BMJ journal publishes the apple cider vinegar weight-loss trial that goes global

In March 2024, the journal BMJ Nutrition, Prevention & Health published a randomized, double-blind, placebo-controlled trial claiming that daily doses of apple cider vinegar helped overweight and obese Lebanese adolescents and young adults lose weight over 12 weeks.^[2] The paper generated a press release and a wave of international media coverage, along with a surge in apple cider vinegar product marketing.^[2]

The study gave 120 participants 5, 10, or 15 mL of apple cider vinegar, or a placebo, each day for 12 weeks.^[1] Reported weight loss reached as much as 7 kilograms over that period, a figure one reviewer described as comparable to results seen with GLP-1 drugs like Ozempic and Wegovy, even though there is no known physiological mechanism that would let vinegar produce that kind of effect.^[1] The reviewer also noted the study showed little difference in outcomes between the 5 mL and 10 mL dose groups, which raised questions about whether the results reflected a real dose-response relationship.^[1]

Within weeks of publication, researchers began raising concerns in published rapid responses and letters to the editor about the quality of the work and the size of the reported effect.^[2] BMJ Group's content integrity team then referred the study to independent statisticians, who could not replicate the results and identified multiple analytical errors, along with irregularities in the underlying data set.^[2] The reviewers concluded that the data from each participant would need further independent scrutiny, and the journal found the study also lacked prospective trial registration, a breach of its editorial policy.^[2] The authors described the errors as honest mistakes but agreed with the decision to retract the paper, which BMJ Group did roughly a year after publication.^[2]

Dr. Helen Macdonald, BMJ Group's Publication Ethics and Content Integrity Editor, said that even though it was "tempting" to promote a simple 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."^[2] Martin Kohlmeier, the journal's editor in chief, acknowledged that publishing the study without prospective trial registration was, in hindsight, "the wrong decision."^[2]

Why it matters for patients

People weighing whether to try a supplement instead of, or alongside, a prescription GLP-1 medication may have encountered claims based on this now-retracted study. The retraction means the original 9% weight-loss figure and the vinegar-to-GLP-1 comparison that circulated widely no longer have scientific backing, according to BMJ Group itself.^[2] The episode also illustrates a broader point: publication in a peer-reviewed journal is not a guarantee that findings will hold up, and single studies, especially ones with unusually dramatic results, warrant caution before they inform personal health decisions.^[1] By contrast, the sources in this story do not address the underlying evidence base for prescription GLP-1 drugs like semaglutide or tirzepatide, which is a separate body of research not covered here.

What happens next

According to BMJ Group, the retraction notice instructs journalists and other users not to reference or rely on the original findings going forward.^[2] The sources do not indicate whether the authors or others plan a new, properly registered trial to test apple cider vinegar's effects on weight, so that question remains unresolved as of the available reporting.^[2]