Like a modern-day action movie, the ticking time bomb of autism advances forward, taking a higher and higher percentage of the next generation as scientists frantically search for clues to the mystery. With the estimated rates of autism rising to 1 in 50-something, we all hope for answers which lead to successful therapies. Like the action movie hero searching for the ticking sound before it explodes, researchers must look in the right place or else they will miss the opportunity to triumph over the villain. In autism, should we look at more genetic studies which have shown links to autism, or should we look at environmental factors which show correlations with its occurrence?
In contrast to a scripted action movie, researchers can look in both directions for their answers. In fact, they should be looking at the interplay of both nature (genetics) and nurture (environment) for some of the most impactful answers. If all we consider are genetics, they we are just predicting and reacting to hardwired processes which have to be altered or bypassed rather than outright prevented. If we ignore genetics, then we miss out on the individuality of each child with autism. However, if we understand the genetics of the child before us and recognize the environmental influences which will particularly impact those genetics, we may find the ticking bomb much faster.
The authors of our focus article open with an overview that mentions the problems with focusing solely on genetics. This may obscure the need for research into what triggers these genetics processes to develop into what we know as autism. The secondary reference from Won et al further notes that so far each discovered gene linked with autism only accounts for 1-2% of the total cases at best. There are at least dozens of genes impacting a wide spectrum of neurological processes resulting in autism syndromes. Focusing solely on genetics will leave opportunities to influence how these genes express in the dark.
We can’t change genes, but we must understand how to change their expression. Prior research has demonstrated clear links between environmental exposures and child brain developments (Lanphear 2015) as well as links with autism (Hertz-Picciotto et al 2018, Woodward et al 2015, Volk et al 2021, Chun et al 2020, Oulhote et al 2020). Despite this promising early insight, our primary article by Volk describes the current state of limited epidemiological research into the contribution of environmental factors with genes linked to autism.
One very intriguing work was performed by Carter and others in 2016. They took 206 genes identified as linked with autism and crossmatched them with over 10,000 chemicals whose interactions with genes were known. They identified over 4000 chemicals with the potential to influence at least one of these 206 genes. This obviously offers great opportunities for prevention and therapy at individual levels as well as population levels.
Volk et al simply urges further research in these areas. The article by Won et al offers an extensive list of directions for future research as it walks through most of the now recognized genetic contributors to autism. Meanwhile, in functional medicine, we continue press forward with identifying environmental contributors to autism in our pediatric patients. We work to lower inflammation which impacts on multiple genes. We work to remove toxins which disrupts various metabolic processes. We work to optimize nutrients which may be functionally deficient in genetic susceptible patients. With this and more, we work to help these children live healthier more abundant lives building on what we already know to be relevant from prior research.
Volk, Heather E et al. “Considering Toxic Chemicals in the Etiology of Autism.” Pediatrics vol. 149,1 (2022): e2021053012. doi:10.1542/peds.2021-053012
Carter CJ, Blizard RA. Autism genes are selectively targeted by environmental pollutants including pesticides, heavy metals, bisphenol A, phthalates and many others in food, cosmetics or household products [published online ahead of print October 27, 2016]. Neurochem Int. doi:10.1016/j.neuint.2016.10.011
Chun, HeeKyoung et al. “Maternal exposure to air pollution and risk of autism in children: A systematic review and meta-analysis.” Environmental pollution (Barking, Essex : 1987) vol. 256 (2020): 113307. doi:10.1016/j.envpol.2019.113307
Hertz-Picciotto I, Schmidt RJ, Krakowiak P. Understanding environmental contributions to autism: causal concepts and the state of science. Autism Res. 2018;11(4):554–586
Lan, Anat et al. “Prenatal chlorpyrifos leads to autism-like deficits in C57Bl6/J mice.” Environmental health : a global access science source vol. 16,1 43. 2 May. 2017, doi:10.1186/s12940-017-0251-3
Lanphear, Bruce P. “The impact of toxins on the developing brain.” Annual review of public health vol. 36 (2015): 211-30. doi:10.1146/annurev-publhealth-031912-114413
Oulhote, Youssef et al. “Gestational Exposures to Phthalates and Folic Acid, and Autistic Traits in Canadian Children.” Environmental health perspectives vol. 128,2 (2020): 27004. doi:10.1289/EHP5621
Volk, Heather E et al. “Prenatal air pollution exposure and neurodevelopment: A review and blueprint for a harmonized approach within ECHO.” Environmental research vol. 196 (2021): 110320. doi:10.1016/j.envres.2020.110320
Won, Hyejung et al. “Autism spectrum disorder causes, mechanisms, and treatments: focus on neuronal synapses.” Frontiers in molecular neuroscience vol. 6 19. 5 Aug. 2013, doi:10.3389/fnmol.2013.00019
Woodward, Nicholas et al. “Traffic-related air pollution and brain development.” AIMS environmental science vol. 2,2 (2015): 353-373. doi:10.3934/environsci.2015.2.353
Sanctuary Functional Medicine, under the direction of Dr Eric Potter, IFMCP MD, provides functional medicine services to Nashville, Middle Tennessee and beyond. We frequently treat patients from Kentucky, Alabama, Mississippi, Georgia, Ohio, Indiana, and more... offering the hope of healthier more abundant lives to those with chronic illness.