Apple Cider Vinegar

Scientific Name(s): Malus pumila Mill.
Common Name(s): Apple cider vinegar

Medically reviewed by Drugs.com. Last updated on Oct 8, 2024.

Clinical Overview

Use

Clinical data are limited and results are equivocal for common claims related to apple cider vinegar use for management of glucose and lipid disorders.

Dosing

Dosing is not well established. Misbranding and extreme variability among commercially available products in terms of content and dosing recommendations have been reported.

Contraindications

Severe allergy to apples.

Pregnancy/Lactation

Apple cider vinegar is "generally recognized as safe" (GRAS) when used as food. Avoid amounts greater than those found in food because safety is unproven.

Interactions

None documented.

Adverse Reactions

Cases of dermal chemical burns as a result of topical application of apple cider vinegar home remedies for moles and warts have been reported, particularly when occlusive dressings have been applied.

Toxicology

No data. Hypokalemia and osteoporosis were observed in a young woman consuming excessive amounts (250 mL/day) for several years.

Scientific Family

• Rosaceae (rose)

Botany

Apples are grown in temperate climates throughout the world and are widely available in commercial markets. About 2,500 known varieties (cultivars) of apples are grown in the United States, with more than 7,500 varieties grown worldwide. The fruit is termed a "pome."Lewis 2004 The cultivated apple is thought to have originated in central Asia from the wild species Malus sieversii (Ledeb.) M. Roem. The juice from the fermented fruit, known as cider, is used to make apple cider vinegar.

History

The fruit juice from apples has been consumed fresh, distilled into apple brandy, or fermented as cider, which can be subsequently bioconverted to apple cider vinegar.Stornik 2016 Apple cider vinegar has been used commonly in food preparation and preservation, including in salad dressings, marinades, vinaigrettes, food preservatives, and chutneys. Vinegar has been sold commercially for more than 5,000 years. Use of the combination of apple cider vinegar and honey as an anti-infective remedy was documented in the Old Testament and by Hippocrates.Naziroglu 2014, Yagnik 2018 It was also used as a disinfectant for wounds during the American Civil War.Gopal 2017 Bioconversion of apple cider into vinegar is achieved by both natural and industrial processes; a key factor in bioconversion is the microbes used to convert the ethanol into acetic acid.Stornik 2016

Chemistry

Apple cider vinegar is produced from cider (the fermented apple juice) that has undergone bioconversion to vinegar following conversion of ethyl alcohol to acetic acid by microbes, usually Acetobacter.Yagnik 2018 In natural processes, the native microbes present on the fruit spontaneously carry out the process of converting the apple cider into vinegar. For vinegars, such as apple cider vinegar, that are less than 6% acetic acid, the predominant microbiota are Acetobacter aceti, Acetobacter pasteurianus, and/or Acetobacter pomorum. Studies show that microbiota diversity is higher in vinegars made from organic versus conventionally grown apples. The relatively low acidity (approximately 5% acetic acid) is mostly dependent on the sugar levels in the apples.Stornik 2016, Yagnik 2018 Organic acids, flavonoids, polyphenols, vitamins, and minerals are the main constituents.Yagnik 2018

Apple polyphenols are mainly polyphenolic acid derivatives and other flavonoids. Various maceration and production methods have been shown to significantly affect the chemical composition, total antioxidant activity, acidity, and phenolic content of apple cider vinegar. Chlorogenic acid is the dominant phenolic substance, with higher levels produced by maceration plus surface bioconversion methods compared to submersion methods. Gallic acid, catechin, epicatechin, caffeic acid, and p-coumaric acid are present in low levels.Budak 2011

Uses and Pharmacology

Antibacterial activity

Experimental and in vitro data

An ex vivo study evaluated the antibacterial effects of irrigating solutions and their combinations on 110 single-rooted human teeth inoculated with Enterococcus faecalis. Irrigating solutions included sodium hypochlorite 2.5% solution alone; sodium hypochlorite 2.5% plus citric acid 10%; sodium hypochlorite 2.5% plus apple cider vinegar; apple cider vinegar alone; chlorhexidine 2%; or peracetic acid 1%. The combination of apple cider vinegar with sodium hypochlorite had similar efficacy to the other solutions and significantly reduced E. faecalis counts (P<0.05) immediately after a root canal extraction. After 7 days, however, bacterial growth was higher with the apple cider vinegar combination than with sodium hypochlorite alone. As monotherapy, apple cider vinegar irrigation solution resulted in similar E. faecalis counts at 7 days compared to baseline.(Dornelles-Morgental 2011) Antimicrobial activity of apple cider vinegar has also been demonstrated in vitro against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Bacillus subtilis at concentrations as low as 1%.(Gopal 2017, Yagnik 2018)

When studied as a food sanitizer with samples of lettuce, an apple cider vinegar 5% solution (0.3% acetic acid) provided a maximum mean reduction in E. coli counts of 2.7 log₁₀ CFU/g of lettuce; only the white vinegar solution (35% solution with 1.9% acetic acid) provided higher mean reductions (5.4 log₁₀ CFU/g of lettuce). The vehicle control of distilled water yielded a mean reduction in E. coli of 0.9 log₁₀ CFU/g of lettuce. The mean reduction in aerobic plate counts for apple cider vinegar was 1.2 log₁₀ CFU/g of lettuce compared to 0.6 log₁₀ CFU/g of lettuce for the vehicle control, and 2.3 log₁₀ CFU/g of lettuce for white vinegar. Compared to the other sanitizer solutions, consumer ratings for likeability consistently identified white vinegar as the least liked (P<0.05) for appearance, taste, texture, and overall acceptability; the apple cider vinegar 5% solution, lemon juice 13% solution, and distilled water were similar in terms of ratings and were consistently the most likeable.(Vijayakumar 2002) Similarly, apple cider vinegar marinades for chicken breast fillets proved to be one of the most effective against indigenous total aerobes, including significant reductions in Pseudomonas species, Brocothrix thermosphacta, and Enterobacteriaceae (P<0.05).(Lytou 2017)

Antifungal activity

In vitro data

Antifungal activity of apple cider vinegar has been demonstrated in vitro against Candida albicans and Candida tropicalis.(Mota 2015, Yagnik 2018) In one study, the minimum inhibitory concentration (MIC) for apple cider vinegar tablets at which no growth of C. albicans was visible was 250 mcg/mL, equivalent to a minimum dose required to restrict growth of undiluted apple cider vinegar (5% acidity).(Yagnik 2018) Of 8 strains of C. albicans and C. tropicalis tested in another study, 2 strains showed a minimum fungicidal concentration (MFC) of 5,000 mcg/mL and 1 strain of C. tropicalis showed an MFC of 10,000 mcg/mL. At 4 times the MIC (equivalent to 10,000 mcg/mL), apple cider vinegar (4% malic acid) exhibited significantly improved inhibition of C. albicans growth on denture acrylic resin compared to the positive control nystatin (P<0.05).(Mota 2015) Aspergillus niger and Saccharomyces cerevisiae are also susceptible to apple cider vinegar at concentrations ranging from 25% to 100%.(Gopal 2017)

Clinical data

A woman with a 5-year-history of recalcitrant chronic vaginal candidiasis was treated with a 4-month regimen of an apple cider vinegar douche applied vaginally twice daily. The dose was 20 mL of apple cider vinegar mixed with 1 L of water. The patient continued to be symptom free at the 24-month follow-up.(Ozen 2017)

Anti-inflammatory activity

In vitro data

A significant dose-dependent decrease in mononuclear-derived tumor necrosis factor alpha and interleukin 6, markers of inflammation, were observed in vitro by monocytes cocultured with apple cider vinegar and either E. coli, S. aureus, or C. albicans. Phagocytic function of the monocytes was also significantly upregulated in the presence of apple cider vinegar when infected with the same microbes, as well as when compared to unstimulated monocytes. Additionally, a number of key enzymes and proteins required for cell division, glycolysis, immunogenicity, and other cell functions were not expressed. These included DNA proteins, 50S ribosomal proteins, chaperone protein Dnak, pyruvate kinase, and others.(Yagnik 2018)

Antioxidant activity

Animal and in vitro data

Antioxidant activity has been demonstrated using various assay methods that indicate the free radical scavenging activity of apple cider vinegar is very high.(Gopal 2017) Additionally, various vinegar production methods (ie, surface vs submersion) can significantly affect the total phenolic content and antioxidant activity of apple cider vinegars (P<0.05).(Budak 2011) Animal data support these results. (Halima 2018, Naziroglu 2014) In rats, administration of apple cider vinegar for 6 and/or 9 weeks significantly improved the worsening of several liver and kidney antioxidant markers resulting from a high-fat diet (P<0.05 to P<0.001 vs high-fat diet alone and standard diet groups), specifically, malondialdehye, thiol group levels, superoxide dismutase, and catalase. Improvements in glutathione peroxidase (GSH-Px) activity were significant in the liver but insignificant in the kidney.(Halima 2018) In a menopausal mouse model, significant improvements were observed in antioxidant biomarkers (ie, lipid peroxidation, GSH-Px, glutathione) as well as in antioxidant vitamin concentrations, including vitamins C and E and beta-carotene (P<0.05).(Naziroglu 2014)

Dermatitis

Clinical data

In one small non-blinded, split-arm, randomized study (N=22), the baseline composition of skin microbiomes was significantly different between atopic dermatitis patients and controls (P=0.011), with the atopic dermatitis group showing less abundance of Halomonas, Delftia, Massilia, Cutibacterium, Shewanella, Leuconostoc, and Sphingomonas, and a greater abundance of Staphylococcus genera with S. aureus being significantly greater than that of controls (5.73% vs 0.01%, respectively; P<0.001). By Week 2 of daily 10-minute soaks, per-protocol analysis of compliant participants revealed a significant reduction in S. aureus on the apple cider vinegar arm in dermatitis patients compared to a slight increase in those of controls (3.61% vs 0.05%, respectively; P<0.05); however, it was not reported if this result was adjusted for baseline differences. Additionally, a significant change (P=0.031) was observed in the skin microbiome on the arm of atopic dermatitis patients treated with water such that they became similar to that of controls. Significance, however, was lost at the intention-to-treat level.(Luu 2021) In a similar study by the same authors, the effect of apple cider vinegar 0.5% and water soaks on transepidermal water loss (TEWL) were assessed in 11 atopic dermatitis patients and 11 healthy controls. At baseline, TEWL was significantly elevated in atopic dermatitis patients compared to controls and increased significantly in both groups following the vinegar soaks (P<0.01). TEWL returned to baseline levels within 30 minutes after the soak in dermatitis patients and within 60 minutes in controls. No significant difference was found in TEWL between vinegar and water soaks between groups. Additionally, although skin pH of the 2 groups was similar at baseline, it shifted significantly towards an alkaline pH in dermatitis patients after the water soak compared to healthy controls (P<0.01). In contrast, after the vinegar soak, the pH in the dermatitis patients was comparable to that of controls.(Luu 2019)

Diabetes mellitus and glucose metabolism

Animal data

Administration of apple cider vinegar (5% acetic acid) significantly improved, and often normalized, the increases in body weight, glucose, creatinine, liver enzymes, lipid parameters, and trace minerals that resulted from feeding normal rats a high-fat diet (P<0.01 to P<0.001 vs high-fat diet alone and standard diet groups).(Halima 2018) Similarly, in a diabetic rat model, administration of apple cider vinegar significantly improved glycemic and lipid parameters. Although fasting blood glucose was not affected, reductions in glycosylated hemoglobin (HbA_1c) (by 18.8%) and triglycerides (by 28.2%) were significant compared to controls (P<0.05).(Shishehbor 2008) In contrast, rats fed a high-cholesterol diet plus apple cider vinegar exhibited significantly higher blood glucose levels compared to both normal controls and controls fed a high-cholesterol diet alone (P<0.05). Weight gain was also significantly increased in both controls and in rats fed apple cider vinegars produced using macerated apples, but not in those fed vinegars without macerated apples (P<0.05).(Budak 2011)

Clinical data

Limited clinical data are available and several factors affect the interpretation of study results, including the growing method of the apples (organic vs conventional), production method of the apple cider vinegar (natural, submersion, or surface), complexity of carbohydrates ingested with the test meal (complex vs monosaccharides), and the glycemic index of the test meal (high vs low).(Budak 2011, Mitrou 2015, Stornik 2016) A systematic review and meta-analysis of 11 clinical studies (N=240) investigating vinegar consumption in patients with and without glucose metabolism disorders, including diabetes mellitus, documented an overall statistically significant reduction in glucose area under the curve (AUC) with vinegar compared to controls (standard mean difference, −0.6; 95% CI, −1.08 to −0.11; P=0.01). Similar results were found for insulin AUC (8 studies). Study sample sizes were small, ranging from 5 to 12 participants, and heterogeneity was significant. Subgroup analysis identified the type of vinegar (apple or white) and participant condition (with or without diabetes) to influence heterogeneity. It should be noted, that the authors erroneously stated only 2 of the 11 studies (instead of the actual 4) used apple cider vinegar. Therefore, conclusions cannot be drawn from the subgroup analysis.(Shishehbor 2017)

In a small, 2-week study in insulin-dependent diabetic patients (N=10) with diabetic gastroparesis, consumption of 30 mL/day of apple cider vinegar (5% acetic acid) every morning before breakfast significantly worsened delayed gastric emptying (P<0.05). Consumption of other vinegars during the study was not restricted.(Hlebowicz 2007) In 11 newly diagnosed, treatment-naive patients with type 2 diabetes, consumption of a single 30 mL dose of apple cider vinegar (6% acetic acid) prior to a test meal significantly improved postprandial insulin secretion (P<0.046), blood glucose (P=0.028), and muscle glucose uptake (P=0.036) compared to placebo. Postprandial hypertriglyceridemia was also significantly decreased (P=0.044).(Mitrou 2015)

The effect of apple cider vinegar on glucose metabolism in nondiabetic subjects has also been explored.(Panetta 2013, Salbe 2009) Recruitment was stopped early in one study (N=5) when early results showed that enteral glucose absorption was not suppressed by 20 mL of apple cider vinegar (5% acetic acid) given 2 minutes prior to a test meal.(Salbe 2009) In a larger double-blind, randomized, placebo-controlled trial in nondiabetic subjects (N=114), no significant benefits of apple cider vinegar (30 mL/day) given for 2 months, with measurements collected at 8 and 16 weeks, were observed for HbA_1c or high-sensitivity C-reactive protein levels.(Panetta 2013)

Lipids and liver metabolism

Animal data

Improvement in lipid parameters with apple cider vinegar has been noted in normal as well as diabetic and menopausal animal models.(Budak 2011, Halima 2018, Naziroglu 2014, Shishehbor 2008) Administration of apple cider vinegar (5% acetic acid) significantly improved, and often normalized, the increases in lipid parameters that resulted from feeding normal rats a high-fat diet (P<0.01 to 0.001 vs high-fat diet alone and standard diet groups).(Halima 2018) Similarly, in a diabetic rat model and a menopausal mouse model, administration of apple cider vinegar significantly improved various lipid parameters. Reductions in triglycerides, very low–density lipoprotein cholesterol (VLDL-C), and total cholesterol were significant in ovariectomized and nonovarectomized mice receiving apple cider vinegar compared to controls (P<0.001),(Niziroglu 2014) and high-density lipoprotein cholesterol (HDL-C) was significantly increased in diabetic rats (18%; P<0.05) compared to baseline.(Shishehbor 2008) In the diabetic rat study, significant changes were also observed in normal rats, with a 47% reduction in low-density lipoprotein cholesterol (LDL-C) and a 34% increase in HDL (P<0.005 each).(Shishehbor 2008) Another study conducted in rats fed a high-cholesterol diet found that various vinegar production methods affected lipid metabolism differently. Only the vinegar prepared by the surface method without macerated apples significantly improved all lipid parameters (ie, triglycerides, VLDL, total cholesterol, HDL, LDL) (P<0.05). Apple cider vinegar produced by either the surface or submersion method led to significant improvements in liver function tests, while steatosis was improved only by vinegars produced by the submersion method without macerated apples (P<0.05). However, increases in liver enzymes (ie, AST, ALT, alkaline phosphatase [ALP]) caused by the high-cholesterol diet were decreased significantly by all production methods compared to high-cholesterol–fed control animals not receiving apple cider vinegar (P<0.05).(Budak 2011)

Clinical data

A systematic review and meta-analysis of data from 8 randomized controlled trials (N=605) demonstrated an overall significant reduction in mean total cholesterol by −6.06 mg/dL (P=0.002), with moderate heterogeneity in patients on apple cider vinegar compared to controls. No significant difference was observed overall in LDL, HDL, or triglyceride levels, although the latter trended toward significance but with very high heterogeneity. However, subgroup analyses of homogeneous data revealed notable improvements in both total cholesterol and triglycerides in patients with type 2 diabetes and for doses of 15 mL/day or less with mean differences ranging from −11.51 to −10.22 mg/dL for total cholesterol and −22.46 to −21.91 mg/dL for triglycerides with the 95% confidence interval (CI) remaining less than 0 for all comparisons. Additionally, HDL values were improved in non-diabetics +1.73 mg/dL (95% CI, 0.28 to 3.18) with no heterogeneity observed. Studies with durations of supplementation for more than 8 weeks also showed improvements in both total cholesterol and triglycerides (−7.61 mg/dL and −48.22 mg/dL, respectively); however, heterogeneity remained high. Otherwise, no significant changes were found in lipid parameters for apple cider vinegar for non-diabetics, studies administering more than 15 mL/day, or those with a duration of 8 weeks or less. Patient populations included those with diabetes (5 trials), overweight/obese (2 trials), type 2 diabetes patients with dyslipidemia (1 trial), and 1 did not report the conditions. The dosage of apple cider vinegar supplementation ranged from 15 to 770 mL/day taken for 30 to 90 days.(Hadi 2021)

In one double-blind, randomized, placebo-controlled trial of nondiabetic subjects (N=114), apple cider vinegar (30 mL/day) given for 2 months did not result in significant benefits in total cholesterol, HDL, LDL, triglycerides, or high-sensitivity C-reactive protein when measured at 8 and 16 weeks. Mean age of participants was 56.7 years, 65% were female, and approximately 30% were taking concomitant statins, fish oil, and/or aspirin for cardiac conditions.(Panetta 2013) In 11 newly diagnosed, treatment-naive patients with type 2 diabetes, consumption of a single 30 mL dose of apple cider vinegar (6% acetic acid) prior to a test meal significantly decreased postprandial hypertriglyceridemia (P=0.044 vs placebo).(Mitrou 2015)

Dosing

Dosing is not well established.

In a product sampling of 7 brands of apple cider vinegar tablets, extreme variability was found that contributed to significant misbranding. Readings for pH varied from 2.9 to 5.7, acetic acid content ranged from 1.04% to 10.57% and citric acid content ranged from 0.24% to 18.5%; malic acid content was 49.12% in one product. Dosing recommendations on the labels varied 10-fold, ranging from 300 mg/day to 3,000 mg/day. Two products each labeled as consisting of 35% acetic acid, the marker for the presence of apple cider vinegar, were found to contain only 2% and 3.2% acetic acid. Had these 2 products actually contained the amounts of acetic acid claimed on the labels, they would have resulted in poisoning (defined as acetic acid concentration of 20% or more). Additionally, 3 of the products were contaminated with yeast and mold, one of which was labeled as "yeast-free."Hill 2005 One commercially available apple cider vinegar product for weight loss was found by the FDA to be tainted with sibutramine.FDA 2018

Related/similar drugs

turmeric, Ginkgo Biloba, creatine

Pregnancy / Lactation

Vinegar is considered by the FDA to be GRAS when used as a food.(FDA 1989) Avoid amounts greater than those found in food because adverse events have been documented and safety is unproven.(Lhotta 1998)

Interactions

None documented.

Adverse Reactions

Multiple reports of chemical burns with apple cider vinegar have been documented.Hill 2005 Cases of dermal chemical burns, particularly with the use of occlusive dressings, have also been reported.Ashchyan 2018, Bunick 2012, Feldstein 2017 In an 8-year-old boy with multiple mollusca contagiosa lesions on the leg, a home remedy consisting of cotton balls soaked in apple cider vinegar (approximately 5% acetic acid) was applied and secured in place with adhesive bandages overnight for a duration of approximately 8 hours. Violet discolored macules and patches were observed the next morning, accompanied by a low-grade fever and tenderness of the leg. The area with the greatest occlusive dressing exhibited the most prominent lesion. Abrupt epidermal necrosis was observed microscopically. The chemical burns healed without intervention; however, the mollusca did not resolve and required topical drug therapy.Bunick 2012 An 11-year-old girl used this occluded apple cider vinegar-cotton ball method on a melanocytic nevus after watching a tutorial video online. When the girl’s mother noticed the bandage 3 days later, she removed it and a few weeks later sought medical treatment for her daughter when the nevus repigmented. Microscopically, scar formation was observed that extended into the mid-dermis.Ashchyan 2018 Similarly, a 14-year-old female self-treated her unwanted moles (nevi) on her nose with a "natural remedy" she found on the internet. For 3 days, she applied several drops of apple cider vinegar to the moles and occluded the area with a bandage. She experienced significant redness and irritation at the application site as well as resolution of her moles. The noninflammatory and poorly defined erosions that remained were treated medically for several weeks.Feldstein 2017 Upon oral administration, esophageal tissue injury, tenderness of the larynx, and pain during swallowing were reported by a 48-year-old woman after an apple cider vinegar tablet had been lodged in her throat for approximately 30 minutes. Subsequent product testing revealed significant misbranding of this and other apple cider vinegar tablets sampled. In particular, the acetic acid content of the particular product used was more than twice per tablet that found in apple cider vinegar (mean, 10.57%).Hill 2005

Toxicology

Data are lacking; apple cider vinegar is considered GRAS when used as food. Unexplained hypokalemia and drastically reduced bone mineral density in a 28-year-old woman revealed that consumption of long-term, high doses of apple cider vinegar was the likely cause of her osteoporosis. She presented with muscle cramps, hypokalemia, potassium wasting, high sodium excretion, and resulting stimulation of plasma renin activity. She admitted a 6-year history of 250 mL/day of apple cider vinegar diluted in water. Laboratory results suggested a complex effect of acetic acid ingestion on bone metabolism.Lhotta 1998

References

Disclaimer

This information relates to an herbal, vitamin, mineral or other dietary supplement. This product has not been reviewed by the FDA to determine whether it is safe or effective and is not subject to the quality standards and safety information collection standards that are applicable to most prescription drugs. This information should not be used to decide whether or not to take this product. This information does not endorse this product as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about this product. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this product. This information is not specific medical advice and does not replace information you receive from your health care provider. You should talk with your health care provider for complete information about the risks and benefits of using this product.

This product may adversely interact with certain health and medical conditions, other prescription and over-the-counter drugs, foods, or other dietary supplements. This product may be unsafe when used before surgery or other medical procedures. It is important to fully inform your doctor about the herbal, vitamins, mineral or any other supplements you are taking before any kind of surgery or medical procedure. With the exception of certain products that are generally recognized as safe in normal quantities, including use of folic acid and prenatal vitamins during pregnancy, this product has not been sufficiently studied to determine whether it is safe to use during pregnancy or nursing or by persons younger than 2 years of age.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Medical Disclaimer

Copyright © 2024 Wolters Kluwer Health