Phthalates Linked with Autism in Boys, say researchers

A new study has linked pregnant women’s exposure to phthalate chemicals (common in U.S. food packaging and personal care/home care products) to brain health in boys.  More specifically, a first of its kind new study has demonstrated a link between pregnant women’s exposure to the endocrine disrupting toxic chemical family known as “phthalates” and autism in boys.  (Boys are four times more likely to develop Autism Spectrum Disorder (ASD) than girls.)

The good news (there is rarely good news attached to these type of findings) is that pregnant women can mediate these adverse outcomes by taking folic acid as a dietary supplement during the first trimester of pregnancy.

“One of the most important findings is how adequate folic acid supplementation in pregnancy may offset the potential harmful effects of phthalates in regard to autistic traits.”

-Dr. Youssef Oulhote, study coauthor and assistant professor of biostatistics and epidemiology, University of Massachusetts-Amherst-

Study overview

“The researchers analyzed data from the Maternal-Infant Research on Environmental Chemicals, or MIREC, project, which enrolled 2,001 women during their first trimester of pregnancy from 10 cities in Canada between 2008 and 2011…

For the new study, the team measured 11 different phthalate metabolites in the pregnant women’s urine samples taken during their first trimester and recorded the women’s folic acid supplement intake. Later, they performed neuro-psychological assessments on 601 three- and four-year-old children of the participating women, screening for ASD.”

Abstract: Researchers enrolled 2,001 women>18years of age during the first trimester of pregnancy between 2008 and 2011 from 10 cities in Canada. At 3–4 years of age, 610 children underwent neuropsychological assessments including the Social Responsiveness Scale–II (SRS-2) as a measure of autistic traits and social impairment. We measured 11 phthalate metabolites in maternal first trimester urine samples and assessed folic acid supplementation from reported intakes. We estimated covariate-adjusted differences in SRS-2 T-scores with a doubling in phthalate concentrations in 510 children with complete data.

Results overview

The researchers found that “increases in urinary concentrations of phthalate chemicals were associated with increases in the presence of ASD traits. Fewer of these autistic traits — which are characterized by social behavior, repetitive behaviors and restricted interests, but do not necessarily constitute an autism diagnosis — were found among boys whose mothers had taken the recommended dose of supplementary folic acid — 400 mcg daily — during their first trimester of pregnancy.  The links between phthalate exposure and ASD traits were more significant in boys than in girls.” (source)


Journal Reference: Y. Oulhote, et al. (2020). Gestational Exposures to Phthalates and Folic Acid, and Autistic Traits in Canadian Children, Environmental Health Perspectives Journal,Vol. 128, No. 2. CID: 027004.