Genetics and Environmental Causes: Links to Autism

Entry By: Dr. Esther Hess

I just reviewed the following article by Sallie Bernard which gives her thoughts on a recent conference on autism. The debate over genetic and/or environmental causes of autism rages on….Esther Hess, Ph.D.

Click here to read the article: “Feeling exposed? Insights from a new meeting on environmental impacts in autism by Sallie Bernard, Autism Speaks’ Board Member, co-founder and Executive Director of Safe Minds

Given the historic inattention of the scientific establishment to the environmental contributions to autism, it was nice to see a day-long conference on the topic held this week by a major research center. “Exploring the Environmental Causes of Autism and Learning Disabilities” was put together by the Children’s Center for Environmental Health at the Mount Sinai School of Medicine in New York City. The center is run by Dr. Phil Landrigan, who has been a prominent researcher on the harmful effects of environmental toxicants for decades. He told the incredible story of the harms of lead exposure on children’s cognition and behavior, and how the successful effort to remove leaded gasoline from the market in the 1970s resulted in rising IQ scores and economic gain to the country. I hope this same massive effort will be applied to autism and the chemicals which underlie the increase in its prevalence.

Also of note was the presence at the meeting of Linda Birnbaum. Dr. Birnbaum is the director of the National Institute of Environmental Health Sciences (NIEHS) which holds the autism/environment portfolio at NIH. The Mt. Sinai meeting follows on a workshop held at NIEHS several months ago which explored the role of the environment in autism. Large scientific initiatives in the field fall to the NIH, so without its support, gains will be painfully slow. Hopefully Dr. Birnbaum’s personal involvement signals a heightened interest at NIEHS to look at autism. Although Dr. Birnbaum stated at the conference that her institute spends $30 million on children’s environmental health, at a Senate hearing earlier this year, it was shown that just $8 million of this is for autism specifically.

A few interesting bits of information came out of the conference. One was the definition of “environment” that the insiders use. It covers synthetic chemicals like pesticides, flame retardants and plasticizers; heavy metals like arsenic, lead and mercury; combustion and industrial by-products; diet and nutrients; medications, medical interventions, and substance abuse; infections; the microbiome; heat and radiation; and lifestyle factors. Some may be harmful; others protective. They may operate before conception, during pregnancy or in early life, and some may alter gene expression through epigenetic modifications to chemicals surrounding our genes. Craig Newshaffer, who runs the EARLI study to look at environmental factors among younger autism siblings, referred to the concept of the “exposome”, that is, everything we are exposed to and its effects on health. Dr. Birnbaum’ made the point that health does not equal medicine, and prevention through reduction in chemical exposures is of equal importance to health. Colleen Boyle from the CDC stated that the next prevalence report will be issued in April 2011. We will see if the 1 in 110 number from last year’s report has changed. New research from Korea was unable to confirm increased risk of autism due to parental age or low birth weight, which have been identified as risk factors in Western studies.

The most informative talk was by Dr. Irva Hertz-Picciotto from UC-Davis. She explained how changes in diagnosis do not account for most of the increase in autism rates, and how recent research by their group on mercury and flame retardant blood levels do not address whether these substances are causative for autism because the blood samples were taken years after the autism diagnosis. A paper out this week from UC-Davis found that proximity to traffic air pollution during pregnancy almost doubles the risk of autism. Another paper just accepted by a journal has found higher antibodies to cerebellar tissue in children with autism relative to controls, highlighting the immune component in autism.

Other than these interesting items, the conference covered minimal new ground as far as the science goes. Rather, the points of the meeting seemed to be to make the case that environmental factors research in autism must now be considered mainstream science and to showcase the work being done or about to be done to investigate the issue. Dr. Landrigan made the case for an environmental role by noting that the rate of autism has increased too much to be solely genetic, and that at most, genetics alone will end up explaining 40% of autism cases with the likely percentage much lower.


  1. When I was recently pregnant, I wondered about the use of folic acid. I know it is essential, because it decreases the chances of neural tube defects, but doctors seem to be reccomending very high amounts of folic acid and mothers are taking these high amounts during a very critical time of development for the fetus. When I searched to find some research on any links between increased folic acid and autism/ other learning disorders, I found nothing. I would love to know at what time in history did doctors start reccomending more folic acid and if that in any way corelates with a time in history that we started seeing a rise cases of autism. This is just a thought though, as I said there is no research that I know of on this.

    • Hi C. Diamond, OT.
      There is a inborn gene error called the MTHFR, and 50% of the entire worlds women have 1 copy, another = or – 14% have 2 copies. The action is that you can not convert folic acid in what the body can use or have a significant reduction in conversion ability. Women who have 2 copies have to take a L-Methylfolate, which is much closer to the actual end product. Folic acid is used in every cell throughout the body and having two copies of the gene puts you at risk for all kinds of vascual issues. Tweleve to nine years ago, I went through years and years of infertility treatment, only after I put myself on 2mg of folic acid AM and PM did I grow an endometrium thick enough that implantation could take place. They snickered, but it worked and i got a healthy baby. The consenscious was that I was just peeing it out. Well, actually, if i understand this, the liver can not use the folic acid and it just sits in the blood stream, as it can’t be picked up. Any GP can do the MTHFR blood test and it is a non fasting test. you can be tested at any time. Turns out my 94 y/o Mom has 2 copies, one from her Mom and one from her Dad, and I have two copies, one from my Mom and my Dad. I call it the ‘double whammy’. Not only was I starved for folic acid while in utero, but, once born, I still did not get enough folic acid. I would say that doctors started suggesting more folic acid when they realized half the world had one copy of the gene. Hence the push for eating green veggies and taking folic acid when pregnant. The Metallothioneines (MTs) , I, II work with zinc and folic acid to pull heavy metals out of the body.Folic acid is also needed to keep the gut healthy or the metallothioneines proteins working.

  2. I have often wondered if there have been any genetic studies done on the prevalence of substance abuse, by the fathers of children affected with incidences of autism, or other pervasive developmental diseases. Although, it would be difficult to ascertain accurate data.

  3. I am a nurse with some background in mental health and grandmother to an autistic five-year old. I read your article, and while I found it interesting, found no new information raised.

  4. I feel we need to have one research hospital decide to eliminate the use of epidurals and pitocin for a select group of mothers (those who have no history of autism, and have a 90% chance of delivering without interventions)in order to determine if there would be fewer cases of autism in that study group. I base this on the fact that no midwife deliveries have seen an increase in autism. Research experts have already stated that genetics cannot be the only cause, and I believe it has to be a very strong chemical that babies are exposed to at either delivery time, or during the vulnerable months in which they receive their first immunizations. Pharmaceutical companies will fight this research, but the widespread use of pitocin, epidurals, and certain immunizations have to be linked to the cause of autism. There is no definitive research how pitocin and epidurals affect the developing infant brain, and yet, they continue to be used during delivery. We also have several cases of mothers stating that their typically developing infant suddenly changes following the exposure to immunizations. We don’t have research on the effect of immunizations on the young infant brain either. Don’t waiste the time looking at exposure to gasoline, traffic, pollution as we have been exposed to these chemicals for decades. But, the use of strong pharmaceutical chemicals such as pitocin, epidurals, and certain immunizations have not been around for very long.

    • I have know a friend who’s son has a form of Autism, Aspberger’s Syndrome. The Doctor’s have no clue how and why he developed autism starting at 18 mo. of age. He apeared normal until around that age when he stopped talking, started to bang his head against his crib to calm himself to go to sleep and resisted physical touch to comfort and calm him. She did not let any of her children recieve immunizations because she was afriad of the side affects from them. She also did not have epidurals during her deliveries. She also was very careful to not feed her children food that had additives, preservatives etc. So if your theory is correct what expains this case of autism?

    • Epidurals have been used in childbirth since the 1940’s. Pitocin, the synthetic version of oxytocin a naturally occurring hormone, has actually been shown to reduce the negative symptoms of autism. And there have now been 1000’s of studies worldwide by the most respected physicians and researchers, such as the Institute of Medicine, that have shown absolutely no possible connection between autism and vaccines. None. These people like the SafeMinds group, are perpetrating a fraud, and are indirectly committing child abuse, in my opinion, by encouraging parents not to have their children vaccinated resulting in the deaths of kids who are contracting illnesses that are preventable. Yes, more research should be done in the arena of environmental causes of autism, but they need to look elsewhere, not at vaccines.

  5. I was recently reading about lead exposure from living in an older home (before lead paint was banned). The article was talking about how children today can be exposed to breathing lead dust every time an old window is opened and closed. This sands off the paint in dust and it lands everywhere. Children crawling on the floor- of course- later place their hands in their mouths and ingest the lead.
    I wondered if these same house paints (when wet) exposed to the skin on peoples’ hands (before the ban) could have started the problem for many mental illnesses, not just autism. Is there any data where some one studied a group of painters? I know the woman who used to hand paint clock numbers with radioactive paint had radiation poisening.