autism and environmental toxicity
TRANSCRIPT
Refl ection and Reaction
http://neurology.thelancet.com Vol 6 April 2007 297
Autism and environmental toxicityIn Autism, Brain and Environment, recently reviewed in The Lancet Neurology,1 Richard Lathe makes three inter-related claims: that there is an epidemic of autism; that this epidemic is caused by environmental toxins; and that the resulting defi cits can be rectifi ed by a range of biomedical treatments. Though these claims have some appeal among parents of autistic children (and among providers of treatments), this book reveals that they lack a scientifi c basis.
Though the concept of an “autism epidemic” has become a notion of faith among parent campaigners, most authorities in the fi eld believe that the increased prevalence of autism can be readily explained by widening diagnostic categories and increased professional and public awareness.2 Yet, without presenting evidence to challenge this consensus, Lathe concludes that the increase in prevalence “may be real”, dubs this “new phase autism”, and proceeds on the assumption that it is real.
Belief in an autism epidemic is linked to the conviction that environmental toxicity is of increasing importance in the causation of autism (which is inconsistent with the prevailing emphasis on genetic factors).3 Though Lathe concedes that the clinical features of autism are distinct from those of mercury poisoning, he still speculates that exposure to mercury (notably in vaccines) is “far the most likely” explanation for the rise in cases of autism. This is contrary to the evidence that any environmental factor causing autism is likely to act in the earliest days of fetal life—and also contrary to the conclusions of the recent Medical Research Council inquiry (ignored by Lathe).4
On these insubstantial foundations, Lathe proceeds to endorse various investigations and treatments
purporting to identify and correct the biochemical defi cits alleged to result from environmental toxicity. Treatments include exclusion diets, multivitamins and enzymes, antibiotics and antifungals, and heavy-metal chelation therapy. The common features of these methods, apart from the absence of a coherent scientifi c rationale and vast expense, are a lack of evidence of effi cacy or safety. Indeed, a 5-year-old autistic boy from the UK recently died undergoing chelation in a private clinic in the USA.
Mark Geier’s enthusiasm in his review of Lathe’s book1 is understandable. While Lathe wonders whether high concentrations of testosterone may be associated with autistic behaviour, Geier (in collaboration with his son David) treats autistic children with a combination of chelation and leuprorelin (Lupron), a gonadorelin analogue that inhibits androgen production (and induces “chemical castration” in prostate cancer). Following a devastating critique by Kathleen Seidel, a parent activist in the USA, the Geiers’ report on the treatment of 100 children, according to their “Lupron Protocol”, was recently withdrawn from publication.
Michael FitzpatrickBarton House Health Centre, London UKfi [email protected]
MF is a GP, father of an autistic son and author of MMR and Autism: What Parents Need To Know, Routledge 2004.
1 Geier, MR. Evolving views on the causes of autistic spectrum disorders. Lancet Neurol 2007; 6: 212.
2 Roy Richard Grinker, Unstrange Minds: Remapping the World of Autism, Basic Books, 2007.
3 Veenstra-Vanderweele J, Christian SL, Cook EH. Autism as a paradigmatic complex genetic disorder. Annu Rev Genomics Hum Genet 2004; 5: 379–405.
4 Medical Research Council, Review of Autism Research: Epidemiology and Causes, December 2001.