June 2 (UPI) -- Scientific studies that last year suggested smokers are less likely to fall ill with COVID-19 have been discredited, according to a paper published Wednesday by The BMJ.
In April 2020, two French studies suggested that nicotine might be a protective defense against COVID-19, with the theory being dubbed the "nicotine hypothesis."
The stories made global headlines, leading to concern that decades of tobacco control could be undermined as people around the world scrambled to prevent getting sick with the coronavirus.
Since then, it's been disproved that smoking -- or nicotine, the addictive drug in tobacco products -- protects against COVID-19. Several studies have since shown that smoking is actually associated with an increased chance of COVID-19-related death.
Written by two journalists -- Stephane Horel of Le Monde and Ties Keyzer of The Investigative Desk -- the paper reports previously undisclosed financial links between some authors of last year's studies and the tobacco industry.
Horel and Keyzer discovered that one of the study authors, Professor Jean-Pierre Changeux, has a history of receiving funds from the Council for Tobacco Research.
The organization's purpose was to fund research that could cast doubt on the dangers of smoking and focus on the positive effects of nicotine, according to the reporters.
Documents show that Changeux's laboratory received $268,675 from the Council for Tobacco Research, though Changeux told the reporters that he didn't receive any funding linked directly or indirectly with the tobacco industry since the 1990s.
Greek researcher Konstantinos Farsalinos was the first to publish the "nicotine hypothesis" in an editorial in Toxicology Reports.
That journal's editor-in-chief, Aristisdis Tsatsakis, was a co-author of the study, as was Wallace Haynes, a member of Philip Morris International's scientific advisory board in 2013.
Another co-author was Konstantinos Poulas, head of the Molecular Biology and Immunology Laboratory at the University of Patras.
The lab received funding from Nobacco, the market leader in Greek e-cigarettes and distributor of nicotine delivery systems made by British American Tobacco, which bills itself as the largest tobacco company in the world.
Though Farsalinos and Poulas never declared the funding in their articles, Horel and Keyzer show two grants from the Foundation for a Smoke Free World -- a non-profit established by Philip Morris International in 2017 -- to "Patras Science Park."
The grants came close to $101,000 and went to NOSMOKE, a university start-up incubator headed by Poulas which markers an "organic" vaping product.
After Poulas and Farsalinos failed to disclose conflicts of interest, the European Respiratory Journal retracted a paper co-written by the two.
That paper had found that "current smoking was not associated with adverse outcome" in patients admitted to hospitals with COVID-19, claiming that smokers had a significantly lower risk of acquiring the virus.
According to Horel and Keyzer, the Foundation for a Smoke Free World set aside $1.1 million for research to "better understand the associations between smoking and/or nicotine use, and COVID-19 infection and outcome" in June 2020.
The tobacco industry's efforts during the COVID-19 pandemic, they said, are in line with previous actions aimed at undercutting public messaging about the health risks of tobacco and nicotine.
"Tobacco industry executives are increasingly pushing a narrative of nicotine as the solution to an addiction that they themselves created, with the aim of persuading policy makers to give them ample room to market their 'smoke-free' products," Horel and Keyzer wrote.
"This makes studies on the hypothetical values of nicotine most welcome indeed," they wrote.