Chelation therapy

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Chelation therapy is a process involving the use of chelating agents to remove heavy metals from the body. For the most common forms of heavy metal intoxication, those involving lead, arsenic or mercury, the standard of care in the US dictates the use of DMSA. This, in addition to other chelating agents such as DMPS and alpha lipoic acid (ALA), are used in conventional and alternative medicine.

Contents

[edit] Discovery in medicine

Chelating agents were introduced into medicine as a result of the use of poison gas in World War I. The first widely used chelating agent, dimercaprol, also named British Anti-Lewisite, or BAL, was used as an antidote to the arsenic based poison gas, Lewisite. BAL bound the arsenic in Lewisite, forming a water soluble compound that entered the blood-stream, allowing it to be removed from the body by the kidneys and liver. BAL is an organic di-thiol compound which binds arsenic with two strong chemical bonds formed between the arsenic and the thiols, SH groups, which are also known as "mercaptans". The latter name comes from their ability to react and form strong bonds with, or "capture," mercury - in addition to lead and arsenic. BAL had severe and unpleasant side-effects.

After World War II medicine was confronted with a large number of navy personnel who had become occupationally lead poisoned through their jobs repainting the hulls of navy ships. It is at this time that EDTA was introduced into medicine as a lead chelating agent. EDTA is a synthetic amino-acid of different structure from chemicals like BAL. In particular, it contains no mercaptans. While EDTA had some uncomfortable side effects, they were nowhere near as severe as BAL.

Subsequent to this, in the 1960s, BAL was modified into DMSA, a related di-thiol with far fewer side effects. DMSA quickly replaced both BAL and EDTA, becoming the US Standard of Care for the treatment of lead, arsenic and mercury poisoning, which it remains today.

Research in the former Soviet Union lead to the introduction of DMPS, another di-thiol, as a mercury chelating agent. They also introduced ALA, which is transformed by the body into a di-thiol, dihydrolipoic acid, which is a mercury and arsenic chelating agent. DMPS has been given only experimental FDA status in the US. ALA is a common nutritional supplement.

Other chelating agents have been discovered. They all have the properties that they bind with metallic ions so that the ion is held by several chemical bonds and thus render it much less chemically reactive, produce a complex that is water soluble, and thus allow the ion to enter the blood-stream and be excreted harmlessly.

[edit] Uses in conventional medicine

Heavy metal poisoning is a medical condition usually identified among those occupationally exposed, and which can have significant effects on nearly every organ system [1]. Mercury, for example, has been strongly implicated as "a potential etiological factor in neurodegeneration" [2]. Chelation therapy is used as a treatment for acute mercury, iron, arsenic, lead, plutonium and other forms of heavy metal poisoning, where the amounts are so high that there is enough risk to the health of the patient to justify the therapy. The buildup of iron in thalassemia has led to use in treatment of that disease as well.

One example of successful chelation therapy is the case of Harold McCluskey, a nuclear worker who became very badly contaminated internally with americium in 1976. He was treated with diethylene triamine pentaacetic acid (DTPA) over many years to remove americium from his body. While it was not possible to remove all of the americium, it was possible to mitigate the effects of the accident. Harold McCluskey had 41 MBq (1.1 mCi) of 241Am removed from his body, a significant proportion. Harold McCluskey died of unrelated causes 11 years after being contaminated.

The chelating agent may be administered intravenously, intramuscularly, or orally, depending on the agent and the type of poisoning.

[edit] Examples of chelating agents

The choice of chelating agent depends on which metal is involved. Common chelating agents include:

[edit] Uses in alternative medicine

There are two general areas of alternative medicine in which chelation is used. One, is in the area of what the practitioners claim to be common but conventionally unrecognized heavy metal poisoning. Such practitioners commonly employ DMSA, DMPS, ALA or EDTA. The second is in the area of heart disease. Such practitioners make use of EDTA.

[edit] Heavy metal poisoning

Use of chelating agents for heavy metal poisoning began with the introduction of BAL during the First World War. Certain medical doctors claimed to see substantial lead and arsenic poisoning in their patients due to the heavy use of pesticides. The most common early pesticides were the arsenic based "Paris Green", later supplanted by lead-arsenate; both of which were extensively used on fruit.

BAL, having serious side effects, was given up by both alternative and conventional medicine when alternative appeared. Today DMSA, developed in the US, is the conventional chelating agent of choice. Alternative practitioners make use of this agent; they also make use of DMPS and ALA, both developed in and first studied extensively in the ex-Soviet Union. In addition EDTA, considered by the conventional medical system as an obsolete lead chelating agent with undesireable side effects (though nowhere near as severe as BAL), continues to be used by some alternative practitioners.

Furthermore, folklore has given rise to the use of various high sulfur foods as "chelating agents". These include onions, garlic, green foods and sea-weeds. Sulfur supplements like MSM or NAC have also been used. These are not actually chelating agents, as chelators involve multiple bonds to the metal atom and these foods and supplements involve compounds that are only mono-thiols. Cilanthro has also been introduced through folklore and is present in numerous alternative medications like "PCA-Rx", "Metal-Free" (both of which also contain ALA) and "NDF". Since no one seems to know what chelating substances may or may not be in cilanthro, and since chelators can be dangerous due to their movement of neurotoxic heavy-metals, they should be approached with caution.

What continues to distinguish the alternative practitioner's use of these chelating agents for heavy metal poisoning is that conventional medicine rarely diagnoses heavy metal poisoning outside of occupational medicine. Alternative practitioners claim to recognize extensive environmental exposures, such as through contact with treated lumber. Many of their patients claim to have been exposed to mercury through their dental amalgam fillings. Others claim that they or their children have become mercury poisoned through the thimerosal, an ethyl-mercury compound used as a preservative in vaccines. Others are treated for mercury, lead or arsenic poisoning of unspecified etiology.

As heavy metals are neuro-toxins, any use of chelators, conventional or alternative, should be approached with a great deal of care.

[edit] Heart disease

Some alternative practitioners use chelation to treat hardening of the arteries. The concept was first introduced by a podiatrist named Palmer from California[citations needed]. The safety and efficacy of EDTA chelation therapy as a treatment for coronary artery disease are being assessed by NCCAM in a five-year study which began in 2002. [3] [4]

The original theory behind calcium chelation therapy was that EDTA forms a complex with the calcium in the walls of arteries. One problem with this theory is that EDTA cannot penetrate the cell walls in the arteries and therefore cannot get access to the calcium. Another is that it binds preferentially to other metals. Finally, it is noted that calcium poses minimal danger in comparison to say, cholesterol.

A number of dangers have been associated with the therapy including hypocalcaemia and decreased blood coagulation ability (possibly due to loss of calcium). Also associated with this practice is the risk of leaching of necessary trace metals.

Some alternative practitioners believe intravenous chelation therapy "reverses and slows the progression of atherosclerosis and other age-related and degenerative diseases" [5], such as coronary artery disease and macular degeneration. Some chelation advocates claim that autism, a neurodevelopmental disorder that appears in early childhood, might be caused or aggravated by heavy metal poisoning and might be ameliorated by chelation therapy, but there is no scientific evidence to support this hypothesis.

A private corporation calling itself the American College for Advancement in Medicine (ACAM) claims that 800,000 patient visits for chelation therapy, with an average of forty visits per patient, were made in the United States in 1997 [6]. That is about 0.007% of the total US population. They claim that by 2001 that the number of people who have undergone chelation therapy equaled the number of people having had bypass surgery. A May 2004 survey by the National Center for Complementary and Alternative Medicine (NCCAM) estimated that 0.1%, plus or minus 0.02% of the adult US population had used chelation therapy at some point in their life.

In 1998, the U.S. Federal Trade Commission charged that ACAM's Web site and a brochure had made false or unsubstantiated claims. In December 1998, the FTC announced that it had secured a consent agreement barring ACAM from making unsubstantiated advertising claims that chelation therapy is effective against atherosclerosis or any other disease of the circulatory system.

The efficacy, safety, and much of the theory behind these practices are disputed by legitimate scientists. In 2001, researchers at the University of Calgary reported that cardiac patients receiving chelation therapy fared no better than those who received placebo treatment [7].

In August 2005, an autistic boy went into cardiac arrest fifty minutes after an infusion of acidic Endrate and died with hypocalcemia. The initial coroner's report ruled the death accidental.[8] Dr. Mary Jean Brown, chief of the Lead Poisoning Prevention Branch of the Centers for Disease Control and Prevention, said that the child died because he was given the wrong chelation agent. [9]

[edit] External links

  • The American College for Advancement in Medicine (ACAM) - alternative medicine organization
  • ExtremeHealthUSA.com Chelation and Nutritional Replacement Therapy for Chemical & Heavy Metal Toxicity and Cardiovascular Disease Overview
  • Archive.org - 'Chelation Therapy Revolution' (describes use of EDTA as a chelating agent, 1999)
  • NoAmalgam.Com - Website promoting a book with a good discussion of the dangers of the unconsidered use of chelators.
  • GenerationRescue.org -(parent-led advocacy group promoting use of chelation therapy claiming it is a cure for autism)
  • ScienceDaily.com - 'The Age of Autism: Heavy metal', Dan Olmsted, Science Daily (May 24, 2005)
  • Your-Doctor.com - 'Quack Therapies: Chelation Therapy' (discusses use of chelation therapy in conventional medicine and the hazards of chelation therapy by alternative practitioners)
  • Quackwatch "Chelation Therapy: Unproven Claims and Unsound Theories" by Sam Green
Pervasive developmental disorders / Autistic spectrum
Diagnoses
Autism | Asperger syndrome | Autistic enterocolitis | Childhood disintegrative disorder | Conditions comorbid to autism | Fragile X syndrome
Rett syndrome | PDD-NOS | Sensory Integration Dysfunction | Multiple-complex Developmental Disorder
Controversy
Andrew Wakefield | Incidence | An epidemic? | Autism rights movement | Biomedical intervention | Causes | Chelation
Generation Rescue | Heritability | Neurodiversity | Refrigerator mother | Therapies
See also: List of autism-related topics
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Chelation therapy

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