Chelation therapy is a treatment that involves repeated intravenous administration of a synthetic solution called ethylenediaminetetraacetic acid, or EDTA, to pull toxins from the bloodstream. The word chelate comes from the Greek root chele, which means "to claw." EDTA chelation therapy is approved by the Food and Drug Administration (FDA) as a treatment for lead and heavy metal poisoning. An estimated 500,000 to 1,000,000 people in the United States are treated with EDTA chelation therapy every year -- roughly 100,000 of these individuals, however, have received this therapy for the unapproved use of heart disease. Many providers who perform this procedure are trained and certified by the American College for Advancement in Medicine (ACAM).

Proponents of chelation therapy for heart disease claim that EDTA, in combination with oral vitamins and minerals, helps dissolve plaques and mineral deposits associated with atherosclerosis (blockage of arteries that can lead to heart attack or stroke). Although many Americans with heart disease have turned to EDTA chelation therapy to improve their condition, the FDA has not approved this therapy as an alternative treatment for heart disease. In fact, many important medical organizations including the National Institutes of Health (NIH), the American Medical Association (AMA), the American Heart Association (AHA), and the American College of Cardiology (ACC) have publicly criticized and denounced the practice of EDTA chelation therapy for heart disease.

The criticism regarding this procedure rests on several issues. First, most of the reports to date of the value of chelation for heart disease have been largely based on poorly designed human studies called case series and a few animal studies that may not apply to people. Secondly, several large-scale clinical trials published in peer-reviewed journals have found that EDTA chelation therapy is no better than placebo in improving symptoms associated with heart disease. Thirdly, some medical experts argue that the theories about why chelation might be of benefit for atherosclerotic plaque depend on an outdated understanding of how heart disease develops (see Uses section). Finally, and probably most importantly, the safety of EDTA chelation therapy for people with heart disease is not known.

The NIH National Center for Complementary and Alternative Medicine (NCCAM) is currently funding an important study to resolve the outstanding questions and controversies about the effectiveness and safety of EDTA chelation therapy for heart disease. The results of the pending NIH study may help sort out the debate between those who believe in the value of EDTA chelation for heart disease (including the members of the ACAM) and those who, based on the lack of scientific information and concerns about safety, do not.

Lead Poisoning and Heavy Metal Toxicity
Chelation therapy using EDTA is the medically accepted treatment for lead poisoning. EDTA is injected intravenously in a medical setting, such as a clinic or a hospital. Once in the bloodstream, EDTA latches onto lead and other metals to form a compound that can be excreted in the urine. The process generally takes between 1 and 3 hours. Other heavy metal toxicities treated with chelation include mercury, arsenic, aluminum, chromium, cobalt, manganese, nickel, selenium, zinc, tin, and thallium. Chelating agents other than EDTA are also used to clear several of these substances from the bloodstream.

Digoxin Toxicity
Although not considered standard therapy, EDTA has also been used to treat digoxin toxicity. In this case, EDTA helps remove excess levels of digoxin, a medication known as a digitalis glycoside that is used to treat abnormal rhythms of the heart. Digoxin toxicity occurs when the body accumulates more digitalis than it can tolerate.

Atherosclerosis
Proponents of EDTA chelation therapy for heart disease believe that this process may help people with atherosclerosis or peripheral vascular disease (namely, decreased blood flow to the legs) by clearing clogged arteries and improving blood flow. However, this proposed mechanism has not been proven. For example, in a study of 30 people with atherosclerosis of the carotid arteries (vessels that supply blood to the brain), 10 months of EDTA chelation treatments significantly improved blood flow to the brain. The problem with the information from this study, however, is that these patients were not compared to any other group. Therefore, it is not clear if they got better simply by chance or because the EDTA intervention really made a difference.

Plus, as stated earlier, the theory that EDTA clears clogged arteries and improves blood flow is based on a somewhat outdated model about the probable causes of heart disease and other vascular disorders. Other newer theories about how chelation may work include the possibility that EDTA functions like an antioxidant, preventing damaging molecules known as free radicals from injuring blood vessel walls. Some laboratory studies also suggest that EDTA chelation may prevent collection of platelets (which can otherwise lead to formation of blood clots and prevent blood flow) on the walls of blood vessels. These ideas are theoretical, however.

Most studies investigating the effectiveness of EDTA chelation therapy for heart disease and vascular disorders have found that this controversial treatment is no better than placebo. For example, one scientifically rigorous study comparing EDTA chelation therapy to placebo in 84 people with heart disease concluded that those receiving EDTA chelation did no better than those receiving placebo in terms of changes in exercise capacity and quality of life. Similarly, several studies evaluating EDTA chelation therapy for atherosclerosis of the legs (called peripheral vascular disease) did not find any difference between those receiving EDTA and those receiving placebo. And, evaluation of EDTA for diminished ability to have an erection due to decreased blood flow to the penis, again, found no improvement in those receiving EDTA compared to those receiving placebo.

EDTA is synthetic and not found naturally. Because there is concern that EDTA may deplete important vitamins and minerals, EDTA chelation therapy is often administered together with essential nutrients (including B vitamins, vitamin C, and magnesium).

There are advertisements for oral chelating agents available on the market, some of which contain EDTA. There is no proof, however, that these agents work and there is some concern that they may deplete levels of essential minerals.

EDTA chelation therapy is often administered together with magnesium and vitamins B and C over a period of one to three hours.

Pediatric

For the treatment of lead poisoning, EDTA is administered intravenously by a healthcare professional in the appropriate setting. The dose depends upon the amount of lead in the child's blood as well as the child's height and weight. Daily treatment for up to 5 days may be required.

Adult

Intravenous EDTA for heavy metal toxicity is generally delivered over one to three hours. The recommended adult dosage varies depending on the size of the person and the amount of lead or other metal in the body. For an average-sized person, the amount may range from 700 to 3,500 mg every 12 hours until the substance is significantly reduced in the bloodstream. The amount used would be determined in a hospital setting.

Although not approved by the FDA and most medical organizations, the following EDTA chelation guidelines have been established by ACAM for heart disease and vascular disorders. Doses of 2,500 to 3,000mg in 500 mL of saline are generally used over a period of one to three hours. For the prevention and treatment of heart disease, only one dose of EDTA is administered in a single 24-hour period; 2 to 3 weekly treatments are typical. Most heart patients are given 20 to 30 infusions, but the number of treatments suggested by the provider may be as high as 50. The cost can range from $2,000 to $5,000.

EDTA infusions must be given slowly and treatments are scheduled at least 24 hours apart. The most common side effect reported is a burning sensation at the site of the intravenous injection. In addition, some individuals may have an allergic reaction to EDTA. Other serious side effects that have been reported include low blood sugar, diminished calcium levels, headache, nausea, dangerously low blood pressure, kidney failure, organ damage, irregular heartbeat, seizures, or even death.

A qualified healthcare provider will monitor blood pressure, blood glucose, cholesterol, organ function, and other vital statistics during treatment with EDTA. EDTA may diminish desirable nutrients such as calcium and zinc. For this reason, your health care provider will keep a close eye on these as well.

Antibiotics, Cephalosporins
Animal studies suggest that EDTA may increase the absorption of cefmetazole, an antibiotic in a class known as cephalosporins. However, further studies in humans are needed to draw definitive conclusions for people.

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