Elevated Heavy Metals and Autism
Children with autism and developmental delays have higher levels of heavy metals. Heavy metals such as mercury and lead negatively impact language, behavioural regulation and cognitive function in autism.
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 role of heavy metals and other environmental toxins in autism. The objective the study was to determine if proximity to sources of the heavy metals, such as mercury pollution in 1998 were related to autism prevalence in 2002. The findings showed that for every 1000 pounds of industrial release, there was an increase of 2.6% in autism rates. Likewise a 3.7% increase was associated with power plant emissions. Conversely for every 10 miles away from industrial or power plant sources, there was 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. Moreover each 1,000 lb of environmentally released mercury resulted in a 61% increase in ASD. Similarly, the same study showed an increase of 43% in the rate of special education rates.
Toxins and human health:
Toxins certainly affect every aspect of our body. Renowned medical doctor and researcher Dr. Needleman has shown the detrimental effect of lead on cognitive development. Elevated lead levels increase rates of 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. Umbilical cord blood collected by Red Cross contained 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.
Elimination of toxins:
There are three Important systems that need to be supported in treatment of elevated heavy metals. Firstly, the glutathione detoxification pathway. Secondly, the metallothionein system, and lastly 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.
Heavy metal transport:
Metallothioneins (MTs) are part of a group of intracellular cysteine-rich, metal-binding proteins that have been found in bacteria, plants, invertebrates and vertebrates. For mammals, metallothioneins bind zinc, but excess copper or cadmium will replace zinc. MTs have the capacity to bind both physiological (such as zinc, copper, selenium) and xenobiotic (such as cadmum, 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.
Metallothionein research in 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 therefore 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
- Incomplete maturation of the digestive tract and brain
- Loss of MTs ability to detoxify heavy metals including, mercury and lead
- Impaired immune function
- Immature digestive tract
Environmental and heavy metal toxicity plays and important role in gene regulation. Toxicity, especially heavy metal toxicity, changes which genes are “on” or “off”. Many experts agree that autism is akin to a canary in a coal mine.
Increasing MT production:
Research has shown that the genes themselves are not the problem. Metallothioneins are “turned off” by genetic and environmental factors in autism. 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. Methyl B12 makes glutathione via the methylation cycle.
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. Her research also shows that methyl B12 injections improve glutathione status.