Professor Bauld on Nicotine

Posted 29th April 2020 by Dave Cross
Professor Linda Bauld spoke to BBC’s Inside Health program about the link between nicotine and COVID-19, and what this means for smokers. The presenter asked her about the apparently “contradictory stories” and if smoking led to increased risks of becoming infected with the virus.

Linda Bauld is a Professor of Public Health at the University of Edinburgh and Chair in Behavioural Research and Cancer Prevention at Cancer Research UK. She opened by saying: “Smoking status is being very poorly recorded and even in the UK we have far to go to get that right.”

She went on to add that this leaves us with a small number of studies to pick from. Bauld referred to colleagues at University College London and the Royal Veterinary Collage, who are doing a live review (AKA a rapid review) which is being updated regularly, and they’ve pulled up 28 studies, but again they displayed poor levels of recording of smoker status.

“Smoking status is not being accurately recorded. Staff are busy, that patients may be too unwell, there’s definitely no validation of smoking status by using a carbon monoxide test. So, we just don’t know.”

“The second explanation might be more intriguing – that there might be something real going on. Which means that fewer smokers when they come into contact with the virus are developing COVID or, alternatively, need to go into hospital.”

“Essentially, what happens with SARS-COVID2 (which is the virus rather than the disease), when it enters cells through a particular receptor, the ACE 2 receptor. And we know there’s some evidence of gene expression and receptor levels are higher in the airways of smokers, and that might put them at more risk – but alternatively, studies show that nicotine…downregulates that receptor.”

“So, it’s possible that the nicotine, and this is just a hypothesis at the moment, is providing some kind of protective effect against the disease developing when people come into contact with the virus.”

Bauld went on to talk about the dichotomy going on here: “We know from many studies that smoking increases the risk of respiratory viral and bacterial infections, and it’s also associated with worse outcomes when people are infected.”

“But first point is we are not seeing smokers are more likely to get [COVID-19], for whatever reason that might be, but we do find some evidence that when they are going into hospital they do have worse outcomes. So, what we call disease severity, and that is like from admission to intensive care to needing oxygen or even death. And there’s ten studies in the UCL revue, but only two of them were high quality where smoking status was adequately recorded and they could conduct a meta-analysis, where they combine the data, and that showed that smokers were at greater risk of experiencing severe disease compared with never smokers.”

Bauld added that smoking during “an horrific respiratory disease pandemic” would be awful as it impacts recovery as well as “harming almost every organ in the body”.

She continued: “So, the main advice, and the clear advice, from public health agencies around the world is that this is an even better time to stop smoking – despite some of the intriguing findings we’re seeing around the possible relationship with nicotine.”

The FDA has claimed that smoking increases the likelihood of contracting COVID-19, but Bauld said she had been unable to find the data to support that statement. However, she was adamant that smokers experiencing heavy COVID symptoms would experience “worse outcomes”.

She said that maybe there is a link between the hand-to-mouth movements of smokers that could increase transmission of the disease, although that runs contrary to her admission that this is not being seen in hospitals.

Stopping smoking is the best thing any smoker can do for their health – but we can’t say that it makes them more susceptible to COVID” – Linda Bauld

“Everyone understands that smoking is damaging to health, but I think it’s very important that where we have uncertainties about the mechanisms that we don’t overclaim. So, stopping smoking is the best thing any smoker can do for their health – but we can’t say that it makes them more susceptible to COVID.”

How realistic is it that researchers should try giving NRT patches to non-smokers to see if it alleviates the symptoms of COVID? Bauld thinks: “It’s an interesting study. They definitely found from around 480 patients, 350 who got into hospital because of COVID, that those who smoked everyday were less likely to develop symptoms of severe infections.”

“They’ve done their research on nicotine, they know how it works with receptors and in the body, so what they’re proposing to do is to give COVID patients nicotine replacement therapy patches. And, of course, NRT is a medicine.”

“The first point of why that may be a good idea is that scientists around the world are focussing on repurposing existing medicines to see if they will help people as a treatment. So, it’s entirely appropriate, especially as NRT if low cost, it’s very cheap to try this. It will be fascinating to see what they find,” she added.

“Nobody is advising that we give mass nicotine replacement therapy to people – but, I would say, people accessing NRT as part of a quit attempt, we do know that’s highly effective, particularly when used as part of combination therapy (the gum and the patch).”

Related to this, some doctors in Wales are now amplifying that nicotine can help to reduce symptoms.

Wales Online is reporting that Jonathan Davies, a consultant orthopaedic surgeon at the Royal Glamorgan Hospital, is calling nicotine a “powerful drug” that “has the potential to block the virus from entering cells”.

Mr Davies, Dr Nerys Conway, and Dr Robert Davies claim to be the first to suggest the use of NRT patches to treat COVID patients.

Related:

  • “Why Welsh doctors claim nicotine patches could be used for treating coronavirus”, Wales Online – [link]


 Dave Cross
Article by Dave Cross
Freelance writer, physicist, karateka, dog walker