What is causing the unprecedented rise in autism - and how are we to deal with it? Michelle Berriedale-Johnson has been reading up on the research and sitting in on Autism Unravelled's recent conference
Autism, like diabetes, is spiralling - and no one really knows why. The need to discover some causes - and to support the ever growing number of families effected - has spawned a number of autism support groups. Some, the National Autistic Society or Allergy Induced Autism, focus on patient support, others, such as Autism Unravelled, concentrate on research. Meanwhile, in the USA, Dr William Walsh at the Pfeiffer Treatment Center near Chicago has been investigating the possibility of a metallothionein disorder as the primary cause of autism.
In a lengthy interview in Latitudes Dr Walsh describes the research carried out on 503 autistic spectrum patients who had been evaluated at the Pfeiffer Center. In 95 to 160 separate analyses of blood, urine and scalp hair, 499 of the 503 patients exhibited evidence of metallothionein (MT) disorder.
Metallothionein (MT) is a family of short, linear, cysteine rich proteins, composed of 61-68 amino acids. These MT proteins are very versatile and crucial to many human functions including the detoxification of heavy metals, immune function, the regulation of copper and zinc levels, and the development of brain cells and synaptic connections (the contact points between the neurons or nerve cells which make up the nervous system and connect it to the brain).
The researchers then studied over 1,200 published articles on MT proteins from which they learned that virtually all of the classic features of autism could have resulted from disabled or defective MT. They therefore suggested that autism is caused by the intersection of two factors: (1) a genetic defect that results in impaired MT functioning and (2) an environmental insult during early development which disables MT. This explanation seems to address all the known and common aspects of autism:
1. High copper level in ASD are common. MT malfunction effects copper/zinc ratios.
2. Age onset of ASD. MT proteins are directly involved in brain development, which is normally complete by the age of three - after which an environmental insult will no longer provoke autism in genetically at risk children.
3. The vaccine connection. Because MT function effects the immune system you would expect MT deficient children to be hypersensitive to mercury (until recently a component in vaccines) and to the viruses in a vaccine, especially if there were several, as in the MMR vaccine.
4. The success of casein & gluten free diets. The enzymes that break down these proteins in the gut are zinc dependent. A MT dysfunction would deplete zinc levels and diminish these enzymes’ efficiency in breaking down casein and gluten.
5. Huge preponderance of males with ASD. Estrogen and progesterone help promote the body’s production if MT. As a result, males may have less protection against mercury and the other environmental insults which may provoke autism.
For the full details of the interview and Dr Walsh's theories contact
Latitudes, PO Box 210848, Royal Palm Beach
Meanwhile, back at the Autism Unravelled conference, a wide range of experts provided much further food for thought.
Dr Ken Aitkin, who has had a clinical and research involvement in Autistic Spectrum Disorders for the last 25 years, gave an overview of the current tests and treatments available for ASD.
Dr John Richer from the John Radcliffe Hospital in Oxford then described the behaviour scales which he and his group are constructing by which it will be possible to measure improvements in behaviour, the effects of specific treatments etc. For example:
1. Tolerance /frustration/fear/anxiety levels. High fear levels will result in total avoidance. This may moderate to a low fear level which will produce the 'over the top', 'attention seeking' reaction typical of some ASD children.
2. How well they can accommodate another's point of view and react within a group.
3. The extent of their acquired skills such as language - from none, through repetition of single words, to monologues, to asking questions, to being able to take part in a conversation.
4. Interaction with other children - from totally ignoring to full reactive play.
Dr Rosemary Waring from the School of Biosciences in Birmingham, described the importance of the process of sulphation in the biochemistry of the body. Faulty absorption of sulphate can inactivate neurotransmitters and reduce the capacity of the intestinal tract to digest proteins. It has been shown that autistic children often have high levels of plasma cytokines (as a result of autoimmune dysfunction, infections or, possibly vaccination) which can reduce the production of sulphate. This is turn could lead to a ‘cascade’ process which could effect many biological pathways.
Max Bingham from the Food Microbial Sciences Unit at Reading University described the work his group were doing on the relationship between the overgrowth of gut bacteria such as Candida and Clostridia, and ASD symptoms. He also described the possible use of probiotics (‘good’ bacteria) and prebiotics (food for ‘good’ bacteria) in the treatment of ASD.
Dr Gordon Bell from the University of Stirling explained the possible relationship between fatty acid deficiency/imbalance (common in ASD/ Aspergers) and unbalanced phospholipid production. This in turn can have significant effects on the neural and gastrointestinal tracts and on immune function. He also described how cells which were persistently infected with measles showed an altered phospholipid metabolism.
Dr Alex Richardson from Oxford described the heavy clinical overlap between dyslexia, dyspraxia, ADHD and autistic spectrum disorders. She suggested there there was also a strong biological overlap in these conditions. Many shared features which are consistent with an imbalance in certain of the highly unsaturated fatty acids (HUFAs) that are crucial for normal brain functioning e.g. neurodevelopmental anomolies, excess of males, a link with allergies and other autoimmune deficiencies, visual, perceptual and motor co-ordination problems, problems with spoken language; disrupted appetite, digestion, sleep and temperature regulation. Her ongoing research suggests that HUFA supplementation with special emphasis on the fatty acid EPA may be beneficial for all such groups.
Dr Marion Ross from the Highland Psychiatric Research Foundation suggested that the lower levels of essential fatty acids found in all such neurodevelopmental disorders may be the result of oxidative stress (an overproduction of free radicals in the absence of sufficient protection by antioxidants). Oxidative stress can also create an increase in hydrocarbon gases which are excreted in the breath, thus allowing a measurement of such stress by a breath test. Dr Ross pointed out that parents of ASD and dyspraxic children have reported strange smells on their breaths and sometimes in their sweat.
For more details about this fascinating conference contact:
Autism Unravelled www.autism-unravelled.org
First Published in 2002