Chelation therapy is a legitimate and effective treatment for heavy metal poisoning, particularly lead, mercury and arsenic poisoning. Ethylenediaminetetraacetic acid, or EDTA, is a chelate used to treat lead poisoning. The controversy surrounding EDTA chelation therapy comes from claims that it also can be used to treat certain other conditions or diseases despite the fact that the United States Food and Drug Administration (FDA) states that those claims are unfounded and has not approved it.
In chelation therapy, a chelating agent that bonds to the heavy metals in the bloodstream is administered to the patient. When the bonding occurs, the heavy metal becomes water soluble, allowing it to be easily excreted from the body. Use of heavy metal chelation treatment began during World War I, when it was used to clear arsenic-based gas from the system. Current use includes treatment for plutonium, uranium and iron poisoning as well.
A synthetic amino acid, EDTA was introduced after World War II to treat lead poisoning in those who repainted hulls of ships. This chelating agent remains in common use to treat lead poisoning, though other chelating agents also are recommended to treat this type of heavy metal poisoning, including dimercaptosuccinic acid (DMSA) and alpha lipoic acid (ALA), all of which cause fewer side effects than previously developed agents. However, recently there has been a controversy surrounding EDTA chelation therapy for uses other than that for which it was developed.
The controversy surrounding EDTA chelation therapy mainly comes from claims that it can be used to treat atherosclerosis or hardening of the arteries, a precursor of heart disease. Proponents of this type of chelation therapy claim that EDTA can bond to elements in the plaque that causes hardened arteries and carry it from the body in the same way it would carry heavy metals from the bloodstream. The controversy surrounding EDTA chelation therapy is strengthened by the fact that the U.S. Food and Drug Administration states that there is no reliable evidence that EDTA chelation therapy works in atherosclerosis treatment, so the FDA has not issued an approval for the treatment.
Another element of the controversy surrounding EDTA chelation therapy is its use to treat supposed mercury poisoning. Those who make use of this therapy claim that mercury from dental amalgam, used for silver fillings, is absorbed into the system, causing a long term buildup of the element. They also cite the use of mercury as a preservative in various types of childhood vaccinations. Presence of mercury in the system is then blamed for numerous problems, including autism. In spite of continued evidence from the FDA and other organizations that these claims are untrue, the controversy surrounding EDTA chelation therapy continues.