Weight Loss Study on Apple Cider Vinegar Retracted by BMJ Nutrition, Prevention & Health
Reports suggesting young people could lose weight using simple apple cider vinegar gained traction in the media, including coverage from Süddeutsche Zeitung (SZ). However, a study published in the journal BMJ Nutrition, Prevention and Health supporting this claim has now been retracted.
From its initial publication, the six-page study faced significant criticism from experts. Concerns raised included inadequate subject facts and a lack of pre-study registration – a standard practice in many countries and a requirement for publication in numerous specialist journals. Study registration promotes transparency by informing other researchers about project methodology and goals.
Skeptics also questioned the biological plausibility of apple cider vinegar causing the reported weight loss. The study claimed participants lost an average of five to seven kilograms over twelve weeks while consuming the acidic liquid, either as a placebo or in varying doses. researchers then statistically compared the groups over different time periods.
The study’s statistical methods where a major point of contention. experts argued the methods used by the Lebanese researchers to demonstrate the robustness of their results were inappropriate. Furthermore, the statistical uncertainties were amplified by comparing groups with relatively small participant numbers.
A deeper examination commissioned by the BMJ Group, the publisher, involved a team of statistics experts who were unable to replicate the study’s results. They identified multiple errors in the statistical analysis and discovered irregularities in the original participant data, prompting a further independent review.
Ultimately, the authors agreed to the retraction and acknowledged flaws in their work. these included rounding errors and issues transferring data from statistical software to the text’s tables, as well as confusion between different versions of the manuscript.
Helen Macdonald, editor responsible for ethics and integrity at the BMJ Group, stated, “As tempting as it may be to draw readers to an apparently simple and apparently helpful means of weight loss – the results of the study are currently unreliable” and should not be disseminated further.
Martin Kohlmeier, editor-in-chief of the journal, acknowledged the decision to initially publish the study was a mistake. He explained the journal aims to prioritize high-quality evidence, often derived from clinical studies, but these are relatively scarce in the field of nutritional science, and the authors came from a scientific surroundings underrepresented in nutritional research.
