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Heavy metals and its role in Autism

Heavy metals are known to impair the functioning of numerous enzymes, cell signaling processes, and also found to generate oxidative stress which leads to apoptosis. These factors can significantly lead to the cause of Autism. Children on the spectrum are generally found to present with elevated levels of toxic heavy metals.

Mercury (Hg) levels in children with ASD

The organic forms of mercury exerts stronger cytotoxic and neurotoxic effects. The common source of mercury poisoning is Thimerosal, used in many vaccines, eg. influenza, tetanus, meningococcal vaccine. Mercury exposure can cause autoimmunity, oxidative stress, neuritis, neuronal damage, and loss of neuronal connectivity, as the detoxification ability of the body is impaired, along with the ability to make glutathione.


Researchers have found that aluminum can replace calcium present in bone, hence disrupting normal bone formation. In the circulatory system, Aluminium binds to transferrin, forming the Al - transferrin complex which has ability to cross the blood-brain and blood-cerebrospinal fluid barriers. Aluminum also hampers the absorption and uptake of iron.


There lies an inverse relationship between dietary calcium intake and blood lead concentration in autistic children. The elevated lead levels might provoke the increased release of neurotransmitters, disrupting the normal brain functioning of children with ASD and other disorders, e.g. ADHD.

Essential elements imbalances in Autism Spectrum Disorders

Zinc and Copper

Zinc has been considered as the one of the important metals or the proper functioning and development of the central nervous system (CNS). It is majorly found in synaptic vesicles.

Zinc deficiency can lead to neuropsychological disorders, cognitive dysfunctions, as well as mental retardation.

Increase in Copper can be due to increased oxidative stress and abnormally high cytokine levels which can be due to a change in the intestinal microflora.

Copper and Zn are metabolic antagonists. Reduced Copper absorption leads to impaired iron utilization and heme synthesis.

Iron deficiency

Iron is an essential element for cognitive, behavioral, and physical development of children. Iron is a part of multiple enzymes involved in the synthesis of neurotransmitters. The reduced iron concentration in the brain leads to changes in cortical fibre conductivity and myelogenesis. Thus iron deficiencies can contribute to impaired cognitive development and functionality in children with ASD.


Magnesium is essential for converting thiamine into thiamine pyrophosphate, which provides secretin in gastric juice. The lack of this secretin can lead to autism. Mg deficiency has also been related with personality changes, apathy, depression, and anxiety.

Supplementing the patients with B6 and Mg has been found to have a positive impact on the personality of children on the spectrum.

Manganese, Selenium & Chromium disturbances

In children on the spectrum, researchers have found a significantly lower Se/Hg and Se/Pb levels ratios. This confirms that selenium deficiency in ASD increases Hg and Pb toxicity.

Cr (+3) is an essential trace element that is required in glucose and cholesterol metabolism.

Cytotoxic Cr (+6) through oxidative stress leads to lipid peroxidation, oxidative degradation of proteins, damage to genomic DNA, loss of membrane integrity, cellular dysfunction, and ultimately cell death. Cr (+6) is seen to lower GSH and cysteine glutathione levels, which is commonly noted in autism.


The level of these elements in the blood are basic bioindicators, which plays an essential role in causing Autism symptoms. Hence its extremely important to evaluate the levels of heavy metals in the body. Not only this, ratios of mineral and heavy metals are also important to determine their impact. A hair sample analysis for heavy metals, minerals and their ratios is a good way to get started with.

Addressing heavy metals and balancing minerals is a key strategy in helping children with Autism/ADHD/ASD at Functional Medicine Clinic.

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  1. Adams J.B et al. The Severity of Autism Is Associated with Toxic Metal Body Burden and Red Blood Cell Glutathione Levels. J Toxicol. 2009.462-467

  2. Eman Ahmed Zaky. Toxic Heavy Metals and Autism Spectrum Disorder; Is There a Link. Journal of Child and Adolescent Behavior.20176

  3. Geier DA, Kern JK, Garver CR, Adams JB, Audhya T, et al. (2009) Biomarkers of environmental toxicity and susceptibility in autism. J Neurol Sci 280: 101-108.


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