, restricted and repetitive behaviors. Dietary supplementation (omega-3, vitamin supplementation, and/or other supplementation) was more effective than placebo in treating the following clinical domains: core symptoms, associated symptoms, autism global, and clinical global impression.

Omega-3 supplementation was more effective than placebo in treating the following symptoms and/or functions groups: language (general) and social-autistic (see Table 2). Omega-3 supplementation was more effective than placebo in treating the following clinical domains: core symptoms and associated symptoms.

Vitamin supplementation was more effective than placebo in treating the following symptoms and/or functions groups: global severity, language (general), stereotypies, restricted and repetitive behaviors, behavioral problems and impulsivity, and hyperactivity and irritability. Vitamin supplementation was more effective than placebo in treating the following clinical domains: core symptoms, associated symptoms, and clinical global impression 

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For all types of dietary intervention, significant meta-analyses revealed small effect size  relative to placebo, low statistical heterogeneity, and low risk of publication bias.