Metal chelation is the process of using a chelating agent to remove metals from the body. Chelating agents bind to metal ions and hold them in harmless suspension until they are excreted. Metal chelation therapy is most often used to remove toxic levels of lead, mercury, and arsenic from the bloodstream and tissues. It is sometimes used as an alternative treatment for hemochromatosis, an excess of iron in the blood.
Chelation therapy is approved for use only for the treatment of heavy metal toxicity. The therapy has been promoted as a cure for a variety of conditions, such as Parkinson’s disease, Alzheimer’s disease, and autism. There have been numerous large-scale studies on the effectiveness of metal chelation as an alternative treatment for these conditions. The studies show that chelation therapy has no effect on any condition other than heavy metal toxicity.
There are several compounds capable of isolating and binding to metal ions. Ethylenediamine tetraacetic acid, or EDTA, is used in cases of lead toxicity. Dimercaprol binds to both arsenic and mercury. Copper toxicity is treated with penicillamine. Dimercaptosuccinic acid, or DMSA, binds to lead, mercury, and arsenic.
Metal chelation has a low occurrence of serious side effects when administered under a physician’s supervision. According to the United States Centers for Disease Control, however, the use of an improper form of EDTA was responsible for several deaths. In these cases, disodium EDTA was used rather than the more common calcium EDTA. The main danger of chelation therapy is that the chelating agents bind indiscriminately to metal ions, removing needed minerals such as zinc at the same time they remove the toxic heavy metals.
Chelation therapy is a long-term medical treatment. The chelating agents may be administered intravenously, intramuscularly, or orally. An intravenous infusion may take up to four hours to complete. The therapy continues for up to 12 weeks and includes repeated administration of chelating agents. It is the preferred method to remove toxic metals over an extended period of time as faster removal of the metals has been associated with more serious side effects.
The administration of chelating agents may cause dangerously low levels of serum calcium. Metal chelation therapy may also cause kidney damage. During the course of treatment, the physician performs blood tests to check serum calcium levels and to monitor kidney functions. Patients are also given high-dose supplemental vitamins and minerals to replace what is removed during chelation.