Assessing Chemical Intolerance in Parents Predicts the Risk of Autism and ADHD in Their Children

Abstract

Background: We sought to replicate our 2015 findings linking chemical intolerance in parents with the risk of their children developing autism and/or ADHD. Drawing upon our 2021 discovery of a strong association between chemical intolerance and mast cells, we propose an explanation for this link.

Methods: In a population-based survey of U.S. adults, we used the internationally validated Quick Environmental Exposure and Sensitivity Inventory (QEESI) to assess symptom severity and chemical intolerance. Parents were asked how many of their biological children had been diagnosed with autism and/or ADHD.

Results: Parents with chemical intolerance scores in the top versus bottom tenth percentile had 5.7 times the risk of reporting a child with autism and 2.1 times for ADHD.

Conclusions: High chemical intolerance scores among parents of children with autism, coupled with our 2021 discovery of mast cell activation as a plausible biomechanism for chemical intolerance, suggest that (1) the QEESI can identify individuals at increased risk, (2) environmental counseling may reduce personal exposures and risk, and (3) the global rise in autism and ADHD may be due to fossil-fuel-derived and biogenic toxicants epigenetically "turning on" or "turning off" critical mast cell genes that can be transmitted transgenerationally. It is important to note that this study was observational in nature; as such, further research is needed using controlled trials to confirm causality and explore the proposed mechanism.

Keywords: Asperger’s; QEESI; TILT; autism; environment; exposure; fossil fuels; mast cells; toxicants; xenobiotics.

Figure 1

Toxicant-Induced Loss of Tolerance (TILT). Initiation is the first of two stages in the disease process, Toxicant-Induced Loss of Tolerance, or TILT. As shown here, Initiation (Stage 1 of TILT) involves a single major exposure or repeated exposures to toxicants such as pesticides, solvents, or toxic mold. In Stage 2 of TILT, called Triggering, tiny quantities of previously tolerated substances that never bothered the person before and do not bother most people trigger symptoms. Triggers often include diesel exhaust, cleaning products, fragrances, foods/food additives, drugs and their excipients, and food/drug combinations such as red wine, beer, coffee, or chocolate. A physician sees only the tip of the iceberg—the patient’s symptoms—and formulates a diagnosis based on them, e.g., asthma, ADHD, autism, or an autoimmune disorder. Background exposures “mask” or hide the relationship between symptoms and triggers. The initial exposure event that led to a loss of tolerance may go unrecognized. Adults may not recall initiating exposures that occurred during their childhood, for example, riding their bikes behind a truck spraying DDT, living where pesticides were applied, or residing in homes where coal, oil, natural gas/propane, or wood was used for heating or cooking [32,33].

Figure 2

Conditions that may have their origins in TILT.

Figure 3

Potential initiators and triggers for TILT.

Figure 4

QEESI Chemical Exposures Scale. The sum of the symptom severity ratings for all 10 of these structurally unrelated chemical inhalants is the Total Chemical Intolerance score (0–100).

Figure 5

Data exclusion flow. Note: Same non-zero score means responses that had all the same number responses (e.g., all 1′s or all 2′s, etc.).

Figure 6

Percent of children with autism by decile for the QEESI total symptoms and chemical intolerance scores.

Figure 7

Percent of children with ADHD by decile for the QEESI total symptoms and chemical intolerance scores.

Figure 8

Reported autism and ADHD by QEESI Chemical Intolerance categories.