Causes of Autism
The causes of Autism spectrum Disorders are relatively still unclear. However, the emerging scientific model relates to how Genes and nutrients interact to make the thousands of enzymes (functional proteins) each with their own specific functions. It is this continuous interaction between the genetic code and nutrients (Nutrigenomics) that grows a human being in the womb and in the early years, as well as maintains optimum health and function throughout the lifespan. Genetic mutations (Single Nucleotide Polymorphisms) affect the efficacy of these enzymes
Furthermore, each of these genes requires specific nutrient co-factors (mostly vitamins and minerals). Hence, deficits in these nutrients in our modern diet and in the diet of children with Autism can further reduce the effectiveness of these enzymes, leading to dysfunction in the gut wall and in various systems in the body, including brain cells.
Recent research suggests that Autism may result when a child with a genetic susceptibility and/or abnormal Omega-3 fatty acid profile in cell membranes is exposed to one or more environmental insults (heavy metal exposure, virus or bacteria) resulting in malfunctioning cells (often in the gut and brain). This model my explain the rise in autism since the 1960s.
Eventually these dysfunctional interactions can affect body systems, most obviously the gastrointestinal, endocrine, immune system and the central nervous system. The complexity of the thousands if not millions of possible interactions may well defy description. We can however, build a basic biomedical model of autism, based on the published scientific evidence to-date.
The following is an outline of some of the most common mechanisms that have been implicated in the aetiology of Autism Spectrum Disorder:
Genetic evidence in Autism
Toxicity of Wheat
Wheat is one of the most consumed cereal grains worldwide and makes up a substantial part of the human diet. Although government-supported dietary guidelines in Europe and the U.S.A advise individuals to eat adequate amounts of (whole) grain products per day, cereal grains contain anti-nutrients, such as wheat gluten and wheat lectin, that in humans can elicit dysfunction and disease. There is substantial evidence from in vitro, in vivo and human intervention studies that describe how not only the consumption of wheat, but also other cereal grains, can contribute to the manifestation of chronic inflammation and autoimmune diseases by increasing intestinal permeability and initiating a pro-inflammatory immune response. Click here to download a paper on 'The Dietary Intake of Wheat and other Cereal Grains and Their Role in Inflammation'.
Autism and Folate Metabolism
Research over the last 20 years has suggested a relationship between maternal diet and the birth of an affected infant, and recent evidence has confirmed that folic acid, a water soluble vitamin, found in many fruits (particularly oranges, berries and bananas), leafy green vegetables, cereals and legumes, may prevent the majority of neural tube defects.
Normal brain development and function depend on the active transport of folates across the blood-brain barrier. A study reported on the clinical and metabolic findings among five children with normal neurodevelopmental progress during the first four to six months followed by the acquisition of marked irritability, decelerating head growth, psychomotor retardation, cerebellar ataxia, dyskinesias, pyramidal signs in the lower limbs and occasional seizures. After the age of six years the two oldest patients also manifested a central visual disorder. Known disorders had been ruled out by extensive investigations. Despite normal folate levels in serum and red blood cells with normal homocysteine, analysis of Cerebro Spinal Fluid suggested disturbed transport of folates across the blood-brain barrier. Oral treatment with folinic acid resulted in clinical amelioration. Little, J., Epidemiology of neurodevelopmental disorders in children. Prostaglandins Leukot Essent Fatty Acids, 2000. 63(1-2): p. 11-20.This study and others like it supports our contention that normal methylation is vitally important for the prevention and treatment of neurodevelopmental disorders including Autism.
Why the diversity of behaviours in Autism
This model goes a long way to explaining why there is such diversity in Autistic behaviours. It also explains why some interventions work for some children and not others, highlighting the need for conducting Biomedical testing as a basis for formulating hypotheses and to justify treatment approaches..
There is emerging evidence that Autism is a multifaceted Nutrigenomic disorder (interaction between genes and nutrients). Since our genetic code is unlikely to have changed or mutated in the last 100 years, genetics cannot account for the rise in all modern diseases, including Autism, in that short period. According to the US Bureau of Statistics, the incidence of Autism has increased 870% in ten years. However, while genetics have not changed, our diet and food chain has changed dramatically in that time and may be responsible for the observed increase in Autism Spectrum Disorder.
Nutritional deficiencies interacting with pre-existing genetic polymorphisms result in cellular structures and internal cellular apparatus that are less than optimum. When these cells are later exposed to toxic chemicals, heavy metals and antigens such as bacteria and viruses they can be easily damaged and consequently fail to perform their normal functions.These cells are distributed throughout the body’s systems, such as: Immune System, Central Nervous System, Gastrointestinal system, Neuroendocrine and musculoskeletal systems and others. Consequently Autism has been described as a multi-systemic disorder.
Copyright © Australian Autism ADHD Foundation 2014. All Rights reserved.