Journals Flag Concerns in Three Dozen Papers by Nutrition Researchers

Retraction Watch Staff

November 12, 2020

Journals have flagged more than three dozen articles by a team of authors in Iran for concern over the integrity of their data. The moves have come in the 15 months since data sleuths raised questions about the data in more than 170 papers from the group.

Among the most recent moves, a nutrition journal has issued expressions of concern for three of the team's articles. The papers, which appeared in the Journal of the American College of Nutrition (JACN), from Taylor & Francis, were published in 2015 and 2017. The senior author on all three articles was Zatollah Asemi (also listed as Zatolla Asemi), a specialist in metabolic diseases who sits on the faculty of Kashan University of Medical Sciences.

Concerns about the findings from Asemi's shop have been circulating for several years. The group came under scrutiny on PubPeer three years ago, when a commenter noticed apparent irregularities in the data in a 2017 paper in the Journal of Clinical Lipidology. That paper has yet to be flagged in any way.

But what should have been the biggest blow was struck in July 2019, when the data sleuths notified journals that they'd discovered suspicious findings in 172 papers on clinical trials from the Iranian researchers. Last June, the sleuths, working with Alison Avenell, of the University of Aberdeen, in Scotland — who helped illuminate the bogus data from the prolific fraudster Yoshihiro Sato, who sits at No. 3 on the Retraction Watch leaderboard, with 96 — published a report in Anaesthesia which mentions their deep dive into the Irani group's results, which appeared between 2012 and 2018 in 65 journals belonging to 20 publishers.

In an appendix to that report, whose authors included Alan Gaby, who first flagged the issues to Grey and colleagues, the sleuths say their concerns include:

  1. Evidence that random allocation of participants could not have produced the treatment groups reported in this large body of trials.

  2. Evidence that the distribution of numbers of participants withdrawing from the trials is implausible.

  3. Evidence that reporting of the size of participant populations is frequently contradictory.

  4. Astonishingly and implausibly prolific research activity.

  5. Unethical conduct of trials.

  6. Very frequent discrepancies between trial registration documents and journal publications for study conduct, study location, participant age and participant number.

  7. Evidence of compromised integrity in numerous individual publications.

According to Andrew Grey, a bone scientist at the University of Auckland and a co-author of Avenell's, the National Ethics Committee of Iran investigated, but he has seen the conclusion of the inquiry. The committee:

left it to the Ethics Committee of the author's institution, Kashan University of Medical Sciences, to 'respond to all journal questions and ambiguities in detail'. That KUMS committee includes several members who are co-authors on the affected papers.

Grey added that, shortly after his group notified the journals of their investigation:

we became aware that Dr Asemi and colleagues were extensively revising the trial registration documents at the Iranian Clinical Trial Registry, and frequently the changes being made were to align those documents with the publications. The changes very frequently altered fundamental trial characteristics, such as primary outcome, randomization procedure, participant eligibility criteria, sample size, study location(s), and dates of ethics approval. We notified these concerns to affected journals and publishers in late 2019. None acted on this information (and none of the current Expressions of Concern mention it), making one wonder whether journals and publishers respect clinical trial registration.

Grey's group published a paper on the saga in Accountability in Research in August.

Meanwhile, the reaction from the journals has disappointed Grey and his colleagues. Fourteen papers, including the three in the JACN, now carry expressions of concern, Grey said. And Springer Nature pinned editor's notes on 23 of the articles it had published — a milquetoast stance that the publisher says it uses because it doesn't require a response from the authors, according to their policy, but also means that the note is not indexed in PubMed or elsewhere.

Here's a representative statement, from the European Journal of Clinical Nutrition, for a 2012 article titled "Effect of daily consumption of probiotic yoghurt on insulin resistance in pregnant women: a randomized controlled trial":

The Co-Editors-in-Chief are currently investigating this article as concerns have been raised about integrity of the clinical trial reported here. There is also an ongoing investigation by the Iranian National Committee for Ethics in Biomedical Researches. Further editorial action will be taken as appropriate once the investigation into the concerns is complete and all parties have been given an opportunity to respond in full.

Last month, the American Journal of Clinical Nutrition flagged a 2013 paper by Asemi and colleagues titled "Effects of vitamin D supplementation on glucose metabolism, lipid concentrations, inflammation, and oxidative stress in gestational diabetes: a double-blind randomized controlled clinical trial":

With this notice, AJCN states its awareness of concerns regarding the validity of participant data in this study, the timing of ethical approval and trial registration, the statistical analysis, and citation to another article reporting on this trial. These concerns are under investigation. This statement will be updated at the conclusion of the investigation.

That paper, by the way, seems to be a twin of this 2014 article in the Avicenna Journal of Nursing and Midwifery Care.

The expression of concern for the JACN reads:

We, the Publisher and Editor of Journal of the American College of Nutrition, are issuing an Expression of Concern for the following articles:


Fereashteh Bahmani, Maryam Tajadadi-Ebrahimi, Fariba Kolahdooz, Marjan Mazouchi, Haleh Hadaegh, Atefeh-Sadat Jamal, Navid Mazroii, Shiva Asemi & Zatolla Asemi (2016) The Consumption of Synbiotic Bread Containing Lactobacillus sporogenes and Inulin Affects Nitric Oxide and Malondialdehyde in Patients with Type 2 Diabetes Mellitus: Randomized, Double-Blind, Placebo-Controlled Trial, Journal of the American College of Nutrition, 35:6, 506–513, DOI: 10.1080/07315724.2015.1032443

Omid Reza Tamtaji, Ebrahim Kouchaki, Mahmoud Salami, Esmat Aghadavod, Elmira Akbari, Maryam Tajabadi-Ebrahimi & Zatollah Asemi (2017) The Effects of Probiotic Supplementation on Gene Expression Related to Inflammation, Insulin, and Lipids in Patients With Multiple Sclerosis: A Randomized, Double-Blind, Placebo-Controlled Trial, Journal of the American College of Nutrition, 36:8, 660–665, DOI: 10.1080/07315724.2017.1347074

Tahereh Gholnari, Esmat Aghadavod, Alireza Soleimani, Gholam Ali Hamidi, Nasrin Sharifi & Zatollah Asemi (2018) The Effects of Coenzyme Q10 Supplementation on Glucose Metabolism, Lipid Profiles, Inflammation, and Oxidative Stress in Patients With Diabetic Nephropathy: A Randomized, Double-Blind, Placebo-Controlled Trial, Journal of the American College of Nutrition, 37:3, 188–193, DOI: 10.1080/07315724.2017.1386140

Since publication of these articles, serious concerns have been raised about the integrity of the reported methods, results and analysis. We have contacted the authors and the ethics committee of the institutions to respond to the concerns raised and they are cooperating with the investigation. However, the authors have not been able to provide the original data associated with this article, and so as we continue to work through the issues raised, we advise readers to interpret the information presented in the article with due caution. We will provide an update following the conclusion of our investigation. The authors have been notified about this Expression of Concern.

We emailed Asemi, who told us:

As I have previously stated, SPSS datasets of whole 172 papers are available. Also, integrity of papers related to your journal has been confirmed by Iran National Bioethics Committee and ethics committee of Kashan University of Medical Sciences.

Asemi also sent us some of his data, which we have made available here.

Rachel Kopec, the editor of the JACN, told us:

Because the investigation of the articles in question is ongoing, I can not share more detail at this time. However, once the investigation is completed to our satisfaction, we will be making a decision on how to proceed with these articles.
Such delays are problematic, Grey said, who noted that many journals never bothered to respond to him and his colleagues:
Some replied, some did not – failure to respond to such enquiries is, sadly, quite common. An overarching theme among respondents was that they were waiting to hear the outcome of the institutional investigation, a position adopted because of the COPE guidelines.


We have recently suggested that publication integrity can and should be considered separately from the investigation of researcher conduct, which is the primary focus of institutional investigations (Nature 2020). One might therefore question whether the COPE guidelines are fit for purpose.

The upshot of the current process has been a very long, and incomplete, process to notify the most important stakeholders in publication integrity, the readers of the journals and the patients they treat or whose clinical care is affected, of the concerns about this large body of work. An allied serious concern is that these trials have been incorporated into many systematic reviews, including a large number published by Dr Asemi's group. They are often the only evidence (or the major evidence) for treatment benefits in these reviews. Delays in resolving the matter and in notifying the public worsen the adverse impact of the research.


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