“Many people were surprised, therefore, when researchers reported late in April that only 5% of 482 covid-19 patients who came to the Pitié-Salpêtrière hospital in Paris between February 28th and April 9th were daily smokers,” says an article in the Economist.
This meta-analysis on smoking and COVID-19 “sets the record straight”, according to Farsalinos. “Very few smokers have higher odds for adverse outcome,” he says, adding that the “protective effects of nicotine need to be studied”.
“Current smoking, former smoking, and adverse outcome among hospitalized COVID-19 patients: a systematic review and meta-analysis” has been published and displays the evidence for all to see – not how anti-vape campaigners would wish it to be.
Farsalinos, together with Barbouni, Poulas, Polosa, Caponnetto, and Niaura identified 18 from a total of 1398 relevant studies. The association between current, compared with non-current and former, smoking and adverse outcome was examined.
“Hospitalized current smokers had higher odds compared with non-current smokers but lower odds compared with former smokers for an adverse outcome. Smoking cannot be considered a protective measure for COVID-19. However, the hypothesis that nicotine may have a protective effect in COVID-19 that is partially masked by smoking-related toxicity and by the abrupt cessation of nicotine intake when smokers are hospitalized should be explored in laboratory studies and clinical trials using pharmaceutical nicotine products.”
Ricardo Polosa commented: “As with any viral infection, the symptoms and severity of symptoms generally depend on two key factors: the viral load and the immuno-competence of the host. For SARS-CoV-2, about 80% of the infected population seems to deal adequately with the viral infection developing only asymptomatic forms or slight symptomatic disease.
“However, there are 20% of individuals that will go on to develop a severely symptomatic form of the disease, either because they have been exposed to a highly elevated viral load, as in hospital staff, or due to depressed immunologic defences, as in elderly people with comorbidities.
“Smokers do not seem to be more susceptible to infection or disease caused by the coronavirus, and, quite surprisingly, the scientific evidence suggests the opposite, that smoking may be protective against COVID-19. This is still an area of active research and the Jury is still out.”
He suggests that the first alternative to smoking is to not smoke, “but stopping smoking is not easy, and many smokers like cigarettes. For smokers who cannot or do not want to quit, there is an alternative, which is switching to much less harmful, combustion-free products such as e-cigarettes or heated tobacco products.”
- “Current smoking, former smoking and adverse outcome among hospitalized COVID-19 patients: a systematic review and meta-analysis” by Farsalinos, Polosa et al. – [link]