The Full Story
Vinegar, from the French vin aigre (sour wine), is a flavoring agent in many cuisines. Vinegar can be made from numerous fermentable carbohydrates including fruits, grains, honey, wine, and even potatoes. Acetic acid is one product of the fermentation process and gives vinegar its sharp flavor and pungent odor. White distilled vinegars are generally 4%-7% acetic acid. Cider and wine vinegars are 5%-6% acetic acid. Acetic acid, however, is NOT synonymous with vinegar. Vinegar contains many other ingredients such as amino acids, mineral salts, and nonvolatile organic acids. The US Food and Drug Administration states that diluted acetic acid is not vinegar and should not be added to food products that would be expected to contain vinegar.
Specialty vinegars are herbal or fruit vinegars. Herbal vinegars are wine or white distilled vinegars that can be seasoned with garlic, basil, tarragon, or other spices. Fruit varieties are wine and white vinegars sweetened with fruit or fruit juice. A popular example of a tradition fruit vinegar is the balsamic variety of Modena, Italy, which is made from white Trebbiano grapes fermented slowly and then aged in casks of various woods.
Topical use of vinegar as an anti-infective is centuries old, especially before the discovery of antibiotics. Diluted white vinegar was thought to be useful for treating swimmer’s ear (otitis externa). This is because the acetic acid lowers the pH in the ear, and a lower pH might restrict the growth of bacteria and fungi. However, vinegar can be quite painful due to irritation of already inflamed tissue. This can affect patient compliance since ear irrigation with diluted white vinegar might be required several times a day for up to 3 weeks. Using specific antibiotics to treat otitis externa both reduces the time of treatment and is safer and more effective than treatment with vinegar.
Vinegar should not be used to treat wounds. Vinegar is not effective at inhibiting the growth of many bacteria that cause wound infections and it can be caustic with prolonged contact.
There are many sources that recommend pouring vinegar on jellyfish stings. The available medical evidence is inconsistent regarding vinegar’s ability to relieve pain, prevent further release of nematocysts, or inactivate toxins. Nematocysts are tiny tubules injected by the jellyfish that contain spines and toxins used to capture and paralyze prey.
In a systematic medical literature review of studies evaluating treatments for jellyfish stings, the use of vinegar got mixed results. In one study, pouring vinegar was shown to provide relief from stings by the Australian box jellyfish (Chironex fleckeri), which is not found in North America or Hawaii. Another study supported vinegar use for treatment of stings by Olindias sambaquiensis, a jellyfish found only in the South Atlantic. However, vinegar might actually cause nematocyst discharge in some North American jellyfish.
Apple cider vinegar products are popularly advertised as treatments for a variety of conditions including weight loss, high blood pressure, arthritis, aging, and type 2 (non-insulin-dependent) diabetes mellitus. Limited, small studies suggest that ingestion of apple cider vinegar pills, pickles, or liquid vinegar might help control blood sugar in some people with type 2 diabetes mellitus. A variety of mechanisms have been proposed, but none is clearly established. Diabetics should not self-treat with vinegar and should discuss any diabetes treatment with their health care provider before using them.
Vinegar has been used as a component of homemade cleaning solutions, Vinegar should never be mixed with chlorine bleach. The combination creates highly irritating chlorine gas.
When vinegar gets in the eyes, irritation and redness are common and corneal injury can occur. The eyes should be rinsed immediately. Remove contact lenses and use lots of room-temperature water. For children, pour water onto the bridge of the nose and let it gently run into the eyes. Encourage blinking. Then check with Poison Control after rinsing.
If you suspect someone has swallowed vinegar and is having a problem, do not make the person vomit. Immediately check the webPOISONCONTROL® online tool for help, or call Poison Control at 1-800-222-1222.
Mary Elizabeth May, RN, BA, MPH
Certified Specialist in Poison Information
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Hill LL, Woodruff LH, Foote JC, Barreto-Alcoba M. Esophageal injury by apple cider vinegar tablets and subsequent evaluation of products. J Am Diet Assoc 2005;105:1141-4.
Johnston CS, Gaas CA. Vinegar: medicinal uses and antiglycemic effect. MedGenMed 2006;8:61.
Korkmaz A, Sahiner U, Yurdakok M. Chemical burn caused by topical vinegar application in a newborn infant. Pediatr Dermatol 2000;17:34-6.
Kuniyuki S, Oonishi H. Chemical burn from acetic acid with deep ulceration. Contact Dermatitis 1997;36:169-70.
Ward NT, Darracq MA, Tomaszewski C, Clark RF. Evidence-based treatment of jellyfish stings in North America and Hawaii. Ann Emerg Med 2012;60:399-414.
- Do not mix vinegar with chlorine bleach. This results in release of chlorine gas that is very irritating to the airways, eyes, nose, and throat.
- Do not use dietary supplements containing vinegar without the approval of your health care provider.
- Do not attempt to treat fevers, sunburns, or other conditions by applying vinegar compresses to the skin. This can cause burns.
- Keep vinegar and dietary supplements containing vinegar away from children.
This Really Happened
Case 1. A 48-year-old woman swallowed an apple cider vinegar tablet and developed severe pain and trouble swallowing when the tablet became lodged in her throat. An endoscopy 2 weeks later appeared normal, but she still complained of pain and trouble swallowing 6 months after the incident.
Case 2. A 25-day-old boy with a fever suffered first-degree burns on his neck, shoulders, chest, and back after his grandmother applied compresses soaked in grape vinegar (5% acetic acid) in an attempt to lower his body temperature. After 2 days of treatment in the hospital, his burns began to fade and disappeared within 10 days without scarring.
Case 3. A 59-year-old woman twisted her ankle while mountain climbing. She covered her ankle with a homemade poultice made of gauze soaked in a 50-50 mixture of flour vinegar and rice vinegar, containing 4%-5% acetic acid. She kept the gauze on for 2 hours. When she removed it, the area was dark red and partially brown-black, and swollen. She required hospitalization and received a skin graft about a month later.
Case 4. A 25-year-old woman mixed bleach and vinegar to clean her kitchen. Very irritating fumes developed. Her chest burned and she had a runny nose. She called Poison Control and was advised to fill her bathroom with steam by running a hot shower and to inhale the warm, humid air for 15-20 minutes at a time while drinking fluids. She still had chest soreness that night but no trouble breathing. The next day, when Poison Control checked back on her, the symptoms had resolved.
Case 5. A 45-year-old man unintentionally splashed vinegar into his eye. He flushed his eye in the shower but 2 days later still had irritation and blurred vision. He then called Poison Control and was referred to an ophthalmologist. The ophthalmologist found small scratches on his cornea. He was treated with antibiotic eye drops. Poison Control called him regularly, and his symptoms resolved in 4 days.