Autism

Autism and Environmental Triggers

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by Matthew Hogg

Autism spectrum disorders are an ever increasing problem in the developed world, being the most prevalent developmental disorders by far. Currently more than 1 in 200 children are believed to be afflicted, and this could mean as many as 1 in 100 boys, as they are more widely affected than girls. The numbers continue to rise and actual figures for those affected may be much higher than what is reported as there is a general feeling that many pediatricians continue to miss telltale signs of autism spectrum disorders.

For a long time, research efforts have concentrated on finding genetic clues to the origins of autism. The general view within the medical community has been that the condition is entirely predetermined by a child’s genes and there is nothing that can currently be done about it medically with regards to treatment. Over recent years however, a considerable amount of evidence has started to pile up suggesting that environmental triggers probably play a major role in autistic spectrum disorders.

An increasing number of people, including individuals and families affected by the conditions and many medical professionals, feel that the correlation between increases in autism and the increasing presence of chemicals and other pollutants in the environment is too strong to ignore. Babies and young children are exposed to a terrifying array of chemicals including ingredients in household cleaning products and personal care products, soft plastics in toys that are known to end up in children’s body’s, as well as such controversial substances as thimerosal, the mercury containing preservative used in some vaccinations. A child’s vulnerable body also has to deal with an added assault from vaccinations themselves, as well as many pharmaceutical drugs such as antibiotics that tend to be given too freely.

Perhaps even more frightening is the fact that a child in the 21st century is exposed to a wide variety of synthetic chemical toxins before it is even born through contamination of its mother’s body. Organizations such as National Geographic, Environmental Defence in Canada, and The World Wildlife Fund (WWF) in the UK have all funded investigations that have revealed that everybody in the developed world is carrying a cocktail of the chemicals around with them in their bodies. Environmental Defence recently tested four prominent Canadian politicians for the presence of residues from 103 different chemical pollutants. The group included Health Minister Tony Clement. The results showed that around 50 pollutants were present in each of the politicians. Amongst the chemicals detected was arsenic, the toxic heavy metal, organophosphate pesticides whose residues persist on our food and in the water supply, as well as various flame retardant chemicals used in a multitude of products from computers to soft furnishings. Many of the chemicals detected are known neurotoxins that likely pose a risk to a child’s delicate developing brain. Environmental Defence had previous tested a much larger number of ordinary Canadians and detected a large number of chemical pollutants in everybody involved. It seems nobody can escape in the modern world.

Thankfully things are starting to change and the link between environmental triggers and autism is beginning to get the attention it needs. There is a growing consensus that autism spectrum disorders are likely to result from interplay between genetic susceptibilities and exposures to environmental triggers such as those we’ve discussed. This new realization is being helped in no small part by advocate groups such as the Autism Society of America (ASA) who are doing much to raise awareness of the issue. The ASA recently launched a major initiative aimed at raising awareness of the role environmental triggers play in the development of autistic disorders. The campaign includes a special issue of their magazine, the Autism Advocate, as well as a new website section devoted to the subject.

Let’s take a closer look at specific environmental triggers that may play a role in autistic spectrum disorders:

Heavy Metals
These highly toxic heavy metals include mercury, arsenic, and cadmium. A number of researchers have found that autistic children tend to have more of these substances in their body than healthy children. The most common of these tends to be mercury. This metal is a known neurotoxin and could be especially damaging to the sensitive brains of young children. Mercury can also disrupt the function of various enzyme systems and damage cell membranes and many proteins involved in all bodily functions. Recent research studies have concluded that the exposure of children to low levels of mercury during critical stages of development is associated with neurological disorders, including ADHD, learning difficulties, and speech delays. Mercury is a by-product of many industries and often ends up in rivers, lakes and oceans. The mercury then accumulates in the food chain so that large predatory fish such as tuna often contain high concentrations. Contamination of water and food supplies is now a major source of mercury and may pose a risk to the health of children. Equally, or perhaps more, frightening is the fact that mercury has been routinely added to childhood vaccinations in the form of the preservative thimerosal. This substance is approximately 50% mercury. An article published in the journal Neurotoxicology by The Coalition for Safe Minds in 2001 reported on the finding that a child given a regular vaccination schedule in the US, using thimerosal containing vaccines, would have a blood level of mercury that is higher than the Environmental Protection Agency’s (EPA) own safe upper limit. Other studies have found that low concentrations of thimerosal trigger an immune response and the production of antibodies in autistic children. This sets the scene for autoimmune reactions if thimerosal is bound to the body’s tissues. Some research and anecdotal reports suggest that therapies to remove heavy metals from the body, known as chelation therapies, are effective in treating the symptoms of autism.

Chemical Exposure
Over the past few decades a number of hazardous chemicals such as lead, asbestos, and organochlorine based insecticides have all disappeared from common use in developed nations. In contrast other supposedly safer alternatives, such as organophosphate pesticides, have become more widespread in the environment. The Autism Research Unit at the University of Sunderland in the UK has published extensively on a potential connection between these organophosphate pesticides and autism. They note that autistic individuals show increased levels of IAG, a chemical which is only produced as a result of the incorrect metabolism of the amino acid tryptophan. This amino acid is the starting point for the production of the important neurotransmitter serotonin which is essential for regulating mood and other brain functions. The researchers believe that organophosphate pesticides may be causing the elevated IAG and the resulting serotonin dysfunction. Organophosphates had their birth as chemical warfare agents, so called ‘nerve gases’. They fulfilled this function because of their ability to cause paralysis by inhibiting certain enzyme systems. Even modern organophosphate pesticides tend to be fairly unspecific in their action so have the unfortunate ability to compromise various other enzyme systems as well, including those that metabolise tryptophan to produce serotonin. This could account for the symptoms of autism and other developmental disorders. Additionally, high levels of organophosphate compounds in the environment could reportedly result in increased permeability of the intestines, so called ‘leaky gut syndrome’ as well as blood-brain barrier. This could result in partially digested food molecules passing into the bloodstream and causing the production of antibodies. This would lead to allergic and autoimmune reactions which are a common feature of autism. These molecules would also play havoc with brain function directly as they could more easily pass through the weakened blood-brain barrier. Organophosphate pesticides are by no means the only potential chemical triggers of autism, but they are certainly a leading candidate. As mentioned previously, everyday items such as consumer electronic products are also a major worry due to their content of chemicals such as flame retardants.

Vaccinations
Probably the most controversial subject regarding environmental triggers and autism is the role of vaccinations. Aside from the thimerosal issue it has been suggested that multiple vaccinations early in life may cause unhealthy changes in the immune systems of susceptible children. A high prevalence of allergies, autoimmune disease, and gut infections in autistic children would seem to lend weight to this idea. It’s worth noting that in the natural order of things, infectious agents must enter the body through the mucous membranes of the intestines or lungs which have a high concentration of specialized immune cells designed to be the body’s first line of defense. Injecting people with infectious agents in vaccines bypasses this vital first step of the immune response. Some highly qualified individuals have postulated that vaccines inherently cause a shift to a Th2 immune response in susceptible individuals of any age. The Th2 response is associated with allergies and autoimmunity. The most controversial aspect of the already controversial subject of vaccinations is undoubtedly the combined Measles-Mumps-Rubella (MMR) vaccine. In 1998 research published by Dr. Andrew Wakefield in the UK sent the media into a frenzy. Dr. Wakefield was studying the connection between gut disorders and autism in a group of children that presented with both. He unexpectedly found traces of viruses from the MMR vaccine in the children’s intestinal tissue in areas of inflammation. The parents also reported that problems had started around the time the children had received the MMR vaccine. This led to the assertion that the MMR vaccine had caused the autism and gut problems. The debate has raged ever since over whether MMR vaccines do actually play a role in autism and opinions have become polarized. Since the publishing of Dr. Wakefield’s paper researchers have attempted to validate or refute the connection. Whilst some have said there is no connection at all, some researchers have noted that autistic children with gut problems that became ill after receiving the MMR vaccine show unique biochemical abnormalities. They suggest that these children may represent a subset of autism that differs from the classical diagnosis.

Intestinal Yeast/Candida
In health, the human intestines contain many billions of bacteria, yeasts, and other micro-organisms. These micro-organisms perform many important functions such as regulating immune-function and preventing infection. They live symbiotically with the human host and the competition for space ensures that no single type of organism becomes dominant. Unfortunately, factors such as antibiotic use and lack of breastfeeding can compromise the gut flora and allow organisms such as Candida Albicans to become the predominant species. This yeast can become parasitic when it is allowed to increase in numbers. It produces many toxic substances as a result of its metabolism, the main ones being ethanol (drinking alcohol) and acetaldehyde, an even more toxic chemical formed when ethanol is broken down in the human body. We all know the effects of drinking alcoholic beverages, imagine how a baby or small child would be affected if constantly exposed to ethanol and acetaldehyde being produced in its intestines by yeast such as Candida. This is not the end of the story either as Candida species produce dozens of other potentially toxic substances in addition to these two. In relation to autism, a number of researchers report detecting high levels of yeast metabolites in the blood and urine of autistic children. Dr. Shaw of The Great Plains Laboratory, formerly a medical director at the Centers for Disease Control (CDC), reports that he routinely finds high levels of tartaric acid in the urine of children with autism and that the most likely source is intestinal yeast overgrowth. He states that when treated with Nystatin, an antifungal drug that is not absorbed from the intestines, the children show remarkable improvements in their condition. Critics suggest that tartaric acid is not a reliable marker for yeast infection. This issue may be resolved in future when autistic children are tested for an accepted definitive marker such as the ’sugar alcohol’, D- arabinitol.

Gluten & Casein
There is a theory for the causation of autism known as the ‘opioid excess theory’. What this says is that various peptides (chains of amino acids) from incompletely digested foods, particularly gluten from wheat and other grains, and casein from milk products, are able to enter the bloodstream as a result of poor digestion and leaky gut syndrome. Once in the bloodstream a proportion of these peptides are able to cross the blood-brain barrier and enter the brain. If the barrier has been weakened by organophosphate pesticides or other chemical agents then a higher proportion of peptides will be able to penetrate. In the brain these peptides are able to interfere with normal brain function. The name of the theory comes from the startling fact that gluten, casein, and other peptides actually mimic the opioids (morphine-like chemicals). These peptides act likes the bodies own natural opioids (such as the enkephalins or endorphins) and cause various behavioural changes. Gluten and casein don’t usually directly act as neurotransmitters, such as serotonin or dopamine, but their opioid activity often causes changes in the function of these important neurotransmitters, usually in a negative fashion.

Conclusion
As you can see there is ample evidence that environmental triggers play a central role in the autistic spectrum disorders. A lot more research is needed and the new awareness initiatives discussed should help with reaching this goal.

On a final note, although the information presented here may be worrying, it should be seen as good news for those affected by autism. The involvement of environmental triggers in the condition provides a great opportunity for effective therapies to be used to correct the biological dysfunction they cause. With such treatments, hopes of leading a normal life are much improved.

About the Author:

Matthew has suffered from chronic fatigue syndrome, IBS and environmental illness for 15 years after being diagnosed at age 11. Having learned much about these illnesses through personal experience and research, he decided to share this knowledge by setting up The Environmental Illness Resource - www.ei-resource.org

© Matthew Hogg. This article may be freely used so long as author bio remains.

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