Heavy Metals and Autism

Environmental exposure to toxic heavy metals may have a causal role in autism. Compared to control groups, children and adults on the autism spectrum have higher levels of lead, mercury, cadmium, and aluminum.

Mercury has been associated with impaired neurological development in children and neurological damage in adults. Postnatal mercury exposure appears to be far more significant in males compared to females. Mercury is especially toxic to the developing brain and immune system.

Exposure to the mercury found in fish was thought to be stronger than the mercury found in drug contamination. New research has found that mercury from drug contaminated medication is 50 times more toxic than the mercury from fish. Exposure to all mercury species initially induces profound immunosuppression followed by vigorous immune stimulation

and the development of systemic autoimmunity and the deposition of inflammatory immune complexes

Is there any research directly linking heavy metals to autism?

A ground breaking study in 2009, done by researchers at the University of Texas, revealed startling evidence of the environment’s role in autism. The objective the study was to determine if proximity to sources of mercury pollution in 1998 were related to autism prevalence in 2002. The findings showed that for every 1000 pounds of industrial release, there were a corresponding 2.6% increase in autism rates and a 3.7% increase associated with power plant emissions. For every 10 miles from industrial or power plant sources, there a decrease in autism rates.

An earlier study released by the same group of investigators revealed an association between environmentally released mercury and autism rates in Texas.  For each 1,000 lb of environmentally released mercury, there was a 61% increase in ASD. The same study showed an increase of 43% in the rate of special education rates.

Toxins affect every aspect of our body. Renowned medical doctor and researcher Dr. Needleman has shown the detrimental effect of lead on cognitive development. Lead levels have been linked to autism, PDD and ADHD and learning disabilities.

A study by the Environmental Working Group (EWG) in found an average of 200 industrial chemicals and pollutants in umbilical cord blood from 10 babies born in U.S. hospitals in 2004.  Tests revealed a total of 287 chemicals in this small group of children. The umbilical cord blood collected by Red Cross after the cord was cut, identified pesticides, consumer product ingredients, and wastes from burning coal, gasoline, and garbage.

Heavy metals can impact brain development, but also can cause changes in the methylation pathways.

Important systems in treatment of heavy metal detoxification are consideration of glutathione detoxification pathway, support for the metallothionein system, and proper function of the digestive system. Metals sequestered inside tissues have to be moved into metallathionein units which are then moved to the liver for detoxification in the glutathione conjugation pathway and then prompt removal from the body by the digestive system. 

How is the heavy metal transported?

Metallothioneins (MTs) belong to the group of intracellular cysteine-rich, metal-binding proteins that have been found in bacteria, plants, invertebrates and vertebrates. For mammals, metallothioneins bind zinc, but with excess copper or cadmium, zinc can be easily replaced by these metals. MTs have the capacity to bind both physiological (such as zinc, copper, selenium) and xenobiotic (such as cadmium, mercury, silver, arsenic) heavy metals through the thiol group of its cysteine residues.

The research of Dr. William Walsh, Ph.D, and Dr. Anjum Usman, MD, have found alterations in the functioning of metallothionein protein (MT) in children with autism. This impairment impacts brain development and causes extreme sensitivity to toxic metals and other environmental substances. This supports and begins to explain why environmental toxicity combined with genetic susceptibility leads to autism.

In a study of 503 autistic patients, Dr. Walsh and Usman found abnormal levels of copper and zinc in blood. This indicates defective functioning of MT proteins. These MT proteins regulate blood levels of these trace minerals, detoxify mercury and other heavy metals, and assist in development of the nervous system. Consequences of defective MT during pregnancy or early infancy are consistent with several classic symptoms of autism. This has led many leading experts to believe that MT impairment is a causative factor in autism.

Consequences of MT malfunction in a newborn:

  • Abnormal copper and zinc levels in the blood and brain
  • Impaired neuronal development, especially in the first 30 months of life, which could result in incomplete maturation of the digestive tract and brain
  • Loss of MTs ability to detoxify heavy metals including cadmium, mercury and other toxic heavy metal
  • Impaired immune function
  • Immature digestive tract

Environmental and heavy metal toxicity plays and important role in gene regulation. Toxicity, especially heavy metal toxicity, will change which genes are turned “on” or “off”. Many experts agree that autism is akin to a canary in a coal mine. The rising autism rates are as a result of genetics being negatively impacted by a toxic environment. The result, impaired development.

Can MT production be increased?

Research has shown that the genes themselves are not the problem.  The impairment of metallothioneins proteins in children with ASD has somehow been “turned off” by other genetic and environmental factors. By stimulating the production of MT proteins through biomedical treatment, it is possible to restore your child’s ability to naturally rid itself of accumulated heavy metals, help the digestive tract to mature, and correct the immune system impairments.

Why is restoring MT so important?

Metallothioneins are directly involved in development of the brain and maturation gut and immune system. By age three, these systems may have sufficiently matured so that environmental toxins can no longer provoke autism.

What is glutathione and why is it important?

Glutathione is the body’s chief detoxifier. It works with metallothioneins to remove heavy metals and other harmful substances like pesticides and PCBs.

Research by Dr. S. Jill James, a professor at the University of Arkansas and Director of the Genomics Laboratory, has shown that children with ASD have low levels of glutathione. Dr. James has just received an NIH (National Institute of Health) grant for her ground breaking research.

How do you test for heavy metals?

There are a number of different laboratory assessments for heavy metal toxicity. Hair, urine, stool and blood can be testing to identify metals that have been identified as causative factors in autism.

You can also find more information on environmental toxicity and developmental disorders at Generation Rescue. http://www.generationrescue.org/latest-news/4-biggest-heavy-metal-offenders-how-to-safely-remove-them/



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