Autism Research Unit, University of Sunderland, UK
The opioid-excess theory of the causation of autism dates back to the early 1980's after the zoologist Panksepp (1979) had recorded his observations on the similarities of the symptoms of autism and the effects of morphine on young animals, notably chicks and puppies. From these observations he suggested that autism may result from an increase in the levels of endogenously produced opioids, and particularly beta-endorphin, in children with autism. He suggested that, for some reason, the comparatively high levels, which are known to exist in the developing foetus, do not drop to the much lower levels normally present in the developing infant.
At about the same time, Reichelt (1981) produced evidence of an abnormal peptide complement in the urine of children with autism (and some other conditions) and proposed that the source of this opioid activity could be exogenously produced opioid peptides. He proposed that such activity could be derived from peptides which have resulted from the incomplete breakdown of certain foods and, in particular, the proteins gluten (from wheat and some other cereals) and casein from milk (and dairy related compounds). Since then, there has been limited confirmatory evidence from Shattock (1990) and a growing interest in the ideas among parents. Reichelt and his colleagues in Norway went on to test their hypothesis by utilising a diet free of gluten and or casein as appropriate, and subjecting the subjects, mainly children, to a series of psychological and performance tests. The results have produced encouraging results (Knivsberg et al, 1991) but the ideas have as yet not been widely accepted. Interestingly, a number of parents have, independently of any knowledge of the theoretical basis, found that their children are adversely affected by gluten, casein or some other foods, and maintained their children on a dietary regime avoiding these foods. These results have never claimed to be conclusive and the proposals have never been subjected to the rigours of a double-blind cross-over trial. Indeed the design of such a study would present severe methodological problems. However, the claims that are made are too persistent and frequent to be completely ignored. This brief study describes the reports of parents of 10 children all of whom have been utilising a programme involving the exclusion of gluten and/or casein from the diet.
The parents of 10 people (aged 3-24; mean 10.3 yrs) who were utilising this form of dietary intervention and who were prepared to be interviewed were recruited. The majority of the subjects were located via the Autism contact list which operates on the Internet or had made direct contact with the Autism Research Unit. For logistic reasons, the subjects had to be easily accessible from the North East of England. Interviews were conducted on a 1:1 basis. The questions were designed to be comparatively simple to answer but also as open as possible. The interviews were semi-structured but the prompt questions were general in order not to lead the responder into any particular form of answer. If responders were vague in their answers, supplementary questions were utilised in order to elicit more specific responses. Although the main objective of the study was to assess the effectiveness of dietary intervention against the symptoms of autism, the effects on the whole family had to be taken into consideration. The interviews were conducted in the homes of individuals. In 7 of the 10 cases, the mother provided the answers, in 1 it was the father, and in the other two cases both parents were present. All the interviewees were keen to discuss their trial and many parents commented on the lack of support or dismissive attitude of the professionals. I had been concerned that since I am the sister of a man with autism, there would be some awkwardness. In fact the opposite was the case. I felt that parents appreciated that I had some experience of their problems and so were more open to me than would otherwise have been the case. I was not in a position to be able to confirm the accurate diagnosis of any subjects. However, all of the parents confirmed that their children had received such a diagnosis from an experienced clinician. The description of behaviours and abnormalities of the subjects, and my own observations, would seem to confirm these diagnoses.
The parents of all 10 subjects were aware of developmental problems before the official diagnosis was made. All parents had, by the time of interview, removed gluten and casein containing products from the diet.
Health problems other than autism.
|Severe allergies to other foods (eggs, soya, grapes)||7/10 (70%)|
|No other health problems||4/10 (40%)|
|Claiming dietary intervention had significantly helped||10/10 (100%)|
|Wishing they had initiated the programme earlier||10/10 (100%)|
|Child experienced side effects associated with diet*||5/10 (50%)|
*Side effects included: clinginess, crying, dizziness, anxiety, tantrums.
|Time taken to see improvements:|
|Less than 7 days||5 / 10 (50%)|
|More than 7 days||5 / 10 (50%)|
|Less aggression||4/10 (40%)|
|More sociable||6/10 (60%)|
|Less self-injury (head-banging)||4/10 (40%)|
Each parent also gave other examples not individually recorded here.
|Dramatic deterioration following ingestion of foods||8/10 (80%)|
|Child reports improvement||4/10 (40%)|
|Ready acceptance of diet||10/10 (100%)|
|Worth the cost||10/10 (100%)|
An attempt was made (notice on the Autism lists on the Internet) to locate subjects with negative or no results but no responses were forthcoming.
Discussion & Conclusion
It must be immediately conceded that the results cannot be taken as conclusive proof of the efficacy of dietary intervention in reducing the symptoms of autism. Nevertheless, the results of parental reports are consistent in a number of respects that give them added credence. A number of parents had previously had no contact or knowledge of any other individuals using this intervention or any published material on the hypothesis, yet their observations were broadly in line with those reported by other parents. One parent cried because she was being listened to for the first time in 3 years of dietary intervention. Each of the parents were adamant that their child had been significantly helped by the intervention although none made any pretence that their child was cured.
A rather surprising feature was the incidence of allergies amongst the subjects and, in particular, the nature of the products reportedly responsible. Contact with eggs, in one case physical contact with egg white, would produce very severe reactions in 2 (possibly 3) of the subjects. Whereas eggs and soya (also quoted) are basically proteinaceous in nature, and so perhaps likely candidates for such activity, the effects of certain fruits was not anticipated. Apples and oranges have, however, been cited on a number of occasions in anecdotal reports. From the interviews it was unclear whether or not the situation improved after dietary intervention. Quite clearly this report can only be of a very preliminary nature and does not pretend to provide a definitive answer to the question posed in the title. However, the evidence is compatible with the current interpretations of the opioid-excess theory of autism and would suggest that further more substantive investigation would be appropriate.