Chelation and Autism Ranking:

Future Research

Summary of Existing Research

There is no high quality research evidence to show that heavy metals (such as lead or mercury) cause autism or any of the associated problems faced by autistic people.

There is no high quality research evidence to suggest that chelating agents (such as DMSA, DMPS or EDTA) prevent or reduce the core features of autism in autistic people.

There is no high quality research evidence to suggest that chelating agents (such as DMSA, DMPS or EDTA) prevent or reduce any of the problems faced by autistic people.

There is mixed research evidence on the benefits of N-Acetyl-L-cysteine which is sometimes used as a chelating agent. However there is no evidence to suggest that any benefits which may or may not have arisen from the use of N-Acetyl-L-cysteine were due to the effects of removing heavy metals from the body.

There is some high quality research evidence which suggests that some chelating agents (whether used in treatment or in provocation tests) are potentially extremely hazardous.

Recommendations for Future Research

We agree with the authors of the Cochrane Review of chelation for autism spectrum disorder (ASD) - James et al (2015) - which made the following recommendations

“At the present time, the theory that heavy metals may cause autism or might worsen symptoms has not been established. This underlying theory needs to be tested and confirmed before future trials that assess chelation for ASD symptoms are implemented. However, the numerous side effects of chelation therapy, including hypocalcaemia, renal impairment, musculoskeletal and gastrointestinal symptoms and even death (Morgan, 2002; Brown, 2006; Kosnett, 2010), have led to the withdrawal of at least one planned study. It is therefore unlikely that institutional review boards will approve future trials for chelation for ASD unless safety in children can be assured through the current approach to research.

“If evidence emerges that supports a causal link between heavy metals and autism, further trials with methods suitable to ensure safety and to demonstrate that chelation removes heavy metals, improves social communication and reduces restricted repetitive behaviours seen in autism will be needed.”

Updated

16 Jun 2022

Last Review

01 Dec 2016

Next Review

01 Apr 2023