Initial conclusions about smokers being less susceptible to Covid-19 appear to be incomplete.
Tobacco is often considered to be the factor that makes respiratory diseases worse. Smoking causes damage to the alveoli, reducing the air exchange function of the lungs. Smokers are also more susceptible to flu and colds, and smoking for many years will leave permanent damage on the lungs.
However, research published in late April found that the percentage of smokers who needed Covid-19 was significantly lower than that of smokers in society. This is a study conducted by Pitié-Salpêtrière Hospital, the largest hospital in France. This result is also found in research conducted in China, Italy. Scientists think the nicotine in tobacco has led to this result.
“The data seems to be repeated in many different countries,” said Alberto Nájera at the University of Castilla-La Mancha, Spain. His team analyzed results from 18 different studies, and suggested that the nicotine in cigarettes reduced the ability of the immune system to work too hard and damage healthy organs, a phenomenon called cytokine storm.
Leading French neurologist Jean-Pierre Changeux argues that nicotine reduces the number of ACE2 receptors in the lungs. ACE2 is the receptor to which SARS-CoV-2 virus attaches to human cells.
However, these results are still subject to many question marks. The accuracy of the study may be influenced by many factors, such as in Italy the number of emergency beds may not be enough for all patients to be hospitalized. Besides, according to Professor Nick Hopkinson at the Imperial College London, who is noted “no smoking” may have just stopped smoking recently due to the epidemic, or lying.
The biggest question for scientists is to compare the rates of infected smokers and the proportion of smokers in society. Professor Eleanor Murray, from Boston University, thinks that people with Covid-19 infection and hospitalized are usually elderly, while older people have lower smoking rates.
Using the British monitoring application Covid-19 with user-input data, Hopkinson said smokers are 25% more likely to get Covid-19 symptoms than ordinary people. Although the study has not been published, Hopkinson warns once again that smokers cannot be subjective to Covid-19.
“To say smoking helps protect yourself from the disease is an interesting but inaccurate statement,” said a professor at Imperial College London.
“It’s clear that something in cigarettes protects a smoker from corona virus, but you should not come to the conclusion that you should smoke. There are many dangerous, toxic substances in cigarette smoke,” the team said. in France warns people who think this result suggests more smoking.
Since then, researchers in France have proposed testing the nicotine patch on anti-epidemic patients and frontline health workers. This is a patch that attaches to the skin, providing nicotine to the brain to produce the same effect without smoking a real cigarette. This measure is also used to assist smokers.