Complementary and Alternative Medicine
Complementary and Alternative Medicine has been described by the American Academy of Paediatrics as "strategies that have not met the standards of clinical effectiveness, either through randomised controlled clinical trials or through the consensus of the biomedical community".
Gluten Free, Casein Free Diet (GFCF)
The most popular of CAM approaches are diets that eliminate foods containing either gluten or casein, or both. Four overlapping biological theories contribute most to the support for the diet; opioid excess, reduced peptidase activity, immune dysfunction or autoimmunity and, gastrointestinal abnormalities. Both gluten and casein are broken down in the gut into compounds with opiate agonist properties. It has been hypothesised that children with autism have abnormal leakage from the gut and these metabolites then pass into the central nervous system (CNS) to produce intensified brain opioid activity and disruption of brain function. Clinical trials with opiate antagonists have not been as successful as initially claimed, but there may be some benefit in a few select individuals regarding hyperactivity and self injurious behaviour . The "leaky gut theory" however remains controversial with no rigorous scientific study or substantiated evidence. The most recent review of the scientific evidence available on the role of elimination diets in Autism Spectrum Disorder was published by Christianson & Ivany, 2006. They noted that significant design flaws in all the current studies weaken the confidence that can be placed in their findings, and they suggested that the future/current double blind placebo controlled studies should evaluate diets eliminating both gluten and casein (rather than either alone) and that outcome measures should include assessments of non-verbal cognition. While no major side effects of the diet were noted, some concerns were raised regarding the cost of an unnecessary diet and further restricting dietary intake in individuals who already have rigidity around food intake.
Chelation
There are no published peer review publications regarding the efficacy of chelation agents for the treatment of autism. It is known that up to a third of children with autism may present with apparent regression in milestones in their second year of life, and from this arose the proposed theory of immunisation as a cause for the regression and autism. One of the reasons immunisation was blamed was due to the Thimerosal, which is an ethyl mercury derivative used to stabilise killed virus vaccination packaged in multi-dosed vials. It is important to note that the live virus vaccines like the trivalent measles, mumps, rubella vaccine do not contain Thimerosal. Thimerosal is no longer present in childhood vaccines except in the DT influenza vaccine. In Australia, even when thiomersal-containing vaccines were being used in the past, the maximum possible number of doses of thiomersal-containing vaccines was six (two doses of triple antigen, two doses of hepatitis B, two doses of lyophilised pedvax Hib), giving a maximum mercury dose below the WHO limit of 3.3 µg/kg per week (MacIntyre & Leask, 2003). Thimerosal was removed from childhood vaccines in Denmark in 1992. This allowed (Madsen, Lauritsen, & Pederson, 2003) to examine the rate of reported autism before and after this change in practice. The rate of reported autism began increasing before Thimerosal was removed from the childhood vaccines and this trend continued on the same upward trajectory after the removal of Thimerosal. No associations were identified and causality could not be implied. In the case of documented lead poisoning with neurological complications, chelation of the lead has not been shown to improve neurological function. Renal and hepatic toxicity must be monitored with DSMA chelation. Due to the lack of evidence and the potential significant harm and toxicity, this intervention should be viewed with extreme caution.
With-holding MMR Vaccine
In 1993, a group of researchers led by Dr Wakefield at the Royal Free Hospital, London, suggested an association between both wild and vaccine measles viruses and inflammatory bowel disease (IBD), based on a small case series of children with Crohn's disease (Wakefield, Pittilo, & Sim, 1993). In 1998, the same researchers reported another series of 12 children, and described an apparently new syndrome of an unusual type of IBD associated with developmental disorders such as (but not limited to) autism (Wakefield et al., 1998). They suggested that measles-mumps-rubella (MMR) vaccine may cause IBD, which then results in decreased intestinal absorption of essential vitamins and nutrients, which may then lead to developmental disorders such as autism. Expert groups around the world have found the suggested associations weak and the studies significantly flawed. The studies had no controls, were un-blinded, potentially biased and not designed to test aetiology or harm. The association between vaccination and autism was primarily based on parental recall, and subject to recall bias (MacIntyre & Leask, 2003). Numerous large epidemiological studies have suggested no causal relationship between the MMR vaccine (or any other vaccine) and autism (Dales, Hammer, & Smith, 2001; Demicheli, Jefferson, Rivetti, & Price, 2005; MacIntyre & Leask, 2003; Madsen et al., 2003; Patja et al., 2000).
See full text at http://www.health.gov.au/internet/main/publishing.nsf/Content/mental-child-autrev-toc~mental-child-autrev-ref for references.
Vitamin B6 and magnesium
Interest in mega doses of vitamins to treat autism arose from a 1960's theory that some psychiatric disorders might be the result of relative deficiencies in certain vitamins and minerals. There has been particular interest in Vitamin B6 because it is involved in the synthesis of several neurotransmitters. Magnesium is administered with mega doses of Vitamin B6 to reduce toxic side effects. The Cochrane review of the research into the effect of this therapy did not find any studies that met the standard for clinical control trials (Nye & Brice, 2003). Sikich (2001) suggested that an overview of the limited research evidence indicates that vitamin B6 and magnesium are possibly efficacious in some autistic individuals. There are potential difficulties in administering the agents (bitterness) and the effect appears to be relatively small, even in individuals who do respond. Howlin (1997) suggested that there are reported side effects such as sensory neuropathy, headache, depression, vomiting, and photosensitivity and urges caution in the use of large doses of vitamins.
Yeast overgrowth: (probiotics, anti-fungal agents, "yeast free diet")
No clinical trials to date have been published in peer reviewed literature examining these interventions for autism although they still remain popular. Chronic use of antifungal agents such as Fluconazole requires monitoring for liver toxicity and exfoliative dermatitis. Nystatin is not systemically absorbed and may result in diarrhoea. It is important to note that yeast is a normal commensal in the bowel and stool, and candidal overgrowth in the intestine has not been documented by endoscopy.