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Kathleen Schuler

Let’s focus on environment and diet to help prevent autism
Used under creative commons license from buzzymelibee

Now that autism affects one in fifty school-aged kids—up from 1 in 150 as measured in 2000—we should be asking ourselves some pretty serious questions about why so many kids have autism. Sure, we know that the health and educational systems are better at diagnosing autism, but better diagnosis explains only part of the increase. With exponential increases in rates of autism over the past two decades, there is more going on than better diagnosis.

As more kids are diagnosed with autism, most of our attention is focused on providing services. Serving kids with autism is essential, but there is also a need to examine the possible myriad of factors that might be contributing to this autism epidemic.  If we knew how to prevent autism, it would be our responsibility as a society to commit resources at our disposal to do so.

Preventing autism requires that we look at the whole picture. The bulk of research in autism has been focused on genetics, which plays a contributing role in risk for autism. Emerging from more recent research, however, is a pattern of links between risk for autism and environmental and dietary factors. While the etiology of autism is complex, with both genetic and environmental components, it is clear that the role of the immune system is key. A child’s prenatal and postnatal environments, including diet, clearly impact immune health. Autism is likely the result of multiple assaults on the immune system. One of these assaults then tips the person over a threshold into the autism state.

IATP's latest fact sheet, Autism: What Do Environment and Diet Have to Do With It? by Kathleen Schuler, MPH, explores countless studies that point to increased risk of autism and autistic behaviors from numerous environmental toxin exposures, including:

  • Pollution. Living near a pollution site, hazardous air pollutants, and residence near a freeway.
  • Pesticides. Residence near agricultural pesticide applications and prenatal exposure to the organophosphate pesticides.
  • Phthalates. Prenatal exposure to phthalates.
  • Heavy metals. Exposure to environmental neurotoxins including mercury, aluminum, lead and cadmium. 
  • Persistent organic pollutants. Prenatal exposure to high levels of PCBs and DDE (metabolite of DDT).
  • Parental occupation. Mother’s occupational exposure to exhaust and combustion products and parental work at night or in handling of solvents.

Environmental toxins like mercury and pesticides cause adverse neurodevelopmental impacts through altering gene expression and interact with dietary factors that can either protect or cause harm to health. Specific nutrients play critical roles in metabolic processes that detoxify and eliminate harmful toxins from the body. For example, deficiencies in zinc and magnesium may interact with toxic metal burdens to increase risk for autism. There is emerging evidence that faulty gene expression may play a role in autism and that environmental and dietary factors are key factors in gene expression.

What about prevention?

We have more to learnabout the factors that contribute to autism but we already know enough to apply public health approaches to prevent and treat autism. Education of women of childbearing age and expecting parents on environmental and dietary factors linked to autism could help reduce exposures that might trigger autism. Behavioral interventions for children with autism could be supplemented with dietary interventions. Numerous studies point to the benefits of nutritional supplements for patients with autism. Prenatal care should include an assessment of nutritional status and a close look at treating and preventing metabolic disorders that increase the risk of autism.

While we know that there’s no one chemical or no one exposure that causes autism, implementing policies that prevent unnecessary exposures to neurotoxins and hormone-disrupting chemicals is a smart public health prevention strategy. One of the first policy steps to reduce exposures to toxic chemicals is to reform the Toxic Substances Control Act (TSCA), the outdated and ineffective law that allows thousands of toxic, untested chemicals to continue to be used in consumer products, including in food packaging, without basic information about effects on human health.

In addition to federal action to reduce exposures to toxic chemicals in our environment, state action to protect citizens, especially children, from toxic chemicals in everyday consumer products is also important. Implementing policies such as addressing chemicals in children’s products, as proposed by Minnesota’s Toxic Free Kids Act, will contribute to a healthy environment for the optimal growth and development of our children. To get involved visit Healthy Legacy's Facebook page or contact them at

Read IATP's Autism: What Do Environment and Diet Have to Do With It? by Kathleen Schuler, MPH.