On Thursday 8th February Dr. Mike Tettenborn spoke to the NAS Surrey Branch meeting in Woking. Dr. Tettenborn is consultant paediatrician at Frimley Children’s Centre, and he has a special interest in the role of diet in autism. He started by explaining that there are different patterns in the development of austistic spectrum disorders, and not all of them respond to dietary interventions. The one which seems to benefit from a change in diet is where the child has appeared to be developing normally then regresses and develops autistic symptoms during their second year. Environmental factors such as diet are unlikely to cause the autistic behaviour directly. It is likely that there may be something in the family’s medical history which indicates a genetic predisposition to food reactions. He also said that there appears to be some overlap of Attention Deficit Disorder with autistic spectrum disorders, and some children with ADD may also respond to a special diet.
The theory behind the dietary intervention is that autistic spectrum characteristics can sometimes be affected by natural opiods produced by incomplete digestion of certain foods. Many of us may have these opiods in our digestive system, but a ‘leaky gut’ may cause the opiods to get into the bloodstream and travel to the brain. Normally proteins from food pass through the cells lining the gut wall, and are altered during the process to become harmless. In ‘leaky gut syndrome’ the proteins pass between the cells and are not therefore, made safe. One theory as to why this happens is that there are too many ‘wrong’ bacteria in the bowels. This could be caused by a child having received too many antibiotics when very young, too much sugar or simply the environment these days being too hygienic. The result is that the immune system is damaged. Dr. Tettenborn does not believe that the MMR causes these problems. It is possible that it could be one extra ‘trigger’ on top of all the others, but if that was the case the single measles vaccine would be likely to have the same effect. The measles virus found in the gut of some autistic children may be there as a result of the damage to the gut wall - not the cause of it.
Many doctors are sceptical about the role of diet in treating autistic disorders, and this may be because they are meant to rely on ‘evidence based medicine’ - treatments which have been scientifically proven by double-blind placebo trials. However, it is very difficult to run such trials on therapies for life-long disorders such as autism, especially where young children are involved who cannot give consent. Parents are unlikely to want to stick to one regime only for a whole year; e.g. gluten-free diet but no early intervention therapy of any kind. It is also very hard to measure the effectiveness of a treatment where a disorder cannot be cured. Drug companies fund much of the medical research which takes place, but they will not pay for research which gives no possibility of recouping their money in new drug development.
For the above reasons the research that Dr. Tettenborn is carrying out is based on observational trials; that is, making note of the effects of different diet regimes on individual children. As well as any obvious changes to the child’s digestion and reports from parents, comments are noted from outside observers. For instance, a teacher who is not aware that the child has started a special diet talking to parents about the sudden improvement in their child’s behaviour and work.
The most common features of children who are likely to benefit from dietary intervention include: severely disordered language; clear regression having developed normally during the first year of life; altered bowel habit; having had illnesses requiring antibiotics when very young; excessive thirst; cravings for dairy or wheat products; pale face/dark shadows under the eyes; persistent nasal congestion. There are laboratory tests which can be done, for instance urine tests for the presence of abnormal chemicals/opiods and hair analysis, sweat and serum tests for trace elements, but as some of these tests can be distressing for the child Dr. Tettenborn only uses them when they will determine a change in how the child’s case is managed. In many instances tests are done which do not have a sufficient specificity to allow treatment to be determined.
The regimes used include gluten free and/or casein free (gf/cf) diet and anti-fungal treatment to correct bowel flora such as low refined sugar diet or medicines (nystatin or amphotericin.) The gluten free/casein free diet can take 6 months to show a result and is expensive and difficult to follow. Children often get worse before they get better, and will regress if the diet is stopped.
Dr. Tettenborn has assessed 57 cases he has treated between 1997 and 1999. 24 used anti-fungal treatment, 9 were on the gf/cf diet, 11 used both regimes and 13 had no treatment. 28 children showed a definite sustained improvement, and 15 of these deteriorated when the treatment stopped. 6 more children showed a less certain improvement. There was no obvious difference in the effectiveness of the gluten free diet over the casein free. Social skills seemed to show an immediate improvement when treatment started, language took longer to improve.
Dr. Tettenborn sees NHS patients who have been referred to him by other doctors, and currently has a waiting time of around 13 weeks (although this could have increased if more patients are referred as a result of this talk.) He also sees patients privately, but where possible prefers an NHS referral.