A study out of the University of North Carolina Medical School found that pesticides, including a new class of fungicides, caused transcription (genetic) changes in the brain consistent with brain samples of individuals with autism, advanced age and neurodegenerative diseases such as Alzheimer’s disease and Huntington’s disease.[i]
These chemicals were found to inhibit mitochondrial complex I and III, stimulate free radical production and disrupt microtubules in neurons.
Researcher Dr. Zylka states in Science Daily, “Disrupting microtubules affects the function of synapses in mature neurons and can impair the movement of cells as the brain develops,” said. “We know that deficits in neuron migration can lead to neurodevelopmental abnormalities.”
This study is crucial to the health and future development of our children. We know these changes are taking place in the brains and bodies of children with autism. And while we are not certain the etiology of these changes, this study brings into serious question whether pesticides are causing autism, or possibly aggravating an already susceptible system.
What we do know is that pesticides are not good for anyone, and that pesticide in our food ends up in our bodies and can cause damage. Some individuals are more susceptible to that damage than others.
Equally scary, of the chemicals found to be problematic in this study, all are still in use today, with the exception of pyridaben for which usage has decreased since 2000. The other chemicals have either remained the same such as Rotenone (which has been previously linked to Parkinson’s disease), or have dramatically increased such as the use of all the fungicides in this group. And the highest levels of these fungicides can be found in conventionally grown leafy green vegetables such as lettuce, spinach, and kale.
The good news is that the study found that an both antioxidant and sulforaphane were effective in reducing free radicals, inflammation, and attenuated the transcriptional changes caused by these pesticides (when cells were pre-treated). In fact, sulforaphane is known to increase glutathione production, reduce oxidative stress, increase antioxidant capacity, improve mitochondrial function and reduce neuroinflammmation, all common conditions in autism. Additionally, this new study corroborates pre-existing research showing sulforaphane to be very helping for improving the behaviors in autism.[v]
As a nutritionist that works with children, most specifically those with autism, my key take recommendation from this study are to buy organic food for your family whenever possible, particularly leafy greens and produce that is highly sprayed (such as the EWG’s Dirty Dozen). Remember to also buy organic meat, dairy (if you are not dairy-free), and other animal foods. Add broccoli sprouts, as well as other cruciferous vegetables such as broccoli to your diet as they contain high levels glucoraphanin, the precursor of sulforaphane, particularly broccoli sprouts which contain 30 times the amount of sulforaphane precursor as the mature broccoli plant. There are also sulforaphane supplements on the market for those interested in considering them.
Every day we learn more and more about autism, what are the underlying presentations, and how diet can play a role in helping children get better. This study on pesticides provides us one more piece of that complex puzzle.
[i] Pearson, Brandon L., et al. “Identification of chemicals that mimic transcriptional changes associated with autism, brain aging and neurodegeneration.” Nature Communications 7 (2016).
[ii] Rossignol, D. A., and R. E. Frye. “Mitochondrial dysfunction in autism spectrum disorders: a systematic review and meta-analysis.” Molecular psychiatry 17.3 (2012): 290-314.
[iii] Zoroglu, S. Salih, et al. “Increased oxidative stress and altered activities of erythrocyte free radical scavenging enzymes in autism.” European archives of psychiatry and clinical neuroscience 254.3 (2004): 143-147.
[iv] Maussion, Gilles, et al. “Convergent evidence identifying MAP/microtubule affinity-regulating kinase 1 (MARK1) as a susceptibility gene for autism.” Human molecular genetics 17.16 (2008): 2541-2551.
[v] Singh K. et al. Sulforaphane treatment of autism spectrum disorder (ASD). Proc. Natl Acad. Sci. USA 111, 15550–15555 (2014).