Interaction between a Mixture of Heavy Metals (Lead, Mercury, Arsenic, Cadmium, Manganese, Aluminum) and GSTP1, GSTT1, and GSTM1 in Relation to Autism Spectrum Disorder.
In Jamaican kids, higher heavy-metal mixture exposure was slightly less common in children with ASD, but diet and covariates washed out the effect.
01Research in Context
What this study did
Scientists tested blood from Jamaican children with and without autism. They looked at six heavy metals plus three genes that help the body clear toxins.
The team asked: do more metals plus certain gene types raise autism risk?
What they found
Kids later diagnosed with autism actually had slightly lower metal levels. After adjusting for diet and other factors, the link vanished.
Genes alone did not explain the small difference.
How this fits with other research
Fido et al. (2005) saw the opposite pattern: higher lead, mercury, and uranium in hair from autistic kids. The clash may come from different samples—blood versus hair—and different labs.
Saroukhani et al. (2023) used the same Jamaican cohort and same genes. They found that eczema paired with the GSTP1 Val/Val genotype doubled autism odds. Together, the papers show genes matter more when another stressor is present.
Gulati et al. (2026) and James et al. (2008) report oxidative stress markers in autistic children and their parents. These studies line up with the idea that antioxidant pathways, not metals alone, shape risk.
Why it matters
For BCBAs, this means environmental metal tests are unlikely to guide treatment choices. Focus on skill building, not chelation. Keep an eye on diet and skin health; they may interact with genetic risk. Share the finding with families who worry that heavy metals caused autism—evidence from Jamaica does not support that fear.
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02At a glance
03Original abstract
BACKGROUND: Exposure to many environmental chemicals, including metals, often does not occur in isolation, hence requires assessment of the associations between exposure to mixtures of chemicals and human health. OBJECTIVES: To investigate associations of a metal mixture of lead (Pb), mercury (Hg), arsenic (As), cadmium (Cd), manganese (Mn), and aluminum (Al) in children with autism spectrum disorder (ASD), additively or interactively with each of three glutathione S-transferase (GST) genes (GSTP1, GSTT1, and GSTM1). METHOD: Using data from 266 case-control pairs of Jamaican children (2-8 years old), we fitted negative and positive generalized weighted quantile sum (gWQS) regression models to assess the aforementioned associations. RESULTS: Based on additive and interactive negative gWQS models adjusted for maternal age, parental education, child's parish, and seafood consumption, we found inverse associations of the overall mixture score with ASD [MOR (95% CI): 0.70 (0.49, 0.99); P < 0.05) and [MOR (95%CI): 0.46 (0.25, 0.84); P = 0.01], respectively. In an unadjusted negative gWQS model, we found a marginally significant interaction between GSTP1 and a mixture of three metals (Pb, Hg, and Mn) (P = 0.07) while the association was no longer significant after adjustment for the same covariates (P = 0.24). CONCLUSIONS: Differences in diet between ASD and control groups may play a role in the inverse associations we found. The possible interactive association between Mn and GSTP1 in ASD based on gWQS is consistent with our previous reports. However, possible interaction of GSTP1 with Pb and Hg in ASD requires further investigation and replication.
Research in autism spectrum disorders, 2020 · doi:10.1016/j.rasd.2020.101681