People continue to tout the multiple health benefits of apple cider vinegar (ACV) — from healing skin issues to warding off harmful bacteria — but just how true are these claims?
An alternative remedy from ancient times, ACV is a fermented beverage made from the juice of chopped apples and added bacteria, which converts the juice's natural sugars to alcohol and, eventually, acetic acid.
Some versions of store-bought ACV have the term "with the mother" on the label. While this type of ACV does have a brown, even dirty, appearance, it's nothing to fear: The cloudy strands floating around in the bottle are actually health-promoting enzymes, proteins and probiotics.
Generally speaking, vinegar contains polyphenols, which are antioxidants that may help protect the body against cell damage and disease, explains Palinski-Wade. Yet despite the health hype surrounding ACV, scientific research is limited, and large-scale studies involving humans have yet to take place. However, some of the research regarding ACV's ability to heal certain ailments is encouraging.
Read more: Bragg Apple Cider Vinegar and Weight Loss
Apple Cider Vinegar for Yeast Infections
According to a case study published in the May 2018 International Journal of Dentistry and Oral Health, a 69-year-old adult living with type 2 diabetes was given ACV twice a day for one week as an alternative treatment for an oral yeast infection (oral candidiasis, a common complication of diabetes). The candidal infection decreased by 94 percent, leading researchers to conclude that ACV has antimicrobial and antifungal properties.
Another case study involved a 32-year-old woman who had been suffering from a vaginal yeast infection for five years. The condition caused the patient a variety of symptoms, including foul odor, itching, groin pain and infertility. While traditional treatments did not heal her infection, ACV did, per research in the December 2017 edition of Alternative Therapies in Health and Medicine.
In 2018, researchers from Middlesex University in London stated that ACV has "multiple antimicrobial potential," since the liquid was shown to decrease antibacterial and antifungal activity in certain germs, including the highly contagious Streptococcal bacteria, aka strep, per the January 2018 study in Scientific Reports. "So ACV may offer protection against contagious strep infections, as well," notes Palinski-Wade.
Apple Cider Vinegar and Varicose Veins
Medical researchers from Turkey divided 120 mostly overweight and obese patients into two groups in a study published in the January 2016 edition of Evidence-Based Complementary and Alternative Medicine. Those in the experimental group were instructed to apply ACV to a specific area of the leg affected by varicose veins twice a day for 30 days, while those in the control group wasn't given any treatment.
At the end of the month, all of the participants were reevaluated by physicians. Those in the ACV group experienced fewer physical symptoms, including cramps, edema, itching, pigmentation and so-called "heavy leg." Those participants also reported experiencing less social-appearance anxiety as a result. These physical and emotional health benefits came with zero side effects from the vinegar compound.
Apple Cider Vinegar and Eczema
While there is no substantial research that indicates ACV may improve this chronic inflammatory skin disorder, the National Eczema Association (NEA) offers a theory as to why it may possibly minimize dry and itchy skin. They explain that healthy skin has a pH level under 5.0 and is protected by an acidic barrier. (In chemistry, a pH level is a scale that ranges from 0 to 14 and is used to determine how acidic or basic a substance is.) People with eczema, however, are likely to have higher pH levels, which means their skin's acidic barrier doesn't protect them as it should, allowing irritants and bacteria in while causing moisture to go out.
ACV has some acidity (most types, like Bragg's, have a pH level of 3.2 to 3.5 with an acetic acid level of 5.14), so the NEA suggests that applying this liquid on the skin (for example, adding two cups of ACV to a lukewarm bath) may help balance the skin's pH level and subsequently clear up skin infections. However, the NEA advises consulting with your physician before using ACV as a topical product.
Apple Cider Vinegar for Acid Reflux
Gastroesophageal reflux disease, aka GERD — which is also referred to as acid reflux and heartburn — is a condition in which acid and other contents of the stomach travel back up into the esophagus because a muscle called the lower esophageal sphincter (LES) is weak, according to the National Institute of Diabetes and Digestive and Kidney Diseases. This reaction causes a burning sensation in the throat and chest areas due to stomach acid.
Even though ACV is acidic, some people ingest it to keep GERD at bay. It seems counterintuitive, but it might actually work. "There is a theory stating that what controls the LES is the stomach's acidity," writes Marcelo Campos, MD, a physician and lecturer at Harvard Medical School. "If, for some reason, the stomach is not producing enough acid, the muscles around the LES would relax, resulting in more reflux." In other words, more acid in the stomach might mean less reflux.
There's no hard data supporting this theory, but experts at the Cleveland Clinic say that since this home remedy for GERD is low-risk, it could be worth the effort. Their suggestion? "Use a small amount, such as a teaspoon of apple cider vinegar, and dilute it into a mug of warm water before or after a meal."
Read more: The 10 Worst Foods For Acid Reflux
The Bottom Line
If you're planning to make ACV part of your daily regimen, there are a few precautions to keep in mind. "Slow and steady wins the race and keeps you safe — so always, always, always dilute ACV in a full glass of water," says Palinski-Wade. She also suggests taking it with a meal, whether you add one serving of ACV to water, salad dressing, marinade or a smoothie.
What's more, research published by the University of Washington recommends consuming no more than two tablespoons of ACV per day. The reason: Due to its high acidity content, ACV can cause negative side effects, including tooth decay, upset stomach and tissue damage to the esophagus.
"ACV is not a magic cure-all," says Palinski-Wade. "But it's one of those foods that won't hurt to try. So I have no problem recommending that someone try it for up to three months."
- International Journal of Dentistry and Oral Health: "The Effect of ACV as an Antifungal in a Diabetic Patient with Itraoral Candidosis"
- Alternative Therapies in Health and Medicine: "Vaginal Candidisis Infection Treated Using ACV"
- Scientific Reports: "Antimicrobial Activity of Apple Cider Vinegar Against Escherichia Coli, Staphylococcus Aureus and Candida Albicans; Downregulating Cytokine and Microbial Protein Expression"
- Evidence-Based Complementary and Alternative Medicine: "The Effect of External ACV Application on Varicosity Symptoms, Pain and Social Appearance Anxiety"
- National Eczema Association: "Get the Facts: ACV"
- National Institute of Diabetes and Digestive and Kidney Diseases: "Symptoms and Causes of GERD"
- Harvard Medical School: "ACV...for Heartburn?"
- Cleveland Clinic: "Is ACV Good For Acid Reflux?"
- University of Washington: "Beyond the Hype: ACV as an Alternative Therapy"
- The Urban Clinic: Apple Cider Vinegar