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EDTA Chelation Therapy

Elizabeth Brown

What is chelation?

The word “chelation” comes from the Greek for “claw.”  Chelation is a process by which metal ions in the body are bound to a chelating agent and excreted from the body. 


What is EDTA? 

EDTA, ethylene diamine tetraacetic acid, is a type of chelating agent.  In chelation therapy, it can be delivered orally or intravenously, and different forms can be used for different purposes: disodium EDTA, magnesium disodium EDTA, or calcium disodium EDTA. 


What is EDTA chelation therapy?

Chelation therapy is often a series of 20-30 or more IV infusions of EDTA and vitamin/mineral supplements in a doctor’s office spread out over the course of weeks and months.  EDTA can also be taken orally, although it is not absorbed as well and there is a debate among chelation practitioners over its efficacy.  The EDTA infusions are to be placed in the context of healthy lifestyle changes such as diet, exercise, not smoking, etc. 


What is the purpose of this therapy?

ETDA chelation has been a standard medical treatment for lead poisoning for decades, but its proponents claim that it benefits a variety of other conditions.  Perhaps its most common application is in cardiovascular disease; advocates claim that chelation reverses the hardening and occlusion of the arteries, improving circulation to all parts of the body and avoiding expensive coronary artery bypass grafting and angioplasty.  Other conditions it purportedly benefits include cardiac arrhythmia, diabetes, gangrene from peripheral arterial disease, hypertension, Alzheimer’s, arthritis, senility, cancer, stroke, scleroderma, cataracts, and more. 


What evidence is there to support these claims?

The website of the Mount Ranier Clinic in Yelm, Washington has links to the abstracts of many studies of the different benefits of EDTA chelation therapy, some of which are summarized below: for Dr. Cranton’s discussion of some of these studies.

§        Blood flow to peripheral arteries (as objectively measured by the Doppler ankle/brachial blood pressure ratio) improved by 22% in 77 elderly patients treated with EDTA chelation therapy.

§        A retrospective study of 470 subjects with arteriosclerosis showed improvements of 80-90% with chelation therapy, and 82 out of the 92 patients who were to have surgery no longer needed it. 

§        Four patients with gangrene from severe occlusive peripheral arterial disease were to undergo amputations.  After EDTA chelation (and other treatments in some cases), all four patients were healed and able to walk without pain (with only one subject losing the tips of several toes). 

§        EDTA chelation improved blood flow to the brain (as measured by radioactive technique) and associated symptoms in 15 subjects.

§        A meta-analysis of 19 studies including 22,765 subjects with cardiovascular disease showed that 87% of subjects benefited from chelation therapy.

§        A study of 59 Swiss subjects treated with chelation therapy and followed for 18 years showed a 90% reduction in cancer mortality over untreated residents of the same neighborhood. 

§        EDTA was shown to “enhance overall well-being and quality of life” as measured by the Cornell Medical Index Health questionnaire and broken down by body system.  There was an average of 20% improvement in the subjects. 

§        A case study reported on the reversal of macular degeneration in a 59-year-old woman treated with EDTA chelation therapy.


Many sites, including Dr. Cranton’s, also have links to patient testimonials.  Here are some examples from the website selling Formula #1 Oral Chelation Therapy:

§        “Ed and I are both taking 2 teaspoons a day of Formula #1 Oral Chelation - along with the heart pack that has 2 Formula One Gel Caps in it! In the first two weeks my leg cramps were gone!!! They used to be so bad that they would wake me up at night...I am so glad they are gone. Ed's arm is no longer tingling when he wakes up in the mornings. I did not know he had this problem till he told me it was gone since taking the Formula One Oral Chelation. We look forward to the long term benefits of this product. Ed and Trish Koch U.S.A.

§        “For about a year I was treated for symptoms of heart attack and stroke. I started taking Formula #1 and got results with in two days. I am 68 years old and returned to work full time in construction. I can now work long hours with out any pain. I have reduced my blood pressure medication and feel great with lots of energy. I owe it all to Formula One Oral Chelation! Raymond S., USA EE 12/03”


How does EDTA do all this?

According to Dr. Cranton, “We really do not know how EDTA chelation therapy benefits symptoms of atherosclerosis and arterial blockage. We do know a number of different actions of EDTA within the body, but we do not know which actions are most beneficial. It is quite possible that an unknown and still unsuspected activity is primarily responsible for the observed improvement in blood flow and symptoms.”


Many theories have been put forward for consideration.  One of the more common explanations is that EDTA binds to the calcium in arterial plaques and removes it, thus breaking up the plaque. 


Some people express concern over the binding of calcium, thinking that this process must also strip away calcium from the bones and teeth.  Proponents of the theory explain that the calcium is only removed from inappropriate locations such as the arteries.  Garry Gordon, M.D., D.O., adds that the binding of calcium is actually good for the bones.  Reduced serum calcium levels stimulate the parathyroid gland to secrete parathormone, which not only causes the restoration of appropriate calcium levels but also activates bone-strengthening osteoblasts, effectively reversing the course of osteoporosis.


Cranton, however, rejects the whole theory of removing calcium from plaques as outdated.  He favors explanations involving more recent research into the area of free radical pathology.  Cranton explains that free radicals can disrupt many other important molecules around them and have been implicated in the promotion of atherosclerosis, cancer, and the basic decline in human health with age.  He says that EDTA binds to and removes a particular form of iron that can catalyze the formation of free radicals. 


Cranton also puts forth some other theories.  Since EDTA can bind to many different metals, it can trade one metal for another for which it has a higher affinity as it travels through the body.  This process theoretically has the potential to move trace elements from areas of high concentration (which, according to the cited research, can form in diseased tissue) to other areas where the elements can be of benefit in facilitating healthy enzymatic activity.  He also notes what is perhaps a more commonly understood function of EDTA, the binding and removal of heavy metals that can interfere with enzymatic processes (although in mainstream practice this treatment is only used for known or suspected cases of heavy metal poisoning).


Yet another explanation for cardiovascular improvements after treatment with EDTA is that the removal of heavy metals leads to increased production of nitric oxide in the endothelial cells, causing the arteries to relax and improving flow.

These explanations mostly center on the cardiovascular effects of ETDA, but its proponents think it is effective on a wide range of conditions.  One website explains how EDTA can achieve such broad improvements by saying that once the arteries are opened and the blood flow reestablished, other cells “downstream” will no longer be deprived of nutrients or the opportunity to eliminate waste.  The healing of these cells then ameliorates a number of diseases. 


Why are these people putting out this information? 

In addition to running a clinic that offers EDTA chelation treatments, Dr. Cranton has also written one book and edited another about the subject.  His website has numerous links to the pages where these books can be purchased.  The information from the Townsend Letter article comes from a company that manufactures the Oral Chelation and Age-Less formulas, and two others of the sites are unequivocally trying to sell a product.  Also, although doctors who advocate and administer chelation therapy speak out against the doctors and hospitals who profit from massively expensive cardiovascular procedures, one must keep in mind that these doctors make their own profits from chelation therapy, a full course of which can cost several thousand dollars. 


What does the scientific community say about chelation?

A search of the published scientific literature via PubMed does not necessarily provide definitive answers to the many questions surrounding EDTA chelation therapy.  Article conclusions range from approval of the therapy to (more commonly) disapproval, with many articles indicating the need for further study before firmer judgments can be made. 


Effectiveness of EDTA chelation therapy in the treatment of cardiovascular disease:

A recent literature review by Seely, Wu, and Mills (2005) concluded that “[t]he best available evidence does not support the therapeutic use of EDTA chelation therapy in the treatment of cardiovascular disease.”  The authors examined five randomized controlled trials and found that two supported the use of chelation and three did not.  The two positive trials, however, were far smaller than the other three, and neither was completed as originally planned; one ended early due to placebo group dropouts who weren’t seeing any benefit, and in the other, the researcher broke the double blind code in view of such “dramatic improvements” in what turned out to be the treatment group.  None of the other three studies showed any significant benefit of EDTA chelation as compared to placebo. 


The review also compiled data regarding adverse effects in the studies, finding instances of faintness (6 treatment, 2 control), hypocalcemia (11 treatment, 1 control), and one case in a treatment group of “potential kidney toxicity.”  Based on outside information, the reviewers deemed EDTA to be safer than an alternative such as coronary artery bypass grafting, but also noted that even small risks are unreasonable if the therapy is not truly effective.


An animal study, on the other hand, showed some promise for chelation therapy (Evans, Tariq, Sujata, McCann, and Sobki, 2001).  Researchers fed rabbits a cholesterol-rich diet, giving one group injections of EDTA and magnesium sulfate (a typical ingredient in a chelation treatment).  The EDTA/magnesium sulfate reduced the increase of serum cholesterol, triglyceride, and calcium levels and limited blockage of the aorta compared to the control rabbits on the cholesterol diet.  Researchers took another group of cholesterol-fed rabbits, put them back on a normal diet, and then gave some of them injections of EDTA/magnesium sulfate.  The treatment group had lower levels of serum calcium and aortic blockage than the control group.  These data showed a clear benefit from the chelation therapy, although the researchers mentioned in the discussion that the magnesium sulfate could have been responsible in whole or in part for the favorable results. 


A different animal study gave almost the opposite results (O’Brien, Kelly, Dolphin, and Russell, 2000).  Researchers gave EDTA to rats who were genetically determined to be obese, insulin-resistant, hypertriglyceridemic, and extremely prone to atherosclerosis.  When compared to the control group of rats with similar genetic makeup, the cholesterol levels and aortic health showed no improvement, while the triglyceride levels were significantly higher.  The researchers concluded that “[c]helation therapy using intravenous EDTA has no beneficial effects on the arterial lesions in the atherosclerotic JCR:LA-cp rat. The increase in plasma triglyceride concentrations would be grounds for concern in human patients.” 


Research regarding the mechanisms of EDTA chelation:

Other research has yielded some information about the possible mechanisms of EDTA in the body.  A study published in Free Radical Biology and Medicine (Hininger et al., 2005) investigated whether the large doses of vitamin C (an antioxidant) typically administered with EDTA therapy might actually have a prooxidant effect.  The researchers gave two different groups of subjects EDTA with and without 5 g vitamin C and found that indeed the biochemical measurements of free radicals were markedly increased soon after therapy in the vitamin C group compared to the group that did not receive vitamin C.  However, over the course of 16 treatments, the researchers found that despite the prooxidant activity directly following each treatment, the long-term effects were antioxidant.  They suggested that this therapy might be beneficial to patients with heart disease and diabetes because the long term effects involved protection against lipid peroxidation.  They also noted that “[t]he effects of multiple sessions of chelation therapy, without added vitamin C during the chelation session, may lead to even more beneficial effects and need to be determined.”  While this study is far from conclusive, it indicates that a component of the typical chelation treatment is likely beneficial, and it suggests fairly specific further study to continue learning about the potential antioxidant effects of EDTA. 


Another article (Guldager et al., 1993) provided evidence regarding the theory of how EDTA might reverse osteoporosis (discussed above).  The double-blind study tested the effects of EDTA versus placebo on serum parathyroid hormone (PTH) and biochemical markers of bone turnover.  The researchers found that PTH secretion increased significantly in the treatment group, and other biochemical tests indicated bone “resorption” without “remodeling.”  They concluded that “chelation therapy with EDTA is accompanied by bone loss,” disproving the above theory. 


Another article (Anderson, Hubacek, Wyse, and Knudtson, 2003) looked for evidence to see whether or not EDTA dilates arteries, which would support the theory of its increasing nitric oxide production in the endothelial cells.  This double-blind, randomized study investigated the impact of infusions of EDTA with vitamins and minerals versus placebo (vitamins and minerals only) on endothelium-dependent brachial artery flow-mediated vasodilation in subjects with coronary artery disease who were also being “optimally treated with proven therapies for atherosclerotic risk factors.”  The researchers found no significant difference in flow-mediated vasodilation between the treatment and placebo groups (although they did mention the possibility that the other drugs being used to “optimally treat” the patients could have been so effective that treatments with EDTA and/or vitamin C would not show any further benefit regardless of their intrinsic value).  In the discussion of the results, it was suggested that perhaps the lack of benefit from EDTA was because the small size of the EDTA molecule prevents its completely binding to iron and negates the proposed antioxidant effect (which is also integral to the proposed effect on nitric oxide production).  This study provided support for neither the theory of EDTA as an antioxidant nor the theory of EDTA’s increasing nitric oxide production in endothelial cells. 



Overall, the published scientific literature through PubMed does not support the claims of the many benefits of EDTA chelation therapy.  It must be noted that doctors and scientists on both sides of the debate have serious problems with the methodology of those on the other side.  The proponents of the therapy criticize the designs of the trials that do not demonstrate any benefits as being biased against the therapy, and they claim the results can still be reinterpreted to support its efficacy.  On his website, Cranton criticizes several frequently-cited published studies for such serious shortcomings as breaking of the double blind, small numbers of subjects, high dropout rate, lack of consideration of confounding variables, and “data manipulation and statistical irregularities” (  Chelation advocates also claim that the medical establishment does not want the public to know about this treatment because it would then lose its tremendous income from procedures such as bypass grafting (although one must consider that they themselves profit from chelation therapy). 


Those against the therapy (or at least reserving judgment) criticize the studies of the proponents, saying that they do not provide valid scientific evidence because most of them are small, without a control group for comparison, and much evidence comes from case studies.  For example, the review by Seely et al. (see above) acknowledged that there were criticisms against some of the studies in their review and even conceded that publication bias could possibly have skewed their data (as chelation proponents say it does).  However, the researchers also pointed out the weakness of most studies favoring chelation: lack of a control group.  They explained that several of the studies in their review showed improvement in both the control and treatment groups, and without a control the improvement would naturally be ascribed to the treatment alone, thus producing a type I error. 


Also, some of the material published online by the proponents of chelation therapy (for example seems to lower their credibility due to its emotionally charged nature, and some of the claims (the reversal of gangrene, the >80% benefits) see to violate common sense.   


In view of this controversy, more definitive conclusions may be reached in the relatively near future.  The National Institutes of Health’s National Center for Complementary and Alternative Medicine (NCCAM) and National Heart, Lung, and Blood Institute (NHLBI) announced in 2002 that they would be conducting a large-scale, five-year, double-blind, randomized controlled trial investigating the safety and effectiveness of EDTA chelation as a treatment for coronary artery disease.




(All materials located online via PubMed and accessed when possible through the Vanderbilt library electronic subscriptions)

Anderson, T., J., Hubacek, J., Wyse, D., G., & Knudtson, M. L.  (2003).  Effect of Chelation Therapy on Endothelial Function in Patients With Coronary Artery Disease: PATCH Substudy.  Journal of the American College of Cardiology, 41(3), 420-425. 

Evans, D. A., Tariq, M., Sujata, B., McCann, G., & Sobki, S.  (2001).  The effects of magnesium sulphate and EDTA in the hypercholesterolaemic rabbit.  Diabetes, Obesity and Metabolism, 3(6), 417. 

Guldager B., Brixen K. T., Jorgensen S. J., Nielsen H. K., Mosekilde L., & Jelnes R..  (1993).  Effects of intravenous EDTA treatment on serum parathyroid hormone (1-84) and biochemical markers of bone turnover.  Danish Medical Bulletin, 40(5), 627-630. 

Hininger, I., Waters, R., Osman, M., Garrel, C., Fernholz, K., Roussel, A. M., et al.  (2005).  Acute prooxidant effects of vitamin C in EDTA chelation therapy and long-term antioxidant benefits of therapy.  Free Radical Biology & Medicine,  38, 1565– 1570. 

O’Brien, S. F., Kelly, S. E., Dolphin, P. J., and Russell, J. C.  (2000).  Chelation therapy in the JCR:LA-cp rat: experimental assessment of a putative antiatherosclerotic treatment.  Clinical and investigative medicine, 23(2), 124-131. 

Seely, D. M. R., Wu, P., & Mills, E. J. (2005).  EDTA chelation therapy for cardiovascular disease: a systematic review.  BioMed Central Cardiovascular Disorders, 5, 32. 



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