A five-year-old autistic boy died Tuesday after receiving chelation treatment, a controversial therapy approved only for cases of acute heavy metal poisoning -- but a treatment sought with increasing frequency by parents who think it will help their autistic children. While the cause of death will not be known until after an autopsy, the tragedy is a reminder that doctors providing chelation therapy are acting irresponsibly and in a manner inconsistent with their role as healthcare providers. They may be putting children in harm's way, as well as giving false hope to parents in emotional turmoil.
Many parents believe that their children's autism was caused by exposure to thimerosal, an ethylmercury-based preservative that was used in several pediatric vaccines until 2001 but is now present only in trace amounts in tetanus and some influenza vaccines. In 1999, the Food and Drug Administration (FDA) recommended the discontinuation of thimerosal in routine pediatric vaccines upon realizing that many children, as a result of changes to the pediatric vaccination schedule, were receiving levels of mercury in excess of the Environmental Protection Agency's (EPA's) recommended limit. Around the same time the children were receiving increased amounts of thimerosal in their vaccines, the number of autism diagnoses in the U.S. increased substantially. Noticing the temporal correlation, some hypothesized that autism and thimerosal were linked.
But in fact, a causal link between thimerosal and autism has never been substantiated. This conclusion is currently supported by the majority of research scientists, clinicians, and public health organizations including the Centers for Disease Control, the Institute of Medicine, and the FDA. Many of these experts view better diagnostic skills and wider acceptance of a previously misunderstood disorder as the reasons for the apparent increase in autism cases. (The FDA recommendation to remove thimerosal was precautionary in nature -- not due to any evidence of harm. The EPA's limits have wide safety margins and are based on ethylmercury's more toxic cousin, methylmercury.)
But suspicions persist concerning the thimerosal hypothesis, as do cries of government conspiracy and cover-up. And many parents of autistic children who believe that mercury in vaccines is responsible for their children's condition are willing to try anything in their desperation, even unconventional and dangerous procedures such as heavy metal chelation therapy.
These parents are guilty of nothing more than loving their children and doing everything in their power to ease their children's distress. Autism, even in less extreme cases, can be devastating both for the sufferers and for their families.
The doctors offering chelation as an option to these desperate parents, on the other hand, are guilty of far more.
Chelation, which is not FDA-approved for the treatment of autism, has not been subjected to any rigorous studies showing its safety for autistic children. It is typically used only in the most extreme cases of heavy metal poisoning, confirmed by blood tests. Heavy metal poisoning due to mercury or other heavy metals has not been shown to be related to autism. The doctors who provide this risky therapy are putting children in unnecessary danger. The death of Abubakar Tariq Nadama, age five, may be a testament to that. Chelation has been associated with serious complications ranging from severe kidney damage, dangerously low blood pressure, fast heart rate, dangerously low blood calcium levels, increased risk of bleeding or blood clots, immune reactions, abnormal heart rhythms, allergic reactions, blood sugar imbalances, convulsions, headache, fatigue, fever, nausea, vomiting, gastrointestinal upset, excessive thirst, sweating, and low white blood cell and platelet counts. Chelation is to be avoided if one has liver, heart, or kidney disease. Some patients receiving treatment have stopped breathing. Deaths have been reported, although it is not clear if chelation was the direct cause.
Dr. Cynthia Johnson, Director of the Autism Center at the Children's Hospital of Pittsburgh, says that she doesn't see chelation "as benign, and it's really very scary to me." This same sentiment is felt by Dr. Susan McGrew of Vanderbilt University's TRIAD program (see her comment within my own at the bottom of my earlier piece, "Kirby's 'Evidence of Harm,' Evidently Stoking Fear").
One might ask if parents have been properly informed of such possible adverse effects before having their children treated with chelation. When parents are as understandably desperate -- given how poorly understood autism's causes are -- and are willing to try whatever their doctor advises, a physician's responsibility to inform them of risks is even greater.
Aubrey Stimola is an assistant director of public health at the American Council on Science and Health (ACSH.org, HealthFactsAndFears.com).