A highly addictive habit. If 99% of smokers could enjoy one cigarette a day with morning coffee or afternoon drink then smoking would never become a big issue. Most of them end up with 1-2 packs a day damaging theirs and their family health.
I remember hearing somewhere that even one cigarette will paralyze your alveoli for 24 hours. This would, I assume, make you more susceptible to contagions since foreign particles will make contact with your blood for longer period. If this were true, then even one cig a day would be a real problem, especially in Covid-times.
No evidence of that there. Only that "current smokers were 80% more likely to be admitted to hospital and significantly more likely to die from Covid-19 if they became infected" -- did they control for other factors, that tend to go along with smoking, like obesity (and socioeconomic status)? Where's the link to their paper?
All the genetic stuff too is super suspicious, I would be _shocked_ if "genetic predisposition to smoking" had no impact whatsoever on any other variable that could cause more severe COVID.
> We conducted a cross-sectional, observational study on the 1769 sailors of the same navy aircraft carrier at sea exposed at the same time to SARS-CoV2 to investigate the link between tobacco consumption and Covid-19.
> Current smoking status was associated with a lower risk of developing Covid-19 but cannot be considered as efficient protection against infection. The mechanism of the lower susceptibility of smokers to SARS-CoV-2 requires further research.
> A total of 7162 patients were included, with 482 being smokers. The POR was 0.24 (95%CI 0.19–0.30). Unlike the original study, the association between smoking and disease severity was not statistically significant using random-effects meta-analysis (OR 1.40, 95%CI 0.98–1.98). In agreement with the original study, no statistically significant association was found between smoking and mortality (OR 1.86, 95%CI 0.88–3.94).
> An unusually low prevalence of smoking, approximately 1/4th the expected prevalence, was observed among hospitalized COVID-19 patients. Any association between smoking and COVID-19 severity cannot be generalized but should refer to the seemingly low proportion of smokers who develop severe COVID-19 that requires hospitalization. Smokers should be advised to quit due to long-term health risks, but pharmaceutical nicotine or other nicotinic cholinergic agonists should be explored as potential therapeutic options, based on a recently presented hypothesis.
Last thing I've read: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4403024/ seems to leave it at the very least as an open question. It's not a matter of 'a study' passing or failing. It's not controversial to assert that many parasites are immunomodulating , and there are no shortage of cases where it at least appears on the surface that they may ease some autoimmune maladies. My personal anecdote is from a friend whose allergies were strongly suppressed after getting worms.
I don't really have skin in this game, though, and mostly posted to make the humorous juxtaposition of literally getting worms as a preferable and less harmful alternative to smoking for autoimmune relief.