Apple cider vinegar (ACV) has been used as a healing agent for centuries, but there could be some downsides to this holistic tonic.
Thanks to the proteins, probiotics, enzymes and polyphenolic compounds in the unfiltered version of this fermented liquid made from juice extracted from apples, ACV has been hailed as a medicinal treatment used to either prevent or cure a variety of health conditions.
It's been linked to aiding weight loss as well as managing diabetes, high cholesterol, sore throat and skin infections, to name a few. In fact, ACV dates back to 400 BC when Hippocrates, aka "Father of Medicine," reportedly used it for its cleansing properties, according to Bragg Live Food Products.
While the research behind the benefits of ACV is limited, it continues to remain a trusted home remedy. However, moderation may be the key. A daily intake of 15 milliliters (which is equal to about 1 tablespoon) of vinegar was observed to improve high blood pressure, hyperlipidemia and obesity, according to an April 2016 review published in the journal Current Opinion in Food Science.
But going above and beyond the recommended daily amount of ACV — a highly acidic beverage — could lead to unwanted side effects.
It's not surprising to learn that regularly drinking too much vinegar can lead to dental problems. "Due to its acidity, ACV can definitely affect the enamel on your teeth," Frances Largeman-Roth, RDN, author of Eating in Color and Feed the Belly, tells LIVESTRONG.com. "Acid in food and beverages can cause your enamel to wear away, causing discoloration and leaving your teeth prone to sensitivity and decay."
In fact, once highly acidic foods and drinks begin the process of tooth erosion, bacterial plaque can form and cause cavities or infection, according to Mouth Healthy, which is powered by the American Dental Association. Plus, tooth erosion is permanent, so fillings, crowns, a root canal or (in the most severe cases) tooth removal may be necessary.
According to a January 2014 in vitro study published in the journal Clinical Laboratory, investigators tested the level of dental erosion caused by varieties of vinegar using human enamel samples. While ACV was not one of the five types of vinegar used in this experiment, the samples had a pH level — a scale that ranges from 0 to 14 and is used in order to determine how acidic or basic a substance is — between 2.7 and 3.95. (Bragg Apple Cider Vinegar has a pH level of 3.2 to 3.5.)
As a result, different kinds of vinegar eroded the teeth to various degrees, yet the greatest loss of minerals — 20 percent — came from two varieties of vinegar with a pH level of 2.7 and 3.1.
Therefore, Largeman-Roth advises having a serving of ACV with other food — perhaps as an ingredient in a vinaigrette or smoothie — to prevent damage to your enamel. “Also, if you mix one tablespoon of ACV into a glass of water, consider using a straw to protect the enamel on your pearly whites,” Erin Palinski-Wade, RD, CDE, author of 2-Day Diabetes Diet, tells LIVESTRONG.com.
One of the most well-known, yet alleged, benefits of ACV is that it can help improve digestion. So, how can this tonic ward off heartburn, otherwise known as acid reflux?
When contents from the stomach travel back up the windpipe, it brings stomach acid with it, which is why it leaves behind a burning sensation, according to Harvard Health Publishing. Since the medical community believes that a lack of gastric acid causes the lower esophageal sphincter (a muscle connected to the stomach) to relax — and reflux — some people think that adding more acid to the system will prevent this unpleasant reaction. However, there's no science to back up this claim just yet.
Yet the University of Chicago Medicine states that acidic foods and liquids may actually exacerbate acid reflux. Also, researchers investigating if vinegar works as a natural appetite suppressant found that consuming the liquid led to significant increases in nausea, a small study published in the August 2014 issue of the International Journal of Obesity found.
An acidic beverage can irritate the throat, especially if it's imbibed too often or in large quantities, states the Mayo Clinic. The National Capital Poison Center (Poison Control) warns that vinegar can cause injury if not used properly.
For generations, ACV has been used for skin healing and there is some evidence that supports this concept. In September 2015, researchers from the University of Birmingham in the United Kingdom discovered that applying low concentrations of acetic acid onto serious burn wounds can be an effective topical solution due to the liquid's antibacterial properties.
However, the study authors offered a strong precaution: ACV should not be applied at home. They advise anyone who suffers from a burn to seek medical attention.
Poison Control highlights two cases where three types of vinegar that contained up to 5 percent acetic acid (Bragg Apple Cider Vinegar contains 5.14 percent) were applied to the skin to treat two different ailments. In one case, a grandmother applied a compress soaked in grape vinegar to her 25-year-old grandson in order to reduce his fever. As a result, he suffered from first-degree burns on his neck, shoulders, chest and back, which ended in a two-day hospital stay.
In the second case, a 59-year-old woman wrapped her sprained ankle in a vinegar-soaked gauze for two hours. When she removed the bandage, the skin around her ankle was dark red, partially brown-black and swollen. A hospital stay followed, as well as a skin graft.
A third case study, which was published in the June 2015 edition of The Journal of Clinical and Aesthetic Dermatology, involved a 14-year-old girl who applied a few drops of ACV on her nose for three days straight in order to remove unwanted moles. While the moles peeled off within a couple of days, the treatment left behind an irritation, which a physician defined as "noninflammatory, poorly defined erosions." The teenager was prescribed a topical antibiotic that was to be applied twice a day for several weeks, along with zinc oxide sunscreen.
Bottom line: Avoid applying ACV to your skin at home.
According to the Mayo Clinic, another possible ACV side effect is increasing the risk of drug interactions, specifically of certain diuretics (for the treatment of high blood pressure) and insulin (for managing diabetes).
It's been reported that diets with high amounts of vinegar may cause or worsen low potassium levels, per Harvard Health Publishing. And even though there's research that indicates ACV may lower blood glucose levels in adults at risk for type 2 diabetes, Harvard Medical School warns that vinegar can fluctuate insulin levels — and that people living with diabetes "should be particularly cautious" about adding high amounts of vinegar to their eating plan.
The Bottom Line
As far as using ACV as a natural remedy, you'll want to proceed with caution. Avoid applying it on your skin or consuming it without diluting it first. "While I wouldn't expect earth-shattering results from taking ACV daily," Largeman-Roth says, "it can't hurt when taken at the proper amount."
Read more: Is White Vinegar Good for Health?
- Bragg Live Food Prdoucts: "Bragg Organic Apple Cider Vinegar"
- Current Opinion in Food Science: "Therapeutic Effects of Vinegar: a Review"
- MouthHealthy.org: "Erosion: What You Eat and Drink Can Impact Teeth"
- Clinical Laboratory: "In Vitro Study on Dental Erosion Caused by Different Vinegar Varieties"
- Elmhurst.edu: "pH Scale'
- Harvard Health Publishing: "ACV...For Heartburn?"
- UChicagoMedicine: "Debunking the Health Benefits of ACV"
- International Journal of Obesity: "Influence of the Tolerability of Vinegar as an Oral Source of Short-Chain Fatty Acids on Appetite Control and Food Intake"
- Mayo Clinic: "ACV for Weight Loss Seems Far-Fetched."
- Poison Control: "Vinegar"
- University of Birmingham: "Acetic Acid, Found in Vinegar Shown to Be Effective Against Bacteria Found in Burn Wounds"
- The Journal of Clinical and Aesthetic Dermatology: "Chemical Bum from Vinegar Following an Internet-Based Protocol for Self-Removal of Nevi"
- Harvard Health Publishing: "ACV Diet: Does It Really Work?"
- Mayo Clinic: "Diuretics"
- Journal of Functional Foods: "Vinegar Ingestion at Mealtime Reduced Fasting Blood Glucose Concentrations in Healthy Adults at Risk for Type 2 Diabetes"