At the beginning of the Covid-19 pandemic (April 2020), two French studies (shared as preprints before formal peer review) suggested that nicotine might have a protective effect against Covid-19.

The theory was dubbed the “nicotine hypothesis” and made headlines worldwide, leading to concern that decades of tobacco control could be undermined.

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It has since been disproved that smoking protects against Covid-19, with multiple studies showing that smoking is in fact associated with an increased chance of Covid-19 related deaths (when adjusted for age and sex).

Now, an investigation by BMJ has discredited the papers, as certain authors are reportedly linked to the tobacco and e-cigarette industry in a number of Covid research papers.

The authors of the studies had undisclosed financial links to the tobacco industry

Journalists Stéphane Horel and Ties Keyzer have reported on these undisclosed financial links, pointing out that one of the study authors, Professor Jean-Pierre Changeux, has a history of receiving funding from the Council for Tobacco Research (CTR).

This is concerning, considering the purpose of the CTR was to fund research that would cast doubt on the dangers of smoking and focus on the positive effects of nicotine.

From 1995 to 1998, tobacco industry documents show that Changeux’s laboratory received $220,000 (£155,000; €180,000) from the Council for Tobacco Research. However, Changeux told the BMJ he has not received any funding linked “directly or indirectly with the tobacco industry” since the 1990s.

The first author to publish the “nicotine hypothesis” in a journal was Greek researcher, Konstantinos Farsalinos. His article was published formally in an editorial in Toxicology Reports, the editor of which is Aristidis Tsatsakis, who was featured as a co-author.

A Wallace also featured as a co-author, who is a member of Philip Morris International’s scientific advisory board in 2013, who has served as a paid consultant to the tobacco company.

Another co-author is Konstantinos Poulas, head of the Molecular Biology and Immunology Laboratory at the University of Patras, where Farsalinos is affiliated.

It has now been revealed that the laboratory received funding from Nobacco, the market leader in Greek e-cigarettes and the exclusive distributor of British American Tobacco’s nicotine delivery systems since 2018.

The European Respiratory Journal have retracted a paper written by the authors 

Horel and Keyzer have shown that two grants were attributed in 2018 by the Foundation for a Smoke Free World - a non-profit established by Philip Morris International in 2017 - to “Patras Science Park.”

The grants, which tax documents revealed amounted to nearly €83,000, went to NOSMOKE, a university start-up incubator headed by Poulas, which markets an “organic” vaping product.

Neither Farsalinos nor Poulas has ever declared this funding in their published scientific articles. Now, the European Respiratory Journal retracted a paper co-written by the pair (among others).

The retracted article had found that “current smoking was not associated with adverse outcome” in patients admitted to hospital with Covid-19, and it claimed that smokers had a significantly lower risk of acquiring the virus.

Horel and Keyzer say the foundation has invested heavily in the “nicotine hypothesis”, and in June 2020 it set aside €900,000 for research “to better understand the associations between smoking and/or nicotine use, and covid-19 infection and outcome.”