Scientific papers suggesting that smokers are less likely to fall ill with covid-19 are being discredited as links to the tobacco industry are revealed.
By Ties Keyzer and Stéphane Horel
In the early days of the pandemic, media outlets around the world reported that smokers seemed to be under-represented among patients seriously ill with covid-19 in China and France. The headlines asked, does nicotine protect against covid-19?
The origins of this hype were two preprints published in quick succession in April 2020 by a team at the Pitié-Salpêtrière Hospital in Paris, led by Zahir Amoura. The first found that only 5% of patients with covid-19 were smokers.1 Their second study hypothesised that nicotine might act on ACE2, the virus’s entry receptor. “Nicotine substitutes may provide an effective treatment for acute infections such as covid-19,” the authors argued.2
The stories made headlines worldwide. They were also picked up by libertarian media outlets such as the British online magazine Spiked. “Smoke fags, save lives,” encouraged Christopher Snowdon, director of lifestyle economics at the Institute of Economic Affairs, an industry sponsored think tank supported by the tobacco industry.
The World Health Organization worried that decades of tobacco control could be undermined. “Smoking is responsible for eight million deaths each year from cardiovascular and lung diseases, cancer, diabetes, and hypertension,” WHO stated in response to the French studies, explaining that “available evidence suggests that smoking is associated with increased disease severity and mortality among hospitalized covid-19 patients.”
It has since been roundly disproved that smoking protects against covid-19. Among other studies,345 the OpenSafely dataset, based on the primary care records of 17.3 million adults in the UK, found that smoking, when adjusted for age and sex, was associated with a 14% increased chance of covid-19 related death.6
The BMJ can today also report on undisclosed financial links between certain scientific authors and the tobacco and e-cigarette industry in a number of covid research papers. This follows the high profile retraction of one such paper in the European Respiratory Journal last month,7 after two authors failed to disclose conflicts of interest.
Continue reading in the BMJ.
2 June 2021