Results from the included study show that multiple rounds of oral DMSA did not have an effect on any of the ASD symptoms measured in children found to be high excreters who had already received three doses of a pharmaceutical chelating agent. Currently no clinical trial evidence suggests that pharmaceutical chelation is an effective intervention for ASD. Given prior reports of serious adverse events, such as changes to calcium levels in blood, kidney impairment and reported death, risks of using pharmaceutical chelating agents for ASD currently outweigh proven benefits.
The quality of the evidence is poor, with only one study, which had methodological shortcomings, included in this review. These factors, when combined, preclude confidence in the findings. However, before further trials are conducted, more evidence is needed to show that heavy metals cause or worsen the severity of autism, and the safety of pharmaceutical chelating agents for participants must be established.
This review included data from only one study, which had methodological limitations. As such, no clinical trial evidence was found to suggest that pharmaceutical chelation is an effective intervention
for ASD. Given prior reports of serious adverse events, such as
hypocalcaemia, renal impairment and reported death, the risks of using
chelation for ASD currently outweigh proven benefits. Before further
trials are conducted, evidence that supports a causal link between heavy
metals and autism and methods that ensure the safety of participants
are needed.