Mercury, Autism, and Chelation: A Recipe for Risk
by Brian Dunning
Filed under Alternative Medicine, General Science, Health
July 15, 2007
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Today we're going to examine yet another case where people are willing to put their own and their children's lives at risk in order to embrace popular pseudoscience. It seems that more and more, people are increasingly concerned with joining a politically correct fad when it offers a simpler explanation than medical fact. In this case, parents of autistic children have, in the absence of a medical cure for their child's condition, turned to alternative medicine and put their children at greater risk by avoiding crucial vaccinations or even causing direct injury with chelation.
In Skeptoid episode #36 about amalgam dental fillings, I was widely criticized for mentioning chelation therapy as a valid treatment to remove heavy metals from the body. What I said was misinterpreted as support for the popular misuse of chelation, when it's used for non-existent contamination or for so-called "cleansing". Real chelation therapy is used medically, though rarely, because there is such a thing as real heavy metal contamination that is dangerous. It usually happens occupationally to people who work with heavy elements and are involved in accidents. Medical chelation takes years and is, at best, only partially successful; and carries plenty risk of its own. Kidney damage is among the most common side effects. Chelation therapy in popular alternative medicine, however, brings only the risk and no possible benefit to the recipient.
So how did we get to a point where wrongly informed parents are turning to chelation to treat their autistic children? It's not all that surprising. Many of the indications of autism first become apparent in children at approximately the same age as vaccinations are given. It naturally follows that some people will thus draw an (invalid) causal relationship. Because they happened about the same time, one must have caused the other. This is the same logic flaw that leads Oprah guests to proclaim their cancer was cured by some alternative therapy. Of those lucky few individuals whose cancer spontaneously went into remission, many were probably taking some random alternative therapy at the time; and because the remission occurred about the same time as the therapy, they assumed a causal relationship, when in fact none exists.
No parent wants to see anything bad happen to their child. When it does, it's natural to seek some outside cause, someone or something to blame, something that can be attacked and fought back. Popular media has spread the notion that mercury from vaccination causes autism, and this makes a perfect scapegoat. Something to blame, something to fight, some way to protect the child. An easy answer. A clear answer. A chance. Something more tangible than the doctor's vague explanation of the complex causes of autism, and its tragic incurability. It's the perfect opiate for the psychologically tormented parent.
But it does have its costs. In Pennsylvania, the parents of Abubakar Tariq Nadama, a 5-year-old autistic child killed by chelation therapy in 2005, are suing the individuals and companies involved for wrongful death and lack of informed consent. He was being treated with EDTA, which is approved by the FDA for use only after blood tests confirm acute heavy-metal poisoning. The child's blood tests did not reveal any such poisoning. Howard Carpenter, executive director of the Advisory Board on Autism-Related Disorders, said "It was just a matter of time before something like this would happen." Gary Swanson, a psychiatrist who works with autistic children, said "I can't sit there and endorse it as a viable treatment. It's not something published in peer review journals and studies. It's probably a quack kind of medicine."
As previously mentioned, the exact causes for all the various forms of autism are complicated and are not 100% understood, but that doesn't mean that nothing is known or that non-evidence-based alternative therapy might be useful. One of the factors that is known is that heredity is present in 90% of autism cases. It's largely genetic, not environmental. Studies have determined that a few agents such as thalidomide, when present during the first 8 weeks of gestation, can cause the same chromosomal damage found in autism. No rigorous scientific evidence has ever been found that indicates autism can otherwise be caused environmentally, which eliminates all the pop-culture supposed causes like vaccination, food allergies, or mercury poisoning.
Moreover, a 2007 study by Williams, Hersh, Allard, and Sears published in Research in Autism Spectrum Disorders found no significant difference in the levels of mercury found in hair samples between autistic children and their non-autistic siblings. Siblings were used for this study to eliminate other environmental variables as factors. Consumer Health Digest concludes "Autism has no plausible association with mercury toxicity or other heavy metal exposure."
Proponents of the alleged link between vaccines and autism charge that vaccines contain mercury, which in large enough doses, kills cells and causes neurological damage. What some vaccines contain is actually not plain mercury, but the preservative thimerosal. Thimerosal's main active ingredient is an organic version of mercury called ethylmercury. Ethylmercury is naturally expelled from the body quickly. Methylmercury, on the other hand, is not. It stays in the body. High doses of methylmercury will cause physiological damage. However, ethylmercury and methylmercury are not the same thing, despite the similar names. Methylmercury is not present in thimerosal. In short, vaccines preserved with thimerosal do not even contain the type of mercury that activists say is dangerous. And even if they did, the amount would be too small to be considered a risk.
It doesn't help that this misinformation is spread by celebrity activists like Robert Kennedy Jr., whose only medical experience comes from carefully making lines of cocaine with a razor blade. Kennedy wrote an article for Rolling Stone magazine in 2005 charging that the government knows that vaccines cause autism and is actively covering it up. I wonder what young Abubakar's parents think of Kennedy's contribution to pop-culture. The online version of Kennedy's article is followed by five paragraphs of corrections and clarifications, among them pointing out that he misstated the amount of ethylmercury received by infants at six months of age, by a factor of 133 times the actual amount. His article is bursting at the seams with flawed logic and irrelevant comparisons, such as this one: "infants routinely received three inoculations that contained a total of 62.5 micrograms of ethylmercury -- a level 99 times greater than the EPA's limit for daily exposure to methylmercury." It's OK though, Robert, people don't read too closely.
Rates of vaccination have not been increasing, so why the reported skyrocketing rates of autism diagnoses? An increasingly broad array of conditions being called autism is part of the reason. Autism is not necessarily a single, well-defined disorder. There are five main Autism Spectrum Disorders, including but not limited to Asperger syndrome, Rett syndrome, various childhood disintegrative disorders, and pervasive developmental disorder not otherwise specified, or PDD-NOS. As more of these are broadly called "autism", obviously the rates of autism rise substantially. Between 1987 and 1998, the number of patients classified as autistic rose 273 percent.
If thimerosal were a cause of autism, then wouldn't its removal from vaccines curb the rising rates of diagnosis? Well, obviously, yes it would. But it didn't. The FDA removed thimerosal from childhood vaccines in the US in 1997, as a precautionary measure, partly in response to all the anti-vaccine activism. Autism diagnoses continued to rise unabated. Denmark and Sweden eliminated thimerosal five years earlier. Their rates also continued to climb.
Let's repeat that, since apparently it's not clear to Kennedy and the other activists still warning against vaccination. Ethylmercury-containing thimerosal was removed from childhood vaccines in 1997. Vaccination will not result in mercury poisoning.
Vaccinations save more lives worldwide than any other medical advance in history. Thanks to vaccination, children around the world are now safe from hepatitis A and B, polio, smallpox, measles, rubella, diphtheria, tetanus, rotavirus, mumps, typhoid, and many more. Giving up all of these immunities, due only to an unfounded fear of a compound that's no longer used and was demonstrated safe in every rigorous study ever done, is hardly the best way to serve your child. Exposing an already-vaccinated child to the dangers of chelation in a misguided effort to remove undetected poisons is just as bad. Vaccinate your children. Don't put them or yourself through the risks of chelation therapy, unless of course your job at Three-Mile Island was to drink all the leaked cooling water.
By Brian Dunning
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Cite this article:
Dunning, B. "Mercury, Autism, and Chelation: A Recipe for Risk." Skeptoid Podcast. Skeptoid Media,
15 Jul 2007. Web.
28 Nov 2015. <http://skeptoid.com/episodes/4055>
References & Further Reading
Brown, MJ, Willis, T, Omalu, B, Leiker, R. "Deaths resulting from hypocalcemia after administration of edetate disodium: 2003-2005." Pediatrics. 1 Aug. 2006, Volume 118, Number 2: 534-536.
Doja, A., Roberts, W. "Immunizations and autism: a review of the literature." Canadian Journal of Neurological Science. 1 Nov. 2006, Volume 33, Number 4: 341-346.
FDA Staff. "Thimerosal in Vaccines Questions and Answers." Food and Drug Administration. US Federal Government, 10 Jul. 2009. Web. 13 Nov. 2009. <http://www.fda.gov/BiologicsBloodVaccines/Vaccines/QuestionsaboutVaccines/ucm070430.htm>
Kane, Karen. "Death of 5-year-old boy linked to controversial chelation therapy." Pittsburgh Post-Gazette. 6 Jan. 2006, Volume 79 Number 25: B1.
Taylor, D, Williams, D. Trace Elements Medicine and Chelation Therapy. Cambridge: The Royal Society of Chemistry, 1995.
Williams, P. Gail, Hersh, Joseph H., Allard, AnnaMary, Sears, Lonnie L. "A controlled study of mercury levels in hair samples of children with autism as compared to their typically developing siblings." Research in Autism Spectrum Disorders. 16 May 2007, Volume 2, Issue 1: 170-175.
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