Toxicity has been implicated as a cause for autism. A ground breaking 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 ASD, AD/HD 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.
It is clear that environmental toxicity is impacting all children and adults. Children with ASD are our canaries in a coal mine showing us how detrimental toxins found in food, land, air and water can be on developing brains.
Toxicants damage mitochondrial and therefore damage the ability to create energy to cleaning them up. Toxicants can be categorized into coming from inside the body and coming from outside the body. A xenobiotic is a foreign chemical substance found within an organism that is not made by the body. Toxicants implicated in Autism Spectrum Disorder include pesticides, phthalates, polychlorinated biphenyls (PCBs), solvents, toxic waste sites, air pollutants and heavy metals, with the strongest evidence found for air pollutants and pesticides.
Children with ASD are genetically more susceptible to oxidative damage and environmental toxins than children with typical development. In the 1950’s, Denham Harman, launched the free radical theory of aging. We now know definitely that compounds called free radicals cause oxidative damage and cell death. People with low oxidative stress and high antioxidant status live longer and have less disease.
In autism, research has shown that oxidative stress levels are very high and that antioxidant levels are very low. Antioxidants protect all of us from the many harmful chemicals and substances circulating in food, air, water and land. There are essential for normal development. Environmental toxins like metals, chemicals, pesticides and other harmful substances, lower antioxidant levels.
When people are exposed to toxicants, often these substances deposit into tissue like fat, organ systems, muscle, brain and bone. When detoxification is initiated, the metalloprotein system, moves metals to the liver for transformation and detoxification.
Without metabolism of toxicants in the liver, many xenobiotics would reach toxic concentrations. Most metabolic activity inside the liver cell requires energy, cofactors, and enzymes. The liver has 2 major detoxification pathways called phase I, phase II. Phase I detoxification pathway has to be just as efficient as phase II. When toxicants pass successfully through phase I but wait in queue for phase II, reactive epoxides are made and deposit into general blood circulation into the body instead of completing the liver detoxification process.
Phase III detoxification is located in the digestive system. Toxicants have a final location for shifting their structure for elimination in the digestive system.
Published research by Dr. S. Jill James, PhD and principal researcher at the Arkansas Children’s Hospital Research Institute showed that children with autism have depleted stores of glutathione. Glutathione is one of the body’s most important antioxidants that support detoxification of toxic substances. James’s research identified that children with ASD had up to 80% of this important compound depleted. One of the most important things to understand about glutathione and development is that the brain relies 100% on glutathione to support development. As glutathione levels decrease, so does the “fuel” needed for development.
Genes that are involved in toxicant elimination, and have increased prevalence on those on the Autism Spectrum include PON1, GSTP1, SLC11A3 and MTF1, ALADSLC11A3, and MTF.
References:
Croom E. Metabolism of xenobiotics of human environments. Prog Mol Biol Transl Sci. 2012;112:31-88.
D A Rossignol, S J Genuis, and R E Frye. Environmental toxicants and autism spectrum disorders: a systematic review. Transl Psychiatry. 2014 Feb; 4(2): e360. Published online 2014 Feb 11.
Koufaris C, Sismani C (2015) Modulation of the genome and epigenome of individuals susceptible to autism by environmental risk factors. Int J Mol Sci 16(4):8699
Roberts AL, Lyall K, Hart JE, Laden F, Just AC, Bobb JF, Koenen KC, Ascherio A et al (2013) Perinatal air pollutant exposures and autism spectrum disorder in the children of Nurses’ health study II participants. Environ Health Perspect 121(8):978
Volk HE, Hertz-Picciotto I, Delwiche L, Lurmann F, McConnell R (2011) Residential proximity to freeways and autism in the CHARGE study. Environ Health Perspect 119(6):873