IntroductionParents of children diagnosed with autism spectrumdisorders (ASD), tend to opt for alternative intervention for their children,for example, the use of a gluten-free, casein-free diets, which they perceivedas risk free, to improve the cognitive-behavioural function of their childrenwith ASD. The main focus of this essay is to discuss the most recent advancesin gluten-free research and the evidences that argued for or against the use ofa gluten-free, casein-free diets, especially for children who are diagnosedwith ASD.
It also critically explored the strategies used, the challenges encountered,and the emotional impact experienced by people who followed a gluten-free diet,as evidenced by past research studies. A systematic review of research papers publishedfrom 1970 to date indicated that most studies conducted on children with ASD whoare following a gluten-free diet were mostly tested on randomized controlledtrials, with small sample sizes. Hence, it lacks validity and sound scientificevidence to conclude the effectiveness of adopting a gluten-free diet as a formof intervention. Future research on a larger scale is recommended (O’Shea,Arendt, & Gallaghar, 2014; Zarkadas, Dubois, McIsacc, Cantin, Rashid, Roberts,La Vieille, Godefroy, & Pulido, 2013; Mari-Bauset, Zazpe, Mari-Sanchis,Llopis-Gonzalez, & Morales-Suarez-Varela, 2014). Descriptionand Definition Autism spectrumdisorders (ASD) has been on the rise for the past 30 years and is becomingprevalent, affecting 1 in every 68 persons in United States. It is a highly complexdisorder with multiple causes and various treatment approaches to treat onlythe symptoms as autism is not curable. Children with autism are characterisedby a spectrum of neurological developmental disorders that manifest in earlychildhood. They include persistent deficits in social communication and socialinteraction, along with restricted, repetitive patterns of behaviour,interests, or activities, such as stereotyped or repetitive speech, motormovements or fixative interest in certain object or task.
A variety of genetic,environmental and immunological factors could also affect multiple systems,especially thecognitive-behavioural function of the person with ASD. In past epidemiologicalstudies of prenatal development, metabolic and nutritional factors have beenidentified as one of the contributing risks of autism for the newborn babies (Matelski,& Van de Water, 2016).The ‘opioid excesstheory’ could best explain ‘gluten and casein intolerance’ in persons diagnosedwith ASD. According to Lange, Hauser & Reissmann (2015), when gluten (fromwheat) and casein (from dairy products) are consumed into the body, they aremetabolized to ‘gluteomorphine’ and ‘casomorphine’. These ‘peptides’ then bindto ‘opiate receptors’ in the ‘central nervous system’ and to imitate theeffects of ‘opiate drugs’. During digestion, ‘opioid peptides’ are formed whichthen led to an increased activity in the ‘endogenous opioid system’ andresulted in the symptoms of autism. Hence, a diet low in gluten and casein isbelieved to improve the cognitive-behavioural function of persons with ASD(Lange,Hauser, & Reissmann, 2015, n.
p). Children diagnosed withautism tend to also suffer from comorbid problems which cause gastrointestinalsymptoms and affect their concentration and attention span. Past researchstudies also associated gluten intolerance with ASD and indicated therelationship between ASD and celiac disease, an autoimmune disease that causes gastrointestinalsyndrome (Lange, Hauser, & Reissmann, 2015; Jackson, Eaton, Cascella,Fasano, & Kelly, 2012, pp 95-96). Intervention’sDefinition of Improving Quality of Life The purpose of choosinga non-invasive intervention or therapy is to improve the quality of life forthe diseased. A Gluten Free Diet (GFD) tends to be the preferred interventionused by parents of children with ASD because it is not a form of medication, non-evasivein nature, as compared to other form of therapy, such as stem cell therapy. Currently,GFD is widely used by individuals with celiac disease and by parents who havechildren diagnosed with ASD to improve their children’s quality of life. However,due to misinformation circulating online or by ill advice from unqualifiedsources regarding the benefits or harmful effects of GFD, it is legitimate toexamine the accuracies or inaccuracies, the fact and fiction of using GFD, as aform of intervention.
With the growing popularity of parents putting theirchildren on a GFD, in the belief that it is a risk free intervention to relievetheir children’s autistic symptoms, it might pose important implications forthem (Reilly, 2016). Arecent UK survey indicated that 80% of parents of children withautism spectrum disorders tend to use some form of dietary intervention fortheir child, out of which 29% of the parents placed their child on a gluten-freeand casein-free diet (GFCFD). On examining the effects of using GFCFD on theirchildren, 20–29% of the parents reported significant improvements on thecognitive-behavioural function. The findings also suggested that a gluten-freeand casein-free diet did help to relieve comorbid problems such as gastrointestinalsymptoms, and improve the concentration, and attention span of these children. Althoughparents in the studies gave positive effects of GFCFD on their children, mostscientific evaluations have failed to confirm its therapeutic effects.
Using parentsas informants on their children’s autistic symptoms can be a bias source ofinformation. Perhaps, in future case studies, we need to include clinicians as informantsand assessors of the effects, to introduce standardized test procedures and observationalparameters. It will then complement the measures and give a more completepicture of dietary effects of GFCFD on children with ASD (Lange, Hauser , 2015). The use of GFCFD byparents on their children might have some loop holes that need to be addressed.For example, some parents may go ahead to place their child on GFCFD withouttesting their child for celiac disease or consulting a dietician. Some childrenwith celiac disease may be asymptomatic from the start and thus was not noticedfor having the condition. Furthermore, information on the health and socialconsequences of starting a child on GFCFD are not adequate online or in books,for parents to make an informed choice (Reilly, 2016).
Researchstudies behind Intervention and Evaluations According to Lange, etal. (2015), GFCFD trials evaluating the effects of a GFCFD on autistic symptomshave so far been questionable and inconclusive. The authors also mentioned thatresearch studies investigating the efficacy of a GFCFD in the treatment ofautism are seriously flawed and the therapeutic value of this diet appeared tobe weak and restricted. A systematic review of research papers published from1970 to date also indicated that most research studies conducted on childrenwith ASD who are placed on a gluten-free diet were mostly tested on randomizedcontrolled trials and with a small sampling size. Hence, it lacks validity and reliabilityand is unable to provide a sound scientific evidence to conclude the effectivenessof adopting a gluten-free diet as a form of intervention.Recent research studiesindicated that gluten sensitivity (GS) is an illness distinct from celiacdisease. This new discovery gave rise to new understanding and knowledge of thedisease. Both celiac disease and GS may present with a variety of neurologicand psychiatric co-morbidities.
However, for those with GS, the prime symptomsare extra-intestinal problems. It was found that those with celiac disease havevillous atrophy or antibodies present in their bodies, unlike those with GS whodo not have the antibodies. Hence, GS if remained untreated, can lead topsychiatric and neurologic manifestations in persons with ASD (Jackson, et al.
,2012). Jackson, et al. (2012)also cited a few research studies indicating an increased risk of ASDs inchildren with a ‘maternal history of rheumatoid arthritis’, ‘celiac disease’and ‘irritable bowel syndrome’. Another study used a control group to makecomparison. It was found that persons with ASDs and their family members have ahigh percentage of people with ‘abnormal intestinal permeability’ as comparedto the group without ASDs. Another control group study of GFCFD used on patientswith ASD have found ‘a better intestinal permeability’ as compared to patientson a non-GFCFD. As most of the research studies tend to focus on the use ofGFCFD rather than eliminating GFCFD on persons with ASDs, it makes it dif?cultto determine whether there is additional bene?cial effects if a non-GFCFD isused (p.
95). The beneficial effectsof a GFCFD on autistic symptoms have so far been contradictory and remaineddebatable to date and there is not enough data to support its benefits (Mari-Bauset,etal.,2014; Gaesser & Angadi, 2012, p. 1330). In fact, recent evidencesuggested that a gluten-free diet might reduce beneficial gut bacteria in theintestines.
Other reports also indicated that patients who are obese tend toput on even more weight after being placed on a gluten-free diet. It could bedue to better absorption of nutrients or healing of intestinal lining following a gluten-free diet (Gaesser& Angadi, 2012). This might have an implication on obese children with ASDto put on more weight if they were to use a gluten-free diet as a form ofintervention.
Reilly (2016) assertedthat there is not enough evidence to support the health benefits of agluten-free diet. On the contrary, a gluten-free diet may have negative effectsif it is not prescribed or approved by a registered dietician or physician.Gluten-freepackaged food also tend to have higher sugar and fat content as compared tonon-gluten-free food. Intake of too much sugar and fat may increase the risksof obesity. There are emerging evidences to show that a strictly rice flourgluten-free diet without other varieties of gluten-free products may lead totoxicity due to ‘arsenic’,found in inorganic form in most rice-based gluten-freeproducts. A gluten-free diet may also result in deficiencies in vitamin B,folate and iron. Hence, it is a myth to think that eating a gluten-free diet isa healthier choice (Reilly, 2016, pp.
206-207). A recent research studywas conducted by Hyman, Stewart, Foley, Cain, Peck, Morris, Wang, & Smith (2016),on the safety and ef?cacy of the gluten-free/casein-free (GFCF) on a group of 14children (age 3–5 years) with autism. They were put on GFCF diet for 4–6 weeksand followed by placebo controlled challenge study for 12 weeks whilecontinuing the diet, with a 12-week follow-up. Children were given weeklysnacks that contained gluten, casein, gluten and casein, or placebo during thedietary challenges with nutritional counselling. The findings indicated that theGFCF diet was safe and well-tolerated.
However, the limitation of this studywas that it was unable to track the signi?cant effects on physiologicfunctioning, behaviour problems, or autism symptoms. Due to the small samplingsize, the ?ndings must be interpreted with caution and has to be replicated ona larger scale to validate the findings. The scienti?c communityhas all along tried to establish alternative ways of intervention. To date,there is no pharmacological treatment that is available to gluten-intolerantpatients. Placing patients on a strict, life-long gluten-free diet appeared tobe the only safe solution although it is still not conclusive regarding itseffectiveness.
A research study was conducted by Caputo, Marilena, Stefania& Esposito (2010) on the use of enzymes as additives or as processing aidsin the food biotechnology industry to detoxify gluten. The recent developmentof ‘enzyme therapy’ is a new alternative intervention that focused oninactivating immunogenic gluten epitopes and is administered orally to patients.For people with ASD, it might spell new hope and be a new strategy to relievetheir autism symptoms and improve cognitive-behavioural functions. Personsundergoing this therapy are administered doses of ‘Flavobacteriummeningosepticum’, ‘Sphingomonas capsulate’, and ‘Myxococcus xanthus’. Theseenzymes are believed to help ‘degrading proline-containing peptides’ that areotherwise resistant to degradation by ‘proteases’ in the gastrointestinal tract.
A lifelong gluten-free diet may not be easy to maintain and does cause anegative impact on the quality of life. It is also a costly affair to stick toa gluten-freediet whereas a non-gluten-free diet is commonly available and cheaper tomaintain (Caputo, Marilena, Stefania & Esposito, 2010, pp.4-5; Zarkadas, etal., 2013). A systematic review ofthe medical literature related to GFCFD was conducted by Mari-Bauset, et al. (2014).Theresearchers tracked databases dating back from the 1970s to September, 2013 onpublished research articles or written reports on the use of GFCFD on childrenwith ASD as an intervention.
The systematic review evaluated the findings andreported that none of the studies identified provided conclusive evidence ofGFCFD effectiveness as an intervention for ASD because they were poorly validated.Thestudies are mostlytested on randomized controlled trials, with a small sample size thus cannot beconclusive or represented. A recent research studyconducted in 2008 by Zarkadas, et al.,(2013) investigated the effects ofgluten-free diet among Canadians with coeliac disease. A questionnaire wasmailed to all 1,0693 members of both the Canadian Celiac Association and the Fondationquébécoise de la maladie cœliaque.
A total of 5912 (age?18 years)responded which is equivalent to 72% of the response rate. The findingsreflected the difficulties encountered, the strategies used and the emotionalimpact of following a gluten-free diet. For example, a significantly higherpercentage of women than men reported often feeling frustrated and isolatedduring both time periods of treatment. As there is lack of research studies ongender response in regards to GFCFD’s intervention on persons with ASD, it isworth investigating this aspect. FutureDirections and ConclusionPast research studiesand evidences regarding the effectiveness of a GFCFD as an intervention therapyfor persons with autism are still inconclusive and lack robust evidences.
Despite the diet’s popularity and the positive feedbacks from parents regardingits effects, most scientific evaluations have failed to confirm therapeuticeffects. Adhering to a GFCFD is highly complex, costly and impacts on allactivities involving food, making it difficult to maintain in the long term andmay be perceived as a negative impact on the quality of life. Cross-sectionalstudy of these nature are challenging to evaluate the emotional impact offollowing a gluten-free diet and the difficulties faced by users or the effectivenessof the strategies used (Lange et. al., 2015; Zarkadas, et al., 2013).
Perhaps in futuredietary studies, it should include longitudinal studies on single case or groupstudy. As a GFCFD can be costly, more research studies could be done to explorepotentially cheaper options and a more functional alternative. Other than rice,corn, and potato starch products, the use of chestnut flour and floursdeveloped from fruit by-products, for example, OP and defatted strawberry seedscould be explored (O’Shea, 2014). Apart from parents as informantsof the effectiveness of the GFCFD, clinical expert ratings should also be soughtand behavioural observations be gathered from various sources, to give a more completepicture of the dietary effects of GFCFD on children with ASD.
