Medical researchers are finding that children with autism and their parents suffer in some of the same ways when they encounter certain chemicals in everyday products.

Recently, at the invitation of the Autism Society of America, I presented a national webinar describing how children with autism and their parents often share certain intolerances, and may react in similar ways. Why? I think it’s a case where “Genetics loads the gun, and the environment pulls the trigger.”

We know, for example, that in adults certain acute or chronic chemical exposures sometimes can initiate a process that has come to be known as “Toxicant-induced Loss of Tolerance,” or TILT. TILT may develop after a workplace exposure or remodeling of a home or exposure to petrochemicals or combustion products from a fire. Thereafter, everyday exposures to common chemicals, foods, medications, and even caffeine, can trigger cognitive and mood difficulties, as well as a host of baffling symptoms that can affect the nervous system, digestive tract, airways, and skin.

Notably, many of the same environmental exposures, e.g., certain pesticides, that initiate TILT in adults can also interfere with neurodevelopment in a fetus, starting as early as the first month of pregnancy when the neural tube forms and before the mother even knows she is pregnant!

And, as for chemically intolerant adults, we should make every effort to prevent suspected initiating exposures as well as minimize exposures that can continue to trigger autistic behaviors and other symptoms throughout the lifespan. This also means that continued avoidance of even low-level exposure triggers may be important for treating children and adults with autism.

These differences in susceptibility to environmental chemical exposures, which may predispose to TILT in adults and autism in children, are the consequence of normal human genetic diversity — a good thing! My concern, as we learn more about the important relationships between autism, genes and exposures, is that differences in our genetic susceptibility not be viewed as a defects, but rather normal individual differences. These differences are not new. What is new are our exposures. Since World War II, the petrochemical era has ushered in myriad chemical exposures, exposures unprecedented in human history. There can be as much as a 10,000-fold difference, from person to person, in our ability to detoxify and eliminate substances from our bodies. Currently we are unable predict which exposures can cause TILT or autism in which persons.

Other shared features of autism and chemical intolerance include food cravings (mimicking addiction) and intolerances including gluten (wheat) and milk. From our own studies, mothers of children with autism, compared to mothers of “neurotypical children’” were much more likely to report that common chemical exposures make them sick. These included household cleaners, fragrances and pesticides. We used the validated “Quick Environmental Exposure and Sensitivity Inventory” or QEESI, questionnaire to gauge chemical, food and other environmental intolerances in the mothers. You too can use the QEESI questionnaire to gauge sensitivities.

The underlying causes for autism and the reasons why it now affects a staggering 1 in 110 babies born in the United States — a national epidemic according to the Centers for Disease Control and Prevention (CDC) — continue to elude the medical and scientific communities. There are many clues, and theories. The webinar I presented on behalf of the Autism Society of America, which is available to you free of charge, focuses on the striking and often overlooked parallels between autism and chemical intolerance. The increased use of petrochemically based household products and recent emphasis on greener, more energy efficient homes with little fresh air to dilute contaminants in the United States parallels the rise in autism over the past few decades. Globally, autism has been on the rise in every industrialized nation.

During medical school, my colleagues and I learned that children are not just little adults! There are obvious size and many metabolic differences between children and adults. At the same time, children with autism and chemically intolerant adults are strikingly similar in important ways: They share exposures to petrochemicals, indoor air pollutants and pesticides, and both experience chemical and food intolerances. A crucial difference in the case of autism is timing: Exposures that occur during pregnancy or early childhood have the potential to alter neurodevelopment. One tool that is urgently needed in medicine is an Environmental Medical Unit, or EMU, which would allow physicians and families to determine whether and to what extent autism might be reversible if chemical and food triggers could be avoided systematically for a few weeks. Here is a paper I wrote about EMUs.

Here is the webinar presentation to the Autism Society of America.

To follow the proceedings, you will need to install the Cisco Webex browser software. You will be prompted at the website. Adding the software only takes a few seconds.