However, this initial data was astonishing and caused a surge of study and debate. It wasn’t the cigarettes themselves that drew attention (as one researcher aptly stated, smoking cigarettes to prevent COVID is like "drinking poison to quench thirst"), but rather one of their key components- nicotine. Could nicotine, a substance as reviled as any substance you could name, have a protective effect?
Nicotine is an addictive alkaloid substance that occurs naturally in tobacco plants and, to a much lesser extent, vegetables like tomatoes, potatoes, and eggplant. It activates the pleasure centers of the brain and induces a craving, which is one reason why people get hooked on cigarettes, vaping, and chewing tobacco. The chemical, when smoked in the form of tobacco, is clearly implicated in heart disease, cancer, respiratory illness, strokes, and all the other smoking-related diseases. To say the least, it was surprising that so many researchers zeroed in on a potential “dual nature” for nicotine, in which the substance may be detrimental to human health under some circumstances but could be potentially beneficial in others.
Nicotine targets nicotinic acetylcholine receptors in the brain and throughout the body (it acts as the key for these tiny "locks" on cells). While these receptors are best known for pleasure and craving, they also appear to play a regulatory role in inflammation, and they inhibit overactive immune responses when they’re activated. Nicotine may even work directly against the virus itself, by interacting with ACE2 receptors (in a way that interferes with the ability of the virus to bind, invade, and infect cells). French neuroscientist Jean-Pierre Changeux has been one of the most prominent researchers studying this.
Preliminary results from trials are mixed and non-conclusive. A few small studies show that a controlled amount of nicotine (in the form of the nicotine patch) might mitigate inflammation and possibly neurological symptoms. But much of the data so far is unclear. Smoking cigarettes worsens the outcomes of COVID, and nicotine replacement therapy outside of these trials hasn’t shown much of a significant effect on its own. Currently, there are several active trials, with most focusing on nicotine’s effects on cognitive function. The point of these trials is to see whether removing the smoke component might leave a potential benefit from nicotine.
Stay tuned!