Why this study claiming apple cider vinegar is great for weight loss was suddenly retracted

A viral study claiming a daily shot of apple cider vinegar can help people lose weight was, it appears, as far-fetched as it sounded.

This week, the study was retracted by a major medical publishing group after “multiple analytic errors” were identified, and more than a year after it was originally published, along with a press release.

Apple cider vinegar is a fave of celebrities like Katy Perry, who told Women’s Health she starts each day with a glass of water and apple cider vinegar, or tea and apple cider vinegar. Perry and other vinegar aficionados like Jennifer Aniston claim it boosts immunity and regulates gut health, among other purported health benefits.

In March 2024, researchers reported that, over a period of three months, young apple cider vinegar drinkers also lost significant amounts of weight, including a notable reduction in waist and hip measurements.

However, flags were raised soon after it was published. According to Retraction Watch, if the findings had proved true, apple cider vinegar would be more effective than Ozempic. Here’s what you need to know about the retracted study and apple cider vinegar.

Apple cider vinegar is made from crushed fermented apples, yeast and sugar.

“Its claim to fame is acetic acid, which forms during the fermentation process and is thought to have a variety of health benefits,” according to the Cleveland Clinic.

It also contains amino acids and flavonoids, which have anti-oxidant properties, and has been used for centuries as a remedy for various ailments, from infections to heartburn.

Some studies suggest it may help lower cholesterol and blood sugars.

An earlier systematic review — a study of studies to synthesize the research evidence — suggested acetic acid may, in the short-term, also reduce appetite “and subsequent food intake in humans.”

The Lebanese researchers tested apple cider vinegar’s potential “anti-obesity effect” in 120 young people, average age 17, who were overweight or obese, with a body mass index between 27 and 34. The researchers said that, by slowing gastric emptying, apple cider vinegar “might promote satiety and reduced appetite.”

They randomly assigned participants to drink apple cider vinegar once per day in either five, 10, or 15 ml doses, for 12 weeks, first thing in the morning and before food.

People in a fourth group — the placebo group — were given fake vinegar.

Compared with the placebo group, the vinegar drinkers lost, on average, six to eight kilograms over the study period. Those in the highest doses saw the largest decreases in weight, the researchers reported.

The consumption of apple cider vinegar was also linked to drops in blood glucose, triglycerides (a type of blood fat) and cholesterol. No apparent adverse or harmful effects were reported.

“It is important to note that the diet diary and physical activity did not differ among the three treatment groups and the placebo throughout the whole study,” suggesting that the decrease in weight and improvement in “biochemical parameters” was caused by apple cider vinegar intake, they wrote.

The study was published in the journal BMJ Nutrition, Prevention & Health.

Plenty of reasons, according to the BMJ Group, including concerns raised in rapid response letters and critiques by other experts about the “implausible statistical values,” the reliability of the raw data, “multiple analytical errors,” the lack of trial registration and the inability of outside experts to replicate the results.

“Tempting though it is to alert readers to an ostensibly simple and apparently helpful weight loss aid, at present the results of the study are unreliable, and journalists and others should no longer reference or use the results of this study in any future reporting,” Dr. Helen Macdonald, publication ethics and content integrity editor at BMJ Group, said in a statement.

“While we deal with allegations as swiftly as possible, it’s very important that due process is followed,” she said, adding that investigations “are often complex” and can take several months.

According to the BMJ Group, the authors said the identified errors were “honest mistakes, but that they agree with the decision to retract the study.”

The yanked paper “leaves a residue of misinformation that will not completely disappear,” according to ConscienHealth, which noted that a new review published this week that suggested a daily intake of apple cider vinegar might help people with excess body weight manage their weight “relied in part on the invalid data from the now retracted study.”

That study pooled results from randomized controlled trials published up to March 2025 and lasting at least four weeks that evaluated the effects of apple cider vinegar on body weight, BMI and waist circumference.

Out of 2,961 reports screened, only 10 trials comprising a total of 789 adults 18 and older met criteria for inclusion. The number of people per study ranged from 26 to 126.

The pooled results showed a daily 30 ml dose of apple cider vinegar over four weeks resulted in an average weight loss of 7.4 kilograms, suggesting it “may be a promising and accessible adjunctive strategy for short-term weight management in adults with excess body weight or metabolic complications,” the authors reported.

However, another systematic review and meta-analysis that involved 25 trials conducted up to 2022 comprising 1,320 participants found that while apple cider vinegar lowered total cholesterol and other risk factors for heart disease and diabetes, it had no significant effect on BMI.

While generally safe in small amounts, too much apple cider vinegar can cause nausea, bloating, gastro irritation and heartburn, as well as loss of tooth enamel.

National Post

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