Possible causes of Autism
Autism affects 1 out of 110 American child. This has increased dramatically over the last decade. This is due partly due to the re-definition of autism and the autism spectrum disorders (ASD). But other believe that this redefinition and greater awareness and testing of autism does not account fully for the increase.
Autism is caused by both genetic and environmental factors. There will not be one cause of autism but many possible causes. There is not just one type of autism, there are many types of autism. Hence the name autism spectrum disorders. It is a spectrum with some being more severe than others.
Scientists have not solved the full puzzle yet, but they have some of the pieces. They know that there is a mis-coordination or a problem with the communication of the different parts of the brain in autism. They have found genes related to autism. They now know that there are environmental chemicals and toxins and pesticides may have subtle effects on the immune system and the brain that we did not know before.
Genetic Component of Autism
There will not be one autism related gene. Scientists have found at least 20 different genes that may contribute to autism. However any particular one of those gene relates to a small 1 to 2% of the causes of autism.
In 2010, USAToday reports that there is a higher risk of autism when there is a family history of autoimmune disease. Possibly the same genes that predisposes an individual to autoimmune disease is also involved in autism.
Autism is a body disorder that affects the brain
Dr. Mark Hyman says in the video on the right that autism is not entirely genetic. It is a body disorder that happens to affect the brain. He talks about how he helped a patient with autism.
Gluten sensitivity, gut issues, leaky gut syndrome, systemic inflammation can all be factors in autism.
When Dr. Mercola interviewed Dr. Natasha Campbell-McBride, Campbell-McBride says that autism is a digestive disorder that affects the brain. She had a child that had autism which she cured through the "GAPS" diet that she pioneered. The GAPS diets stands for "Gut and Psychology Syndrome" and you can learn more about it on her site gaps.me.
Environmental Component of Autism
The average American consumes an gallon of pesticides and herbicides a year from conventionally grown foods. [The UltraMind Solution]
When such chemicals were first introduced, many thought that if it didn't cause harm right away, then it was safe; or that if there was no proof then it is safe. It turns out this is not the case. We now know that lack of proof does not mean it has no effect. The effects of chemicals can be subtle and can take years to develop.
PBS News Hour aired April 20, 2011 talked with four researchers of autism including...
- David Amaral, director of the MIND Institute at University of California at Davis. MIND stands for Medical Investigation of Neurodevelopmental Disorders.
- Dr. Gerald Fishbach of science director of the Simons Foundation in New York
- Dr. Martha Herbert, professor of neurology at Harvard Medical School
- Dr. Craig Newschaffer, professor of epidemiology and biostatistics at Drexel University in Philadelphia.
Dr. Herbert says ...
"I think there are lot of things environmentally that are overwhelming our ability to our ability to cope, metabolically, that are overwhelming our immune system. And the synergy -- the collective impact of that is to deplete our protective systems. And I think that's what's causing autism."
And that there are toxic elements in our environment known as endocrine disruptors that mimic our own molecules or hormones. They can damage our cell membrane and our mitochondria (the power-plant of our cells). These endorine disruptors can get confused with our own neurotransmitters. So our system get confused.
Autism and the Immune System
The body's immune system can also get confused where the immune system attacks its own cells. This is the characteristics of autoimmune diseases.
Dr. Amaral says "the immune system is an important component of autism."
Dr. Herbert says ...
"The brain and the immune system and the gut are intimately related. ... They work together seamlessly, and when you disregulate one, you disregulate all the others."
In autism the brain is mis-regulated. But autism may not necessary be a brain disorder, it may be a systemic disorder that happens to affect the brain. The systemic disorder is affected by the gut and the immune system as well.
Dr. Martha Herbert is also the author of the paper, "Autism: A brain disorder, or a disorder that affects the brain?" in which she says ...
"emerging finding and hypotheses support a broader model of the condition as genetically influenced and systemic."
The gut plays a key role in the immune system. In fact some people call it the "second brain". The small intestines has neurons just like those found in the spinal cord. And it communicates back and forth in a two-way dialogue with your brain. The gut also has a nervous system known as the enteric nervous system (as opposed to the central nervous system).
The UltraMind Solution writes ...
"all the information and noise from outside the brain - from the gut, from the immune system, and from toxins - are causing the brain to malfunction"[page 51]
"The gut has to be completely in balance for your brain to be in balance. The brain experiences everything that happens in your gut directly through nervous system feedback, immune activity, cytokines, and other assorted mischievous molecules made in your gut." [page 198]
Autoimmune Inflammatory Diseases increase risk of autistic child
New York Times article An Immune Disorder at the Root of Autism says that many forms of autism is due to immune dysregulation which begins when baby is still in the womb. This dysregulation causes inflammation that does not turn off.
The article writes "The theme here is maternal immune dysregulation".
It says that infections during pregnancy increases risk of autistic child due to mother inflammatory response. Mothers with rheumatoid arthritis (an chronic inflammatory and autoimmune disease) increase child's risk of autism. Mothers with celiac disease (another autoimmune inflammatory disease) increases risk by 350 percent.
Other possible causes
Other studies are looking at other causes at other fronts.
There are some studies that shows that child from parents are that older run a greater risk of autism.
The pre-natal environment may also play a role (how large or small is to be determined)
Kevin Becker wrote paper citing some similarities between autism and autoimmune disorders (such as asthma) and suggests that there is a shared mechanism between the two ...
"shared observations between autism and inflammatory disorders are used in support of the development of a hypothesis for the apparent rise in the prevalence of autism using the framework of the immune hygiene hypotheses."
and suggests that the hygiene hypotheses is something to look at in regards to the growing prevalence of autism.
Vaccines are NOT a cause autism. Dr. Fishbach says ...
"Despite many, many, many epidemiological studies, no evidence that current vaccines in their present form have triggered autism."
-  Autism's Causes: How Close Are We to Solving the Puzzle? | PBS NewsHour | April 20, 2011 | PBS
The rise in the number of reported autism cases has caused a surge in research to find the causes. For the latest thinking, Robert MacNeil speaks with four leading researchers about the issue. It's part three of the Autism Now series of reports.
-  "The UltraMind Solution" by Dr. Mark Hyman
-  Autism, asthma, inammation, and the hygiene hypothesis
-  Autism: A brain disorder, or a disorder that affects the brain?