Perhaps you’ve noticed the ingredient EDTA amongst the dizzying array of acronyms on the back of a can of pecan pie filling or on the label of your bar of soap. EDTA, or ethylenediaminetetraacetic acid, is a popular chelating agent that’s used in food, as a medication in chelation therapy and in many household products.
A chelating agent is a (usually organic) molecule that can form many bonds to a single metal ion. Chelation stabilizes the metal ion by preventing it from chemically reacting with any other substances. The stable metal unit is then excreted from the body through the urine.
TL;DR (Too Long; Didn't Read)
EDTA, or ethylenediaminetetraacetic acid, is a chelating agent used in food, in chelation therapy and in many household products. A chelating agent is a molecule that can form many bonds to a single metal ion, such as calcium, magnesium, lead or iron. The process of chelation stabilizes the metal ion by preventing it from chemical reacting with any other substances. The stable metal unit is then excreted from the body through the urine.
Structure of EDTA
EDTA is a dry, white crystalline powder. EDTA is a hexadentate ligand, which means that it creates 6 bonds with a central metal ion. When it bonds with a calcium ion, it becomes EDTA calcium disodium. EDTA calcium disodium can then chelate other metal ions by exchanging its calcium ion for another metal ion that has a greater affinity for the EDTA molecule.
EDTA calcium disodium, also known as the medication Calcium Disodium Versenate, is given intravenously or intramuscularly to treat heavy metal toxicity, specifically acute and chronic lead poisoning.
Edetate disodium is a different medication which does not contain calcium. It is called “Endrate” and it is used to treat hypercalcemia. It can also treat cardiac arrhythmias caused by the drug Digitalis, a cardiac glycoside.
Use in Food
EDTA is approved by the FDA for use as an additive in many processed foods. It promotes color retention in canned foods like white potatoes, clams, mushrooms, shrimp and pecan pie filling.
EDTA acts as a preservative in salad dressings and mayonnaise by bonding with the natural enzymes responsible for food spoilage, thereby stabilizing the food product. EDTA also promotes flavor retention in canned sodas, pickled cabbage and pickled cucumbers.
Additional Medical Uses
EDTA is used as an anticoagulant in blood banks by chelating calcium in the blood which prevents it from clotting.
In dentistry, EDTA is used before the application of dental adhesives and in root canal therapy. Eye drops that contain EDTA remove calcium deposits from the eye.
Household Product and Cosmetic Use
EDTA is a popular additive to soap. EDTA chelates magnesium and calcium found in hard water, making these substances unable to interfere with the cleansing action of soap on the skin. It’s also used in mouthwashes, cosmetics and other common topical preparations for use on the skin.
Side Effects of Chelation Therapy
Chelation therapy is effective for heavy metal toxicity as we have discussed above. It is NOT effective for treatment of other medical conditions like atherosclerosis and peripheral vascular disease.
Some of the toxic effects of EDTA have resulted from human error. It is easy to confuse the calcium-containing (calcium disodium EDTA) and non-calcium-containing forms of EDTA (edetate disodium).
When edetate disodium was mistakenly administered to patients, it caused rapid hypocalcemia that proved fatal. For this reason, edetate sodium is no longer commercially available in the US. Calcium disodium EDTA hasn’t caused any reported deaths from hypocalcemia.
Because EDTA is excreted by the kidney, it is contraindicated in patients with active renal disease and those who are anuric, or not able to make urine.
Other minor side effects include the following:
- pins and needles sensation around the mouth (temporary)
- mild drop in blood pressure (temporary)
Other Toxicities of EDTA
EDTA calcium disodium is approved by the FDA in low amounts for use in food. There is no evidence of toxicity at rates of normal consumption.
Since EDTA is also present in cosmetics and personal care products like shampoos, soap, creams and lotions, use of these items counts towards daily consumption.