WHAT DOES THE RESEARCH SUGGEST?
1. Blood sugar control
In the early 2000s, Dr Johnston, who had been studying how certain diets could help manage Type 2 diabetes, came across a study from 1988 showing that acetic acid could lower blood sugar spikes in rats after they were given a starch solution.
She was intrigued and decided to test the idea in people with Type 2 diabetes and insulin resistance.
Since then, Dr Johnston and other researchers have found in small limited studies that drinking one to two tablespoons of apple cider or other types of vinegar mixed with water just before high-carbohydrate meals resulted in less drastic blood sugar spikes than meals without vinegar did.
Some studies suggest that vinegar may slow the movement of food through the digestive tract and interfere with certain enzymes that break carbohydrates down into simple sugars, resulting in lower blood sugar spikes.
But more research is needed to show that apple cider vinegar is safe and beneficial for long-term use, said Paul Gill, a researcher at Monash University in Australia.
2. Weight loss
Several small, short-term studies in adults who were classified as overweight or obese have found associations between apple cider vinegar and weight loss.
In a 2009 study of 155 adults in Japan, for instance, researchers found that those who drank two tablespoons of apple cider vinegar in water every day for three months lost about 4 pounds (1.8kg). And in one 2024 trial of 120 people aged 12 to 25 in Lebanon, researchers reported that those who took one tablespoon of apple cider vinegar with water each morning for three months lost an average of 15 pounds.
But the one study that tracked participants after they stopped taking apple cider vinegar found that, on average, they regained most of the weight within a month. And just as many studies on similar groups of people have found no links to weight loss.
Given the lack of robust data and the short time frames of the studies, Beth Czerwony, a dietitian at the Cleveland Clinic, said that she did not recommend that her patients use apple cider vinegar for weight loss.
If vinegar does indeed help people lose weight, it may do so by slowing digestion, which can make you feel fuller for longer, she said.
Animal research has also shown that acetic acid can reduce the accumulation of fat in certain tissues and may help increase the secretion of hormones that signal fullness. So while the evidence in humans is mixed, it’s plausible that vinegar could help with weight loss, Dr Damman said.
3. Gut health
Tamara Duker Freuman, a dietitian in New York City who specialises in digestive conditions, said that many of her patients remark that drinking apple cider vinegar before or after meals reduces their symptoms of acid reflux.
“I believe them,” she said. But, she noted, “hundreds of other patients with horrible reflux” have said that vinegar worsened their symptoms.
Unfortunately, there’s no good research on vinegar and digestive health, said Dr Nitin K Ahuja, a gastroenterologist at Penn Medicine.
People who use vinegar to treat reflux, which is commonly caused by stomach acid escaping into the oesophagus, say that the acid from the vinegar prompts the stomach to produce less acid, Dr Ahuja said. But, he added, there’s no supportive data, and “mechanistically, it doesn’t make sense” that adding acid to the stomach will somehow help to control it.
Studies performed in petri dishes suggest that apple cider vinegar can kill certain microbes, which could potentially create gut microbiome changes that might reduce bloating, Dr Ahuja said. But again, he added, this has not been studied in humans.
If you have frequent or severe reflux symptoms, get treatment from a doctor, he said.
