This article is from the Alternative Medicine Therapies guide.
Intravenous chelation (pronounced key-LAY-shun) therapy has been a respected and widely used medical treatment for heavy-metal poisoning--especially lead poisoning--for more than 50 years. However, some physicians also promote the therapy as an alternative treatment for arteriosclerosis (hardening of the arteries), including coronary artery disease, peripheral vascular disease (blockage or narrowing of blood vessels in the legs), and the mental deterioration caused by small strokes.
Over the years, suggesting chelation therapy for anything other than heavy-metal poisoning has been met with considerable controversy. And there have been few trials conducted in a manner satisfactory to all the physicians involved. Doctors who believe that chelation therapy is ineffective (the majority) routinely cite studies that are unacceptable to those physicians (the minority) who believe chelation is helpful. Conversely, studies either conducted or quoted by "believers" suggesting that chelation is effective are routinely disparaged by the "nonbelievers." This, of course, leaves patients quite confused.
What neither side disagrees about, however, is that the chemical EDTA (ethylenediaminetetraacetic acid) does remove toxic metals from the body. During treatment, EDTA is administered intravenously and the drug travels throughout the body gathering up such toxic metals as lead, arsenic, and aluminum from various organs. The term "chelation" is derived from the Greek word chele, which means "to claw." Like a claw, a molecule of EDTA grabs or binds onto a molecule of metal and carries it through the bloodstream to be excreted in the urine.
The origins of chelation therapy. EDTA was first used medically in the 1940s to treat workers from battery factories who had developed lead poisoning. In the early 1950s, Dr. Norman Clarke, Sr., director of research at Providence Hospital in Detroit, Michigan, was using EDTA for lead poisoning and found that his patients also reported less pain from angina (chest pain due to blocked arteries). In addition, they noted improved memory; better sight, hearing, and smell; and an increase in energy.
At the time Clarke and other doctors postulated that it was EDTA's effect on calcium within the body that might account for these results. They theorized that, during chelation, the EDTA could be grabbing onto the calcium within the arterial plaque lining blood vessels and removing it, the way it removed lead in poisoning cases.
With the calcium gone, they felt, the plaque dissolved, circulation improved (not only to the heart, but also to the brain, eyes, and other organs) and patients reported feeling better. One writer at the time even dubbed chelation therapy "a Roto-Rooter for the arteries." Unfortunately, X-rays and biopsies later showed that chelation had no effect at all on calcium within the arteries, and this early theory was discounted.
A second, more widely accepted theory--and one that continues to be popular--suggests that, by removing toxic metals, the EDTA also removed a significant source of destructive oxygen molecules known as free radicals. With free-radical production slowed, the arteries could then heal, shedding their plaque and lessening the symptoms of heart disease. Today antioxidant vitamins are thought to play a key roll in "mopping up" free radicals throughout the body and, for this reason, large doses of antioxidants are typically administered along with the EDTA.
The controversy continues. While many chelation studies have been done over the years, very few rigorous studies have ever been performed on humans. Critics of the therapy note that most studies showing its effectiveness have been done by physicians with a financial interest in the therapy. Proponents respond by saying that studies disproving chelation have typically been performed under the supervision of physicians with a financial interest in costly surgical procedures.
Despite the disagreements, interest in chelation as an alternative treatment for heart and vascular problems has continued to grow, with thousands of people seeking out the therapy annually as an option to coronary bypass surgery and balloon angioplasty.