By Susan Silverman, Certified Family Nurse Practitioner and Naturopath

In the past few decades, the problem of environmental pollution has become increasingly obvious. Toxic metal poisoning, along with chemical and other forms toxicity have been implicated in contributing to a rising incidence of autoimmune diseases and other degenerative conditions.  Because toxic metals tend to become firmly attached to body tissues such as bone, kidneys, liver, and nerves, they are difficult to remove from the body.

What is Chelation Therapy?

Chelation is defined as the administration of chelating agents to remove heavy metals from the body. Chelation refers to the ability of certain molecules to bind to specific metals and carry them out of the body through the bowels or kidneys. The word chelation is derived from Greek “chelè”, meaning claw; the active portions of the chelating substance binds around the central metal atom like the claws of a lobster.

For the most common forms of heavy metal intoxication—those involving lead, arsenic or mercury—the standard of care in the USA dictates the use of dimercaptosuccinic acid (DMSA). Other chelating agents, such as 2,3-dimercapto-1-propanesulfonic acid (DMPS) and alpha lipoic acid (ALA), are used in conventional and alternative medicine.

Calcium-disodium EDTA chelation is approved by the U.S. Food and Drug Administration for the removal of lead and arsenic and other common toxic metals, and is generally easily tolerated when given intravenously by a trained health professional.

EDTA chelation therapy

Chelation therapy is used, although somewhat differently, by both allopathic (conventional Western) medicine and alternative medicine as a means of removing toxic metals and minerals from the body. Practitioners of chelation therapy argue that it is an effective way of removing toxins and harmful body wastes, thereby helping to prevent or treat many other conditions.

The most popular form of chelation therapy practiced by alternative practitioners employs a drug called EDTA (ethylene diamine tetraacetic acid) administered intravenously. Calcium EDTA is approved by the Food and Drug Administration (FDA) for treatment of lead and heavy metal poisoning but not for other forms of toxicity or circulatory problems. EDTA works by attaching itself to specific minerals, which are carried out of the body via urinary excretion.

The most common and toxic heavy metals that can poison our systems and lead to fatigue and illness are iron, lead, cadmium, and mercury. Iron is by far the most common of the heavy metals that predisposes individuals to heart disease. It promotes free radical activity and thereby leads to accelerated arterial damage. Lead and cadmium are common industrial pollutants that also foster free radical activity and poison critical enzymes which repair tissue. Mercury is found in some kinds of seafood and in dental fillings. Its toxicity can depress the immune system and cause an array of symptoms. Getting the iron, lead, cadmium, and mercury out can be accomplished with chelation therapy.

How does chelation therapy work?

For most of these metals, an intravenous solution of vitamins, certain minerals, and the chelator EDTA is prepared. EDTA is a substance known for its ability to pull heavy metals out of the body. This is infused into the bloodstream through a vein.

EDTA leaves the body in the same form by which it entered, but on its way out, it chelates metals and minerals from the body. Patients usually undergo between 10 and 20 chelation treatments over a period of weeks or months. Each treatment lasts 1-2 hours, during which patients can read or watch a movie.

Beyond its effects on heavy metals, the disodium form of EDTA also helps to remove inappropriate accumulations of calcium from tissue. Calcium gravitates to atherosclerotic plaque in blood vessels, gently and gradually mobilizes calcium from plaque, and contributing to vessel elasticity. At this time, no form of EDTA therapy is specifically approved by the FDA for treatment of heart or blood vessel diseases, but most of its advocates now state that it is thought to work indirectly by removing the toxic metals which produce the free radical molecules that can damage the delicate inner lining of the blood vessels.

While controversial among orthodox cardiologists, several thousand physicians practice chelation throughout North America and the world.  Many belong to a professional organization known as the American College for Advancement in Medicine (ACAM) which publishes a directory of integrative medical practitioners.

It is ACAM’s positionthat chelation therapy is a valid and proper course of treatment, based upon scientific rationale, supported by many published clinical studies, and consistent with sound medical practice. Restricting its use by qualified physicians would amount to a wholly unneeded restraint upon the practice of medicine that would adversely affect the standard of medical care available to patients. Such restriction would be contrary to law and a disservice to the public.

Therapeutic History of Chelation Therapy

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, the organic dithiol compound dimercaprol (also named British Anti-Lewisite or BAL), was used as an antidote to the arsenic-based poison gas, Lewisite. The sulphur atoms in BAL’s mercaptan groups strongly bond to the arsenic in Lewisite, forming a water-soluble compound that entered the bloodstream, allowing it to be removed from the body by the kidneys and liver. BAL had severe side-effects.

After World War II, a large number of navy personnel suffered from lead poisoning as a result of their jobs repainting the hulls of ships, and the medical use of EDTA as a lead chelating agent was introduced. Unlike BAL, it is a synthetic amino acid and contains no mercaptans. EDTA side effects were not considered as severe as BAL.

EDTA (Ethylenediaminetetraacetic acid was first used in the 1940’s for treatment of heavy metal poisoning. It is widely recognized as effective for that use as well as certain others, including emergency treatment of hypercalcemia and the control of ventricular arrhythmias associated with digitalis toxicity. 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.

In the 1960s, BAL was modified into DMSA, a related molecule 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.  We use DMSA to do “provocative challenge testing” in which the patient takes some DMSA orally, and then collects their urine for about 8 hours afterwards.  This pulls out heavy metals that are tightly bound to body tissues and would not otherwise be excreted in the urine. It is therefore a better indicator of overall body burden of mercury and other toxic metals.

Research in the former Soviet Union led to the introduction of DMPS, another mercury-chelating agent. The Soviets also introduced alpha lipoic acid,  ALA, which is transformed by the body into, a mercury- and arsenic-chelating agent.  DMPS has experimental status in the US FDA, while ALA is a common nutritional supplement.

Since the 1970s, iron chelation therapy has been used as an alternative to regular phlebotomy to treat excess iron stores in people with haemochromatosis.

Additional chelating agents have also been discovered. They all function by making several chemical bonds with metal ions, thus rendering them much less chemically reactive. The resulting complex is water-soluble, allowing it to enter the bloodstream and be excreted harmlessly.

There is now widespread agreement that EDTA removes metallic catalysts which cause excessive oxygen free radical proliferation, thereby reducing pathological lipid peroxidation of cell membranes, DNA, enzyme systems and lipoproteins and allowing the body’s natural healing mechanisms to halt and often reverse the disease process.

In its simplest terms, the rationale for its efficacy is that EDTA, in binding ionic metal catalysts and removing them from the body, reduces subsequent abnormal production of oxygen free radical reactive molecules and molecular fragments which react destructively with other molecules. See, E. M. Cranton, J. P. Frackelton, Free Radical Pathology in Age Associated Diseases: Treatment with EDTA Chelation, Nutrition, and Antioxidants, Journal of Advancement in Medicine, Vol. 2, Nos. 1, 2, Spring/Summer, 1989.