Some of the Causes of Autism

Although it's been three hundred years since the first properly documented ncase of autism in 1747, we still do not have a definitive answer to what causes nthe five autism spectrum disorders – Rett Syndrome, Asperger Syndrome, Childhood nDisintegrative Disorder (CDD), PDD-NOS (Pervasive Developmental Disorder – Not nOtherwise Specified) and Kanner's Autism.

Researcher, parents and doctors are still debating whether autism is caused nby genetics, environmental factors or other causes. Here are just some of the ntheories that people put forward as to the cause of autism spectrum ndisorders:-

• Vaccines – The vaccine debate was started in 1998 when research by London's n Royal Free Hospital was published in the British medical journal, “The n Lancet”. This research suggested that some children had developed n developmental disorders and gastrointestinal problems (both symptoms of n autism) after being vaccinated with the MMR vaccine. In the US, autism n crusader Jenny McCarthy has drawn people's attention to the fact that autism n rates have risen along with an increase in the number of vaccines given to n babies and young children. Some people also believe that it's not the live n vaccines themselves, but the fact that vaccines used to contain a mercury n based preservative, thimerosal, that is the problem. Thimerosal has been n removed from children's vaccines but may still be found in vaccines given to n pregnant women and some medicines.

• Birth Injury – Some researchers, like Harch and McCullough (“The Oxygen n Revolution”) are of the opinion that many autistic children have suffered n trauma to the brain during birth.

• Mitochondrial Dysfunction – Some studies, including one carried out in n Portugal, have suggested that there is a link between mitochondrial disease or n dysfunction and autism because mitochondrial dysfunction is more common in n people with autism.

• Gut Problems – Many studies have suggested that there is a n gut-brain link with autism and that autism is caused by an inability to n metabolize certain foods, problems with digestion or an imbalance of flora in n the gut. According to research carried out by Valicenti-McDermot et al., n around 70% of children with autism also have gastrointestinal problems.

• Heavy metals – Many people believe that autism can be caused or n triggered by exposure to heavy metals in the environment. Heavy metals like n cadmium, manganese, lead and mercury are found in the air we breathe, the food n we eat, the water we drink and things around us. Usually the human body can n deal with these heavy metals, excreting them, but studies have suggested that n some children are unable to do this and the heavy metals build up, causing n autism.

• Genes – Some scientists believe that genes have a role to play n in autism, either directly causing autism or by leaving a child susceptible to n having autism triggered by environmental factors.

• Environmental causes – As well as vaccines and heavy metals, our n children are also exposed to toxins like pesticides, PCBs and dioxins, n emissions and solvents. These toxins are known as neurotoxicants because they n can damage the brain and impair a child's development. child could then go on n to develop autism if there is a trigger like an environmental factor or n vaccine.

• Candida Yeast – An overgrowth of candida yeast in the gut can n produce toxins which are then carried around the body and can adversely affect n a child's immune system and brain. Studies have shown that autistic children n often have too much candida yeast in their guts.

• Food intolerances – Foods like gluten and casein are well known n “allergic foods” which some studies have linked to symptoms of autism. Diets n like the GFCF Diet, SCD and Feingold Diet have been affective with many n autistic children.

• A Mother's Antibodies – Research by John Hopkins Children's n Center concluded that a pregnant woman's immune system can actually produce n antibodies against her baby's brain tissue which then cross the placenta, n enter the baby's bloodstream and attack it's brain.

• Nutritional deficiencies – Some research has found that autistic n children are deficient in key nutrients such as vitamin A, D and B group n vitamins, minerals like zinc, calcium and magnesium, and omega 3 essential n fatty acid. These deficiencies can be corrected by a healthy diet and n supplements.

Research is still going on in each of these areas and it may be nthat autism is actually caused or triggered by a combination of nfactors.