Apple cider vinegar weight-loss study retracted over flawed science

BMJ has retracted a viral apple cider vinegar weight-loss study after experts flagged major data flaws and errors. Failed replication attempts and irregularities make its findings unreliable, underscoring the need for transparency in nutrition.

A study that once promised easy weight loss with apple cider vinegar has now been officially withdrawn, after major flaws in its data and methods came to light.

Back in March 2024, a small clinical trial published in BMJ Nutrition, Prevention & Health claimed that daily doses of apple cider vinegar could help people lose weight. The study was quickly picked up by international media, fueling viral headlines and a surge in public interest in vinegar-based “weight-loss hacks.”

Why the Retraction Happened

The excitement didn’t last. Concerns about the study soon surfaced, especially around its statistical analysis, the reliability of its raw data, and incomplete reporting of methods. Importantly, the trial was not registered in advance, breaking BMJ’s editorial policies.

To investigate further, BMJ’s content integrity team referred the paper to independent statistical experts. When they tried to replicate the results, they couldn’t. Multiple analytical errors were identified, along with irregularities in the dataset.

Authors Admit Mistakes

The researchers behind the study acknowledged the errors, calling them “honest mistakes,” and agreed to retract the paper.

Dr. Helen Macdonald, BMJ’s Publication Ethics and Content Integrity Editor, emphasized the importance of transparency, saying:

“At present the results of the study are unreliable, and journalists and others should no longer reference or use the results in future reporting.”

Lessons for Nutrition Science

The journal’s editors admitted that publishing the study in the first place was a misstep. Professor Martin Kohlmeier, Editor-in-Chief of BMJ Nutrition, Prevention & Health, noted that while the journal seeks to amplify underrepresented voices in nutrition research, the lack of trial registration should have been a red flag.

He added that clinical trials in nutrition are rare and difficult to conduct but stressed that high standards must still be maintained to avoid misleading the public.

The Bigger Picture

The retraction serves as a reminder that even widely reported studies must be critically assessed. Quick fixes and “miracle” dietary solutions often crumble under scrutiny. For now, apple cider vinegar may still have culinary uses, but its role as a weight-loss aid is unproven.