A review of gluten- and casein-free diets for treatment of autism: 2005–2015

Abstract

Background The gluten free, casein free (GFCF) diet is heralded by strong anecdotal parental reports to greatly improve and even “cure” symptoms of Autism Spectrum Disorders (ASD). Yet to date, little conclusive empirical evidence exists supporting its use. Objective The purpose of this paper is to provide an overview of the state of the recent evidence regarding use of GFCF diet for treatment of individuals with ASD. Methods Five database providers (PubMed, Web of Knowledge, EBSCO, ProQuest, and WorldCat) were used to search 19 databases yielding a total of 491 articles that were published through February 2015. Peer reviewed articles published between 2005 and February 2015 were included for review if study participants were identified as having ASD and investigated the effects of the GFCF diet on ASD behaviors or the relationship between the diet and these behaviors. Results Evaluation of search results yielded 11 reviews, 7 group experimental studies including 5 randomized controlled trials, 5 case reports, and 4 group observational studies published during the last 10 years. These studies represent a marked increase in number of reported studies as well as increased scientific rigor in investigation of GFCF diets in ASD. Conclusions While strong empirical support for the GFCF diet in ASD is currently lacking, studies point to the need for identifying subsets of individuals (e.g., those with documented gastrointestinal abnormalities) who may be the best responders to the GFCF diet. Identifying these subsets is critically needed to enhance rigor in this research area. Until rigorous research supporting use of GFCF diet is reported, clinicians should continue use caution and consider several factors when advising regarding implementation of the GFCF diet for individuals with ASD.

Dietary Supplement for Core Symptoms of Autism Spectrum Disorder: Where Are We Now and Where Should We Go?

“…The opioid theory was the most cited theory for adopting of a CFGF diet for the treatment of ASD ( 67 , 68 ). It is known that, after digestion, certain types of peptides could cross the intestinal mucosa intact and may further cross the blood–brain barrier through bloodstream transportation and reach the central nervous system even to a high level in the case of impairments in intestinal track or celiac disease ( 69 ).…”

“…Numerous reviews on this topic have been published, and they all concluded GFCF diet as lack of evidence for improving autistic symptoms ( 67 , 68 , 79 – 81 ). Overall, findings from current best evidence suggest that GFCF dietary may not help to reduce core symptoms of ASD neither gluten nor casein supplementation increase the symptoms.…”

The Problem of Curcumin and Its Bioavailability: Could Its Gastrointestinal Influence Contribute to Its Overall Health-Enhancing Effects?

“…Although, to our knowledge, this is the only study conducted to date, and further replication and extension of this study is required to elaborate on this finding, it has potential implications for people suffering from food allergies, because curcumin may influence allergenic responses to certain foods. Food allergies and sensitivities, particularly those associated with gluten, have been implicated in several diseases, including gastrointestinal disorders (103,104), rheumatic diseases (105), and even neurological and neuropsychiatric conditions such as depression (106), schizophrenia (107), autism (108,109), and dementia (110). However, the research is limited and often inconsistent.…”

Elimination diets’ efficacy and mechanisms in attention deficit hyperactivity disorder and autism spectrum disorder

“…There is increasing research into the effectiveness of the GFCF diet in children diagnosed with ASD. Several systematic reviews of GFCF diet studies in ASD have appeared [ 19 , 35 – 40 ]. However, the number of high quality RCTs is too small for drawing firm conclusions at this point and there are no meta-analyses available.…”