Chelation therapy: what it is, when it is used
In chelation therapy, a biologically based therapy, a drug is used to bind and remove a hypothetical excess or toxic amount of a metal or mineral (e.g., lead, copper, iron, calcium) from the blood stream
In conventional medicine, chelation therapy is a widely accepted way of treating lead poisoning and other heavy metals
Heavy metal toxicity, usually due to environmental exposure, can be a risk factor for dementia (1), cardiovascular disease, and chronic kidney disease.
Chelation therapy with ethylenediaminetetraacetic acid has been proposed as a method to remove calcium and thus treat atherosclerosis.
However, despite > 50 years of study, researchers have not identified any mechanism to explain how chelation therapy could treat atherosclerosis or prevent heart attacks or strokes.
In 2012, a large randomised placebo-controlled trial of chelation (called Trial to Assess Chelation Therapy [TACT]) found a significant benefit for chelation over placebo for composite (outcome) outcomes (26.5% vs 30% for placebo), but not for individual outcomes (e.g., death, cardiovascular events, stroke, hospitalisations).
This study had methodological flaws and did not end the controversy over chelation therapy; however, a retrospective review of the data showed a significant reduction in the composite endpoint in patients with diabetes and peripheral artery disease in the chelation group compared to the control group, as well as a reduction in mortality.
A subsequent systematic review of 38 studies showed the possible but unclear benefits of chelation in relation to secondary prevention of recurrent cardiac events.
Risks of chelation therapy include
- Hypocalcaemia (which is potentially serious)
- Infusion site reaction, fever, nausea, vomiting
- Renal damage
- Delay in more effective treatment
- Killin LO, Starr JM, Shiue IJ, et al: Environmental risk factors for dementia: a systematic review. BMC Geriatr 16(1):175, 2016. doi: 10.1186/s12877-016-0342-y
- Chowdhury R, Ramond A, O’Keeffe LM, et al: Environmental toxic metal contaminants and risk of cardiovascular disease: systematic review and meta-analysis. BMJ 362:k3310, 2018. doi: 10.1136/bmj.k3310
- Farkhondeh T, Naseri K, Esform A, et al: Drinking water heavy metal toxicity and chronic kidney diseases: a systematic review. Rev Environ Health. 2020 Nov 2:/j/reveh.ahead-of-print/reveh-2020-0110/reveh-2020-0110.xml. doi: 10.1515/reveh-2020-0110
- Lamas GA, Goertz C, Boineau R, et al: Effect of disodium EDTA chelation regimen on cardiovascular events in patients with previous myocardial infarction: the TACT randomized trial. JAMA. 309(12):1241–50, 2013. doi: 10.1001/jama.2013.2107
- Ujueta F, Arenas IA, Escolar E, et al: The effect of EDTA-based chelation on patients with diabetes and peripheral artery disease in the Trial to Assess Chelation Therapy (TACT). J Diabetes Complications 33(7):490-494, 2019. doi: 10.1016/j.jdiacomp.2019.04.005
- Ibad A, Khalid R, Thompson PD, et al: Chelation therapy in the treatment of cardiovascular diseases. J Clin Lipidol 10(1):58-62, 2016. doi: 10.1016/j.jacl.2015.09.005