A pilot study to evaluate nutritional influences on gastrointestinal symptoms and behavior patterns in children with Autism Spectrum Disorder1-s2.0-S0965229912001203-main

1. Complementary Therapies in Medicine (2012) 20, 437—440
Available online at www.sciencedirect.com
journal homepage: www.elsevierhealth.com/journals/ctim
SHORT REPORT
A pilot study to evaluate nutritional influences on
gastrointestinal symptoms and behavior patterns in
children with Autism Spectrum Disorder
Cristen Harris∗
, Bethany Card
Department of Nutrition & Exercise Science, School of Natural Health Arts & Sciences, Bastyr University, 14500 Juanita Drive, NE
Kenmore, WA 98028-4966, United States
Available online 19 September 2012
KEYWORDS
Autism;
Gluten;
Casein;
GFCF diet;
Autism spectrum
disorder (ASD);
Gastrointestinal
Summary
Background: One in 110 children in the US have autism spectrum disorder (ASD), a debilitating
and life-long disorder that affects the health, relationships, and learning of affected children.
Existing research on the etiology, contributing factors, and treatment for ASD is limited and
controversial. Studies suggest that GI symptoms are related to behavior issues in children with
ASD, which may be improved by a gluten-free, casein-free (GFCF) diet.
Objectives: To evaluate the relationship between a GFCF diet and gastrointestinal symptoms
and behavior patterns in children with ASD.
Design and setting: Cross-sectional design in which parents completed an online survey
regarding general health, diet (adapted food-frequency questionnaire (FFQ)), gastrointestinal
symptoms, and behavior patterns of their children with ASD.
Main outcome measures: Scores on the Gastrointestinal Symptoms Rating Scale (GSRS) and
Childhood Autism Rating Scale (CARS).
Results: Seven of thirteen children (median age 9 years) were on a GFCF diet, consuming sig-
nificantly fewer gluten- and casein-containing foods than those not on a GFCF diet. GSRS and
CARS scores did not differ significantly according to diet. Parents of all the children on a GFCF
diet reported improved GI symptoms and behavior patterns.
Conclusions: This study provides evidence that the adapted FFQ is an effective tool for evalu-
ating adherence to a GFCF diet. Continued well-controlled research is necessary to elucidate
the gut—brain relationship in ASD.
© 2012 Elsevier Ltd. All rights reserved.
∗ Corresponding author. Tel.: +1 425 602 3098;
fax: +1 425 823 6222.
E-mail address: charris@bastyr.edu (C. Harris).
Background
Autism spectrum disorder (ASD) is characterized by varying
degrees of impairment of communication skills and social
interaction, and unusual and repetitive behavior, estimated
to effect 1 in 110 children.1
ASD can have a significant impact
on quality of life since most children remain within the spec-
trum as adults and continue to experience problems with
0965-2299/$ — see front matter © 2012 Elsevier Ltd. All rights reserved.
http://dx.doi.org/10.1016/j.ctim.2012.08.004

2. 438 C. Harris, B. Card
Table 1 Adapted food frequency questionnaire.
Foods Number of times per day Number of times per week
Chips, crackers, pretzels
Rice cakes, rice crackers
Cakes, cookies, pies, pastries
Muffins, English muffins, biscuits
Soy products (soy milk, tofu, tempeh, etc.)
Dairy products (milk, cheese, yogurt, ice cream)
Fish sticks, imitation crab
Wheat flour pasta
Wheat flour bread products
Rice pasta
Rice or tapioca flour bread products
Cereals
Quinoa, millet, rice
Almond milk, almond flour
Flour tortillas
Corn tortillas
Frozen dinners
Fast food
Fermented vegetables, kimchi, sauerkraut
Cultured soy, tempeh, soy yogurt, kefir, miso
independent living, employment, relationships, and mental
health.2
Some research suggests that gastrointestinal (GI) dis-
orders are related to behavioral issues in children with
ASD.3
Many children experience severe GI symptoms such as
esophageal reflux, abdominal pain, diarrhea, constipation,
and bloating.4
These symptoms may be due to intestinal
dysbiosis, characterized by a disruption of endogenous gut
microflora promoting overgrowth of pathogenic microor-
ganisms suspected to produce neurotoxins.5
GI symptoms
may also be related to a disruption in the mucosal lin-
ing of the gut, causing malabsorption of large proteins
such as gliadin and casein, which can cause inflammation
and are precursors to neuropeptides that alter neurologic
function.6
A gluten-free, casein-free (GFCF) diet has been asso-
ciated with improved symptoms in children with ASD.7,8
However, a review of the literature revealed that a GFCF
diet should not be recommended as standard treatment for
ASD due to inconclusive evidence.9
The purpose of this study
was to evaluate the relationship between GI symptoms and
behavior patterns, and the influence of a GFCF diet on these
issues in children diagnosed with ASD.
Methods
Subjects and recruitment
Data for this cross-sectional study were obtained through a
convenience sample of parents who had children with diag-
nosed ASD residing in the Seattle, Washington area. Parents
were recruited from the Asperger’s Support Network website
and were eligible to participate if they had an autistic child
between the ages of 5 and 12 years old. Ethical approval
for this study was granted by the Institutional Review Board
at Bastyr University; all subjects gave informed consent to
participate.
Measurement tools
The online survey included questions about general health,
demographics, GI symptoms and behavior patterns, and
a food frequency questionnaire (FFQ) that each parent
answered regarding their child with ASD. Adherence to
a GFCF diet was determined by the number of gluten-
and casein-containing foods consumed per week, and was
measured using a FFQ specifically adapted for this study
(Table 1).
Gastrointestinal symptoms were evaluated using the
Gastrointestinal Symptoms Rating Scale (GSRS), which
is a fifteen-question survey that rates the severity of
symptoms including abdominal pain, heartburn, nau-
sea, flatus, and stools on a scale of 0—3. A total
GSRS score ranges from 0 to 45, and categorizes
symptoms by severity: low <15, moderate 16—29, and
severe >30.10,11
Behavior patterns were evaluated using the Child-
hood Autism Rating Scale (CARS), consisting of fifteen
questions/domains that are scored on a scale of 1—4: relat-
ing to people; imitation; emotional response; body use;
object use; adaptation to change; visual response; listen-
ing response; taste, smell, and touch response and use; fear
or nervousness; verbal communication; nonverbal commu-
nication; activity level; level and consistency of intellectual
response; and general impressions.12
The total score varies
from 15 to 60 with 30—36.5 indicating mild to moderate
autism, and 37—60 severe.8

3. A pilot study to evaluate nutritional influences on gastrointestinal symptoms and behavior patterns in children with ASD439
Table 2 Characteristics of subjects (n = 13).
Characteristic %
Race
Caucasian 92.3
African American 7.7
Gender
Male 69.2
Female 30.8
Family income level ($)
<10,000 7.7
10,000—30,000 0
30,000—60,000 7.7
60,000—100,000 46.1
>100,000 30.8
Declined to comment 7.7
Type of autism spectrum disorder
Asperger 15.4
Autism 69.2
Child disintegrative disorder 0
Autism not otherwise specified 15.4
Health conditions
Ulcerative colitis 15.4
Asthma 23.1
Allergies 53.8
Food sensitivities 76.9
Eczema 46.2
No condition 15.4
Diet
GFCF diet 53.8
Non-GFCF diet 46.2
Statistical analysis
Descriptive characteristics were generated for demograph-
ics, general health, and outcome variables. Kendall’s Tau
correlation was used to assess relationships among sever-
ity of GI symptoms, behavior patterns, and adherence to
a GFCF diet. Mann—Whitney U-tests were used to evaluate
differences in CARS scores, GSRS scores, and dietary adher-
ence with respect to reported diet. PASW (Version 18.0) was
used for all statistical analyses. The level of significance was
p < 0.05.
Results
Thirteen subjects completed the online survey. The mean
age (±SD) of children with ASD was 9 ± 1.9 years. Demo-
graphics and health characteristics are shown in Table 2.
There were no statistically significant differences in any
response variable by age, race, gender, income, or type
of ASD. Four children had tested positive for antibodies to
gluten or casein, and more than half were on a GFCF diet,
consuming an average of 8.7 gluten- and casein-containing
foods per week. In contrast, children not on a GFCF diet ate
53. This difference was statistically significant (p < 0.001),
shown in Table 3.
Parental report indicated that 53.8% of children experi-
enced post-prandial GI symptoms. The mean score on the
Table 3 Mean (±SD) scores for diet adherence, gastroin-
testinal symptoms, and behavior patterns in relation to
reported diet.a
Questionnaire GFCF diet Non-GFCF
diet
(GFCF − non-
GFCF)
FFQ 8.7 ± 7.1 53 ± 20 44.3†
CARS 44.6 ± 11.6 43 ± 11 1.3
GSRS 20.3 ± 5.1 17.8 ± 3.8 2.5
a Abbreviations: GFCF — gluten-free, casein-free diet; FFQ
— food frequency questionnaire, representing the number of
gluten and casein containing foods consumed per week; CARS —
total score on Childhood Autism Rating Scale; and GSRS — total
score on Gastrointestinal Symptoms Rating Scale.
† Statistically significant difference, p < 0.001; n = 13.
GSRS was of 19.2, and the mean score on the CARS was
43.9. GSRS and CARS scores did not differ according to diet
(Table 3). However, 100% of the parents with children on
a GFCF diet (n = 7) reported that both GI symptoms and
behavior patterns improved with diet. Correlational anal-
yses of GSRS scores, CARS scores, and diet adherence were
non-significant.
Discussion
This study provides evidence that the adapted FFQ is an
effective tool for evaluating adherence to a GFCF diet; it
significantly differentiated between those on a GFCF diet
and those who were not. The data failed to reveal sig-
nificant relationships among consumption of gluten- and
casein-containing foods, GI symptoms and behavior patterns
in children with ASD. Strengths of this study include the use
of validated questionnaires and the relative homogeneity
of the sample. Limitations include small sample size, the
subjective nature of the questionnaires, and the uncertain
ability of parents to accurately quantify the severity of their
children’s symptoms. These factors may have resulted in
under- and/or over-reporting by parents.
Results of a recent report based on parental survey13
suggest that compliance with strict diet elimination may
be an important consideration in optimizing the efficacy
of a GFCF diet for children with ASD. Experimental stud-
ies have attempted to ensure dietary compliance with
extensive nutritional support14
and the provision of all
meals and snacks, which failed to allay concerns regarding
compliance.8
These studies could be strengthened with
an adapted FFQ, such as the one utilized in our study
that can be completed by parents, teachers and caregivers
to assess dietary compliance both within and outside the
home.
Anecdotal reports from the parents in our study var-
ied from non-significant findings. Although parents reported
improvement of GI symptoms and behavior patterns in chil-
dren on a GFCF diet, the GSRS and CARS scores did not
support this relationship. This is consistent with the results
of another study8
in which parents reported positive sub-
jective clinical changes while their child was on the GFCF
diet and wanted to continue it, even with the knowledge
that there was no empirical support for doing so. The

4. 440 C. Harris, B. Card
discrepancy between anecdotal and empirical reports may
be influenced by parents’ unrealistic expectations and
beliefs related to treatments.15
In summary, compliance with a GFCF diet is a concern
among studies that aim to explore the relationship between
diet and ASD outcomes. An adapted FFQ that quickly and
effectively assesses compliance can strengthen the results
of such studies. Future research should be aimed at test-
ing the validity and reliability of the adapted FFQ among
larger samples of children with ASD. Such a valid and reliable
tool will enhance the strength of well-controlled studies
that are necessary to elucidate the gut—brain relationship in
ASD.
Conflict of interest statement
None declared.
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