Apple Cider Vinegar
Acetum (fermented Malus domestica)
Acetic acid tonic with modest, inconsistent metabolic signals — and big claims that outrun the data.
Evidence tier
Mixed
Research weight
Citations
19 verified / 19
Classification
Heart & Metabolic
❝
What the evidence says. Conflicting results across studies; benefit uncertain.
What is Apple Cider Vinegar?
Apple Cider Vinegar (Acetum (fermented Malus domestica)) is a heart and metabolic supplement used for modest post-meal and fasting glucose blunting: meta-analyses in adults (often type 2 diabetes) report fasting glucose reductions of roughly 8-22 mg/dl. NutriDex grades the human evidence as Mixed. Apple cider vinegar is a fermented liquid whose main bioactive is acetic acid, marketed heavily for weight loss, "detox," and blood-sugar control. The strongest human evidence is for modest glycemic effects: meta-analyses of small controlled trials report meaningful drops in fasting glucose (roughly 8-22 mg/dL) and small HbA1c reductions, mostly in people with type 2 diabetes, though heterogeneity is high and insulin sensitivity (HOMA-IR) is largely unchanged. Body-composition meta-analyses show statistically significant but small short-term reductions in weight, BMI, and waist circumference, yet the single most publicized weight-loss RCT (BMJ Nutrition, Prevention & Health, 2024) was retracted in 2025 for implausible data and flawed statistics, which substantially weakens the weight narrative. Sweeping detox, fat-melting, and disease-curing claims are not supported by credible evidence. Overall the realistic picture is a mild, adjunctive metabolic nudge — not a primary therapy — and undiluted use carries real risks of dental erosion and esophageal injury, so the evidence is best described as mixed.
Purported Benefits
✓Modest post-meal and fasting glucose blunting: meta-analyses in adults (often type 2 diabetes) report fasting glucose reductions of roughly 8-22 mg/dL
✓Small short-term reductions in HbA1c (about 0.5 percentage points), though driven by a few small trials and statistically fragile
✓Minor improvements in total cholesterol (around -6 mg/dL) in pooled small trials
✓Short-term weight/BMI/waist signals in small RCTs (4-12 weeks), but the most-cited weight-loss trial was retracted for data and statistical problems
✓Broad 'detox,' fat-burning, and disease-cure marketing claims are unsupported
Evidence by outcome
The same supplement can be well-proven for one use and unproven for another — here is the human evidence graded outcome by outcome.
| Outcome | Evidence | Effect | Studies |
|---|---|---|---|
| Fasting glucose reductionSeveral MAs report FPG drops of ~8-22 mg/dL, mainly in T2D, though heterogeneity is high. | Moderate | ↑ benefit · small | 4 |
| HbA1c reductionMAs show ~0.5-1.5% HbA1c drop but estimates are sensitive to single small studies and statistically fragile. | Mixed | ↑ benefit · small | 3 |
| Postprandial glucose/insulin bluntingAcute crossover trials and a MA consistently show attenuated post-meal glucose/insulin AUC with a meal. | Moderate | ↑ benefit · moderate | 3 |
| Total cholesterol reductionPooled small trials show ~-6 mg/dL TC; other lipids (LDL, HDL, TG) largely unchanged. | Preliminary | ↑ benefit · small | 2 |
| Weight / BMI / waist reductionSome MAs show small short-term drops, but the most-cited weight-loss RCT was retracted and other MAs find no BMI effect. | Mixed | ↔ mixed · small | 2 |
| Esophageal/dental injury and other harmsCase reports and in vitro work show enamel erosion, esophageal injury, hypokalemia and rare hepatotoxicity from concentrated use. | Preliminary | ⚠ risk | 4 |
| Detox / fat-burning / disease-cure claimsNo credible evidence; appetite-suppression signal was driven by nausea, not genuine satiety. | No Evidence | — no effect | 1 |
Dosing & Compounds
Typical Dose
Commonly studied at 10-30 mL/day (about 1-2 tablespoons) of ~5% liquid vinegar, diluted in a large glass of water and taken with or before meals; higher amounts add risk without proven benefit.
Active Compounds
Safety & Cautions
Always dilute in water and avoid drinking it straight — undiluted vinegar (pH ~3) causes dental enamel erosion (documented severe decay in a teen using it daily) and can cause esophageal/throat irritation, ulceration, or corrosive injury, including from ACV tablets that lodge in the esophagus. Use a straw and rinse the mouth afterward; avoid brushing immediately after. May cause nausea, indigestion, and delayed gastric emptying (caution in gastroparesis). It can lower potassium and may compound the effects of glucose-lowering drugs (insulin, sulfonylureas), diuretics, digoxin, and potassium-affecting medications — diabetics should monitor blood sugar and consult a clinician before regular use. People with low potassium, chronic kidney disease, severe acid reflux/GERD, gastroparesis, or eating disorders should avoid or use only under medical supervision; pregnant and breastfeeding individuals should treat it as food, not a supplement, and unpasteurized products carry a small infection risk. It is not a substitute for prescribed metabolic or weight therapies. Educational only — always check with your doctor or pharmacist before combining Apple Cider Vinegar with any medicine.
Key Studies ★ 19 studies
Meta-analysis
Hadi 2025
✓ Full text
GRADE-assessed dose-response meta-analysis (7 controlled trials, 463 participants) found apple cider vinegar reduced fasting blood sugar by 21.93 mg/dL (95% CI -29.19 to -14.67, moderate certainty) and HbA1c by 1.53% (95% CI -2.65 to -0.41), with a linear dose-response above 10 mL/day in type 2 diabetes.
Meta-analysis
Shishehbor 2017 (meta-analysis of clinical trials)
✓ PubMed
Vinegar taken with a meal significantly attenuated postprandial glucose AUC (SMD -0.60, 95% CI -1.08 to -0.11) and insulin AUC (SMD -1.30, 95% CI -1.98 to -0.62) versus control, supporting an acute glycemic-blunting effect.
Systematic review / dose-response meta-analysis
7 controlled trials, 463 adults with type 2 diabetes
✓ PubMed
GRADE-assessed dose-response meta-analysis found ACV significantly lowered fasting blood glucose (WMD -21.9 mg/dL) and HbA1c (WMD -1.53%), but did not improve HOMA-IR and slightly raised insulin.
Systematic review / meta-analysis of RCTs
9 trials, 686 participants
✓ PubMed
Meta-analysis of RCTs reported small but significant reductions in total cholesterol (-6.06 mg/dL), fasting glucose (-7.97 mg/dL) and HbA1c (-0.50), with HbA1c results sensitive to a single study.
Systematic review / meta-analysis of RCTs
10 RCTs, 789 adults (overweight/obese and/or T2D)
✓ PubMed
Meta-analysis found daily ACV significantly reduced body weight (SMD -0.39), BMI (SMD -0.65) and waist circumference (SMD -0.34), with no significant change in waist-to-hip ratio, over 4-12 week interventions.
systematic review and meta-analysis
25 clinical trials (33 arms), 1320 adults
✓ Full text
Systematic review/meta-analysis found ACV significantly lowered fasting blood glucose (-21.2 mg/dL), HbA1c (-0.91) and total cholesterol (-6.72 mg/dL), but showed no significant effect on BMI, HOMA-IR, insulin, triglycerides, LDL-C or HDL-C.
meta-analysis
GRADE-assessed dose-response meta-analysis of RCTs (hypertensive/at-risk adults)
✓ PubMed
Each 30 mL/day increment in vinegar intake was associated with significant reductions in systolic blood pressure (-3.25 mmHg, 95% CI -5.54 to -0.96) and diastolic blood pressure (-3.33 mmHg, 95% CI -4.16 to -2.49), though the certainty of evidence was rated LOW.
RCT
Najafi 2026
✓ PubMed
Adjunctive effects of apple cider vinegar on metabolic syndrome and insulin resistance in polycystic ovary syndrome patients receiving metformin: a randomized clinical trial
RCT
Baker 2026
✓ PubMed
Apple cider vinegar for prevention of urinary lithiasis (APUL): a randomized crossover trial
Retracted randomized controlled trial
120 Lebanese adolescents/young adults (retracted RCT)
✓ Full text
A widely cited 12-week RCT claiming 5-15 mL/day ACV reduced weight and BMI vs placebo was RETRACTED in 2025 for implausible statistical values, unreliable raw data, and lack of trial registration.
RCT
Abou-Khalil 2024 (RETRACTED)
✓ Full text
This double-blind placebo-controlled RCT in 120 Lebanese adolescents/young adults reported large reductions in weight, BMI, and fasting glucose with 5-15 mL/day ACV, but was RETRACTED in September 2025 for data-integrity and reproducibility failures and should not be cited as positive evidence.
randomized crossover trial
12 healthy volunteers, randomized crossover
✓ PubMed
Vinegar added to a white-wheat-bread meal produced a dose-dependent reduction in postprandial blood glucose (at 30 and 45 min) and insulin (at 15 and 30 min) and increased satiety ratings, with the highest acetic acid dose (28 mmol) giving the largest effect.
crossover pilot trial
10 type 1 diabetes patients with gastroparesis, blinded crossover
✓ PubMed
30 mL apple cider vinegar further slowed already-delayed gastric emptying (median gastric emptying rate fell from 27% to 17%, p<0.05), which the authors warned may worsen glycemic control in patients with diabetic gastroparesis.
randomized controlled trial
Randomized crossover feeding study, 16 healthy adults
✓ PubMed
Vinegar ingestion suppressed appetite and food intake but the effect was largely driven by poor tolerability and nausea rather than genuine satiety, leading the authors to conclude that promoting vinegar as an appetite suppressant is inappropriate.
RCT
Johnston 2004 (Diabetes Care RCT/crossover)
✓ PubMed
Landmark trial: vinegar ingested before a high-carbohydrate meal improved postprandial insulin sensitivity and attenuated glucose and insulin responses, with the largest effect in insulin-resistant subjects; modest response in established type 2 diabetes.
Case report / product analysis
Case report
✓ PubMed
An apple cider vinegar tablet lodged in the throat caused esophageal injury, and product testing showed highly variable, sometimes corrosive acid content, illustrating real mucosal-injury risk from concentrated ACV.
case report
Case report (28-year-old woman)
✓ PubMed
A woman who drank ~250 mL (8 oz) of cider vinegar diluted in water daily for 6 years developed hypokalemia, elevated renin (hyperreninemia) and osteoporosis, attributed to chronic acid loading leaching minerals from bone.
case report
Case report (60-year-old man)
✓ Full text
A man taking ~30 mL apple cider vinegar three times weekly for 4 years developed severe hepatocellular liver injury (ALT 1792 U/L, AST 1168 U/L, bilirubin 17 mg/dL) with stage-2 fibrosis on biopsy that resolved after stopping ACV, implicating ACV as a cause of drug-induced hepatotoxicity.
in vitro erosion study
In vitro, 5 vinegar varieties on human enamel
✓ PubMed
Vinegars (pH 2.7-3.1) caused measurable enamel demineralization, with the most erosive variety producing ~20% mineral loss at 45 microm depth after 8 hours, indicating a real dental-erosion risk from regular acidic vinegar exposure.