The Odd Case of Tobacco, Nicotine, and COVID-19

In the early reports of patients in the hospital for COVID-19, careful observers noticed an odd pattern. COVID-19 is primarily a respiratory syndrome and smoking badly damages lungs. But hospitalization was not more likely for smokers. In fact, it was less likely. This correlation kept appearing in sample after sample  – though with substantial uncertainty. So these researchers and others began pondering whether something in tobacco smoke might actually be causing a beneficial effect. Their attention turned to two potential roles of nicotine in COVID-19. One role, they reasoned, might be in reducing the risk of initial infection. The other role might be in moderating the overactive response of the immune system.

The evidence is also clear for smokers once they land in the hospital. Those smokers have a greater risk for both the disease worsening and for death than nonsmokers. Of course, this is consistent with conventional wisdom.

Curiosity Prompts Questions

As ConscienHealth frequently reminds us, correlation is not causation. A host of potential explanations other than nicotine might account for the observed pattern of COVID-19 infection and hospital admissions. For example, the data-collection systems may not be accurate from prior records of the patients. Patients (and/or their loved ones) may be reluctant to volunteer positive smoking status. Concern of stigma harming the odds of receiving optimal care might come into play. Even the concept of collider bias can be in play.

But here is where curiosity either enters or flees. Some researchers want to study the role of nicotine directly. In fact, the French team cited above has planned a randomized trial to do just that. Others (here, here, and here) are comfortable declaring any suggestion of nicotine playing a helpful role is proof of a sinister plot from the tobacco industry. Thus this entire line of inquiry should be ignored, they say.

Speaking for myself, and only myself, I was very skeptical of the initial epidemiologic findings, for the reasons above (Except for collider bias. I just learned about that very recently!) But when a neuroscientist of such reputation as Jean-Pierre Changeux was willing to speculate on potential mechanisms and recommend clinical trials, I had to take it more seriously.

Diverging Agendas

A depressing fear I have is that at least some of the opposition to curiosity in this matter results from the way this discussion explicitly, and powerfully, splits nicotine from tobacco smoke in public conception. Nicotine has long been conflated with smoking, such that most of the public believe that nicotine is not only what makes smoking addictive but also what makes it so harmful. Opponents of harm reduction approaches to smoking take advantage of this confusion, and they may realize that this research imperils that unfair “advantage.”

I just want to know what science will tell us about this observation. If nicotine does have some protective effect in COVID-19, then I know that the physician-researchers working on this will be able to recommend how best to take advantage of it. And if it does not, then I really want to know that, too, so we can move on to something that has actual promise.

I will try to stay curious, and I hope others will, too.

Today’s post comes from our friend Joe Gitchell, who has devoted his career to behavioral health and especially nicotine and tobacco policy. By way of disclosures, he tells us:

My employer, PinneyAssociates, provides consulting services regarding tobacco harm minimization and vaping products to JUUL Labs, Inc, on an exclusive basis. I also own an interest in a nicotine gum that has not been developed nor commercialized.

Drying Tobacco, photograph © Ken Dodds / flickr

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June 14, 2020