The Chinese are among the biggest smokers with over half of adult men indulging in the habit.
As a cardiologist with a career devoted to smoking elimination and tobacco harm reduction, I obviously closely monitor health developments in the country that consumes approximately one third of the planet’s cigarettes.
So, when Covid-19 surged in China, I was struck by one statistic that stood out: Few of the hospitalised smoked. This appeared to be counterintuitive. Coronavirus attacks the lungs and airways, and smoking raises susceptibility and severity of respiratory infections.
My comprehensive and systematic review of all the data was published last month as the world’s first peer-reviewed study into the subject, followed by two more analyses, one published and one in press.
I recommended that pharmaceutical nicotine be tested in clinical trials as a potential treatment for Covid-19 patients. Indeed, researchers in France and Wales have announced they are doing just that.
The findings were met with some animosity but I insist on following the science. I am not funded by any party with interests in the tobacco industry. But if nicotine has some protective effects against Covid-19, and knowing that the disease is here for many years, public health bodies have a duty to reconsider their approach.
In Kenya specifically, the authorities may have to review their stance towards new nicotine technology. E-cigarettes, for example, are regulated and taxed to the point of extinction. This leaves smokers with no access to smoking cessation services or are unable quit with only one option: To continue smoking.
And whether nicotine ultimately proves to be protective or not, smokers may want to use Covid-19 as a reason to switch to less harmful alternatives.
So, back to the peer-reviewed findings, which some find so upsetting.
I performed a systematic literature review of 13 Covid-19 studies, focusing on hospitalisation data, classifying patients into less and more severe disease status.
Among 5,960 patients in hospital with the diagnosis, 450 were smokers. The prevalence of smokers was 6.5 per cent in a country where 26.6 per cent of the people smoke.
These results have been echoed in other research in France, the US and Germany. At the University Hospitals Pitié Salpêtrière, in Paris, researchers led by neuroscientist Jean-Pierre Changeux found that 4.4 per cent of 343 hospitalised patients were smokers. Of 139 outpatients studied, 5.3 per cent were smokers.
The Pitié Salpêtrière report authors wrote: “Our cross-sectional study strongly suggests that those who smoke everyday are much less likely to develop a symptomatic or severe infection with Sars-CoV-2.
“The effect is significant. Only one-fifth of the expected smokers were ambulatory patients with Covid-19, and a quarter were admitted to hospital. We rarely see this in medicine.”
In the US, the Center for Disease Control reports that in a study of 7,162 patients, only 1.3 per cent were smokers while the smoking prevalence is 13.8 per cent.
My other research of 11 studies on 11,654 Covid-19 patients found, once again, that the patients who smoked was a fifth of the expected proportion.
All these studies have reflected the same thing: An unexpectedly low number of smokers appear to be developing Covid-19 to the degree that they need hospital treatment.
My own hypothesis is, essentially, that nicotine has certain properties that might provide benefit in coronavirus infection. The most severe symptoms seem to come from an overreaction of the immune system, a “cytokine storm”.
During that storm, the immune system targets an infection but over-reacts, causing substantial inflammation to the organs. Nicotine might dampen that intensity and control the immune response.
There is no clinical evidence that current smoking is a predisposing factor for hospitalisation for Covid-19. On the contrary, the data I and other experts have studied suggests the contrary. We believe this is because of nicotine. That’s why significant further research is under way.
Nobody — least of all me — would tell anyone to start or continue smoking to protect themselves against Covid-19. But providing nicotine replacement therapies to smokers might be necessary during the Covid-19 pandemic. These medications, patches, gums and sprays have been available for years.
Lastly, governments should adopt an evidence-based approach to tobacco harm reduction — one that encourages innovation and creates awareness of less harmful alternatives.
Dr Farsalinos is a cardiologist and research fellow at the Onassis Cardiac Surgery Center, University of Patras and National School of Public Health, all in Greece. @FarsalinosK