Nicotine Rumors: Does Smoking Protect From Corona?
What leads to over seven million deaths a year, and the trend is rising? Smoking cigarettes.
This makes cigarette smoking the leading cause of avoidable death and illness. For example, it kills with lung cancer and lung disease COPD.
Smoking as a risk
Smoking is also a potentially unfavourable factor in Coro-infection, such as recognized institutions such as the World Health Organization (WHO) and the Robert Koch Institute. It seems plausible that smokers are more at risk: that is, Covid-19 tends to be more difficult or even fatal. Finally, the immune system and lungs are pre-stressed.
Two reviews from China also report that smoking could be a risk factor for an unfavourable Covid 19 course. This corresponds to the current state of knowledge, which is currently changing rapidly.
As a contrast to this, a French research group published a bold statement in April 2020. They do not present any solid scientific evidence – but they point out that nicotine from tobacco may have a protective effect against a corona infection. According to their hypothesis, nicotine may block certain docking points in the body and possibly inhibit pathological processes.
According to the team of authors of the purely theoretical work, this would make it more difficult for coronaviruses to spread in smokers. Accordingly, nicotine could possibly protect against severe courses that require ventilation in the intensive care unit or even lead to death.
Where are the smokers?
The research group named a single observation study from a Parisian hospital as the basis for their idea. The quality of this hospital study leaves much to doubt about the informative value.
For the study, a scientific snapshot was taken of 482 patients with Covid-19. Smoking habits were also recorded: A total of 22 infected people said they smoke every day.
According to the research team, the proportion of smokers was surprisingly low at around 5 per cent. After all, around 25 per cent of the general population in France would smoke, the team said. The research team concludes that smokers are supposed to be “absent” among the corona infected people: nicotine may be able to protect against severe Covid 19 course.
Defects, gaps, exaggeration
Unfortunately, the publication has serious shortcomings and significant gaps in reporting. Therefore, we cannot draw any conclusions and certainly not read out any possible protective effects of nicotine.
For example, patients from intensive care units were not considered in the study. So maybe the worst affected were missing? It cannot be answered in this way whether smokers frequently develop a severe form of Covid-19. No deaths are reported.
In addition, the total population cannot be inferred from the data from a single hospital. There are also ambiguities in the selection of patients and in the determination of smoking status.
From our point of view, it is also not conducive to trust in the hypothesis of perhaps protective nicotine: First author Jean-Pierre Changeux has received payments from the tobacco industry in the past. He is a neurobiologist and researches, among other things, the effect of nicotine on the nervous system.
Furthermore, we lack self-critical classification by the study team and a comparison with the current state of the science. The conclusions seem too euphoric to us. There is talk, for example, of the hope that this knowledge may save lives in the future.
Follow a press release
It is therefore not surprising that the international news agency Agence France-Presse took up the study.
At least in France, media reports about the supposed protective effect triggered hamster purchases of nicotine replacement products (plasters, etc.).
Better information soon
We assume that better information on protective factors and risk factors will be available shortly. Because of the published knowledge about corona infection grows every day.
Even if information about the still nebulous nicotine protection effect should condense – it is highly unlikely that such an effect can outweigh the many clearly proven negative effects of cigarette smoking.
More about Corona
You can find more information about the coronavirus and the Covid-19.
Smoking in Austria
In Austria, an estimated 14,000 people die each year from the consequences of tobacco use. The country is known by some as the “ashtray of Europe” due to the high proportion of smokers.
Even people who smoke little have an increased risk of many diseases, such as osteoporosis, impotence, stomach ulcers and pregnancy complications. Passive smoking is also a trigger for illnesses and deaths. So there is no safe level for safe smoking.
Nicotine is a natural compound that occurs, for example, in the Nicotiana tabacum tobacco plant. Nicotine quickly becomes highly addictive and is responsible for the high addiction potential when smoking.
People mainly ingest nicotine through cigarette smoke. Other sources of nicotine include chewing tobacco, e-cigarettes and various smoking cessation products such as plasters, sprays and chewing gum.
Nicotine binds to special docking sites called nicotinic acetylcholine receptors. These occur, for example, in the nervous system. It triggers nicotine for the well-known relaxing or stimulating effects.
The studies in detail
The work cited as a source of ideas for the nicotine protection hypothesis is a cross-sectional study. It delivers snapshots from the Paris University Hospital “Hôpital Universitaire Pitié Salpêtrière”.
For this purpose, a research team recorded some properties of 482 Covid 19 patients: age, gender and smoking status. These people were cared for in the hospital between February and April 2020. They were either in a normal ward. Or they just visited the outpatient clinic and then recovered at home. Because the study lacks data from patients in intensive care units, we suspect that the people included were probably only slightly to moderately affected.
The scientists then made a comparison: were there as many smokers among the outpatient and inpatient care people as in the general population?
The research team reports that the proportion of smokers among the corona infected was exceptionally low. Only 22 out of 482 people stated that they smoke daily, i.e. 4.4% (outpatient clinic) and 5.3% (ward). In contrast, according to a telephone survey in 2018, over 25% of the general population smoked.
The researchers interpret this big difference as follows: It could be that nicotine from cigarette smoke could have a protective effect and maybe prevent a severe course of the infection.
We are not alone with our strong doubts about this statement or cannot understand the derivation: This study delivers an astonishing result at first glance. But it is in no way suitable to suggest a protective effect of nicotine and smoking. It is unclear how the difference came about.
Here are some criticisms:
- The number of subjects was small so that statistical random findings can easily have occurred. Only 22 “confessing” smokers were in the sample.
- It is uncertain whether the patients have given truthful information about their smoking habits. Perhaps they flickered when asked about their current cigarette consumption. An underestimation is quite possible. One indication of this is the unusually high proportion of former smokers.
- Nothing precise can be found in the publication about the survey method and its trustworthiness.
- It is not explained in detail why the data of the worst affected Covid 19 patients were not included in the study: all those who were in the intensive care unit. For the included infected, the information “outpatient clinic” or “ward” is the only indirect indications of the severity and course. There is no information about deaths.
- It is unclear whether the comparisons between infected people and the general population really made sense. It is likely that those affected by Covid were not a representative image of the French general population.
- In the discussion section, it is mentioned that an above-average number of Covid-19 sufferers were health workers. This can have led to distortions. This professional group does not reflect the general population. Health workers are smokeless on average. At the same time, these people have a higher risk of infection due to their job.
- Both publications were published on the online platform “Qeios” without peer review. This means peer review and criticism. The peer review, while not a perfect one, is an important mechanism for ensuring the quality of publications in science.
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