It's a common treatment for poisoning with lead, iron, copper, zinc, aluminum, manganese and other metals. In chelation therapy, a person receives EDTA through an intravenous injection. The EDTA binds to various metals in the bloodstream and allows the body to excrete them in the urine. Chelation therapy is expensive, and some cases of metal poisoning may require as many as 30 to 50 treatments. Since the 1950s, some doctors have used and promoted chelation therapy as treatment for atherosclerosis, the gradual buildup of deposits called plaques in arteries.
Proponents recommend chelation therapy as an alternative to coronary bypass surgery or angioplasty.
Chelation therapy removes from the body the excess metals that foster free radicals natural compounds that cause oxidation and tissue damage. Free radicals have been implicated as a cause of blood vessel damage. No scientific evidence supports either theory. Two controlled clinical trials showed no evidence of benefit from chelation therapy for atherosclerosis. Proponents argue that the studies were too small and don't rule out a possible modest benefit from chelation therapy.