Smoking weakens the lungs and increases the risk of severe illness from a coronavirus infection. Nicotine also affects receptors, making it easier for the virus to enter human cells. As of March 26, 2020, the Johns Hopkins Coronavirus Resource Center reports that 487,648 people have been infected with SARS-CoV-2, with 113,769 people recovering and 21,100 deaths. While children and younger adults typically experience mild symptoms, seniors and those with pre-existing conditions are more likely to develop severe illness, accounting for 15-20% of all infections. Recent studies have shown that smokers are also at risk for severe illness from the virus, as tobacco smoke makes the lungs more susceptible to respiratory illnesses and colds. Epidemiological data from China also shows that men are more likely to experience severe illness, likely due to the fact that more than half of Chinese men smoke compared to only 3% of women.
A study published in the Chinese Medical Journal analyzed health data from three hospitals in Wuhan and found that smokers have a 13% higher risk of severe illness from COVID-19. However, a metastudy from the University of Verona published in the European Journal of Internal Medicine only found a trend towards more severe illness among smokers, without a significant correlation. According to Guiseppe Lippe, there is currently not enough evidence to definitively link smoking to severe illness from the virus. However, a study published by James Olds and Nadine Kabbani in The FEBS Journal contradicts the Italian metastudy, finding that smoking not only weakens the lungs but also increases the number of ACE2 receptors, which the virus uses to enter cells. This makes smokers more susceptible to infection and severe illness from the virus.
Olds and Kabbani’s research suggests that smoking is directly involved in the COVID-19 infection process and its progression, making smokers more likely to experience severe illness. They note that “analyses of large RNA and DNA expression databases support the notion that smoking leads to increased ACE2 expression in the lungs.” As such, smokers may be predisposed to severe illness from the virus due to the direct effects of nicotine on the virus’s docking site. It is clear that smoking is a risk factor for severe illness from COVID-19, and smokers should take extra precautions to protect themselves from the virus.
