Misleading/exaggerated. This claim is based on a Daily Mail article citing independent tests by Lead Safe Mama (LSM), a consumer-advocacy group that appears to do its testing with Purity Inc., a lab offering expanded analytical services since 2013. LSM’s findings do seem to align with a meta-analysis of eleven studies on heavy metals in commercial toothpastes, all of which detected at least one toxic metal (including lead and mercury). Those researchers warn that “chronic low-level exposure through daily use could contribute to bioaccumulation and potential adverse health effects (e.g., oxidative stress, carcinogenesis, kidney or neurological damage).” So it appears true that there are low levels of heavy metals in consumer-facing toothpastes–but do they cause autism?
Although the World Health Organization states that “no level of lead exposure is known to be without harmful effects,” evidence directly linking lead exposure to autism remains inconclusive. Some studies do report higher lead burdens in children with autism spectrum disorder (ASD), but a clinical review of ASD and lead poisoning concludes:
"...current scientific evidence does not support this hypothesis [that lead poisoning in a child can cause ASD]. Instead, any association of ASD and lead poisoning is more likely secondary to pica habits, the compulsive chewing and eating of nonfood items, seen commonly in children with ASD. This behavior puts them at high risk for exposure to lead-containing dust and other lead-contaminated objects."
Mercury’s role is similarly unclear. One analysis found no statistically significant difference in overall mercury levels between individuals with ASD and neurotypical controls, even though blood and red-cell mercury concentrations were higher in the ASD group, suggesting a weakened ability to metabolize mercury rather than a direct causal link.
