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Fresh Reads from the Science 'o sphere!

Wednesday, August 27, 2008

Dangers Of Chelation Therapy

There is an ongoing discussion at The Online Citizen about alternative medicine and autism entitled "A Straits Times campaign against alternative therapies?"

For some unknown reason I keep getting an error message when I try to post my response.

I've tried numerous times but I only succeeded in getting a few words out. Thus, I've given up and will not be continuing the conversation there.

The discussion was with Mr. Richard Seah and Mr. John Yeo, both alternative medicine proponents.

This was my full reply -

Mr. Seah says:

"Several discussions are already available on - eg studies on chelation, probiotics, vitamin B12, HBOT, neurofeedback, etc."

Since you don't want to pick a study to discuss, I'll pick one for you.

The key claim in chelation therapy is that mercury in vaccines is a significant cause of autism, and that drugs such as DMSA (which removes heavy metals such as mercury from the bloodstream) is an effective treatment for autism.

But do children with autism have higher levels of mercury in their blood, and/or difficulty excreting it?

Both you and Mr. Yeo have referenced this study:

Bradstreet J, Geier DA, Kartzinell JJ, Adams JB, Geier MR, 2003. A case-control study of mercury burden in children with Autism Spectrum Disorders. J.Am. Phys. Surg 8(3): 76-79

Original paper -

It is a single-blind retrospective study with 221 cases and 18 controls, which is a good sample size.

However, this study has some irregularities.

1. Instead of directly measuring mercury concentration in blood, the researchers measured the amount of mercury excreted in urine.

According to their results, even before DMSA treatment, children with autism have more than 3 times the amount of mercury in their urine than control subjects.

After a 3-day DMSA treatment, children with autism have six times the amount of mercury in their urine compared to controls!

However, both vaccinated and unvaccinated control subjects do not have elevated levels of mercury in their urine. This indicates that vaccination is not a direct cause of high mercury in urine.

The result only shows that for some unexplained reason, there is high mercury in the urine of autistic patients.

It could be due to higher mercury intake, or lower tissue retention, or even that control subjects are retaining more mercury in their bloodstream!

Without data from blood, we cannot conclude much from these results.

2. The quality of the data doesn't look good. Mean urinary mercury level is measured in micrograms per gram of creatinine units (mcg/g), and this is the data for children with autism:

Mercury level before treatment = 4.06 +/- 8.59 mcg/g

Mercury level after treatment = 6.42 +/- 12.69 mcg/g

The error bars are huge. The standard deviation is even larger than the mean itself, indicating that many children have no mercury in their urine at all.

Thus the results may be statistically significant, but not physiologically significant.

3. The paper contains a clause regarding two of the authors in this study:

"Potential conflict of interest: Dr. Mark Geier has been an expert witness and a consultant in cases involving adverse reactions to vaccines before the U.S. Vaccine Compensation Act and in civil litigation. David Geier has been a consultant in cases involving adverse reactions to vaccines before the U.S. Vaccine Compensation Act and in civil litigation."

I have read many scientific papers, probably as much as Mr. Yeo has, however, this is the first time I've come across such a statement in any paper.

This suggests that these authors have vested interests. To learn more about Dr. Mark Geier, here's a primer:

Dr. Geier is a controversial figure. In fact one of his recent papers to Autoimmunity Reviews has been retracted. To have a paper retracted is a serious setback for the reputation of a researcher.

On top of this, although DMSA is approved for the treatment of mercury and lead poisoning, it can also remove essential minerals such as calcium and iron.

Thus DMSA has potentially serious side effects for developing children.

As Mr. Yeo has pointed out in his website ( a study on DMSA funded by US NIH has been halted due to safety concerns.

In the light of all these facts, I would like to know on what basis does Mr. Seah and Mr. Yeo continue to support chelation therapy, and how do they intend to establish the safe dose of DMSA for their patients?


Ed said...

Hello LH!

I was about to discuss this chelation issue on my blog but thank goodness I checked back with your's first. No wonder that name sounded familiar, I read about him and the whole MMR vaccine thing some time back. What a shame that children's lives are put as risk due to irresponsible people promoting potentially dangerous therapies.

Lim Leng Hiong said...

Thanks for your well-written responses at The Online Citizen!

HanSolo said...

Hi Ed,

Would you share with us your blog url? I like the sound of what you've been saying so far, and would like to read more of your posts.

Leng Hiong,

Why don't you repost your comment on TOC but remove the links?


angry doc said...

Thanks for all your posts on TOC, guys. I think one good thing that comes out of the article is that it brings people like us out of the woodwork and together. :)

Lab Rat said...

Yow, the antivaccinationists and chelation guys have shown up in Singapore...guess it was a matter of time.

Respectful Insolence would be the place to check out, with plenty of critiques of such studies.

Ed said...

Hello Hansolo,

My blog is Vexillum II, listed in Leng Hiong's clearthought blogroll.

It sure takes such nonsense to bring us together to clear the air.

Anonymous said...

The whole thing about chelation is misunderstood. The use with DMSA is that it destroys certain pathogens, for example DMSA has a patent for being effective against extra cellular chlamydia pneumoniae bacterias, and so is acetylcysteine as well. Trevor Marshall has largely solved this problem, he cures his patients with the so called Marshall protocol that is able to cure virtually any chronic disease in some years. It uses only antibiotics + an immunomodulator. The symptoms people experience with DMSA or antibiotics is called immunopathology, and is a result of bacterial die-off, which temporarily increases inflammation. Mercury is not an issue, so DMSA is useful even if no mercury is excreted. Mercury does, however, also cause chronic diseases because it is immunosuppressive (even low levels of it). The vaccines are problematic because they contain bacterias mutated by mercury too.