Does Apple Cider Vinegar Help Digestion?

If you type "does apple cider vinegar make you" into Google, the first thing it suggests is "poop." Further down the same list are "gassy," "constipated," and "bloated," which means that plenty of people are asking whether the shot they took for their stomach is causing the problem it was supposed to fix. Most of them are drinking it for digestion in the first place: "does apple cider vinegar help with bloating," "with constipation," and "with digestion" all make the top ten of what Google fills in.

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No trial has shown that apple cider vinegar helps digestion in healthy people. What researchers have measured is that vinegar makes your stomach hold onto a meal longer, and one trial, paid for by a vinegar company, found that a vinegar drink added bowel movements for adults who were mildly constipated.

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It slows your stomach down

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In a 1998 study at Lund University in Sweden, 10 healthy adults ate white bread, once with vinegar added and once without. With the vinegar, their blood sugar and insulin rose less after the meal. To see why, the researchers had people take paracetamol (the drug in Tylenol) with the bread as a marker, and it reached their blood more slowly on the vinegar day. The authors concluded that "the mechanism is probably a delayed gastric emptying rate," meaning that food left the stomach for the small intestine later than usual.

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That slowdown is why vinegar gets studied for blood sugar, and it's also what makes it an odd pick for digestion. A 2007 pilot study in Malmö, Sweden, gave 10 people with type 1 diabetes and gastroparesis (a condition where the stomach empties too slowly) 30 mL of apple cider vinegar in water, about two tablespoons, before breakfast every day for two weeks. Their stomachs were already slow, and vinegar slowed them "even further." These were people averaging 68 years old who'd had diabetes for about 41 years, so the result tells you which direction vinegar pushes a stomach and nothing directly about a teenager's.

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Carol Johnston, a nutrition researcher at Arizona State who has studied vinegar for most of her career (her own 2026 review says that this "may be perceived as a potential conflict of perspective"), reads the Malmö result as a warning. For those patients, she writes, slower emptying "may accentuate feelings of nausea, belly bloating and pain, fullness, and acid reflux." The American College of Gastroenterology (the ACG, the main professional group of gut doctors in the US) treats a slow stomach as something to reverse. Its guideline for gastroparesis recommends "a small particle diet" (food broken down into small pieces) to make the stomach empty faster.

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For a healthy stomach, nobody has shown that holding one meal a little longer does any harm.

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Does it make you poop?

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In a 2026 trial in Japan, 44 healthy adults who went to the bathroom only three to five times a week drank either a vinegar drink or a placebo at breakfast for four weeks, without knowing which one they had. At the end, the vinegar group was going more often. The rest of what the researchers measured "showed no consistent differences across all time points," and the variety of bacteria in people's stool didn't change. Mizkan, the company behind Nakano rice vinegar, paid for the study, and three of its eight authors work there. The paper calls the drink a vinegar beverage and never says the word apple.

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So "does apple cider vinegar make you poop" gets a maybe, resting on one small trial funded by a vinegar company, in adults who were already a little backed up. If you're dealing with that yourself, our constipation article goes through what has better evidence behind it.

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The ACG's guidelines for IBS (irritable bowel syndrome), for indigestion, and for gastroparesis don't contain the word "vinegar" anywhere. If bloating is what sent you looking, this guide to bloating covers the causes that do have evidence.

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What about heartburn?

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Cleveland Clinic dietitian Beth Czerwony says that "there's no real science to back up the claims about ACV's anti-heartburn power," and Harvard Health's Dr. Marcelo Campos writes that "there is no research published in medical journals that addresses using raw apple cider vinegar to treat heartburn." The one study anyone has run is an unpublished 2016 master's thesis at Arizona State with seven usable subjects, and its main result found no effect. The ACG's reflux guideline lists "acidic foods such as citrus and tomatoes" among things that can make reflux worse, and Cleveland Clinic points out that apple cider vinegar "is, itself, highly acidic." Our heartburn article explains why the theory behind the vinegar advice, that heartburn comes from too little stomach acid, doesn't hold up.

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Most of the research is about weight

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A 2025 meta-analysis (a study that pools the results of many trials) of 10 trials and 789 adults measured body weight, BMI, and waist size, and reported lower numbers on all three with daily apple cider vinegar. None of those three is digestion. One of those 10 was a Lebanese trial of 120 people aged 12 to 25, which got a lot of attention in 2024 for big weight loss. The journal, BMJ Nutrition, Prevention & Health, retracted it "because the authors' analyses could not be replicated and multiple errors were identified," and the notice says the data showed "patterns inconsistent with random allocation." BMJ's ethics editor, Dr. Helen Macdonald, said that "journalists and others should no longer reference or use the results." The meta-analysis came out four days before that retraction, with the trial still counted, even though its own rules said it left out trials involving adolescents.

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What it does to teeth and throats

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Dutch dentists reported a 15-year-old girl whose tooth enamel had worn away, and after checking the other possible causes, they traced it to "daily consumption of a glass of apple cider vinegar." They noted that women in North African families have used it to lose weight for generations. The American Dental Association says that acidic foods and drinks "wear away the enamel that protects your teeth."

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Pediatricians in Seoul reported a 15-year-old boy who'd been drinking 100 to 150 mL (about half a cup) of a pomegranate vinegar drink "with no sufficient dilution" every morning for a month. He came in vomiting blood, and a scope found ulcers along his entire esophagus (the tube from your throat to your stomach). He recovered within about a week of treatment, and his doctors wrote that "vinegar beverages should be considered as corrosive agents." His drink was 2.7% acid. ConsumerLab (a company that lab-tests supplements) puts ordinary vinegar at about 5%.

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A 2005 paper in the Journal of the American Dietetic Association was titled "Esophageal injury by apple cider vinegar tablets," and when the authors tested eight tablet brands, they found that "doubt remains as to whether apple cider vinegar was in fact an ingredient." The Seoul doctors, citing that paper, note that "the acid concentration of most commercial vinegar tablets was 3 to 10-fold that of house vinegar."

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ConsumerLab found that a tablespoon of liquid vinegar carries about 700 to 900 mg of acetic acid (the acid that vinegar studies are about), and the pills, gummies, and liquids it tested ran anywhere from 27.1 mg to 882.2 mg per serving. The ad industry's own watchdog, the National Advertising Division, found that Goli's gummies implied the health benefits of apple cider vinegar, "a message that was not supported" because those benefits are "tied to a much higher amount of acetic acid" than the gummies' suggested dose provides. Goli appealed, and the appeal panel ruled only that the product name itself "is not literally false."

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If you drink it anyway

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Water it down. Johnston writes that vinegar "should not be consumed undiluted," and Cleveland Clinic suggests "adding a tablespoon to a mug of warm water." The American Dental Association says to "wait an hour before you brush after eating acidic foods to give your saliva a chance to naturally wash away acids and re-harden your enamel," and for acidic drinks like soda, it suggests using a straw.

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Cleveland Clinic also notes that apple cider vinegar "interacts with some medications, including insulin and diuretics (water pills)." If you have diabetes or have been told that your stomach empties slowly, talk to your doctor before you start taking it daily, since the only people in whom vinegar measurably made a stomach problem worse were the Malmö patients. And if bloating or constipation keeps coming back, it's worth seeing a doctor about the cause.

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