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Other common name(s):
none
Scientific/medical name(s): ethylene
diamine tetraacetic acid (EDTA), edetate sodium
Description
Chelation therapy is a mainstream treatment that is used to
treat heavy metal poisoning. However, this term is also used to promote
a type of alternative therapy that is supposed to treat heart disease,
cancer, and other conditions. It most often involves the injection of
ethylene diamine tetraacetic acid (EDTA), a chemical that binds
(chelates) heavy metals which include iron, lead, mercury, cadmium, and
zinc. The term "chelation" comes from the Greek word "chele," which
means claw, referring to the way the chemical grabs onto these metals.
Overview
Chelation therapy is one of several effective treatments for
lead poisoning. However, Available scientific evidence does not support
claims that it is effective for treating other conditions such as
cancer. Chelation therapy can be toxic and has the potential to cause
kidney damage, irregular heartbeat, and even death.
How is it promoted for use?
Chelation therapy with EDTA has been approved by the FDA as a
treatment for lead poisoning for more than 40 years. The human body
can’t break down heavy metals, which can build up to toxic levels in
the body and interfere with normal functioning. EDTA and other
chelating drugs lower high blood levels of metals such as lead,
mercury, cadmium, and zinc by attaching to the heavy metal molecules,
which helps the body remove them through urination.
Because EDTA can reduce the amount of calcium in the
bloodstream, some practitioners suggest chelation therapy may help
reopen arteries blocked by mineral deposits (hardening of the arteries,
or atherosclerosis). They claim it is an effective and less expensive
alternative to coronary bypass (‘open heart’) surgery, angioplasty, and
other techniques designed to unclog blocked arteries.
Chelation therapy has also been promoted as an alternative
treatment for many unrelated conditions, such as gangrene, thyroid
disorders, multiple sclerosis, muscular dystrophy, psoriasis, diabetes,
arthritis, Alzheimer’s disease, and the improvement of memory, sight,
hearing, and smell.
Some alternative practitioners further claim chelation
therapy can be used as a cancer treatment to remove ‘environmental
toxins’ from the body or to block the production of a group of harmful
molecules called free radicals (unstable oxygen molecules, which can
cause cell damage). Available scientific evidence does not support
these claims.
What does it involve?
Chelation therapy is most often given into a vein
(intravenously), either as a short injection or over a period of 2 to 4
hours. A typical treatment cycle may include 20 injections or infusions
spread over 10 to 12 weeks. Chelation therapy can also be given by
mouth.
Practitioners recommend at least 20 to 40 treatments to
start; however, some may recommend continued therapy for up to 100
treatments over a period of several years.
Because the therapy removes some important minerals from the
body, patients often receive high-dose vitamin and mineral supplements
during treatment.
What is the history behind it?
The chemical solution used in chelation therapy, EDTA, was
first made in Germany in the 1930s. It is now widely accepted as an
effective treatment for heavy metal poisoning. In the 1950s, some
scientists had a theory that EDTA could remove calcium from the body
(which can build up on artery walls and cause heart disease) and
thereby help to unclog blocked arteries.
In some early studies, researchers reported positive results
among patients with heart disease who received EDTA. Some said that
chelation therapy relieved angina (chest pain) caused by blocked
arteries. These first observations have not been backed up by larger,
more rigorous studies, but they led some practitioners to begin using
chelation therapy for heart and circulatory problems and later, for
several other illnesses. It is estimated that tens of thousands of
Americans currently undergo chelation therapy for heart disease.
In 1998, the Federal Trade Commission charged the American
College of Advancement in Medicine (ACAM), the principal group
promoting chelation therapy, with presenting false advertising and
unsubstantiated statements about the benefits of chelation therapy. The
ACAM agreed to stop publishing any claims that were not based on
reliable scientific evidence.
What is the evidence?
Chelation therapy is a proven treatment for lead poisoning
and poisoning from other heavy metals. However, available scientific
evidence does not support claims that the treatment benefits patients
with cancer, heart disease, or any medical problems other than
heavy-metal poisoning.
Cancer: There are no published studies that reliably
show benefit from using EDTA chelation against cancer. Some laboratory
studies have suggested that certain agents that chelate copper or iron
(chelating agents other than EDTA) may have an effect on cancer cells
or on the formation of tumor blood vessels. In a small clinical trial,
researchers studied iron chelating agents to see if they would reduce
the growth of neuroblastoma (a type of cancer in infants and young
children) in mice. The results, published in 1998, concluded that
chelation therapy did not shrink tumors. Few studies of the use of
chelation therapy against cancer in humans have been published in
peer-reviewed medical journals. These few studies have been small and
have not shown a significant level of effectiveness. Research studies
continue in this area.
Heart and vascular disease: Randomized clinical
trials have found that chelation therapy drugs did not benefit patients
with impaired circulation in their legs. In 1993, a review of all
chelation therapy studies reported during the previous 37 years
concluded that scientific data did not support claims that the
treatment was useful for treating heart problems. Studies published
since then have generally reached the same conclusion. A very large,
placebo-controlled study sponsored by the National Center for
Complementary and Alternative Medicine (NCCAM) is now under way and
should provide a more definitive answer as to whether chelation therapy
has any effects on heart disease.
Several well respected organizations have found no scientific evidence
that chelation therapy is an effective treatment for any medical
condition except heavy metal poisoning, including: the American Heart
Association, American Medical Association, Centers for Disease Control
and Prevention, American Osteopathic Association, the American Academy
of Family Physicians, and the FDA.
Are there any possible problems
or complications?
Available scientific evidence does not support claims that
chelation therapy is a safe treatment for any type of cancer. Chelation
therapy may produce toxic effects, including kidney damage, irregular
heart beat, and swelling of the veins. It may also cause nausea,
vomiting, diarrhea, and temporary lowering of blood pressure.
Since the therapy removes minerals from the body, there is a
risk of developing low calcium levels (hypocalcemia) and bone damage.
Chelation therapy may also impair the immune system and decrease the
body's ability to produce insulin. People may also feel pain at the
site of EDTA injection.
Chelation therapy may be dangerous in people with kidney
disease, liver disease, or bleeding disorders. Women who are pregnant
or breast-feeding should not use this method.
Chelation therapy is often given along with large doses of
vitamins and other minerals, which may actually contribute to the
processes that produce dangerous free radicals in the body. Loss of
zinc can also lead to changes (mutations) in cells. For this reason,
chelation therapy may actually increase the risk of cancer.
The possible interactions between chelation therapy and
prescription or over-the-counter medicines are not entirely known.
Relying on this type of treatment alone, and avoiding or
delaying conventional medical care, may have serious health
consequences.
Additional Resources
More Information From Your
American Cancer Society
The following information on complementary and alternative
therapies may also be helpful to you. These materials may be ordered
from our toll-free number (1-800-ACS-2345).
References
Cassileth B. The Alternative Medicine Handbook.
New York, NY: W. W. Norton & Co; 1998.
Ernst E, ed. The Desktop Guide to Complementary and
Alternative Medicine: An Evidence-Based Approach. London, UK:
Mosby; 2001.
Green S. Chelation therapy: Unproven claims and unsound
theories. 2002. Available online at:
www.quackwatch.org/01QuackeryRelatedTopics/chelation.html. Accessed
June 21, 2007.
Grier MT, Meyers DG. So much writing, so little science: a
review of 37 years of literature on edetate sodium chelation therapy. Ann Pharmacother.
1993;27:1504-1509.
Guldager B, Jelnes R, Jorgensen SJ, et al. EDTA treatment of
intermittent claudication: a double-blind placebo-controlled study. J Intern Med.
1992;231:261-267.
Knudtson ML, Wyse DG, Galbraith PD, Brant R, Hildebrand K,
Paterson D, Richardson D, Burkart C, Burgess E. Chelation therapy for
ischemic heart disease: a randomized controlled trial. JAMA.
2002;287(4):481-486.
MD Anderson Cancer Center. Comlementary Practice: Chelation
(EDTA) Therapy. Available at:
http://www.mdanderson.org/departments/cimer/display.cfm?id=4230febd-e954-4025-86affa94c7a8fc71&method=displayfull&pn=6eb86a59-ebd9-11d4-810100508b603a14.
Accessed June 21, 2007.
Redman BG, Esper P, Pan Q, Dunn RL, Hussain HK, Chenevert T,
Brewer GJ, Merajver SD. Phase II trial of tetrathiomolybdate in
patients with advanced kidney cancer. Clin Cancer Res.
2003;9(5):1666-1672.
Selig RA, White L, Gramacho C, Sterling-Levis K, Fraser IW,
Naidoo D. Failure of iron chelators to reduce tumor growth in human
neuroblastoma xenografts. Cancer
Res 1998;58:473-478.
van Rij AM, Solomon C, Packer SG, Hopkins WG. Chelation
therapy for intermittent claudication. A double-blind, randomized,
controlled trial. Circulation.
1994;90:1194-1199.
Note: This information may not
cover all possible claims, uses, actions, precautions, side effects or
interactions, is not intended as medical advice. It should not be
relied upon as a substitute for consultation with your doctor, who is
familiar with your medical situation.
Revised: 07/20/2007
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