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Parents' and Child Health Professionals' Attitudes Towards Dietary Interventions for Children with Autism Spectrum Disorders

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Parents of children with autism spectrum disorders (ASD) use a wide range of interventions including poorly evidenced dietary interventions. To investigate parents' and professionals' experience of dietary interventions and attitudes towards a proposed trial to evaluate the gluten free casein free diet (GFCFD). Survey of UK parents of children with ASD, and professionals. 258 parents and 244 professionals participated. 83 % of children had received a range of dietary manipulations; three quarters of professionals have been asked for advice about GFCFD. Respondents identified an inadequate evidence base for dietary interventions in ASD and suggested modifications to a proposed trial design. Both parents and professionals supported the need for further evaluation of dietary interventions in ASD.
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ORIGINAL PAPER
Parents’ and Child Health Professionals’ Attitudes
Towards Dietary Interventions for Children with Autism
Spectrum Disorders
Elizabeth Winburn
Jenna Charlton
Helen McConachie
Elaine McColl
Jeremy Parr
Anne O’Hare
Gillian Baird
Paul Gringras
David C. Wilson
Ashley Adamson
Sandra Adams
Ann Le Couteur
Published online: 1 September 2013
Ó Springer Science+Business Media New York 2013
Abstract Parents of children with autism spectrum dis-
orders (ASD) use a wide range of interventions including
poorly evidenced dietary interventions. To investigate
parents’ and professionals’ experience of dietary inter-
ventions and attitudes towards a proposed trial to evaluate
the gluten free casein free diet (GFCFD). Survey of UK
parents of children with ASD, and professionals. 258 par-
ents and 244 professionals participated. 83 % of children
had received a range of dietary manipulations; three
quarters of professionals have been asked for advice about
GFCFD. Respondents identified an inadequate evidence
base for dietary interventions in ASD and suggested
modifications to a proposed trial design. Both parents and
professionals supported the need for further evaluation of
dietary interventions in ASD.
Keywords Autism ASD Dietary interventions
Gluten Casein
Introduction
Recent ASD studies have reported a prevalence of at least 1 %
of the child population (Baird et al. 2006; Kogan et al. 2009).
Although there is no cure for ASD, there is general agreement
that early diagnosis and access to appropriate therapeutic
interventions may improve outcome (Dawson et al. 2010;
Green et al. 2010;Reaven2011; Volkmar et al. 2004). A variety
of interventions have been proposed but there is little evidence
to inform parents and professionals about which intervention or
combination of interventions might benefit an individual child
at any particular time (Carter et al. 2011a;Lordetal.2006;
Ospina et al. 2008). Many interventions are time consuming
and costly with little information about their efficacy, effec-
tiveness or their potential to do harm. Parents report a lack of
advice from professionals about which interventions to choose,
E. Winburn
Solent NHS Trust, Southampton SO16 9QX, UK
J. Charlton
Communication and Language Sciences, Newcastle University,
Newcastle upon Tyne, UK
H. McConachie A. Le Couteur (& )
Institute of Health and Society, Sir James Spence Institute,
Newcastle University, 3rd Floor, Royal Victoria Infirmary,
Newcastle upon Tyne NE1 4LP, UK
e-mail: a.s.le-couteur@newcastle.ac.uk
E. McColl
Newcastle Clinical Trials Unit, The Medical School, Newcastle
University, Newcastle upon Tyne NE2 4HH, UK
J. Parr
Institute of Neuroscience, Newcastle University, Newcastle upon
Tyne, UK
A. O’Hare D. C. Wilson
Child Life and Health, University of Edinburgh, Edinburgh
EH9 1UW, Scotland, UK
G. Baird P. Gringras
Guys and Thomas’ NHS Foundation Trust, London SE1 7EH,
UK
A. Adamson
Institute of Health & Society and Human Nutrition Research
Centre, Newcastle University, Newcastle upon Tyne NE2 4HH,
UK
S. Adams
Department of Nutrition and Dietetics, North Tyneside General
Hospital, North Shields, UK
123
J Autism Dev Disord (2014) 44:747–757
DOI 10.1007/s10803-013-1922-8
and look to alternative sources for information: usually other
parents, the media and the internet (Mackintosh et al. 2005).
The US Interagency Autism Coordinating Committee
(IACC) Strategic Plan has called for a balance between
rigorous evaluation of existing interventions (large-scale
randomized controlled trials, including comparative stud-
ies) and research into novel, targeted treatments (Inter-
agency Autism Coordinating Committee 2010). In the UK,
the need to support autism intervention research has been
identified as a key priority, with both researchers and
parents agreeing that dietary interventions should be a
particular research focus (Charman and Clare 2004; Med-
ical Research Council 2001; Rutter 2011).
Despite the lack of evidence, parents understandably
pursue a range of different types of interventions. Several
recent surveys have identified that on average children are
receiving between four and six interventions, with younger
children more likely to be using dietary and behavioral/
educational/alternative interventions, and pharmacological
interventions being more widely used for adolescents
(Green et al. 2006; Carter et al. 2011b; Goin-Kochel et al.
2007). Dietary interventions, such as restrictive diets and
dietary supplements are used, with many parents falsely
believing that such interventions are likely to be free of
adverse effects, and safer than medications (Goin-Kochel
et al. 2007; Hanson et al. 2007). However the use of
restrictive diets is likely to pose additional risks for chil-
dren with ASD who may already have feeding problems
including a ‘self-imposed’ restrictive diet. Previous studies
have found that children with ASD have more amino acid
deficiencies and lower bone density than age matched
controls, and in these studies there was a greater problem in
those children on restricted diets (Arnold et al. 2003;
Hediger et al. 2008; Keen 2008). However although several
authors have reported that children with ASD have more
restricted diets than age matched controls without ASD
(Ahearn et al. 2001; Keen 2008), a recent general popu-
lation study (using the Avon Longitudinal sample—AL-
SPAC sample) reported no differences in energy intake or
growth for children with ASD (Emond et al. 2010). A
further study compared food records and body mass index
(BMI) of children with ASD aged 2–11 with matched
controls (Hyman et al. 2012). No differences in nutritional
intake were found between groups, but children with ASD
were more likely to be overweight in the aged 2–5 group,
and underweight in the aged 5–11 group.
The most commonly used restrictive dietary intervention
is the gluten free casein free diet (GFCFD; Elder 2008;
Carter et al. 2011b). This diet can place a substantial bur-
den on families, and has considerable resource implications
for healthcare services (Bowers 2002; Parr 2010). Parental
reports make claims for high rates of success using the
GFCFD as an intervention in ASD. For example (Goin-
Kochel et al. 2009), reported that 51 % of parents said that
their children improved while on the GFCFD. However in
their online survey it was difficult to know how parents
attributed their efficacy ratings to individual treatments
since most of the children were receiving multiple treat-
ments. Further since parents used the same Likert-like four
point rating for each intervention, it was not possible to
identify what specific behavioral outcomes parents saw as
changed. (Goin-Kochel et al. 2007).
There have been a number of small scale exploratory
studies of the effectiveness of the GFCFD (Knivsberg et al.
2002; Elder et al. 2006; Johnson et al.
2011). Knivsberg
et al. (2002) was a small (10 subjects per group) single
blind Randomised Controlled Trial of the GFCFD imple-
mented by parents for 12 months. Subjects were selected if
they had a diagnosis of autism and urinary peptide abnor-
malities (believed to reflect incomplete breakdown of gli-
adin, gluten and casein). The diet intervention group
showed significant improvements in ‘autistic traits’ as
reported from parent interviews. Compliance with the diet
was not measured. Elder et al. (2006) was a pilot study of
GFCFD for 6 weeks in a heterogeneous sample that
reported no effect. Johnson et al. (2011)reported a 3-month,
open label, randomised, parallel group design using the
GFCFD and a healthy, low sugar diet thus controlling for
the increased time and attention that is required to imple-
ment a diet such as the GFCFD. No significant differences
were noted between the groups but the authors questioned
whether the GFCFD might need to be implemented for a
longer period of time before gains can be observed. No
significant nutritional differences or side effects were
reported but the authors identified that adherence to the
GFCFD was difficult. The largest study to date used a
single blind, non-placebo controlled design, involved 72
children, and found improvements in core autism symp-
tomatology for those using the GFCFD (Whiteley et al.
2010). Initially in the first 12 months there was a placebo
control, however all participants were assigned to GFCFD
in the second phase of the trial. In the first phase 21 %
withdrew from the study. Reasons for withdrawal included
lack of time to support the GFCFD, children not wanting to
be on the diet or no reported intervention effect. In the
second 12 month phase when all children were offered the
GFCFD more than a third of the remaining sample with-
drew (Whiteley et al. 2010).
There is no plausible biological mechanism for the
GFCFD. The ‘opioid-excess theory’ proposed that some
individuals cannot digest gluten and casein leading to the
absorption of excess peptides into the blood and then the
brain, resulting in a range of autistic behaviours. An
abnormal urinary pattern of proteins has also been reported
(Panksepp et al. 1979; Reichelt et al. 1981; Shattock et al.
1990; Whiteley et al. 1999), but these findings have not
748 J Autism Dev Disord (2014) 44:747–757
123
replicated by independent groups (Alcorn et al. 2004; Cass
et al. 2008; D’Eufemia et al. 1996; Horvath and Perman
2002; Le Couteur et al. 1988; van Elburg et al. 1995).
As there has been no large-scale randomized controlled
trial of the GFCFD, its effectiveness remains unknown
(Millward et al. 2008). We report the findings of a UK
online survey designed to investigate current attitudes to
dietary interventions, and potential support for a proposed
design for a randomized controlled trial (RCT) of the
GFCFD in young children with ASD.
Methods
Sample Size Estimation
We aimed to survey 246 UK parents of children with an
ASD and 246 UK child health professionals working with
children with ASD. The sample size was calculated to
allow us to report with 95 % confidence the ‘true’ rate of
agreement in the underlying population, to within ±5%,
for survey findings/statements with approximately an 80 %
rate of agreement in our sample www.berrie.dds.nl/calcss.
htm (Woodall et al. 2010).
The study received approval from a UK research ethics
committee and the local (Northumberland, Tyne and Wear)
NHS Trust.
Participants
To achieve the recruitment targets and gain a broad range
of views, pediatricians, pediatric neurologists, pediatric
gastroenterologists, child psychiatrists and pediatric dieti-
tians were contacted. The aim was to recruit UK-wide.
Through the relevant National Royal Colleges, professional
bodies, national professional newsletters and UK multi-
disciplinary Child Development Centers email or postal
invitations to participate in the study were sent to the
majority of relevant professionals. Parents were recruited
through two regional databases, online parent support fora
and national parent support organizations.
Materials
Two versions of a survey questionnaire (parent and pro-
fessional) were designed and piloted. Questionnaire
development was undertaken in consultation with parents
and child health professionals. Most questions required
fixed-choice responses, though for some items there was
the facility for brief free-text responses. The questionnaire
was presented in four sections: demographic characteris-
tics; experience and use of interventions for treatment of
ASD in young children; research priorities; and a final
section contained a summary description (‘vignette’) of the
design for a proposed double-blind, multi-site randomized
controlled trial (RCT) to evaluate the impact of GFCFD in
young pre-school children with ASD together with an
illustrative flow chart (see Appendix’).
The vignette included an explanation of the need for
randomization and the procedures for access to proposed
levels of additional professional support (dietitian and
pediatrician). The vignette also included a description of
‘Test Foods’ (two versions of food products such as bis-
cuits, muffins or porridge), manufactured to be either
GFCF or containing precise quantities of gluten and casein)
that would be included in the children’s diet for the dura-
tion of the RCT, so that all parents and researchers
remained ‘blind’ to the introduction of gluten and casein to
half the children in the trial. Once survey participants had
read the vignette and flowchart, they were asked a series of
questions with fixed-choice responses (with space for brief
free text comments) to ascertain opinions about the pro-
posed trial design and levels of clinical support. This sec-
tion of the questionnaire was devised to investigate
possible barriers and facilitators to recruitment and reten-
tion of families within the proposed research design. Other
details about the trial (such as the inclusion/exclusion cri-
teria and safety plan) were not included, in order to keep
the vignette brief.
Paper forms of the survey questionnaires were available
for respondents who did not have web access or expressed
a preference for a paper version (Copies of the question-
naires are available from the corresponding author on
request).
Procedure
The study took place over 10 months between April 2009
and February 2010. Participants initially accessed the
Newcastle University PADIA (Parents’ and Professionals’
Attitudes towards Dietary Intervention in Autism) research
website (http://research.ncl.ac.uk/cargo-ne/PADIA.html)to
express their interest in the survey, completed a short series
of questions regarding their status (parent or professional),
email address, postcode (zip code) and source from which
they heard about the study. Each participant was allocated
a unique identification (ID) number to access an informa-
tion sheet and consent form before completing the full
survey anonymously. All respondents were given the
opportunity to enter a free prize draw to win a laptop
(separate draws for parents and professionals). The two
stage recruitment procedure was used to ensure collection
of consent and socio-demographic information, protect
confidentiality and reduce risk of repeated responses.
Once a unique ID had been allocated, if the question-
naire had not been completed, automatic reminders were
J Autism Dev Disord (2014) 44:747–757 749
123
sent to the associated email address at 2 and 4 weeks after
registration (Edwards et al. 2007; McColl et al. 2001).
All survey responses were transferred to SPPS 15.0 for
Windows software package for analysis. Descriptive sta-
tistics were used to summarize the experiences and atti-
tudes of parents and professionals.
Results
Sample Composition
Two hundred and fifty eight of 361 (71 %) parents and 244
of 317 (77 %) professionals who expressed an interest
completed relevant versions of the questionnaires. 41 %
(105) of parents were recruited from two regional dat-
abases (North East England and Edinburgh Scotland).
80 % of parents and 89 % of professionals completed the
survey online, with the remainder using a paper copy.
Completeness of the data set for individual questions ran-
ged from 90.3 to 99.6 % (parents) and from 86.8 to 100 %
(professionals). For descriptive statistics the denominator
was adjusted for individual questions as necessary.
Most parents who completed the survey were white
British birth mothers of a child with an ASD (75 %). 80 % of
mothers were homeowners and over half were employed
(54 %) and educated to degree level (57 %). Child charac-
teristics are detailed in Table 1. 65 % of parents reported that
their child experienced three or more problem behaviors per
week. There was no significant relationship between age of
child and frequency of problem behaviors. The most frequent
behaviors were selective eating (51 %), sensory reactions
(52 %) together with temper tantrums (41 %), hyperactivity
(40 %) and sleep problems (40 %). These rates of parent
reported child problem behaviors are similar to a UK rep-
resentative database sample (Maskey et al. 2012).
Considering professionals who completed the survey,
42 % were Pediatricians (including 10 % Pediatric Neu-
rodisability Specialists), 32 % Child and Adolescent Psy-
chiatrists, 17 % Dietitians and 9 % Psychologists.
ASD Intervention Use
Parents reported (from a list of 21 possible interventions)
that they were currently implementing a median of four
interventions (range 0–15) with their child. Current inter-
vention type and rates are detailed in Fig. 1. The use of
speech/communication, and educational interventions and
some form of dietary manipulation were all reported by
over 80 % of parents. Dietary manipulation included use of
special diets such as the GFCFD and dietary supplements
(these were grouped as a single category within the fixed
response format, with the descriptor ‘micronutrients, vita-
mins, minerals, fish oils).
Although 75 % of professionals reported that they had
been approached by families for information about the
GFCFD, most (the majority of whom were Child and
Adolescent Psychiatrists) estimated that fewer than 10 %
of the children with ASD on their current caseload were
using the GFCFD. However 26 % of professionals (mostly
Pediatric Dietitians and Pediatricians) reported that
10–20 % of the children with ASD they see are using the
GFCFD. A smaller number of Pediatric Neurodisability
specialists and Child and Adolescent Psychiatrists reported
that at least 20 % of their ASD caseload were on the
GFCFD.
Table 1 Child characteristics (n = 258)
Child characteristic % (n =)
Gender
Male:female 84.16 (216:42) (ratio 4:1)
Age at survey completion
\2 years 11 months 2 (5)
3–5 years 11 months 31 (81)
6–11 years 67 (172)
ASD diagnosis
Autism 27 (70)
Asperger’s syndrome 20 (52)
Autism spectrum disorder 49 (127)
PDD-NOS/atypical autism 4 (9)
Age at diagnosis
\2 years 11 months 27 (70)
3–5 years 11 months 57 (146)
6–11 years 16 (42)
Language level
No meaningful speech 19 (50)
Single words and phrases 28 (70)
Sentences with good grammar 51 (132)
Other (no details) 1 (5)
Learning disability 31 (81)
Type of educational establishment attended
Mainstream (school, nursery, unit
attached)
71 (179)
Specialist provision 28 (70)
Home ed. 2 (4)
Educational support
Individual education plan
a
57 (150)
Statement of special educational needs
b
55 (144)
a
An Individual Education Plan (IEP) is a teaching and learning plan
devised to identify the targets, provision and outcomes for a child
identified with special educational needs
b
Statement of Special Educational Needs is a legal document issued
by the Local Authority responsible for education, following an in-
depth multidisciplinary assessment of the child’s needs
750 J Autism Dev Disord (2014) 44:747–757
123
Attitudes Towards Dietary Interventions
Eighty three percent of parents had tried a range of dietary
manipulations (including any special diet and use of dietary
supplements) with their child. 35 % were currently using a
special diet and 46 % were currently using dietary sup-
plements. There was no significant relationship between
age of child and rate of dietary intervention use. The
majority (86 %) of parents were aware of the GFCFD and
29 % were currently implementing it. For the small number
of parents implementing other diets, there was no consis-
tent pattern discernable from the few free-text descriptors
provided by parents (examples included the CHO (carbo-
hydrate) diet and soya diet).
For the 76 children currently on the GFCFD, most
parents reported a change in their child’s behavior with
‘significant improvements’ (5 point scale: significant
decline, decline, no change, improvement, significant
improvement) most frequently reported for gastrointestinal
symptoms (54 %). Other symptoms reported to ‘signifi-
cantly improve’ included concentration and attention
(42 %), communication (29 %), social interaction (25 %)
and repetitive interests and behaviors (20 %). A further 22
parents (29 % of children on the GFCFD) reported ‘some
improvement’ in gastrointestinal symptoms. Thus the
majority of children (83 %, n = 63) on the GFCFD
experienced at least some improvement in gastrointestinal
symptoms. Only 8 of these 63 children had no reported
change in social interaction and 13 had no reported change
in communication. A higher figure of 20 children were
reported to show no change in repetitive interests and
behaviors.
For 10 children there was worsening anxiety and
aggression (Table 2).
Seventy three percent of professionals stated that there
was ‘insufficient evidence about the benefits or otherwise’
of the GFCFD. Nearly two thirds of professionals felt that
they had sufficient knowledge about the GFCFD to discuss
it with families. Most reported that they would support
families wishing to pursue the GFCFD but would not
specifically recommend it to families. 19 % stated that they
would advise parents against the use of the GFCFD.
Research Priorities
Parents and professionals were asked to rate their top 3
priorities from a list of 22 ASD research topics. The option
topics were based on previous surveys (Charman and Clare
2004; Mills and Wing 2005) and findings from consultation
with parents and professionals during the questionnaire
development. 16 % (the second largest grouping) of pro-
fessionals and just under 10 % of parents (by fourth largest
group of parents) rated dietary interventions and behavioral
difficulties as their top priority for ASD research (data
Fig. 1 Interventions currently
used by parents. Single asterisk
Dietary manipulations included
use of special diets such as the
GFCFD and dietary
supplements (micronutrients,
vitamins, minerals, fish oils).
Double asterisk complementary
and Alternative Therapies
included homeopathy,
acupuncture and massage
Table 2 Parent reports of
current use of dietary
interventions (special diets and
supplements)
Age Dietary
Supplement
%(n)
Special Diet
%(n)
GFCF Diet
%(n)
3 or more behaviour
problems
%(n)
\2 year 11 months 40 (2) 20 (1) 20 (1) 40 (2)
3–5 year–11 months 41 (33) 37 (30) 31 (25) 66 (54)
6–11 years 50 (86) 34 (59) 29 (50) 67 (115)
Total 47 (121) 35 (90) 29 (76) 66 (171)
J Autism Dev Disord (2014) 44:747–757 751
123
available from last author). Parents with children under the
age of 3 (only 5 children) prioritized research into causes
and early intervention; aged 3–5 years 11 months—com-
munication, causes, early intervention, behavior difficulties
and dietary interventions. For children aged 6 years–
11 years, parents were most interested in research into
causes, communication, dietary interventions and behavior
difficulties. For children talking in sentences, parents rated
causes, behavioral difficulties, communication, early
intervention, dietary interventions and anxiety as their top
priorities.
Professionals top 5 research priorities were: behavioral
difficulties (17 %), dietary interventions (16 %), causes
(14 %), early intervention (just under 12 %) and diagnosis
(8 %) (further details available from last author).
Barriers and Facilitators Towards Participation
in a Proposed Randomized Controlled Trial
of the GFCFD
Seventy eight percent of parents reported they would
consider taking part in the proposed RCT. Of these, the
majority 109 (85 %) answered ‘yes’ and a further 13
(10 %) ‘maybe’ when asked if they would be prepared for
their child to be randomly allocated to a ‘Test Food group
with a 50 % chance of being in the gluten and casein free
group’. Of the parents who suggested they would ‘agree’
to take part, nearly half (45 %) answered a subsequent
item by scoring that ‘yes’ they would be more likely to
do so if they were not ‘blind’ to group allocation. For
parents who would not take part, most (63 %) would be
no more likely to take part if they were not blind. to
group allocation.
Parents were more likely to agree to take part if they
were not currently implementing the GFCFD for their child
(v
2
= 11.670, df = 2, p = \0.01). Of the 60 parents who
had previously taken part in an autism research project,
most responded positively to considering the proposed trial
but 19 who had taken part in previous research, indicated
they would definitely not take part (v
2
= 7.287, df = 2,
p = 0.026). All these parents expressed concerns about the
proposed study—citing for example concerns about the
impact of the research on their child’s existing limited diet,
or that their child was already on the GFCFD and they
would be reluctant to discontinue this intervention.
Considering the trial protocol, 77 % of parents thought
there was sufficient dietitian support and this was signifi-
cantly associated with likelihood to take part (v
2
= 30.539,
df = 2, p \ 0.001). Despite this, when asked what might
be the most difficult part of the study, 44 % of parents
expressed concern about getting their child to eat the range
of ‘Test’ foods that would be included in the child’s diet for
the duration of the trial to maintain blinding.
Professionals’ Views
Seventy five percent of professionals reported that they
would be prepared to recruit children to the proposed
GFCFD trial. Just under one third (31 %) had previously
referred families to ASD research studies. Professionals
highlighted a need for parents to have reliable access to
dietitians (telephone and face-to-face). Perceived barriers
to participation included that ‘the child’s diet may be too
limited to take part in the trial, and whether families would
be able to follow the procedure for the duration of the trial
(i.e. 6 months).
Discussion
This study has identified that most parents of children with
ASD who responded to this UK survey use a variety of
interventions (most frequently speech/communication,
educational and a mixture of dietary manipulations) and are
usually implementing several interventions at the same
time. These findings are in keeping with other recent sur-
veys of parents of children with ASD conducted in US and
Australia and highlight the multimodal approaches adopted
by parents as they combine different types of interventions
for their children (Carter et al. 2011b; Goin-Kochel et al.
2007; Green et al. 2006). The majority of respondents
(parents and professionals) were aware of the GFCFD and
indeed many parents had considered and/or tried the
GFCFD. The most popular dietary manipulations (again
often used in combination) were a range of dietary sup-
plements and use of special diets (usually the GFCFD). The
number of parents who reported that they were currently
implementing the GFCFD was at the higher end of previ-
ously reported surveys (Levy and Hyman 2003; Perrin
et al. 2012).
When parents were asked to specify the observed effects
of the GFCFD, in line with other surveys, they reported
improvement across a wide range of behaviors. Most par-
ents reported at least some improvement in gastrointestinal
symptoms often in combination with other behaviors.
Some parents reported significant improvements in other
behaviors (including concentration, attention and less fre-
quently in some of the core ASD behaviors). The parents’
preference for combinations of dietary manipulations, and
the lack of specificity in reported improved behaviors (but
usually including GI symptoms); add complexity to deci-
sions about appropriate research design and choice of pri-
mary outcome measure(s) for evaluation of the impact of a
complex intervention such as the GFCFD as an interven-
tion for ASD.
There was general agreement from both parent and
professional respondents for the need for more information
752 J Autism Dev Disord (2014) 44:747–757
123
about, and for more research on, a range of interventions
including dietary supplements and the use of ‘special’
diets. Professionals considered that they had sufficient
knowledge to discuss the GFCFD with parents who are
considering implementing the diet. These discussions may
well include issues such as the lack of a robust evidence
base for the GFCFD (Isherwood et al. 2011).
Dietary interventions were not the number one priority
for the majority of parents, but for parents with children of
different ages it was in the top 4–5 research topics. For
professionals, research into dietary intervention was the
second highest rated research priority. Many professionals
also indicated that they would appreciate further training in
dietary and other biomedical interventions. Since all pro-
fessionals who participated in this study indicated that they
saw a varying number of children with ASD whose parents
were considering and/or implementing the GFCFD, this
training would be relevant to all professional groups.
Indeed in the light of the professionals’ reported experience
(irrespective of their discipline), all professional groups do
need to be aware that at any one time at least some families
on their caseload may be contemplating/implementing the
GFCFD.
These findings may reflect the bias of those who com-
pleted the survey but, in keeping with previous research
recommendations (Medical Research Council 2001), it also
suggests that the dilemma of whether or not to attempt to
implement dietary interventions (such as the GFCFD) in
the absence of a robust evidence base continues to be a
relevant topic for both research and current clinical prac-
tice, with the inevitable resource implications for affected
families, research funding and service providers.
The novel use of a vignette protocol and flow chart to
illustrate the proposed design for an RCT within the survey
format appeared to be a successful way of investigating
attitudes to and identifying potential facilitators and bar-
riers for, a proposed trial to investigate the impact of the
GFCFD in young children with ASD. Respondents were
able to complete the sections of the questionnaire dedicated
to the proposed trial design. Over three-quarters of parents
and professionals stated their preparedness to be involved
in a proposed RCT of the GFCFD and provided valuable
feedback in response to structured questions about the trial
design. This reported willingness of both parents and
practitioners to engage in robustly designed research to
investigate a ‘controversial’ dietary intervention, where
there is a lack of scientific evidence, is encouraging for
potential researchers and grant funding organizations.
However, for an intervention such as the GFCFD, what is
the likelihood that funding one or more fully powered
RCTs will alter patterns of demand and uptake for the
intervention? An example of another ‘controversial’ bio-
medical but non-dietary intervention previously reported as
a treatment for ASD was the use of secretin (a gastroin-
testinal hormone). Following the publication of a series of
RCTs that reported an important and significant placebo
effect, but a lack of response to secretin, there has been a
consistent decline in and now virtual absence of parents’
requests for this hormone as a treatment for ASD (Sandler
2005; Williams et al. 2005).
From the parents’ and professionals’ responses, three
factors (current use of GFCFD, previous experience of
research and level of professional support) were identified
as potential barriers to recruitment and retention for the
proposed trial.
For some parents currently implementing the GFCFD it
might be that if they have already identified that their child is
benefitting or hope that there will be benefit from the
GFCFD, they may not want to risk allocation to the control
group. However for the majority of the parents neither pre-
vious use of the GFCFD nor the consideration of future
implementation of the GFCFD appeared to affect potential
for successful recruitment. Further consideration is needed
to clarify for parents who may be particularly committed to
this intervention, what might be the circumstances in which
they would be prepared to support the evaluation of the
GFCFD in their own child and in the wider ASD population.
There was a small subgroup of parents with prior
experience of taking part in research who were not pre-
pared for their child to take part in this proposed trial. All
gave reasons related to their child’s diet and/or other
constraints about the study—such as that their child was
already on the GFCFD and they would be reluctant to
discontinue this intervention. No parents cited their previ-
ous experience of research as a barrier to taking part.
However understanding service user attitudes to research,
their knowledge of research methodologies and minimizing
any potential longer term adverse impact of taking part in
research are important considerations. Linked to this con-
sideration of participants’ knowledge and understanding of
research design is another intriguing and unexpected result
that, amongst the parents who agreed that they would be
prepared to take part in the proposed RCT, 45 % also
indicated that they would be more likely to take part if they
were not ‘blind’ to group allocation. Whether this finding
indicated a lack of understanding about the proposed
research design, ambivalence about randomization or an
ambiguity in the design of the question is unclear. This
finding highlights the importance of detailed explanation
and a probable need for ongoing discussion to maximise
understanding at time of recruitment and to support com-
pliance and retention of participants. In the UK organiza-
tions such as INVOLVE funded by the National Institute
for Health Research promote knowledge and learning on
public engagement, partnership and involvement in
research (INVOLVE 2010).
J Autism Dev Disord (2014) 44:747–757 753
123
Parents agreed that the proposed levels of professional
support within the trial design presented would be suffi-
cient, but in common with the professionals they were
concerned about following the diet protocol for 6 months.
Consideration of reducing the duration of the GFCFD
protocol to 3 months might have been more acceptable to
parents and professionals but other authors have queried
whether this would then be a sufficient duration to detect a
beneficial effect (Johnson et al. 2011). Professionals rec-
ommended the need for additional professional support in
the form of ‘reliable’ telephone access with the dietitian.
This would allow parents to access urgent advice in addi-
tion to planned appointments with professionals. However
professionals also had specific concerns about the risks of
including children with very restricted diets (despite the
proposed funded availability of additional professional
support). A small feasibility study has already been
undertaken by our multisite collaboration which has dem-
onstrated that young children with ASD are prepared to eat
the Test Foods products (Adams et al. 2008).
Understanding the barriers and facilitators that impact
on recruitment and retention to evaluation studies is
important to the successful outcome of intervention
research (Friedman et al. 2010; Woodall et al. 2010). Most
of the factors identified in this study appear specific to the
complexity of research involving young children with
ASD. This information will be useful for refining the
research design and protocol for the evaluation of complex
interventions such as the GFCFD and other ASD inter-
ventions for which there is no firm evidence base.
The survey had a number of limitations, and also
strengths. The survey has a large sample of parents and
professionals. A two stage recruitment procedure was used
to allow collection of information about respondent char-
acteristics and minimize risk of multiple responses. These
strategies were successful—there was no evidence of sys-
tematic reporting bias from any particular group. Although
inevitably the survey respondents are likely to be those
parents and professionals with a particular interest in this
topic, parents reported a range of experiences with respect
to the GFCFD and professionals also expressed a spread of
opinions from those who wanted more information about
dietary interventions through to a smaller number who
would actively discourage parents from attempting to
implement the GFCFD. This allows us to have confidence
in the reported findings.
As with other internet surveys, parent respondents had
higher educational qualifications and were predominantly
from higher socio-economic groups. The child character-
istics were in keeping with other surveys of early years and
primary school aged children, with just under half having a
diagnosis of ASD, and most also reported to have a range
of additional problems. In this survey the majority of
children were attending mainstream educational provision
a consequence of UK education inclusion policy for chil-
dren with special needs to attend mainstream schools.
Professionals were distributed across the professional
groups which in turn reflects current UK clinical practice
(Bowers 2002; Scottish Intercollegiate Guidelines Network
2009; National Institute for Health and Clinical Excellence
2010).
Less than half the parents (41 %) were recruited from
the two regional databases but, as with previous electronic
survey studies, fathers, unemployed parents and those with
low educational attainment and low incomes were under-
represented. Further the two stage recruitment process was
a more time consuming process and almost certainly con-
tributed to the study attrition. Just over a quarter of parents
(29 %) and just under a quarter (23 %) of professionals
who registered on the PADIA website did not then use their
allocated unique ID number to access and complete the
questionnaires, despite up to two reminders. However no
systematic bias was identified between the respondents
who completed the whole process and those that only
registered an expression of interest. The predominantly
fixed-choice response format of the questionnaire limited
the amount of detailed information obtained from indi-
vidual respondents, for example little detail was obtained
about the range of dietary supplements given to children.
Conclusion
Despite lack of evidence, most parents of children with
ASD continue to implement several interventions at the
same time. Parents of children with ASD, and the profes-
sionals who work in this area, strongly endorse the need for
accurate information about a variety of interventions and
would be prepared to consider taking part in a proposed
RCT design to evaluate the GFCFD. The information
provided by the respondents will be used to improve future
research proposals with the aim to increase the scientific
evidence in this controversial area.
Acknowledgments The authors wish to thank all the parents and
professionals who took the time completing the survey and Rachael
Taylor for administrative assistance. The study was funded by Autism
Speaks.
Conflict of interest The authors declare that they have no conflicts
of interest.
754 J Autism Dev Disord (2014) 44:747–757
123
Appendix
J Autism Dev Disord (2014) 44:747–757 755
123
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... Of the various treatment options, therapeutic diets have received relatively little research despite being widely used by autism families [9]. Several survey studies have reported benefits from therapeutic diets in some ASD symptoms, including behavior, communication, and health, as well as gastrointestinal issues, attention, communication, and socialization [10,11]. Clinical experience also demonstrates that dietary intervention can improve some core ASD symptoms. ...
... Many of the diets discussed above have had little research on them, and there is almost no research to compare the efficacy of one diet vs. another. Survey research on therapeutic diets for ASD provides initial evidence on the benefit and effects of many diet strategies [9][10][11]. However, some studies are rather small with 37 respondents and report on the improvement from therapeutic diets as a whole (not individual diets) [10], and other surveys are limited to results on only one or a few diets [9,11]. ...
... Survey research on therapeutic diets for ASD provides initial evidence on the benefit and effects of many diet strategies [9][10][11]. However, some studies are rather small with 37 respondents and report on the improvement from therapeutic diets as a whole (not individual diets) [10], and other surveys are limited to results on only one or a few diets [9,11]. One huge survey study included data from over 27,000 families [50] on many treatments, including several diets, and reported 45-71% of individuals improved on various diets with rare adverse effects (2-7%), but did not specify which symptoms improved. ...
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This study presents the results of the effectiveness of 13 therapeutic diets for autism spectrum disorder from 818 participants of a national survey, including benefits, adverse effects, and symptom improvements. The average Overall Benefit of diets was 2.36 (0 = no benefit, 4 = great benefit), which was substantially higher than for nutraceuticals (1.59/4.0) and psychiatric/seizure medications (1.39/4.0), p < 0.001. The average Overall Adverse Effects of diets was significantly lower than psychiatric/seizure medications (0.10 vs. 0.93, p < 0.001) and similar to nutraceuticals (0.16). Autism severity decreased slightly over time in participants who used diet vs. increasing slightly in those that did not (p < 0.001). Healthy and Feingold diets were the two top-rated diets by Overall Benefit; the ketogenic diet was the highest for nine symptoms (though had fewer respondents); and the gluten-free/casein-free diet was among the top for overall symptom improvements. Different diets were reported to affect different symptoms, suggesting that an individual’s symptoms could be used to guide which diet(s) may be the most effective. The results suggest that therapeutic diets can be safe and effective interventions for improving some ASD-related symptoms with few adverse effects. We recommend therapeutic diets that include healthy foods and exclude problematic foods. Therapeutic diets are inexpensive treatments that we recommend for consideration by most people with ASD.
... Moreover, evidence from several observational studies and clinical trials suggests that high intake of nuts, seeds, berries and cruciferous vegetables has beneficial effects on the immune system, as well as communication skills and behaviour in the general population (12)(13)(14)(15)(16). Recently, nuclear peroxisome proliferator-activated receptors (PPARs) and regulatory T cells (Tregs) were identified as promising targets for pharmacologic treatment in ASD, alongside nutritional therapy with nuts and berries (17)(18)(19)(20)(21). Diets vary across countries and cultures, and comparisons between them can be compromised due to different backgrounds. Overall, scientific evidence for the elimination of casein and gluten from the diet of autistic children is poor (6,22,23), which contrasts with the unflagging interest of parents in these interventions, for which information is being sought from friends, support groups and media sources more so than from medical professionals (24). Parental descriptions make claims for high rates of success from gluten-and/or casein-free diets as an intervention in ASD, but at the same time it is not possible to identify what specific behavioural outcomes caregivers saw as changed (22,24). ...
... Overall, scientific evidence for the elimination of casein and gluten from the diet of autistic children is poor (6,22,23), which contrasts with the unflagging interest of parents in these interventions, for which information is being sought from friends, support groups and media sources more so than from medical professionals (24). Parental descriptions make claims for high rates of success from gluten-and/or casein-free diets as an intervention in ASD, but at the same time it is not possible to identify what specific behavioural outcomes caregivers saw as changed (22,24). Research exploring the relationship between the introduction of a gluten-free diet (GFD) and a casein-and gluten-free diet (CGFD) in autistic children, and the frequency of consumption of nuts, seeds, berries and cruciferous vegetables has never been undertaken in monoethnic populations. ...
... Research on dietary patterns in children with ASD is often marred by lack of comparison groups; therefore, definitive conclusions cannot be drawn from the literature (23,24). In the presented study, two groups of patients with ASD under dietetic intervention were compared to control patients on a regular diet. ...
Article
Full-text available
Background: The high intake of nuts, seeds, berries and cruciferous vegetables has beneficial effects on the immune system, as well as communication skills and behaviour. Gluten-and/or casein-free diets are the most common interventions in ASD patients; however, scientific evidence for their use is poor. Objective: The aim is to explore the relationship between the implementation of a gluten-free diet or a casein-and gluten-free diet in ASD children and the frequency of consumption of nuts, seeds, berries and cruciferous vegetables. Methods: A sample of 88 ASD patients and their mothers was followed for 12 months after making their free choice of a gluten-free diet, a gluten-and casein-free diet or a regular diet. The Food Frequency Questionnaire (FFQ) was used to gather information about the frequency of consuming assortment groups of products. Results: Children with ASD on a gluten-and casein-free diet have significantly higher intake of seeds, berry fruits and cruciferous vegetables than controls, while patients on a gluten-free diet consumed more frequently seeds and cruciferous vegetables. In both groups, after dietetic intervention, the frequency of nut consumption tended to be higher than in patients on a regular diet. Conclusions: Unflagging interest and frequently reported subjective feelings of improvement in parents of autistic children on elimination diets may be due to the healthy balance of modified diets and their multidirectional impact.
... Several survey studies have highlighted positive outcomes associated with therapeutic diets, showing improvements in specific ASD symptoms such as behavior, communication, and overall health. Additionally, benefits have been reported in managing GI problems, attention issues, communication skills, and social interaction [20,21]. Despite widespread interest in dietary interventions, there is no agreement on effective nutritional therapy. ...
Preprint
Full-text available
Autism spectrum disorder (ASD) involves social communication difficulties and repetitive behaviors, with a growing prevalence worldwide. Symptoms include cognitive impairments, gastrointestinal (GI) issues, feeding difficulties, and psychological problems. A significant concern in ASD is food selectivity, leading to nutrient deficiencies. Common GI issues in ASD, such as constipation and irritable bowel syndrome, stem from abnormal gut flora and immune system dysregulation. Sensory sensitivities and behavioral challenges exacerbate these problems, correlating with neurological symptom severity. Children with ASD also exhibit higher oxidative stress due to low antioxidant levels like glutathione. Therapeutic diets, including ketogenic, high-antioxidant, gluten-free, and casein-free, show potential in managing ASD symptoms like behavior, communication, GI issues, and oxidative stress, though the evidence is limited. Various studies have focused on different populations, but there is increasing concern about the impact on children. This review examines the effect of food selectivity, GI problems, and antioxidant deficiencies in ASD and revises the effectiveness of various therapeutic diets, highlighting the need for further research to confirm their long-term benefits.
... Another reason for the discrepancy may be parents tend to only want information on how to deal with the situation of their children. Efforts should be made to ensure that information from healthcare professionals can lead to parental knowledge and practical skills, including cooking skills, and both parents and professionals can work together to improve the quality of meals for children's healthy development [12,41,42]. It is also suggested that parents and professionals may have different interpretations of diets and meal preparation [8,43], and the understanding of diets and meal preparation may be related to the parental childcare environment and parent-child communication [44]. ...
Article
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Background A gap has been reported between healthcare professionals’ (hereafter “professionals”) recognition of preschool children’s diets and parents’ perception of concern. This study investigated the gap between the concerns reported by professionals and parents’ perceptions regarding health and dietary habits by age (18 months and 3 years) and gender in Japan. Methods The study design consisted of a cross-sectional, multilevel survey. The request letters were sent to all households with target children with the cooperation of local governments. After obtaining written informed consent from parents, questionnaires were distributed to them. The survey included 30 items on children's concerns about health and dietary habits. At the health checkup, parents indicated whether they were concerned in response to each item, and responded child’s height and weight and birth height and weight. Next, the professionals provided counseling to the parents at a health checkup. After that, the professionals noted their concerns in response to the same 30 items as those given to parents. The participation rates were 82.9% (18 months) and 82.8% (3 years). Data of 239 persons for 18 months and 223 persons for 3 years old were analyzed. In the statistical analysis, the items that were judged as concerning by professionals but not by parents were identified; likewise, the items that were of concern to parents but not to professionals were identified. Sensitivity, false negative rate, specificity, false positive rate, and Youden index were calculated to analyze the discordance rate for each item. Results Many parents in this study were concerned about the issues that professionals did not consider to be concerning. Moreover, the parents worried about more issues for 3-year-olds than for 18-month-olds. The items for which ≥ 10 professionals indicated concerns and with higher discordance between the professionals and parents for both boys and girls were “picky eating” for 18-month-olds and “inconsistent amount of food” for 3-year-olds. Conclusions The concerns that professionals have with respect to children's diets and the things that parents worry about show gaps. It might be necessary to provide professional counseling for parents to develop a correct understanding of their children’s dietary habits.
... According to various studies, the adoption rate of such diets in children with ASD is between 17 and 66% (Bandini et al. 2010;Herndon et al. 2009;Perrin et al. 2012;Wong and Smith 2006). Moreover, according to a survey conducted in the UK, 80% of parents reported to have used dietary intervention for their children with ASD, and 29% of them had administered a GF-CF diet (Winburn et al. 2014). ...
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Autism spectrum disorder (ASD) is one of the diverse groups of neurodevelopmental disorders, and with a rising prevalence globally. ASD constitutes a significant public health concern. Challenges in ASD assessment pose barriers in terms of diagnosis, and it might be detected much later in life. It presents a significant health concern during the critical growing years of infancy for the child and the family, with direct psychological consequences. Individuals with ASD might lead an independent life or require lifelong support, accompanied by varying levels of impairment of individual functioning and quality of life. With improvement in the understanding of ASD over the last few decades, there was a revision of the diagnostic criteria in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) and the eleventh edition of the International Classification of Diseases (ICD-11) manuals. Many developmental screening tools are available, and in the absence of specific medical investigations, physicians who make the first contact with patients, such as primary care physicians and pediatricians, must have a relatively high index of suspicion for this disorder. Early diagnosis must be coupled with prompt referral to specialists, developmental pediatricians, child psychiatrists, or psychologists to ensure the coordination of holistic care to the affected children and their families. Pharmacologic agents and non-pharmacologic therapies such as dietary interventions are available. The pharmacological agents include selective serotonin reuptake inhibitors (SSRIs), antidepressants, and psychostimulants. The SSRIs have the most beneficial impact on challenging behaviors in children. Of the proposed dietary approaches, the elimination of diets such as the gluten- and casein-free diet (GF-CF diet) has been shown to address ASD symptoms in some studies. However, the evidence is not strong enough to support recommendations for this intervention in clinical practice. Novel evidence for nutritional interventions is emerging, and ongoing research might elucidate its exact role and the long-term effects on metabolism, metabolic dysfunction, and nutritional deficiencies to address the core symptoms of ASD.KeywordsAutism spectrum disorderAutismASDGluten-free casein-free dietGF-CF dietSelective serotonin reuptake inhibitorsSSRIs
... According to various studies, the adoption rate of such diets in children with ASD is between 17 and 66% (Bandini et al. 2010;Herndon et al. 2009;Perrin et al. 2012;Wong and Smith 2006). Moreover, according to a survey conducted in the UK, 80% of parents reported to have used dietary intervention for their children with ASD, and 29% of them had administered a GF-CF diet (Winburn et al. 2014). ...
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Adhesion G protein-coupled receptors (AGPCRs) are a 33-member subfamily of Class B GPCRs that control many physiological processes and are implicated in disease. AGPCRs play a role in cell-cell adhesion and neuron guidance via different proteins present in the surface of the cells and play a role in the development of glutamatergic synapses in the cortex. The most crucial function of Parkin RBR E3 ubiquitin protein ligase (PARK2) gene is unknown; moreover, the encoded protein is a component of a multiprotein E3 ubiquitin ligase complex that mediates the targeting of substrate proteins for proteasomal degradation. Mutations in the gene are known to cause Parkinson disease and autosomal recessive juvenile Parkinson disease. The researchers have shown that the Contactin-associated protein-like 2 (CNTNAP2) gene is associated with different symptoms of autism spectrum disorders (ASDs) and other neurodevelopmental disorders. The CNTNAP2 gene, coding for the cell adhesion glycoprotein Caspr2, is thought to be one of the major susceptibility genes for ASD. A large number of rare heterozygous missense CNTNAP2 variants have been identified in ASD patients. However, the intricate biochemical and molecular machinery contributing to the neurological disorders is still unknown. Here, we discuss the regulatory role of these proteins in neurodevelopmental disorders (NDDs).KeywordsAttention-deficit/hyperactivity disorderADHDOrphan receptorUnc-5 receptorNetrinADGRL3PARK2CNTNAP2 and neurodevelopmental disorders
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Autism in a neurodevelopmental disorder impairing the social communication, social interaction, and restricted activity, that is usually diagnosed in the first 3 years of life. There has been a growing interest understanding the significance of adopting a gluten-free and casein-free (GFCF) diet. Variations in the interactions between the gut microbiota and the brain are important in several brain-related illnesses, like autism. Autism sufferers typically exhibit an imbalance in the composition of their gut flora, which may be a factor in their gastrointestinal symptoms. In people with ASD, this imbalance also compromises the integrity of the intestinal barrier and the blood–brain barrier (BBB). Toxins, proinflammatory cytokines, and partially digested peptides are among the substances that can pass through the blood–brain barrier and enter the bloodstream, ultimately reaching the central nervous system. The build-up of these chemicals may have detrimental effects on brain activity. According to one theory, partially digested peptides may aggravate behaviors particular to autism and lessen pain sensitivity by functioning as opioid agonists. Dietary therapies, especially elimination diets, are thought to be complementary therapies for this illness. The Gluten-Free Casein-Free (GFCF) diet is one such diet that calls for removing proteins from the regular diet, such as casein and gluten. Nevertheless, there is a paucity of research clarifying the mechanism of the GFCF diet and demonstrating its therapeutic effects on individuals with autism. The opioid theory is consistent with this lack of data. This chapter aims to investigate the gastrointestinal and behavioural problems frequently associated with autism, possible mechanisms of action of GFCF diets, and efficacy of these elimination diets.
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Autism spectrum disorder (ASD) involves social communication difficulties and repetitive behaviors, and it has a growing prevalence worldwide. Symptoms include cognitive impairments, gastrointestinal (GI) issues, feeding difficulties, and psychological problems. A significant concern in ASD is food selectivity, leading to nutrient deficiencies. Common GI issues in ASD, such as constipation and irritable bowel syndrome, stem from abnormal gut flora and immune system dysregulation. Sensory sensitivities and behavioral challenges exacerbate these problems, correlating with neurological symptom severity. Children with ASD also exhibit higher oxidative stress due to low antioxidant levels like glutathione. Therapeutic diets, including ketogenic, high-antioxidant, gluten-free and casein-free, and probiotic-rich diets, show potential in managing ASD symptoms like behavior, communication, GI issues, and oxidative stress, though the evidence is limited. Various studies have focused on different populations, but there is increasing concern about the impact among children. This review aims to highlight the food preferences of the ASD population, analyze the effect of the physicochemical and nutritional properties of foods on the selectivity in its consumption, GI problems, and antioxidant deficiencies in individuals with ASD, and evaluate the effectiveness of therapeutic diets, including diets rich in antioxidants, gluten-free and casein-free, ketogenic and essential fatty acids, and probiotic-rich diets in managing these challenges.
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ASDs (Autism Spectrum Disorders); is a neurodevelopmental disorder in which the symptoms and effects are different in each individual and there is an increase in prevalence worldwide. The increase in ASDs prevalence may be due to the increase in diagnostic criteria. The causes of ASDs are thought to be genetic, environmental and neurobiological factors. In recent years, studies have been conducted on the effect of dietary approaches on improving ASDs symptoms. Researchers are studying on dietary approaches based on the interaction between the brain and the gut. This review includes studies on the most popular dietary approach, the gluten-free and casein-free diet, and the effects of Omega 3, vitamin D, vitamin B12, folic acid and probiotic supplements on ASDs core symptoms. The results of the studies are evaluated according to special ASDs symptom criteria scores. The limited number of studies, the low number of participants in some studies and the lack of significant improvements are seen as limiting aspects of the studies.
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Autism spectrum disorder (ASD) is a neurodevelopmental disorder which can present with a variety of challenges including behavioral concerns, gastrointestinal (GI) complaints, and nutritional concerns. Dietary approaches have been explored as potential interventions that could address the role of the gut-brain axis in ASD. The most commonly proposed dietary approaches include gluten-free diets, casein-free diets, dietary supplementation, and/or probiotics, in an attempt to decrease behavioral and/or GI symptoms. Unfortunately, research on these dietary interventions for behavioral and/or GI symptoms in ASD is limited and results are mixed. Overall, these approaches have not demonstrated any significant benefit when evaluated in research studies. However, many caregivers trial these dietary approaches. More prospective controlled trials with large sample sizes are needed to determine whether specific subpopulations of youth with ASD and behavioral and/or GI symptoms might benefit from certain dietary interventions in order to confidently make recommendations regarding the ideal diet for youth with ASD.
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Background and objective: Children and adolescents with autism spectrum disorder (ASD) often use complementary and alternative medicine (CAM), usually along with other medical care. This study aimed to determine associations of ASD diagnostic category, co-existing conditions, and use of medications with use of CAM. Methods: We used the Autism Speaks Autism Treatment Network patient registry, which collects information on CAM use, medical conditions, and psychotropic medication at enrollment. CAM was categorized as special diets versus "other" CAM; ASD was defined as autism, pervasive developmental disorder (PDD), or Asperger's. Gastrointestinal symptoms, seizure disorders, sleep problems, and medication use were determined from parent report. Child Behavior Checklist (CBCL) scores were used to measure behavioral symptoms. Logistic regression was used to determine associations of diagnostic category, other medical conditions, and medication use with CAM treatments, controlling for demographic characteristics. Results: Of 3413 subjects in the registry as of April 2011, 3173 had complete data on CAM use: 896 (28%) reported any use; 548 (17%), special diets; and 643 (20%), other CAM. Higher rates of CAM use were associated with gastrointestinal symptoms (odds ratio [OR] = 1.88), seizures (OR = 1.58), and CBCL total score >70 (OR = 1.29). Children with PDD (OR = 0.62), Asperger's (OR = 0.66), or using medications (0.69) had lower rates. Conclusions: Children with ASD use more CAM when they have co-existing gastrointestinal symptoms, seizure disorders, and behavior problems. This study suggests the importance of asking about CAM use in children with ASD, especially those with complex symptoms.
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Parents (n=498) of children with autism spectrum disorders (ASD) reported via web-based questionnaires what sources they use for information (M=6.9; range 0 -15) and support (M=5.9, range 0 - 16). The most frequent source of both information and support was other parents of children with ASD. Lower-income parents used fewer information sources and reported fewer supports than middle or upper income parents. In particular, lowerincome parents were less likely to attend group gatherings around autism issues.
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Parents of children with autism spectrum disorders (ASD) try many and varied interventions and therapies in the hopes of improving their children's outcomes; however, empirical evidence supporting (or opposing) the vast majority of treatments is limited or nonexistent. This study examined caregiver efficacy ratings for a wide range of biological and educational/behavioral treatments commonly used for children with ASD. A web-based questionnaire regarding the development of children with ASD was distributed nationally and internationally through more than 200 autism-support organizations; results were analyzed from 479 parents (91% mothers) who reported on their children with autism, Asperger's syndrome, or PDD-NOS (M age=8.3 years, 80.2% male). Improvement – whether small or dramatic – was rated for 50–80% of children in each of 9 drug categories, while ratings of “child became worse” were reported for 15–20.3%. Approximately half of children were said to improve while on a special diet; 51% of those on a gluten-free and/or casein-free (GF/CF) diet were reportedly improved, while no observable effects of the GF/CF diet were indicated for about one quarter of participating children. For 10 of the 16 educational/behavioral therapies, parents reported improvement for approximately 70% of children. The most common rating was “child improved somewhat” followed by “child improved dramatically.” Results are discussed relative to the meaning of “improvement” in ASD and in light of both placebo effects and cost of treatments/therapies.
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Postal and electronic questionnaires are widely used for data collection in epidemiological studies but non-response reduces the effective sample size and can introduce bias. Finding ways to increase response to postal and electronic questionnaires would improve the quality of health research. OBJECTIVES: To identify effective strategies to increase response to postal and electronic questionnaires. SEARCH STRATEGY: We searched 14 electronic databases to February 2008 and manually searched the reference lists of relevant trials and reviews, and all issues of two journals. We contacted the authors of all trials or reviews to ask about unpublished trials. Where necessary, we also contacted authors to confirm methods of allocation used and to clarify results presented. We assessed the eligibility of each trial using pre-defined criteria. SELECTION CRITERIA: Randomised controlled trials of methods to increase response to postal or electronic questionnaires. DATA COLLECTION AND ANALYSIS: We extracted data on the trial participants, the intervention, the number randomised to intervention and comparison groups and allocation concealment. For each strategy, we estimated pooled odds ratios (OR) and 95% confidence intervals (CI) in a random-effects model. We assessed evidence for selection bias using Egger's weighted regression method and Begg's rank correlation test and funnel plot. We assessed heterogeneity among trial odds ratios using a Chi(2) test and the degree of inconsistency between trial results was quantified using the I(2) statistic. MAIN RESULTS: PostalWe found 481 eligible trials. The trials evaluated 110 different ways of increasing response to postal questionnaires. We found substantial heterogeneity among trial results in half of the strategies. The odds of response were at least doubled using monetary incentives (odds ratio 1.87; 95% CI 1.73 to 2.04; heterogeneity P < 0.00001, I(2) = 84%), recorded delivery (1.76; 95% CI 1.43 to 2.18; P = 0.0001, I(2) = 71%), a teaser on the envelope - e.g. a comment suggesting to participants that they may benefit if they open it (3.08; 95% CI 1.27 to 7.44) and a more interesting questionnaire topic (2.00; 95% CI 1.32 to 3.04; P = 0.06, I(2) = 80%). The odds of response were substantially higher with pre-notification (1.45; 95% CI 1.29 to 1.63; P < 0.00001, I(2) = 89%), follow-up contact (1.35; 95% CI 1.18 to 1.55; P < 0.00001, I(2) = 76%), unconditional incentives (1.61; 1.36 to 1.89; P < 0.00001, I(2) = 88%), shorter questionnaires (1.64; 95% CI 1.43 to 1.87; P < 0.00001, I(2) = 91%), providing a second copy of the questionnaire at follow up (1.46; 95% CI 1.13 to 1.90; P < 0.00001, I(2) = 82%), mentioning an obligation to respond (1.61; 95% CI 1.16 to 2.22; P = 0.98, I(2) = 0%) and university sponsorship (1.32; 95% CI 1.13 to 1.54; P < 0.00001, I(2) = 83%). The odds of response were also increased with non-monetary incentives (1.15; 95% CI 1.08 to 1.22; P < 0.00001, I(2) = 79%), personalised questionnaires (1.14; 95% CI 1.07 to 1.22; P < 0.00001, I(2) = 63%), use of hand-written addresses (1.25; 95% CI 1.08 to 1.45; P = 0.32, I(2) = 14%), use of stamped return envelopes as opposed to franked return envelopes (1.24; 95% CI 1.14 to 1.35; P < 0.00001, I(2) = 69%), an assurance of confidentiality (1.33; 95% CI 1.24 to 1.42) and first class outward mailing (1.11; 95% CI 1.02 to 1.21; P = 0.78, I(2) = 0%). The odds of response were reduced when the questionnaire included questions of a sensitive nature (0.94; 95% CI 0.88 to 1.00; P = 0.51, I(2) = 0%).ElectronicWe found 32 eligible trials. The trials evaluated 27 different ways of increasing response to electronic questionnaires. We found substantial heterogeneity among trial results in half of the strategies. The odds of response were increased by more than a half using non-monetary incentives (1.72; 95% CI 1.09 to 2.72; heterogeneity P < 0.00001, I(2) = 95%), shorter e-questionnaires (1.73; 1.40 to 2.13; P = 0.08, I(2) = 68%), including a statement that others had responded (1.52; 95% CI 1.36 to 1.70), and a more interesting topic (1.85; 95% CI 1.52 to 2.26). The odds of response increased by a third using a lottery with immediate notification of results (1.37; 95% CI 1.13 to 1.65), an offer of survey results (1.36; 95% CI 1.15 to 1.61), and using a white background (1.31; 95% CI 1.10 to 1.56). The odds of response were also increased with personalised e-questionnaires (1.24; 95% CI 1.17 to 1.32; P = 0.07, I(2) = 41%), using a simple header (1.23; 95% CI 1.03 to 1.48), using textual representation of response categories (1.19; 95% CI 1.05 to 1.36), and giving a deadline (1.18; 95% CI 1.03 to 1.34). The odds of response tripled when a picture was included in an e-mail (3.05; 95% CI 1.84 to 5.06; P = 0.27, I(2) = 19%). The odds of response were reduced when "Survey" was mentioned in the e-mail subject line (0.81; 95% CI 0.67 to 0.97; P = 0.33, I(2) = 0%), and when the e-mail included a male signature (0.55; 95% CI 0.38 to 0.80; P = 0.96, I(2) = 0%). AUTHORS' CONCLUSIONS: Health researchers using postal and electronic questionnaires can increase response using the strategies shown to be effective in this systematic review.
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Postal questionnaires are widely used for data collection in epidemiological studies but non-response reduces the effective sample size and can introduce bias. Finding ways to increase response rates to postal questionnaires would improve the quality of health research. Objectives To identify effective strategies to increase response rates to postal questionnaires. Search strategy We aimed to find all randomised controlled trials of strategies to increase response rates to postal questionnaires. We searched 14 electronic databases to February 2003 and manually searched the reference lists of relevant trials and reviews, and all issues of two journals. We contacted the authors of all trials or reviews to ask about unpublished trials. Where necessary, authors were also contacted to confirm methods of allocation used and to clarify results presented. We assessed the eligibility of each trial using pre-defined criteria. Selection criteria Randomised controlled trials of methods to increase response rates to postal questionnaires. Data collection and analysis We extracted data on the trial participants, the intervention, the number randomised to intervention and comparison groups and allocation concealment. For each strategy, we estimated pooled odds ratios and 95% confidence intervals in a random effects model. Evidence for selection bias was assessed using Egger's weighted regression method and Begg's rank correlation test and funnel plot. Heterogeneity among trial odds ratios was assessed using a chi-square test at a 5% significance level and the degree of inconsistency between trial results was quantified using I-2. Main results We found 372 eligible trials. The trials evaluated 98 different ways of increasing response rates to postal questionnaires and for 62 of these the combined trials included over 1,000 participants. We found substantial heterogeneity among trial results in half of the strategies. The odds of response were at least doubled using monetary incentives (odds ratio 1.99, 95% CI 1.81 to 2.18; heterogeneity p<0.00001, I-2=78%), recorded delivery (2.04, 1.60 to 2.61; p=0.0004, I-2=69%), a teaser on the envelope - e.g. a comment suggesting to participants that they may benefit if they open it (3.08, 1.27 to 7.44) and a more interesting questionnaire topic (2.44, 1.99 to 3.01; p=0.74, I-2=0%). The odds of response were substantially higher with pre-notification (1.50, 1.29 to 1.74; p<0.00001, I-2=90%), follow-up contact (1.44, 1.25 to 1.65; p<0.0001, I-2=68%), unconditional incentives (1.61, 1.27 to 2.04; p<0.00001, I-2=91%), shorter questionnaires (1.73, 1.47 to 2.03; p<0.00001, I-2=93%), providing a second copy of the questionnaire at follow-up (1.51, 1.13 to 2.00; p<0.00001, I-2=83%), mentioning an obligation to respond (1.61, 1.16 to 2.22; p=0.98, I-2=0%) and university sponsorship (1.32, 1.13 to 1.54; p<0.00001, I-2=83%). The odds of response were also increased with non-monetary incentives (1.13, 1.07 to 1.21; p<0.00001, I-2=71%), personalised questionnaires (1.16, 1.07 to 1.26; p<0.00001, I-2=67%), use of coloured as opposed to blue or black ink (1.39, 1.16 to 1.67), use of stamped return envelopes as opposed to franked return envelopes (1.29, 1.18 to 1.42; p<0.00001, I-2=72%), an assurance of confidentiality (1.33, 1.24 to 1.42) and first class outward mailing (1.12, 1.02 to 1.23). The odds of response were reduced when the questionnaire included questions of a sensitive nature (0.94, 0.88 to 1.00; p=0.51, I-2=0%), when questionnaires began with the most general questions (0.80, 0.67 to 0.96), or when participants were offered the opportunity to opt out of the study (0.76, 0.65 to 0.89; P=0.46, I-2=0%). Authors' conclusions Health researchers using postal questionnaires can increase response rates using the strategies shown to be effective in this systematic review.
Article
Objective: The impact of abnormal feeding behaviors reported for children with autism spectrum disorders (ASDs) on their nutritional status is unknown. We compared nutrient intake from food consumed by children with and without ASD and examined nutrient deficiency and excess. Methods: Prospective 3-day food records and BMI for children (2-11 years) with ASD participating in the Autism Treatment Network (Arkansas, Cincinnati, Colorado, Pittsburgh, and Rochester) were compared with both the National Health and Nutrition Examination Survey data and a matched subset based on age, gender, family income, and race/ethnicity (N = 252 analyzed food records). Results: Children with ASD and matched controls consumed similar amounts of nutrients from food. Only children with ASD aged 4 to 8 years consumed significantly less energy, vitamins A and C, and the mineral Zn; and those 9 to 11 years consumed less phosphorous. A greater percentage of children with ASD met recommendations for vitamins K and E. Few children in either group met the recommended intakes for fiber, choline, calcium, vitamin D, vitamin K, and potassium. Specific age groups consumed excessive amounts of sodium, folate, manganese, zinc, vitamin A (retinol), selenium, and copper. No differences were observed in nutritional sufficiency of children given restricted diets. Children aged 2 to 5 years with ASD had more overweight and obesity, and children 5 to 11 years had more underweight. Conclusions: Children with ASD, like other children in America, consume less than the recommended amounts of certain nutrients from food. Primary care for all children should include nutritional surveillance and attention to BMI.