Synthetic Chelating Agents
The word 'chelation' comes from the Greek word chele meaning claw. It is used to refer to a chemical reaction between a toxic or heavy metal ion and an organic molecule. Many synthetic chelating agents are either ring-shaped or possess a 'cavity' within which the offending metal can be embraced and removed from the body (see images right).
Chelation therapy is the use of a variety of synthetic chelating agents to bind poisonous metals rendering them inert and promoting their excretion from the body without further interaction. In the US, chelation therapy was approved for use by the Food and Drug Administration in 1991.
Any practitioner offering chelation therapy should conduct an initial consultation including a comprehensive medical history, a brief physical examination and the collection of either hair, urine and/or blood samples for laboratory testing. The benefits and potential side-effects of chelation treatment should also be explained.
Prior to commencing treatment, the practitioner needs to establish that the systems of elimination are functioning reasonably well and to this end may suggest a pre-treatment course of liver and kidney supplements. Adequate hydration is also important so drinking plentiful quantities of water should also be recommended and some practitioners may also give minerals as these are likely to be depleted by chelation therapy.
Although many practitioners monitor toxic metal levels using hair analysis, this has its shortcomings and the laboratory should specifically not wash the hair sample prior to testing in order to preserve its mineral profile. Many people who are very toxic are also unable to eliminate metals in the hair and this is explored in the articles Is Dental Amalgam Safe for Humans? and Testing for Toxic Metals.
Chelation therapy is regarded as being of particular benefit to those who suffer from:
Circulatory issues such as cerebrovascular disease, arteriosclerosis, atherosclerosis, cold extremities, coronary artery disease, and impotence
Chronic fatigue syndrome, fibromyalgia, and autoimmune diseases such as lupus (SLE), multiple sclerosis, diabetes mellitus, and scleroderma
Elevated cholesterol, hypertension, heart palpitations and arrhythmia
Thyroid disorders and weight issues
Alzheimer's disease, poor memory, and an inability to concentrate
Chronic pain, and arthritis
Varicose veins, age spots and/or hair loss.
DMSA chelation therapy
DMSA or dimercaptosuccinic acid is a mixed disulphide in which each of the sulphur atoms links with a cysteine molecule to form water soluble chelates. This helps to increase the excretion of heavy metals such as lead and mercury in the urine and has been approved by the US FDA for use in cases of chronic or acute heavy metal intoxication.
However, the reported side-effects of DMSA can include:
Involuntary multiple sclerosis (MS) type movements in adults and seizures in children
Compromised central and peripheral nervous system function
Nausea, diarrhoea, and loss of appetite
Headaches and/or dizziness
Characteristic blood abnormalities such as decreased numbers of neutrophils, increased platelet counts, and elevated blood cholesterol, alkaline phosphatase and urea nitrogen.
These side effects are probably due to the inability of the liver and kidneys to detoxify and excrete the mercury mobilised in the tissues adequately. Thus the mercury circulates in the blood, taxing the brain, lungs, muscles, heart, and excretory organs and may ultimately be re-stored in vulnerable organs such as the brain thus proving not only ineffective, but damaging.
This is known as re-toxification and is a problem inherent in detoxifying all toxic metals, but particularly when mobilising them at a level which exceeds the ability of the organs of excretion to keep pace.
Zinc, in particular, is known to be excreted at twice the normal rate during the administration of DMSA, so mineral supplementation is definitely recommended during therapy. It is also important to ensure adequately hydration before, during and after treatment as kidney function can be compromised using DMSA chelation.
DMSA cannot cross the blood-brain barrier and some practitioners recommend taking DMSA in conjunction with alpha-lipoic acid (ALA) to help the detoxify the brain of heavy metals. Others think that this therapy is merely opening the channels for greater deposition of toxic metals within the brain and central nervous system and that it may be counterproductive.
In any event, using ALA as an adjunctive treatment to DMSA should only be considered after significant detoxification has already taken place.
It is possible that the body is constantly redistributing its toxin burden so that direct access to the central nervous system may not be strictly necessary anyway. Removing metals from other more accessible body compartments may eventually deplete those held within the CNS.
DMSA is also available in capsule form manufactured by Thorne as Captomer 100 (contains 100 mg of DMSA) or Captomer 250 (250 mg of DMSA).
It is recommended that a particular protocol involving cycles of a few days of active treatment followed by a week or more of recovery be followed. Recovery periods should involve replacing minerals that may be lost during active treatment by taking a mineral or multivitamin/mineral complex.
For dosing and a detailed protocol involving DMSA refer to the Post-Amalgam Removal Detoxification Protocol in Chapter 17 of The Natural Recovery Plan book (p203-5).
DMPS chelation therapy
Dimercapto-propane sulphonate (DMPS) is an experimental drug which is sometimes used for chelation, and which has not been approved by the US FDA.
The cardiologist, Dr Thomas Levy, and the anti-amalgam dentist, Dr Hal Huggins, counsel against the use of synthetic chelators in their book Uninformed Consent. They have found that heavy metal chelators can over accelerate the detoxification of mercury in patients after having their dental amalgam fillings replaced. Although they mention DMSA, DMPS, and EDTA, they particularly single out DMPS which they claim induces an immune decline which can result in a clinical illness that may last for weeks or months after a single injection of DMPS.
DMPS side effects include:
Shivering and/or fever
Mild to severe skin reactions
Nausea, dizziness, and weakness
Loss of minerals such as zinc and copper and
The symptoms of mercury poisoning as mercury is mobilised from storage.
DMPS is a more powerful chelator than DMSA and this has both advantages and disadvantages. It means that DMPS has the potential to cause more harm through the mobilisation of greater quantities of toxic metals and also to effect more detoxification. Some also claim that although DMSA is much cheaper dose for dose than DMPS, the total cost of DMPS chelation therapy can work out cheaper as treatment is expedited.
EDTA chelation treatment
Ethylene Diamine Tetra Acetic acid or EDTA is an amino acid that particularly binds toxic metals such as lead, mercury, cadmium, strontium, and aluminium. It binds toxic metals along with ionic calcium in the circulation and promotes their excretion primarily via the kidneys and urine.
EDTA is FDA approved and has traditionally been used to treat lead poisoning, but it is not a natural supplement. EDTA is also only a weak chelator of mercury.
The chelating solution contains sterile water, the EDTA, and a formulation of vitamins and minerals to help optimise the benefits of the treatment. A typical course of EDTA chelation treatment would consist of between 20 and 40 infusions administered ideally two to three times a week depending upon the severity of the symptoms.
However, some chelating treatments may involve as many as 100 EDTA infusions. Each treatment lasts about 3 hours as about half a litre of EDTA is slowly drip fed into the vein of the hand or arm. This does mean that the costs of treatment can prove prohibitive for some. Individuals undertaking this therapy are also encouraged to maximise their diet and lifestyle and to take supplements.
Intravenous chelation therapy at a clinic in the USA
EDTA chelation treatment should be monitored using weight, blood pressure, urine and occasional blood analysis. Vitamin and mineral levels should also be monitored during treatment, because mineral levels are directly affected by chelation, whereas vitamin levels may act synergistically with the chelation.
Potential side effects of EDTA chelation include:
Allergic reactions and
Some practitioners recommend, and some metal toxicity sufferers use, EDTA suppositories. These may be combined with magnesium which is the hardest mineral for the body to absorb because of its large molecular size. In addition, most people are now magnesium deficient because of depletion of the soil through the use of artificial fertilisers which do not contain this mineral. Magnesium also calms and relaxes the body and helps to de-activate the stress mode.
Unlike intravenous administration which encourages excretion mainly via the kidneys, using EDTA chelation suppositories draw heavy metals out through the bowel which can repair within days.
Concerns about intravenous chelation
There are two aspects of concern involving intravenous chelation therapy. One involves the side-effects and potential for reaction to an injected synthetic chemical. The other is the danger posed by the quantities of toxic metals that are mobilised.
Some feel that the body's own natural detoxification mechanisms are best supported and encouraged and that although this approach takes longer there is less potential for possibly permanent damage to organs such as the kidneys. Some specialist practitioners and patients that have suffered adverse effects from chelation therapy definitely think that synthetic chelating agents should be a last resort rather than a preferred option.
On the plus side, when managed successfully chelation therapy is also noted to not only produce improvement in internal organ function, but also to produce cosmetic changes such as stronger hair growth, clearer eyes, improved skin tone and texture, and a more youthful appearance. See the before and after images in the article Illness IS Toxicity for proof.
There is a also known to be a temporary increase in blood levels of mercury after amalgam filling replacement which leads some practitioners to recommend that no intravenous chelation be undertaken for at least six months after any replacement dental work.
The true tissue levels of mercury are usually not apparent in hair, nail, urine or blood tests and, because this is recognised, many practitioners use a provocation or challenge test. This involves administering a chelating agent and then collecting urine samples for analysis. The intention is to give an indication of the levels of mercury in the organs and cells that would not otherwise be apparent.
However, this poses several problems:
More mercury than can be excreted by the liver and kidneys can be mobilised causing an unpleasant toxicity reaction.
The retoxification of vulnerable organs and systems by the toxic metals mobilised.
The potential for an adverse reaction to an injected chelating agent.
The use of normal, unprovoked reference values to assess the results of a provocation test. This can be alarming to both practitioner and patient and is not relevant.
For discussion of the negative effects of DMPS see the DMPS Backfire website and for more information about synthetic chelating agents refer to DMSA Chelation.