Children of Chemically Intolerant Mothers at Risk for Autism and ADHD

Study results published in the July-August 2015 issue of the Journal of the American Board of Family Medicine suggest a potential association between maternal chemical intolerance and a diagnosis of attention deficit hyperactivity disorder (ADHD) or autism spectrum disorder (ASD) in their offspring.

The University of Texas Health Science Center at San Antonio researcher found that mothers with chemical intolerances were three times more likely to report having a child with ASD and 2.3 times more likely to have a child with ADHD when compared with other women.

For the case-control study, 282 mothers of children with ASD, 258 mothers of children with ADHD, and 154 mothers of children without these disorders participated in an online survey consisting of the Quick Environmental Exposure and Sensitivity Inventory (QEESI), a 50-question, validated chemical intolerance screening instrument. Fathers were not assessed.

“We are most concerned about how vulnerable the children with ADHD and autism were to environmental exposures,” said primary author, Lynne P. Heilbrun, MPH, autism research coordinator for the Department of Family and Community Medicine at the UT Health Science Center San Antonio. “Mothers reported that their children were significantly more sensitive to everyday exposures such as engine exhaust, gasoline, smoke, fragrances, and cleaners than their neurotypical peers.”

Mothers of children with ASD or ADHD also reported that their children were more sensitive to adverse effects from infections, medications, chemicals, foods, and allergens. Additionally, these mothers stated that their children had more illnesses or symptoms associated with chemical intolerance when compared with children without these illnesses. Among other findings in the study:

• When compared with control children, those with ADHD and ASD were 1.7 and 4.9 times more likely, respectively, to have had multiple infections requiring prolonged use of antibiotics.
• Children with ASD were 1.6 times more likely—and those with ADHD were twice as likely—as control children to have allergies.
• Children with ASD were 3.5 times more likely—and those with ADHD were twice as likely—as control children to have had nausea, headaches, dizziness, or trouble breathing when exposed to smoke, nail polish remover, engine exhaust, gasoline, air fresheners, or cleaning agents.
• When compared with control children, those with ASD and ADHD were 4.8 times more and twice as likely, respectively, to have strong food preferences or cravings for cheese, chips, bread, pasta, rice, sugar, salt, and chocolate.

“The American College of Obstetrics and Gynecology issued a consensus statement in 2013 saying that there is sufficient evidence linking toxic exposures to adverse birth and developmental outcomes, calling for physicians to inform women to avoid specific environmental exposures even before conception,” Heilbrun said. “Studies that linked tobacco and alcohol to neurological disorders were available for decades before recommendations to avoid these became a major public health initiative. Physicians have the opportunity right now to become proactive in helping mothers protect their children from neurological disorders plaguing US families.”

Heilbrun and colleagues recommended that all mothers and pregnant women take steps to avoid potentially harmful chemicals, including pesticides, solvents, combustion products, and chemicals used during construction and remodeling. The also urged that physicians use QEESI to assess patients for potential chemical intolerance.

Senior author Claudia S. Miller, MD, professor emeritus at the Health Science Center and a visiting senior scientist for the Harvard School of Public Health, said, “It's important for everyone to know that doctors can use a readily available tool to identify more susceptible mothers and to suggest environmental interventions to help protect themselves and their developing children.”