This article was written in 1995
(Updated December 2006).
The Use of Gluten and Casein Free Diets with
People with Autism
Paul Shattock & Paul Whiteley
Autism Research
Unit,
These
notes do not constitute a recommendation or endorsement of a dietary method to
alleviate the symptoms of autism or related pervasive developmental disorder.
Any decision to undertake such a method must lie solely with the person with
autism or with those having responsibility for their care. It is strongly
recommended that anyone considering such interventions seek the support of
their Medical Practitioner and, if possible, a knowledgeable dietician or
nutritionist.
Background
In the
early 1980s a number of researchers, including Herman and Panksepp,
noted the similarities between the behavioural effects on animals of opioids,
such as morphine, and the symptoms of autism. In a very speculative paper,
Panksepp proposed a mechanism whereby people with autism may have elevated
levels of opioids which occur naturally in the Central Nervous
System (CNS) of humans. The best known of these naturally occurring opioid
compounds is beta-endorphin
(endogenous morphine) and certainly
there is a degree of correlation between the known effects of this compound and
the symptoms of autism. Just after this, Gillberg
produced evidence of elevated levels of "endorphin-like substances" in the cerebrospinal fluid of some
people with autism. In particular, elevated levels appeared in those children
who appeared to feel pain less and who exhibited self-injurious
behaviour. At about the same time, Reichelt
produced evidence of abnormal peptides in the urine of people with autism. We
ourselves, like a number of other groups, attempted to replicate his findings.
Although his method was comparatively simple there were technical difficulties
and these attempts were, initially unsuccessful. Later on we switched to a more
sophisticated technique (HPLC) and have been
able to provide partial confirmation of Reichelt's
findings. In the urine of a proportion of people with autism and related
conditions, there appear to be elevated levels of substances with physico-chemical properties similar to those expected from
opioid peptides. The quantities of these compounds, as found in the urine, are
hypothesised to be much too large to be of CNS origin. The quantities are such
that they can only have been derived from the incomplete breakdown of certain
foods.
Proteins consist of long chains
of units known as amino-acids. Normally proteins are digested by enzymes in the
intestines being broken down into these units. However, if for some reason,
this digestion is incomplete, short chains of these amino-acids (known as peptides) will result. It is proposed
that these peptides may be biologically active and could result in some
symptoms similar to which we see in autism. The majority of these peptides will
be dumped in the urine, which is where Reichelt and we speculate that we are
finding them. A small proportion will cross into the brain and interfere with
transmission in such a way that normal activity is altered or disrupted. It may
be that these compounds, themselves, have a direct effect upon transmission or
that they will attach themselves to the enzymes which would break down our own
naturally occurring enzymes. The consequences would be the same in either case.
It is well known that casein
(from human or cow milk) will break down in the stomach to produce a peptide
known as casomorphin which, as the name implies, will have opioid activities.
Similar effects are noted with gluten
from wheat and some other cereals in which case the compounds formed are gluteomorphins. If this opioid excess hypothesis is
correct, there are a number of strategies which can be adopted. Firstly the
anti-opioid drug Naltrexone
could be considered, and promising initial results have been reported. Not all
of the reported trials on Naltrexone have produced positive benefits but where
appropriate very low dose therapies are employed the results seem to be better.
Alternatively, a diet which excludes casein (milk and dairy produce) or gluten
(wheat and some other cereal products) could be considered. It may be possible
to determine, from the pattern of the urinary peptides whether casein or wheat
or both should be avoided but such conclusions may be premature at this stage.
It has been observed that those children whose autism appears at or around the
time of birth may have a problem with casein whereas those whose autism becomes
apparent at about two years of age, when a wheat based diet is more likely to
be adopted, have particular difficulties with gluten. Some children may have
difficulty with both. Norwegian
colleagues of Reichelt have published data which support the effectiveness of
such dietary programmes but these studies cannot be considered as conclusive [see
reference]. Numerous people have experimented on an individual basis and
have reported successful responses but such evidence cannot be considered as,
in any way, conclusive. During preliminary studies of parental reports,
however, the results appear to be very much superior to those obtained with
equivocal drug-based therapy.
Practical Aspects
The theoretical
processes described here are toxicological in nature
rather than allergic. The
results are akin to poisoning rather than an extreme sensitivity such as occurs
in coeliac disease
or sensitivity to certain food colourings. Removal of gluten and/or casein
containing products requires the active participation of all those concerned
with the child's well-being. Tests have often been ruined by a well-meaning
relative who ignores parental instruction or by schools or therapists who feel
that the proposals are rubbish. Carers must satisfy themselves that the diet is
being adhered to before any evaluation is possible. Gluten and Casein free
products, together with advice on their use, are available from most good
Pharmacies. Nutritionist and dieticians are also in a position to give advice.
Initially the reported effects may be negative. Upset stomach, anxiety,
clinginess, dizziness, aches and pains and slight ill-temper have all been
reported. Experience would suggest that these are good signs and precursors of
a positive response. Reichelt recommends a trial period of three months. Experience
also suggests that the results are more easily demonstrated in younger
children. The effects in fully grown individuals appear less impressive. It
should also be noted that the withdrawal effects may also be more noticeable in
small children and that these can sometimes be very marked. Where
younger children are involved (less than 4 years old for example), it may be
appropriate to withdraw the offending foods in stages over a period of two
weeks. Given that there appear to be a number of possible causes of
autism it is not unexpected that no unitary solution will be found for all
cases.
Conclusions
Although
the hypothesis may appear "off the wall" in many respects, there are
a number of pieces of evidence, which seem to support them. The ideas are
compatible with virtually all the accepted biological data on autism and are
therefore worthy of consideration. The dietary method must still be considered
as experimental and no positive results can be promised or are claimed for
every person. Despite continuing scepticism about the efficacy of dietary
intervention amongst some quarters of the professional community, the use of
diet may well be far less harmful than other medical interventions or
therapeutic regimes; although care is still necessary during its
implementation. We would be pleased to receive any feedback of a positive or
negative nature from anyone utilising such dietary modification in the
amelioration of autism.
Additional Published References (abstract only)
Several additional references
pre-1999 are present in the research literature (particularly from Prof. Knivsberg’s group in
Whiteley (1999) A gluten free diet for autism
Knivsberg
(2001) Reports on dietary intervention
Bowers
(2002) Dietetic referrals
Cornish
(2002) Food choice & nutrition
Knivsberg
(2002) Randomised trial of diet
Arnold
(2003) Nutritional intake on diet
Millward (2004) Cochrane review of dietary intervention
Ashwood (2004) Cytokine profiles on diet
Elder
(2006) Double-blind trial of diet
Christison (2006) Elimination diets for autism
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