I was quite interested in the most recent video on "How To Detox Heavy Metals" since I have been dealing with some of the symptoms Leo mentioned. Given that I think the topic is important and the protocol is quite intensive, I began doing some preliminary research which raised questions that I would like to mention here for discussion.
Caveat: I haven't done extensive research.
1. Inadequacy of provoked urine tests
I came across this video: https://nutritionfacts.org/video/heavy-metal-urine-testing-and-chelation-for-autism/, which cites these two papers on provoked urine tests: https://pubmed.ncbi.nlm.nih.gov/24113861/, https://www.mdpi.com/2305-6304/2/3/403, and https://pubmed.ncbi.nlm.nih.gov/20354920/.
In summary, the articles state that the reference ranges in provoked (post-chelation) urine tests are inadequate because they were made for non-provoked tests. Naturally, if you take DMSA you'll have higher values of heavy metals in your urine, so showing the reference ranges for non-provoked tests is misleading. In fact, there seems to be no standardization for provoked tests. In the bottom of Leo's test (2:05:07), one can read: "Reference intervals and corresponding reference values are representative of a healthy population under non-provoked reference conditions. Chelation (provocation) agents can increase urinary excretion of metals/elements."
So, this makes me skeptical that provoked tests are be the most reliable way of testing for heavy metals (as said by Leo). The "American College of Medical Toxicology" even issued a statement stating their position against the use of such tests (second article above).
Note that I am not stating that it is ok to excrete any quantity of heavy metals --- I haven't researched this enough.
2. Study on children with autism
Leo cites this study (Safety and efficacy of oral DMSA therapy for children): https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2774660/. There was a 2013 review on chelation for Autism, which thoroughly analysed the study Leo cites (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6457964/). They mention:
"Quality of the evidence
The quality of the evidence is poor. Only one trial was included in this review, and we judged it to have high or uncertain risk of bias and methodological problems that limited the interpretation of outcomes presented. Of particular concern are the trialists’ questionable data analytical approach and interpretation of findings. It is interesting that trialists found differential directions of heavy metal excretion and change in ASD indices, yet they attempted to convince the reader not to read too much into these differences. Given the deleterious effects of chelation, misinterpretation and misuse of the study of Adams et al to justify the use of chelation for ASD is unethical and potentially places children unnecessarily in harm’s way. Moreover, if these findings are in fact valid, they actually undermine the heavy metal toxicity theory and the rationale for chelation treatment, suggesting that it should not be used in the first place.
The inclusion of only one study, which had a relatively small sample size and a high likelihood of carry‐over effects and other biases, precludes confidence in the findings. Further well‐designed studies from multiple locations and using larger numbers of participants are needed to better ascertain the effects of chelation for ASD.
Implications for practice
This review found no high‐quality evidence to suggest that chelation is an effective treatment for improving ASD symptoms. Cochrane reviews typically avoid making recommendations for practice; however, given that harm resulting from the use of chelation therapy has been reported, and that no proven benefits have been found, it seems reasonable to conclude that use of chelation for the treatment of individuals with ASD symptoms should not be recommended.
Key results
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."