Autism Spectrum Disorder and Pesticide Exposure

Hello everyone, Dr. David Perlmutter here. Today we're going to talk about autism. We are seeing the statistics indicating that rates of autism continue to increase, not only here in the United States but globally, and, you know, that really speaks to there being some form of environmental issue, perhaps even nutritional issue that may be related. Certainly not specifically a genetic issue. If it was purely a genetic issue, then we wouldn't expect there to be increasing rates of this issue over time. To be clear, this may be an environmental issue interplaying with a genetic predisposition, and likely it is. But to address the possibility of identifying an environmental consideration here, I'd like to turn to a recent BMJ 2019 study published in that journal that is entitled Prenatal and Infant Exposure to Ambient Pesticides and Autism Spectrum Disorder in Children: Population-Based Case-Control Study. Now, there's a lot in that title, but we're going to walk through exactly what this study is all about. The authors wanted to determine the relationship or associations between being exposed to various forms of chemicals during early life or even during pregnancy in the case of the mother and risk for ultimately developing autism spectrum disorder. And this was a study done in California's main agricultural region which is called the Central Valley. And the study was carried out looking at data from 1998 until 2010 data obtained from the Office of Vital Statistics. The study incorporated or evaluated 2,961 individuals who in fact were diagnosed with autism spectrum disorder, including of that number 445 who also had intellectual disability as what is called a comorbidity or in addition to, and these were also identified through the evaluation of medical records. Now, these individuals were compared to age and gender matched controls by a ratio of 10 to 1. In other words, 10 controls were looked at for every 1 individual with autism just to really flesh out this study to get as much data as possible. They used geographic— they developed what was called a geographic information tool to estimate the prenatal and infant exposures to a variety of different types of pesticides in terms of pounds of pesticides applied per acre in the fields per month within 2,000 meters from where the mother lived during this period of time. And let's have a look at this chart. This is a chart that shows the application of a pesticide, in this case actually an herbicide that goes by the name of glyphosate, in the Central Valley between the years 1998 and 2010. And you can see in quite a few areas there is an extensive amount of glyphosate of this herbicide glyphosate that's been applied. So, the results of the study are really quite interesting. The risk of autism spectrum disorder was clearly associated with maternal exposure to glyphosate with an odds ratio of 1.16, meaning that in comparison to the controls, those individuals with autism spectrum disorder were likely to have been exposed by a factor of about 16%. Also, relationship was seen with exposure to chlorpyrifos, diazinon, malathion, and ivermectin, other pesticides used. For autism spectrum disorder along with intellectual disability, the estimated odds ratio were in fact quite higher by a factor of about 30% Exposure during the first year of life increased the odds of developing autism spectrum disorder with comorbid intellectual disability by up to 50% with certain of these pesticide substances. What did the authors conclude? I'm going to read it to you. Findings suggest that an offspring's risk of autism spectrum disorder Increases following prenatal exposure to ambient pesticides within 2,000 meters of their mother's residence during pregnancy compared with offspring of women from the same agricultural region without such exposure. Infant exposure could further increase risk for autism spectrum disorder with comorbid intellectual disability. Now, The findings of the study are such that they demonstrate an association, a relationship between living near the use of these agricultural chemicals, specifically one, glyphosate, and risk for having a child with autism, and the risk is higher for autism spectrum disorder along with this intellectual disability. This is not a causality finding. It doesn't demonstrate a mechanism and prove causality, but this is important information nonetheless. Glyphosate is used globally as an herbicide. It is— it has been developed to be used specifically on genetically modified crops, crops that are designed and created such that they can be resistant to the herbicidal approach or activity rather of glyphosate. It's used globally. And now we see that there is at least association evidence that glyphosate exposure for mothers is associated with increased risk of delivering a child who will ultimately be diagnosed as being on the spectrum, autism spectrum disorder. I think this is very important information. It is a reason why we should opt for non-GMO foods because that would mean those crops had been planted in a place where likely no glyphosate would be used. It's certainly a reason to opt for organic vegetables as well. This is interesting information. I hope you appreciate it. Dr. David Perlmutter, that's it for now. Bye-bye.