Does nicotine block the coronavirus? Smokers suffer less from COVID-19, but take it harder

Is it true that smokers are less likely to get COVID-19? Such suggestions from scientists appeared in the media a few weeks ago, causing quite a stir. What do we know about this today? What are the conclusions of the recent research?

1. Since the SARS-CoV-2 coronavirus outbreak, the World Health Organization has been recommending smokers to quit. He also claims that smoking raises the risk of contracting SARS-CoV-2 coronavirus
2. A few months ago, however, there was a controversial French study that found smokers contracted less frequently than previously thought, and that they pass the disease more gently
3. The link between nicotine and COVID-19 was one of the topics at the Global Forum on Nicotine, an online conference held in June this year.
4. While many studies confirm that smokers are a small group among COVID-19 sufferers, doctors warn against the oversimplified conclusion that cigarette smoking fights the SARS-CoV-2 coronavirus. As they admit, the topic requires further research

Smoking protects against the coronavirus? Controversial research

Since the start of the global coronavirus epidemic, the WHO has warned that cigarette smoking raises the risk of contracting the coronavirus. First of all, it is about the act of taking cigarettes in the mouth, which increases the risk of transmission of virus particles from the hand to the face and thus – infection with the coronavirus.

Accordingly, the WHO has even issued numerous appeals to use the pandemic time to quit smoking. It was also pointed out that smoking increases the risk of lung diseases and limits their capacity. It also increases the likelihood of heart disease and cancer, which in turn exposes you to SARS-CoV-2 coronavirus infection and the severe course of COVID-19 disease.

Meanwhile, in April, the results of the study were published leading to completely opposite conclusions. The analysis included 480 patients staying at the Salpetriere hospital in Paris due to SARS-CoV-2 coronavirus infection or treated at home. It turned out that smokers were a minority of both groups. Among hospitalized patients (median age 65), 4% were regular smokers. Among people staying at home (median age 44), 5,3% admitted smoking. sick. Meanwhile, about 40 percent of the entire French population smokes. people aged 44-53 and approx. 11,3% at the age of 65-75.

Then the neuroscientist Jean-Pierre Changeux, who analyzed the results of the research, suggested that nicotine could block the virus from entering cells in the body, thereby preventing its spread. He also found that nicotine can reduce the overreaction of the body’s immune system found in the most severe cases of COVID-19 infection.

1. Cigarettes and COVID-19. New research is controversial

At that time, researchers from China came to similar conclusions, and the Welsh began work on nicotine patches that would facilitate the treatment of COVID-19.

1. Nicotine patches and COVID-19 treatment. Researchers in Wales want to start research

COVID-19 and nicotine. What’s new in research?

Participants at Global Forum on Nicotine, an online conference held in June, looked at many issues related to the health effects of smoking (traditional and electronic), including the link between smoking and COVID-19.

Prof. Riccardo Polosa, a respiratory physician and researcher of the effects of smoking on health, collected in his speech the most recent results of research on the relationship between COVID-19 and cigarette smoking. What’s new in this case?

As he admitted in the introduction to the presentation, before he began to prepare his speech, he thought that proving that smoking has a very harmful effect on the lungs of a person suffering from COVID-19 seemed uncomplicated to him. “I was very wrong,” he admitted, adding that in the light of the available research results, the matter was more complicated.

Smoking raises your risk of catching the flu five times

The starting point was data on influenza. Researchers have established some time ago that cigarette smokers are five times more likely to develop flu, and the risk of developing flu-like diseases is as much as 34 percent. higher. What does this relationship look like in the case of COVID-19?

In the French research led by Dr. Arnaud Fontanet in January this year 661 active smokers participated. They were mainly students and people living with them – parents, siblings, partners. The team of researchers checked in which part of the observed group developed antibodies to SARS-CoV-2. It turned out that 69 people had the antibodies, 592 did not. Hence the simple conclusion – smokers are 4 times less likely to be infected with the virus.

This study, however, was heavily criticized for being a small research sample. It was also noted that many students refuse to openly admit to smoking, which may distort the result.

Smokers are less exposed to COVID-19. There were also smokers

Similar conclusions were led by a British study conducted on a sample of 3802 patients conducted this spring under the supervision of prof. Simon de Lusignan. All participants were tested for SARS-CoV-2. It turned out that 587 people (15.4%) had a positive result. When survey participants were asked about their attitude to smoking, it turned out that smokers are twice as likely to be infected with COVID-19, and former smokers – 13 percent. less compared to people who don’t smoke and have never smoked.

The Israeli research led by prof. Israel. This time it covered as many as 114 thousand. people, in this group a little over 3,5 thousand tested positive for the SARS-CoV-2 virus. Result? Active smokers are 34 percent. less exposed to coronavirus infection, and former smokers by 20 percent.

Smoking increases the risk of hospitalization and death from COVID-19

The studies quoted at the conference showed quite clearly that smoking increases the likelihood that a patient with COVID-19 will end up in the hospital and require the support of a ventilator.

The team led by prof. Jaber Algahtani analyzed the results of 8 studies that looked at patients hospitalized for COVID-19. The group consisted of almost 1,8 thousand. people. The conclusions were clear: if a smoker is already infected with the coronavirus, they are more likely to develop the disease more severely than a non-smoker, and will require breathing support.

Interestingly, Dr. Konstantinos Farsalinos, a Greek physician who undertook a meta-analysis of 30 studies conducted in China, came to a different conclusion. Based on the data at his disposal, he has failed to prove that active smokers are more likely to be hospitalized for COVID-19, but it has certainly been established that they have more severe disease, stay sick for longer, and have more COVID-related ailments. 19. As the author of the meta-analysis emphasizes, the data of patients who suffered from COVID-19 also indicate that former smokers are also exposed to a more severe course of the disease, as Prof. Polosa explains as follows: ex-smokers are often people who quit smoking suddenly and decisively. And smoking-related illnesses are at the root of their decisions.

COVID-19 and nicotine – it’s a complicated relationship

Interesting conclusions can also be drawn from the British study led by prof. Williamson. Or rather: interesting and surprisingly vague. A group of researchers led by prof. Williamson analyzed data from 17 million Britons found in medical records. 5683 deaths from COVID-19 have been closely watched. As established, the risk factors for death from this disease certainly include advanced age, male gender, high BMI and chronic diseases, mainly cancerous. This time, no clear link was made between smoking and death from COVID-19.

As Riccardo Polosa argued in the summary of his speech, the claim that smoking protects against COVID-19 is still a matter of suggestions, not 19% certain conclusions. As he argued, COVID-19 is a very young phenomenon, still intensively researched, and hundreds of articles on this subject are published every day. But growing evidence shows that smoking is not a risk factor for COVID-XNUMX. But also this topic definitely requires further and more careful research.

Nicotine blocks the virus? Scientists explain

Nicotine harms the lungs and increases the risk of disease. The coronavirus mainly affects the lungs of the sick person, causing the greatest damage to them. So how is it possible that smokers are less likely to be infected with the SARS-CoV-2 virus? This paradox was explained by Dr. Konstantinos Farsalinos, a cardiologist at the University of Patras. Indeed, smokers are less susceptible to COVID-19 and have a milder incidence of the disease. As he pointed out, this phenomenon is clearly visible in Chinese society, where almost half of men smoke, but only 6,5 percent of people with COVID-19 smoke smokers. He stipulated, however, that smoking cannot be considered something that protects against the coronavirus, as this habit is very harmful to health and has a negative impact on many organs. He also noted that nicotine can be found in various types of drugs, so if the hypothesis that it blocks the virus is confirmed, it will be used as an ingredient in pharmaceuticals treating the disease.

What is this locking mechanism? It is probably nicotine, which acts on nicotinic receptors, part of the sympathetic nervous system, and thus stimulates the body’s defenses. Scientists are considering the hypothesis that nicotine attaches to the cellular receptors (ACE2) used by the coronavirus, thus preventing it from attaching to the cell. However, as Dr. Farsalinos points out, this topic requires further and more detailed explanation.

It must therefore be strongly emphasized that the links between the COVID-19 disease and nicotine and smoking are still poorly understood, and scientists are moving among assumptions and hypotheses. However, even if it turns out that nicotine actually “blocks” the coronavirus or otherwise reduces the risk of infection, it does not mean that smoking protects us from getting sick.

Regardless of the possible relationship between nicotine and the coronavirus, it is important to remember that smoking leads to many serious diseases.

The most serious of them are:

1. cancer of the lungs, mouth, throat, larynx, esophagus, but also pancreas, stomach, kidneys, bladder, cervix and some types of leukemia. As much as 30 percent. deaths in cancer are caused by smoking,
2. cardiovascular diseases: heart attack, stroke, hypertension, atherosclerosis
3. pulmonary diseases such as chronic obstructive pulmonary disease, COPD, respiratory failure, emphysema, and respiratory infections.

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