Of the numerous chemical compounds available, the compound EDTA has been found to be effective in eliminating accumulated metals from the body. The National Center for Complementary and Alternative Medicine is conducting a 5-year, $30 million study on the use of chelation therapy to treat patients with heart disease. Currently, study researchers are examining claims that intravenous chelation can strip plaque from arteries through the removal of calcium.
Another oral chelating compound known as defasiroz, or Exjade, which is typically used to correct excess iron resulting from multiple blood transfusions, is in question. The drug was initially approved by the Food and Drug Administration in 2005. Several years later, the drug was put in limbo by a warning issued by the FDA and manufacturer, Novartis, that some Exjade users encountered kidney failure and other serious medical problems, sometimes resulting in death. Most of problems arose in the case of patients with advanced, pre-existing diseases of the blood; in several cases, their bone marrow had failed.
A third chelating agent, oral dimercaptosuccinic acid (DMSA), has been investigated by two studies conducted by the Southwest College of Naturopathic Medicine. DMSA is a FDA cleared prescription medicine used for treating lead poisoning. For these studies it is being used off-label to treat heavy metal toxicity in autistic children.
During the study, DMSA was given to 65 children with autism (aged 3 to 8 years) to determine its effects. The investigators discovered that DMSA greatly increased excretion of several toxic metals, including a 10-fold increase in lead excretion. In regards to safety, the study found no evidence of negative effects on kidney or liver function.
The most surprising finding from the study was that DMSA chelation therapy had a powerful effect on glutathione levels. Glutathione is a substance the body uses to defend itself against toxic metals; it is found at highly abnormal levels in autistic children. DMSA treatment over the span of 3 days normalized glutathione levels for the following 1-2 months in nearly all children.
Study author Dr. Matthew Baral claims that toxic metals are a common problem with autistic individuals and that he has witnessed benefits from DMSA therapy. He hopes that this emerging data can help other physicians determine whether chelation therapy is safe and effective for treating children with autism.