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Should We Study Chelation for Autism?

The National Institute of Mental Health (NIMH) supports doing a study on the effects of oral chelation therapy in autism. The proposal is highly controversial, is drawing criticism from many scientists, but has popular support among parents who believe this type of therapy might help their children with autism. The proposal raises many questions about the ethics of biomedical research.

Chelation and Autism

Chelation therapy is a legitimate FDA approved treatment for heavy metal poisoning. The drugs used for chelation, such as disodium EDTA, bind to heavy metals so that they can be removed from the body. Chelation drugs can be given either orally or intravenously. The treatment is somewhat risky because it can also remove needed electrolytes, like calcium, from the body or causes shifts in the electrolytes that can cause arhythmias and changes in brain function. There are reported cases of cardiac arrest and death due to chelation.

Chelation therapy has a long history of quackery – not for its intended use but for other uses for which there is no evidence. The classic example of this is the use of chelation therapy to treat atherosclerosis to prevent heart disease. This claim persists despite the utter lack of evidence for efficacy and the fact that all proposed mechanisms have been shown to be flawed or false.

In the last decade the belief that mercury in some vaccines (mercury-containing thimerosal was removed from routine childhood vaccines in the US by 2002) might be linked to autism. The scientific evidence clearly shows this is not the case (as I have discussed in many previous posts). But belief persists despite the evidence, mostly among anti-vaccinationist ideologues. But many earnest parents, just wanting to help their autistic children, have been caught up in the pseudoscience and conspiracy-mongering.

Naturally, belief that mercury causes autism has led to claims that chelating mercury cures autism. There is no evidence for this and there is no basic-science reason to suspect this might be the case. Now proponents of this treatment want the government to sponsor a study based upon their unsubstantiated treatment which in turn is based upon a false belief regarding the cause of autism.

The Ethics of Medical Research

Medical research has always been ethically tricky – it requires giving humans experimental treatments with unknown benefits and risks. But over the last few decades (originally triggered by Nazi abuses) there has been evolving ethical standards for medical research. They include many principals, among them that any experimental treatment must be more likely to help the subjects of the study than to hurt them, prior research must show that the treatment is probably safe – or at least is not highly toxic or dangerous, and there must be a plausible belief that the treatment is likely to work. Further, study subjects must be given full informed consent, and regardless of the treatment being studied they must receive at least the minimal current standard of care. In other words, you cannot withhold proven therapies in order to study unproven ones.

For this reason many consider using chelation therapy for autism to be unethical. There is insufficient scientific justification to believe that it might work, at least not enough to justify the safety concerns. Subjecting children to a risky treatment that probably doesn’t work is certainly ethically dubious.

But proponents of the study cite the fact that many parents are already using chelation therapy for their autistic children. Among them is Dr. Thomas Insel, Director of the NIHM. He is reported as saying:

“So many moms have said, `It’s saved my kids.'”

“This is an urgent set of questions. Let’s make innovation the centerpiece of this effort as we study autism, its causes and treatments, and think of what we may be missing.”

This justification comes up often with so-called alternative medicine – people are using it and they want choices, so we should study it. This turns out to be a very poor justification, however. The National Center for Complementary and Alternative Medicine (NCCAM) was founded on this idea – but a decade of research and hundreds of millions of dollars spent on this precise form of wishful thinking has lead to nothing. All of the NCCAM research has not added one solid treatment to the arsenal of scientific medicine, nor has it convinced CAM proponents to abandon a single failed therapy. That is the very purpose of medical research – to change practice. Research into dubious therapies promoted by those who eschew science-based medicine does not achieve that purpose.

Therefore, such research is a waste. But it is more than a waste – it subjects the people in the study to the risks of medical research without any benefit to society. If the treatments are highly implausible, then the probability is there was no benefit to the subjects themselves either. Such research seems to be all expense and risk and no benefit.

This puts advocates of science-based and ethical medicine in a difficult position, however. It is hard to argue against doing research – more information always sounds like a good idea. Refusal to even research a question can easily be made by fanatics to seem like suppression of the truth. This can turn the public against those who are most sincerely advocating for their rights, ironically. This motivates some, like Insel, agree to do the research – but this is a sucker’s bargain. We have been there before – doing the research accomplishes nothing because the people who need to be convinced are not basing their conclusions on scientific evidence in the first place.

What about all those parents who feel that their children were helped by chelation? Frankly, this is not compelling evidence. Again – we have been there before with similar treatments. Many parents thought their children were helped by psychomotor patterning, but the evidence showed conclusively that they weren’t. The scientific community abandoned the treatment – but the true believers cling to it still, even after three decades.

Children with developmental and neurological disorders will often improve as they age. This background maturing can easily be mistaken for improvement in response to a treatment. There is also the numerous psychological effects that highly motivate parents to believe their children are being helped, even when they aren’t (such as confirmation bias and expense justification). The simple fact is that history has shown that anecdotal evidence is not reliable. If a treatment is plausible it may be enough to justify doing controlled research. But for risky and implausible treatments it is not enough. Otherwise we would be spending hundreds of millions of dollars studying numerous implausible modalities to no end (wait a minute – we are doing just that with the NCCAM).

Doing this kind of questionable research is also risky. With a study of this size there is a real chance of a false positive – that the study results will be positive even if the treatment does not work. If that happens it will embolden the proponents of chelation for autism and lure more children to this dubious treatment. One small study is not enough to settle a scientific question or establish an unlikely therapy – so a false positive study will lead to a larger follow-up study. That means more money, more time, and more children subjected to chelation as part of the experiment.

This all stems from doing research on an ideologically charged question. Ideally medical science should take its time with a question, conservatively interpret existing research, and carefully consider the next step. This is not possible when there are groups outside the scientific medical community essentially kibitzing the science. Regardless of their intentions, this taints the scientific process and leads to confusion. It creates a situation in which the public is likely to overreact to preliminary research – for example by demanding treatments that probably don’t work.

Conclusion

I am with those who say that this research is highly unethical. It is being promoted by a fringe movement that has a history of anti-scientific attitudes. There is no reason to believe that the results of the research will settle anything, and it is very unlikely to be truly positive given what we know about autism. Doing this type of research in the hopes of convincing the ideologues is a fool’s notion. Don’t say I didn’t tell you so.

Posted in: Clinical Trials, Medical Ethics, Neuroscience/Mental Health, Vaccines

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