Is nicotine an advantage or a disadvantage in case of contagion with the coronavirus?

Smokers are actually considered a risk group for the new SARS-CoV-2 coronavirus. According to a study published in the Chinese Medical Journal, the development of the disease in those who smoke is usually more severe and prolonged than in those who do not smoke, and most of it would be fatal.

However, French researchers led by neurobiologists at the Pasteur Jean-Pierre Changeaux Institute believe that nicotine patches could help prevent infections with the dangerous virus. In their hypothesis, published on the science portal Qeios, they came to a conclusion that contradicts the Chinese study: Apparently there are only a small number of smokers among COVID-19 patients.

The most important results of the study were: 350 of the 500 patients with COVID-19 had been treated in a hospital and 150 had a slight progression of the disease. Only five percent were smokers, Zahir Amoura, head of the study and professor of internal medicine, told AFP news agency. In turn, this would represent 80 percent fewer smokers among COVID-19 patients than in the general population of the same age and sex.

A similar result had already been achieved in a previous study led by Giuseppe Lippi of Verona, Italy, published in the European Journal of Internal Medicine. They also concluded that smokers are not more exposed to COVID-19 than others.

Nicotine as protection?

The French study assumes that nicotine may protect against the coronavirus. It is based on the hypothesis "that nicotine binds to cellular receptors (ACE2) used by the virus, thus preventing it from binding," Changeux explains.

According to the researchers' conclusion, the virus cannot enter the cell and cannot spread in the body. The La Pitié Salpêtrière hospital in Paris will investigate this result in more detail.

What role do ACE2 receptors really play?

However, there is no consensus among researchers that ACE2 receptors have a blocking effect. Neurologists James L. Olds and Nadine Kabbani of Fairfax, Virginia, had already published a study in The FEBS Journal on March 18. In this they assume that nicotine tends to stimulate cell receptors.

In doing so, they assume that viruses have an even better chance of penetrating cells. Something that could explain the especially severe development of the disease in smokers.

Smoking is not a solution

Only deeper investigations will be able to demonstrate whether French or American researchers are right. However, almost all doctors agree that smoking tobacco carries an additional risk of contracting COVID-19. And they advise to stop smoking as soon as possible, because the coronavirus mainly attacks the lungs, which smokers have already damaged previously.

Unlike taking pure nicotine, for example, through nicotine patches like those used by people who want to quit smoking, smoking additionally loads the body with many harmful substances, including those that promote cancer.

Many studies and tests with nicotine patches of different doses are still needed. If the French study turns out to be correct, nicotine might even protect people who are exposed to patients with coronavirus and therefore exposed to an increased risk of infection.

However, taking nicotine is not safe, because it is a toxic substance. When smoking a cigarette, the smoker absorbs one to three milligrams of nicotine. And a cigarette contains approximately 12 milligrams of nicotine.

In the past, scientists studied the possibility that nicotine may also have positive effects on the body. For example, the effect of nicotine-like substances in the treatment of Parkinson's and Alzheimer's was examined. For people with serious illnesses like dementia, the nicotine test was favorable. But the result of this study, so far, does not mean that everyone has to start smoking.