Chelation therapy is a practice whereby certain substances (usually EDTA or deferoxamine) are administered to a patient to "clear them of toxins". The usual claim is that it can treat atherosclerosis. Chelation itself is a chemical term describing a compound or compounds strongly binding to a metal ion. The idea behind chelation therapy is that the chelator binds "bad stuff" in the body, and then it is harmlessly excreted. There is a very limited number of situations where chelation is used legitimately for heavy metal poisoning; for example, in iron overload states where deferoxamine is used as the chelating agent.
Medline, the primary electronic index of medical articles, shows a comparative lack of articles about chelation, suggesting it is not seen as a fruitful and legitimate line of research. Searches for "chelation therapy" show approximately 1500 articles, most of them about genetic iron or copper overload states. A Medline search of "chelation therapy" and "atherosclerosis" returns 22 results. In contrast, aspirin, a proven therapy, gets almost 40,000 hits, and, when combined with "atherosclerosis" gets about 700 hits.
Under pressure from quacks, NCCAM ran a large trial of chelation for heart disease (the TACT trial). Despite including convicted felons and others chosen as being likely to provide evidence supportive of chelation, this entirely failed to support the claims made by quacks.
Claims for chelation therapy vary greatly. The most common claim is that it can treat atherosclerosis (the hardening of the arteries that leads to heart attacks and strokes). For example, "Holisticonline.com" states that:
Studies by the National Academy of Sciences/National Research Council in the late 1960's indicated that EDTA was considered possibly effective in the treatment of occlusive vascular disorders caused by arteriosclerosis.
It is unlikely that they will change this comment even after the publication of the TACT trial which provides no support for this tentative conclusion.
There have also been claims about potential benefits of the use of chelation therapies in the treatment of autism. This claim is disputed by numerous physicians, including Dr. Eric Fombonne, the Director of Pediatric Psychiatry at the Montreal Children's Hospital, saying "…chelation therapies, whereby heavy metals are removed from the body using specific compounds, are not useful in the treatment of autism."
The cost, typically $75 to $125 per treatment, is not covered by most insurance companies; however, practitioners have been reported to misrepresent the reasons for the therapy, stating heavy metal poisoning. This has led to insurance fraud prosecution.
For any medical treatment to be widely accepted, it must be proved safe and effective. For any scientific or medical theory to be taken seriously, there must be a plausible mechanism of action for any observed positive effects. No plausible theories of efficacy of chelation therapy have been proposed. The research usually cited by practitioners was done over 40 years ago and had decidedly negative results: '"At the time of the report, 12 of the 38 [subjects] had died" At that time, the only treatment for heart disease was bedrest and sedatives. Medical science has advanced considerably in the intervening decades. Modern studies of chelation therapy have been done and are ongoing. These studies have shown limited or no efficacy for chelation therapy for atherosclerosis.
There has been evidence of harm from chelation therapy, but no large scale trials have been done, and practitioners are not required to report adverse events. The N.I.H conducted a five-year trial of chelation therapy in 633 patients with diabetes mellitus and a history of cardiac infarct, reporting in 2013. The conclusion was Post-myocardial infarction patients with diabetes mellitus aged ≤50 demonstrated a marked reduction in cardiovascular events with EDTA chelation. These findings support efforts to replicate these findings and define the mechanisms of benefit. However, they do not constitute sufficient evidence to indicate the routine use of chelation therapy for all post-myocardial infarction patients with diabetes mellitus.
Coronary heart disease: the TACT trial
Chelation quacks have long promoted chelation for coronary heart disease,
Tireless woo-enablers NCCAM, ably assisted by woo-industry lobbyists, launched a clinical trial into chelation for heart disease under the name TACT. This was denounced as unethical, given the lack of prior plausibility. It was found that the trial was using dubious "alternative" centers, that some of the investigators were convicted felons, and that there were numerous other irregularities, including lying to patients on consent forms. The results turned out to be equivocal, with each individual primary outcome falling below the pre-defined level of significance and only a combined score providing weak support in some measures, tainted by unusually high dropout rates especially among the placebo arm (a probable sign of a failure of blinding). Quack claims of massive benefit in coronary patients, including avoiding coronary artery bypass grafting (CABG) are unequivocally not supported by these findings, but it can be confidently predicted that this weak and equivocal outcome will be trumpeted by quacks as support for chelation.
Chelation therapy and autism
The autism/vaccine link hysteria has led many to claim that mercury poisoning is the cause of autism. Several opportunists have decided to latch onto this movement and the hype surrounding chelation therapy and claim that it can remove the mercury and "cure" autism. Just as with all the other applications, there is no evidence at all that chelation therapy has an effect on autism — in fact, the evidence goes the other way. The primary proponents of this therapy are Rashid Buttar, Mark Geier and David Geier.
Chelation therapy for autism is particularly horrific since it involves the intravenous injection of dangerous chemicals into a person who, depending on the nature of their autism, may not be able to give consent. Buttar has also stated that he has the most "success" with children under 9 years old, so there are multiple levels of consent issues. The consequences of chelation therapy are not minor either. In fact, in August 2005, a 5 year old autistic boy named Abubakar Tariq Nadama died while receiving his therapy. Roy Kerry, the doctor overseeing Nadama's treatment, was sued for using chelation therapy to treat autism, his license to practise medicine was suspended and he has been barred from chelating minors in future.
Risks and side effects
Even as a treatment of acute metal poisoning, chelation therapy should be monitored by a physician, because a chelating agent will indiscriminately remove all sorts of metals from the body, including essential elements. This can cause the loss of calcium, zinc and copper, toxicity to kidneys and even death. Such side effects are acceptable only when faced with a potentially fatal, acute poisoning. Even so, the chelating agent should be administered promptly, within hours, for it to be effective. Evidence is lacking for its effectiveness in chronic poisoning.
Patients cannot be blamed for seeking help from those who offer it. Harm from these types of therapies cannot be measured only in the harm done by the treatment itself. Atherosclerotic heart disease (ASHD) is a very serious illness, and the advancements in its prevention and treatment have been incredible. If patients forgo standard, proven treatments for patent medicines, the disease will follow its natural course and lead to early death or disability.
- Shrihari JS. Roy A. Prabhakaran D. Reddy KS. Role of EDTA chelation therapy in cardiovascular diseases. National Medical Journal of India. 19(1):24-6, 2006 Jan-Feb.
- Anderson TJ. Hubacek J. Wyse DG. Knudtson ML. Effect of chelation therapy on endothelial function in patients with coronary artery disease: PATCH substudy. Journal of the American College of Cardiology. 41(3):420-5, 2003 Feb 5.
- Anonymous. Chelation therapy ineffective as atherosclerosis treatment. Mayo Clinic Health Letter. 20(6):4, 2002 Jun.
- Grier MT. Meyers DG. So much writing, so little science: a review of 37 years of literature on edetate sodium chelation therapy. Annals of Pharmacotherapy. 27(12):1504-9, 1993 Dec.
- Wirebaugh SR. Geraets DR. Apparent failure of edetic acid chelation therapy for the treatment of coronary atherosclerosis. DICP. 24(1):22-5, 1990 Jan.
- McGillem MJ. Mancini GB. Inefficacy of EDTA chelation therapy for coronary atherosclerosis. New England Journal of Medicine. 318(24):1618-9, 1988 Jun 16.
- Merril L. Knudtson, MD; D. George Wyse, MD,PhD; P. Diane Galbraith, BN; Rollin Brant, PhD; Kathy Hildebrand, BN; Diana Paterson, BScN; Deborah Richardson, RN; Connie Burkart, BN; Ellen Burgess, MD; for the Program to Assess Alternative Treatment Strategies to Achieve Cardiac Health (PATCH) Investigators. Chelation Therapy for Ischemic Heart Disease. JAMA. 2002;287:481-486.
- Morgan BW. Kori S. Thomas JD. Adverse effects in 5 patients receiving EDTA at an outpatient chelation clinic. Veterinary & Human Toxicology. 44(5):274-6, 2002 Oct.
- Kimball Attwood, Science Based Medicine, 2 Apr 2010
- The Trial to Assess Chelation Therapy: Equivocal as Predicted, Kimball Attwood, Science Based Medicine, 4 Nov 2012
- The result of the Trial to Assess Chelation Therapy (TACT): As underwhelming as expected, David Gorski, Science Based medicine, 5 Nov 2012
- NCAHF Policy Statement on Chelation Therapy
- Mayo Clinic on Chelation therapy and autism
- Dr. Buttar has a new protocol
- Boy dies during autism treatment
- Charges in the Nadama case
- Deaths Associated with Hypocalcemia from Chelation Therapy — Texas, Pennsylvania, and Oregon, 2003-2005 (March 3, 2006) MMWR 55(08);204-207.
- Chelation for Heavy Metals (Arsenic, Lead, and Mercury): Protective or Perilous? by M. J. Kosnett (21 July 2010) Clinical Pharmacology & Therapeutics http://doi.org/10.1038/clpt.2010.132.