Vinegar and blood sugar: one narrow effect

Vinegar has trial evidence behind one narrow effect and very little behind the rest of what it gets sold for. About two teaspoons, 10 g, taken with a starchy meal lowered the blood sugar rise over the next two hours by 20 percent in small crossover trials of 9 or 10 people each. The effect shrank when vinegar came 5 hours before the meal and vanished when the carbohydrate was simple sugar. Taken daily for about eight weeks, a meta-analysis of 16 trials in 910 adults found fasting glucose fell by 35.7 mg/dL in people with type 2 diabetes, though the range was wide, from 7.7 to 63.8 mg/dL, and triglycerides, a blood fat, fell by 20.5 mg/dL in people with overweight. HbA1c, the three-month blood sugar average your doctor tracks, did not change, and neither did body mass index. The same review is frank about its weak spots. Five of the 16 trials never stated the dose, none measured acetate in the blood, and most carried unclear or high risk of bias. What those trials gave people was acetic acid, the sour part of vinegar, at 750 to 3,600 mg a day. None of our evidence tested apple cider vinegar gummies or slimming supplements. The only card we hold on such a supplement is a single case of acute pancreatitis in an 84-year-old woman, where the authors call the link only possible. Weight loss is the claim with the least behind it. The EU refused it, a 2024 trial that reported it was retracted in 2025, and in a breakfast study vinegar cut appetite mainly by making people feel sick.

The numbers, per 100 g

How much is actually in it

• FDA guidance expects every vinegar variety, including cider, wine, malt and distilled, to contain 4 g of acetic acid per 100 mL. — vinegar sold in the United States Evidence E source
  Minimum strength 4 g acetic acid per 100 mL at 20 C
• Vinegar carries little of any mineral, and the numbers swing by type: potassium runs from 2 to 112 mg per 100 g across four USDA vinegar records, and cider vinegar has 73 mg in USDA against 34 mg for vinegar in the UK tables. — USDA SR Legacy vinegar records (cider, distilled, red wine, balsamic) and CoFID 2021 (n = 4 USDA records, 1 CoFID record) Evidence E source
  Potassium 2 to 112 mg per 100 g (USDA), cider 73 mg (FDC 173469), CoFID 17-339 34 mg

What a real portion looks like

• A tablespoon of vinegar weighs 15 g and a single-serve packet 9 g, so the 10 g dose that lowered blood glucose in meal trials is about two teaspoons. — US household measures, FNDDS 2021-2023 (n = FNDDS fdc_id 2709351) Evidence E source
  1 tablespoon 15 g, 1 packet 9 g, quantity not specified 30 g

What your body absorbs

• About 10 g of vinegar (two teaspoons) taken with a starchy meal lowered the 2-hour blood glucose response by 20% against placebo, the effect was smaller when vinegar was taken 5 hours before the meal, and it vanished when the carbohydrate was simple sugar. — adults with and without type 2 diabetes, four crossover trials of 9 to 10 people each (n = 9 to 10 per trial) Evidence B source
  Postprandial glucose AUC -20% vs placebo with complex-carbohydrate meals. No effect with monosaccharides or with sodium acetate
• Acetate from 750 mg of acetic acid reached the blood within 15 minutes when taken as a 100 mL vinegar drink and within 30 minutes from capsules, in 30 healthy adults, and both forms were back to baseline by 90 to 120 minutes. — healthy adults after an overnight fast (n = 30) Evidence B source
  Serum acetate peak at 15 min (drink) vs 30 min (capsule). Capsule AUC about 80% of drink AUC, difference not significant

What cooking and storage change

• Boiled potatoes stored cold for 24 hours and dressed with a vinaigrette of 28 g white vinegar had a glycaemic index 43% lower and an insulin index 31% lower than freshly boiled potatoes in 13 healthy adults. — healthy adults, Lund University, breakfast meals with 50 g available carbohydrate (n = 13) Evidence B source
  GI 96 vs 168, insulin index 128 vs 185 (cold potatoes with vinegar vs freshly boiled). Cold storage alone lowered the insulin index by 28%

What it does to your health

• Healthy overweight adults taking 4 tablespoons of vinegar (2.95 g acetic acid) a day for 4 weeks cut PHQ-9 depression scores by 42% against 18% with a vinegar pill holding almost no acetic acid (0.025 g), while the CES-D score did not differ between groups. — healthy overweight adults (n = not stated in abstract) Evidence B source
  PHQ-9 -42% vs -18% (p = 0.036). CES-D -26% vs -5%, not significant
• Adding vinegar with 18 to 28 mmol acetic acid to white bread lowered blood glucose at 30 minutes in 12 healthy adults, yet the glycaemic index calculated over 120 minutes did not differ from bread alone. — healthy volunteers, 50 g available carbohydrate as white wheat bread (n = 12) Evidence B source
  Dose-response at 30 min for glucose and insulin. GI lower at 90 min with the highest dose only, no difference at 120 min
• Observational data from 1,024 Japanese adults associate eating vinegar-based dishes with more frequent bowel movements (odds ratios 1.38 to 1.49), with no link to straining or time on the toilet. — community-dwelling adults, Tarumizu cohort health check 2019 (n = 1024) Evidence C source
  OR 1.38 (sour main dishes), 1.49 (sunomono), 1.41 (salad with sour dressing) for higher defecation frequency

Safety, limits and interactions

• Observational data link vinegar to dental erosion in children: among 309 matched UK children, those with erosion ate fruit and vinegar more often than caries-active or caries-free controls. — children, UK, age and gender matched (n = 309) Evidence C source
  Higher frequency of fruit and vinegar intake in the erosion group (no effect size in abstract)
• Observational data from 329 Greek 8-year-olds tie a preference for lemon or vinegar to erosive wear of permanent teeth (p = 0.041), alongside soft drinks. — Greek schoolchildren aged 8, the only age group the finding covers (263 14-year-olds were also studied) (n = 329) Evidence C source
  Preference for lemon/vinegar associated with wear prevalence and BEWE score in permanent teeth of 8-year-olds
• A single case report describes severe metabolic acidosis in an obese patient combining a ketogenic diet, large amounts of vinegar and metformin, with acute kidney injury as an aggravating factor. — one adult patient with obesity (n = 1) Evidence D source
  Hospitalisation for severe acidosis
• A 2024 case report links acute pancreatitis in an 84-year-old woman to a newly started weight-loss supplement containing apple cider vinegar. — one 84-year-old woman (n = 1) Evidence D source
  Acute pancreatitis, causal link only possible
• Black vinegar raised peak blood levels of the antifungal itraconazole in 10 healthy adults whose stomach acid had been lowered with a proton pump inhibitor. — healthy adults pretreated with a proton pump inhibitor, plus one patient with aspergillosis (n = 10) Evidence D source
  Itraconazole and OH-itraconazole Cmax significantly higher with black vinegar

What people believe that the data does not support

• In 16 healthy adults, vinegar with breakfast reduced appetite and food intake mainly because it caused nausea, and tasting vinegar without swallowing it (14 adults) had no effect, so the authors judged its promotion as an appetite suppressant inappropriate. — healthy, young, normal-weight adults (n = 16 and 14) Evidence B source
  Appetite and energy intake lower with vinegar, together with significantly higher nausea ratings. Sham feeding: no effect
• The EU register lists the claim that apple cider vinegar helps control and normalise body weight as non-authorised, and no vinegar claim in the register is authorised. — EU health claim applications (n = 6 vinegar claims, 0 authorised) Evidence E source
  Weight-control claim non-authorised
• The EU register lists purifying claims for apple cider vinegar, including that it eliminates harmful toxins and has body purifying properties, as non-authorised. — EU health claim applications (n = 1 claim) Evidence E source
  Purifying and toxin claim non-authorised

Who this works differently for

• Across 16 trials in 910 adults taking 750 to 3,600 mg acetic acid a day for about 8 weeks, fasting glucose fell by 35.7 mg/dL in people with type 2 diabetes, though the range was wide, from 7.7 to 63.8 mg/dL. Triglycerides fell by 20.5 mg/dL in people with overweight, with no significant change in HbA1c, HDL or BMI. — adults in randomised trials lasting at least 1 week, with type 2 diabetes, overweight or obesity (n = 910 (16 trials)) Evidence A source
  FBG MD -35.73 mg/dL (95% CI -63.79 to -7.67) in type 2 diabetes. TAG MD -20.51 mg/dL (-32.98 to -8.04) in overweight or obesity, MD -7.37 mg/dL in type 2 diabetes. No effect on HbA1c, HDL, BMI
• In 16 people with type 2 diabetes, adding vinegar to a high-glycaemic meal of mashed potatoes cut the 2-hour glucose area from 311 to 181 mmol min/L, while the same addition to a low-glycaemic wholegrain meal changed nothing. — patients with type 2 diabetes, two matched groups of 8 (n = 16) Evidence B source
  Glucose iAUC 181 vs 311 mmol min/L with a high-GI meal (P=0.04). 229 vs 238 with a low-GI meal (P=0.56)

What is still unknown

• The evidence behind daily vinegar is thin: of 16 trials pooled in 2021, 5 did not state the acetic acid dose, none measured blood acetate, only 1 controlled for other acetic-acid-rich foods, and most carried unclear or high risk of bias. — the 16 randomised trials of dietary acetic acid in adults up to October 2020 (n = 16 trials) Evidence A source
  5 of 16 without dose, 0 of 16 measured blood acetate, 1 of 16 controlled background intake
• In adults who had never had kidney stones, drinking apple cider vinegar daily for 1 week did not change 24-hour urinary citrate, pH or volume in a crossover trial where only 6 people took it. Lemon water raised urinary citrate by 168 mg per 24 hours. — adults who had never formed kidney stones (n = 20 (6 on apple cider vinegar)) Evidence B source
  ACV: no significant change. Lemon water +167.7 mg/24 h citrate (95% CI 16 to 319). Coconut water +273.8 mg/24 h
• The 2024 trial that reported weight loss from daily apple cider vinegar in Lebanese adolescents and young adults was retracted by its journal in 2025 because its analyses could not be replicated. — the retracted trial in adolescents and young adults with overweight and obesity Evidence E source
  All results of the trial withdrawn

The bottom line

If you want to use vinegar for blood sugar, put it on a starchy meal. That is where it worked. In 13 healthy adults, boiled potatoes kept cold for a day and dressed with a vinaigrette had a glycaemic index 43 percent lower than freshly boiled potatoes, and the cold storage by itself did part of that work. In 16 people with type 2 diabetes, vinegar cut the glucose rise after mashed potatoes and did nothing at all to a wholegrain meal that was already slow. With white bread in 12 healthy adults it lowered glucose at 30 minutes, yet over the full two hours the glycaemic index came out the same as bread alone. So the effect is real, early and small. It does not replace a diabetes medicine, and the pooled trials never moved HbA1c. Two newer findings are still open questions. In healthy overweight adults, four tablespoons a day for four weeks lowered one depression score by 42 percent against 18 percent on a vinegar pill with almost no acetic acid, while a second depression score in the same people showed no difference, so the result depends on which ruler you use. Japanese adults who ate more vinegar dishes had more frequent bowel movements, but that is an observational link and nobody fed them the vinegar to test it. Apple cider vinegar is also said to help against kidney stones. In a one-week trial in adults who had never had kidney stones, it did not change urine citrate, while lemon water raised it by 168 mg a day. Only six people drank the vinegar, so this is a weak no rather than a final one. Be careful with vinegar in three situations. It is acid, and two studies of children, 309 in the UK and 329 Greek eight-year-olds, tie frequent fruit and vinegar intake, or a preference for lemon or vinegar, to worn tooth enamel. Those are observational links with no size in one of them, but acid on teeth is the most consistent warning we have. One person on metformin who combined a ketogenic diet with large amounts of vinegar ended up in hospital with severe acidosis, so if you take diabetes medicine and plan to drink vinegar daily, raise it with the person who prescribes it. Black vinegar also raised blood levels of the antifungal drug itraconazole in 10 adults on stomach acid blockers, which matters only if you take that drug. Beyond that we have gaps. We found no agreed upper amount, nothing on pregnancy, and no trial that looked at vinegar drinking in children. That silence means nobody has measured it, and it is not a clean bill of health. As a food, vinegar adds almost nothing beyond sourness. Potassium runs from 2 to 112 mg per 100 g across the four types in our table, and in the US any vinegar is expected to hold at least 4 g of acetic acid per 100 mL.

Sources

1. vng-b3-20 · agency guidance
   Each of the varieties of vinegar listed below should contain 4 grams of acetic acid per 100 mL
   FDA Compliance Policy Guide Sec. 525.825, Vinegar, Definitions, revised 1995 · checked 2026-09-23
2. vng-b3-21 · reference dataset
   USDA SR Legacy Vinegar, cider (FDC 173469) Potassium 73 mg per 100 g, range across 4 USDA vinegar records 2-112 mg · CoFID 2021 17-339 Vinegar Potassium 34 mg per 100 g
   USDA FoodData Central SR Legacy and CoFID 2021, Public Health England / OGL v3.0 · checked 2026-09-23
3. vng-b3-22 · reference dataset
   FNDDS 2709351 Vinegar — 1 tablespoon 15 g · 1 packet 9 g · Quantity not specified 30 g
   USDA FNDDS 2021-2023 · checked 2026-09-23
4. vng-b3-03 · randomised crossover trial
   effectively reduced PPG, and this effect was most pronounced when vinegar was ingested during mealtime as compared to 5 h before the meal. Vinegar did not alter PPG when ingested with monosaccharides ... In these situations, vinegar attenuated PPG by 20% compared to placebo.
   Ann Nutr Metab, 2010 · checked 2026-09-23
5. vng-b3-06 · randomised crossover trial
   In the vinegar drink group, serum acetate concentration increased immediately after intake, peaked at 15 min and returned to baseline at 90 min. That in the vinegar capsule group rose slowly, peaked at 30 min and returned to baseline at 120 min.
   J Nutr Sci Vitaminol (Tokyo), 2010 · checked 2026-09-23
6. vng-b3-05 · randomised crossover meal test
   GI and II of cold potatoes added with vinegar (GI/II=96/128) were significantly reduced by 43 and 31%, respectively, compared with GI/II of freshly boiled potatoes (168/185).
   Eur J Clin Nutr, 2005 · checked 2026-09-23
7. vng-b3-09 · randomised controlled trial
   in healthy overweight adults ingesting 2.95 g acetic acid (4 tablespoons vinegar) vs. 0.025 g acetic acid (one vinegar pill) daily ... At week 4, mean CES-D scores fell 26% and 5% for VIN and CON participants respectively, a non-significant difference between groups, and mean PHQ-9 scores fell 42% and 18% for VIN and CON participants (p = 0.036).
   Nutrients, 2024 · checked 2026-09-23
8. vng-b3-10 · randomised controlled trial
   The low and intermediate levels of vinegar also lowered the 30 min glucose and the 15 min insulin responses significantly compared with the reference meal. When GI and II (insulinaemic indices) were calculated using the 90 min incremental area, a significant lowering was found for the highest amount of acetic acid, although the corresponding values calculated at 120 min did not differ from the reference meal.
   Eur J Clin Nutr, 2005 · checked 2026-09-23
9. vng-b3-16 · cross-sectional
   individuals with a habit of eating vinegar-based dishes, such as "sour main dishes" (odds ratio [OR]: 1.38; p = 0.039), "sunomono" (OR: 1.49; p = 0.035), and "salad with sour dressing" (OR: 1.41; p = 0.049), had a significantly higher defecation frequency. No significant association was observed between the habit of eating vinegar-based dishes and the time required for defecation or straining during defecation.
   Sci Rep, 2025 · checked 2026-09-23
10. vng-b3-11 · case-control
    Fruit and vinegar consumption was higher in the erosion group, as was the taking of vitamin C supplements.
    ASDC J Dent Child, 2000 · checked 2026-09-23
11. vng-b3-12 · cross-sectional
    In their permanent teeth, soft drink consumption (p < 0.0001) and preference for lemon/vinegar (p = 0.041) significantly affected wear prevalence and BEWE scores
    Caries Res, 2016 · checked 2026-09-23
12. vng-b3-13 · case report
    We present a case of severe acidosis secondary to ketogenic diet and acetic acid (vinegar) ingestion. The use of dietary acetic acid is usually well tolerated; however, in this case, the large quantities and presence of acute renal injury may have worsened the acidosis.
    Case Rep Nephrol, 2020 · checked 2026-09-23
13. vng-b3-14 · case report
    We discuss an 84-year-old woman with acute pancreatitis possibly linked to a recently introduced weight loss supplement containing apple cider vinegar.
    ACG Case Rep J, 2024 · checked 2026-09-23
14. vng-b3-15 · case report
    we administered ITCZ capsules with and without black vinegar to 10 healthy adults after preparation with a proton pump inhibitor to decrease gastric acidity, and measured blood concentrations of ITCZ and the metabolite OH-ITCZ. Administration of this combination increased ITCZ and OH-ITCZ Cmax significantly.
    Kansenshogaku Zasshi, 2009 · checked 2026-09-23
15. vng-b3-07 · randomised crossover trial
    ingestion of vinegar significantly reduced quantitative and subjective measures of appetite, which were accompanied by significantly higher nausea ratings, with unpalatable treatment having the greatest effect ... On this basis the promotion of vinegar as a natural appetite suppressant does not seem appropriate.
    Int J Obes (Lond), 2014 · checked 2026-09-23
16. vng-b3-17 · regulatory decision
    POL-HC-6626 Apple cider vinegar Helps control and normalize body weight. Non-authorised
    EU Register on nutrition and health claims, claim POL-HC-6626, snapshot 2026-09-21 · checked 2026-09-23
17. vng-b3-18 · regulatory decision
    POL-HC-6624 Apple cider vinegar 1. Apple cider vinegar has body purifying and healing properties 2. Splits and eliminates harmful toxins/end-products 3. Optimizes and balances the body function 4. Restores the inner balance of the body Non-authorised
    EU Register on nutrition and health claims, claim POL-HC-6624, snapshot 2026-09-21 · checked 2026-09-23
18. vng-b3-01 · meta-analysis of RCTs
    Sixteen studies were included, involving 910 participants who consumed between 750 and 3600 mg acetic acid daily in interventions lasting an average of 8 weeks. ... acetic acid supplementation significantly reduced FBG levels (MD = -35.73 mg/dL [-63.79, -7.67], P = .01) in subjects with type 2 diabetes compared with placebo and low-dose comparators. No other changes were seen for other metabolic or anthropometric outcomes assessed.
    J Acad Nutr Diet, 2021 · checked 2026-09-23
19. vng-b3-04 · randomised controlled trial
    In group A, the incremental area under the curve of glucose (GiAUC(120)) was lower after the addition of vinegar (181+/-78 mmol min/l vs 311+/-124 mmol min/l, P=0.04). ... the addition of vinegar reduces postprandial glycaemia in patients with T2D only when it is added to a high-GI meal.
    Eur J Clin Nutr, 2010 · checked 2026-09-23
20. vng-b3-02 · meta-analysis of RCTs
    Five of the 16 studies did not specify the dose of acetic acid delivered, and no studies measured blood acetate concentrations. Only one study controlled for background acetic acid-rich food consumption during intervention periods. Most studies had an unclear or high risk of bias.
    J Acad Nutr Diet, 2021 · checked 2026-09-23
21. vng-b3-08 · randomised crossover trial
    Six consumed ACV, six coconut water, eight lemon water, and six diet orange soda. ACV did not significantly change 24-h urinary parameters. Coconut water (+ 273.8 mg/24 h, 95% CI 67.9-480 mg/24 h) and lemon water (+ 167.7 mg/24 h, 95% CI 16-319 mg/24 h) were associated with increased urinary citrate.
    Int Urol Nephrol, 2026 · checked 2026-09-23
22. vng-b3-19 · retraction notice
    The paper is being retracted because the authors' analyses could not be replicated and multiple errors were identified.
    BMJ Nutrition, Prevention & Health, retraction notice, 2025 · checked 2026-09-23