Autism is an illness that has several typical defining characteristics. Autistic children and adults typically have difficulties processing language and responding to non-verbal cues. Some people with autism may be severely affected, unable to speak at all or perform daily activities. Others may demonstrate only mild deficits with coordination or social skills.
Researchers have investigated the causes of autism in order to help find effective treatments. One such avenue of investigation has been to look for excessive minerals or chemicals that may be present in people with autism. It has been theorized that people who have an excess of certain substances in their blood or cells may suffer from autism as a result.
Some researchers have hypothesized that autistic sufferers have disproportionate levels of mercury in their bodies. As a result, they suggested that autistic children undergo treatments designed to remove mercury from their blood, such as chelation therapy, even though the symptoms of mercury poisoning and autism do not match. They point to the administration of vaccines as a possible cause.
Thimerosol and Vaccines
Until the early part of the century, many vaccines had very minute amounts of mercury in them. The ethyl mercury compound, known as thimerosol, was designed to act as a preservative and make sure that the vaccines in question remained potent even in the absence of refrigeration.
In recent years, mercury has been removed from nearly all vaccines. Yet autism rates have continued to rise. Researchers have continued to look at the correlation between mercury and autism.
In a study published in the journal Environment Health Perspectives, researchers at the University of California-Davis’s MIND institute examined the levels of mercury in the blood of children with autism and those without autism.
Autism and Mercury
The study was led by Irva Hertz- Picciotto, a professor of occupation health. Dr Hertz-Picciotto and her team studied 452 children. Roughly 55 percent of the children have received a diagnosis of autism. Roughly 30 percent were developing normally and roughly 15 percent have been given a diagnosis of other developmental delays.
Dr. Hertz-Picciotto and her fellow investigators looked for sources of mercury in the children’s diet. They found that the biggest prediction of mercury levels in children was their overall consumption of fish. In general, autistic children tend to be picky eaters. Many of the children in her study ate less fish than their peers.
After accounting for this fact, the UC team found comparable levels of mercury in the blood of all the children in her study.
The study in question is part of a larger study known as CHARGE or Childhood Autism Risks from Genetics and the Environment. CHARGE researchers hope to discover many of the underlying causes of autism in order to help find effective treatments and ultimately a cure.
The causes of autism will continue to be debated. Dr. Hertz-Picciotto and her fellow researchers have helped suggest that autism is not linked with excessive ingestion of mercury.
Source:
Hertz-Picciotto, Irva Environmental Health Perspectives Blood Mercury Concentration in CHARGE Study: Children With and Without Autism 19 Oct 2009
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