Nicotine Receives Health Certification

New research from the Tobacco and Alcohol Research Group (TARG) at the University of Bristol's School of Psychological Science has been described as "very interesting" by harm reduction expert Dr Sarah Jackson. The team used a method called Mendelian Randomisation to discover the actual truth about the level of risk posed by regular nicotine use – and the answer is overwhelmingly positive.

If Dr Sarah Jackson says the results of a research project are “very interesting” then they are very interesting indeed. Dr Jackson is Principal Research Fellow at University College London’s Alcohol and Tobacco Research Group and specialises in evaluating the effectiveness of smoking cessation methods, which includes assessing the real-world effectiveness of all the main stop-smoking aids. This includes analysing the impact of vaping, a topic she frequently addresses with her peers at conferences. In addition, she serves on the advisory committee for Action on Smoking and Health, the board of directors for the Stop Smoking London Transformation Programme, and is an editor for the research journal “Addiction.”

The team at Bristol’s Tobacco and Alcohol Research Group this month published “Assessing the health impacts of nicotine exposure by disentangling the effects of nicotine and non-nicotine components in tobacco smoke: A multivariate Mendelian randomization study”. The research project included the work of Marcus Munafò, another highly respected academic in the field of vaping and tobacco harm reduction research projects.

They state that the impacts of smoking are well known, but the effects of regular nicotine use (not in conjunction with other combusted tobacco products) are far less clear. Given there are now millions of people vaping every day, and have been for years, they believe it has become “increasingly important to understand and disentangle the effects of nicotine use from the effects of exposure to tobacco smoke.”

But, they note, “it is difficult to differentiate the effect of regular nicotine use from that of smoking.”

Professor Michael Russell is credited as being the father of the tobacco harm reduction concept – so important that he had an award named after him posthumously. In 1976, he wrote: “People smoke for nicotine but they die from the tar”, and went on to advocate how the tar-to-nicotine relationship could play a fundamental role in making cigarettes safer – specifically the development of low-tar cigarettes. 

With the advent of vaping devices in the early 2000s, he stated: “there is no logical reason not to encourage people to switch from tobacco products to less harmful nicotine delivery systems.”

The Bristol team asked exactly this: can it be proven that nicotine does not cause ill health?

Dr Jasmine Khouja is the corresponding author on this research, and she explained their work: “There are lots of studies on how nicotine affects health. Mostly these are short-lived effects, like increases in heart rate and blood pressure, which quickly return to normal.

Clinical trials of nicotine patches also show that short-term use is safe, but we know very little about the effects on health of long-term regular use of nicotine.

“Most of what we have learned has come from animal studies and studies of people who smoke. This is very problematic because we don’t know if humans will respond in the same way as animals, and in studies of people who smoke, we cannot easily distinguish the effects of nicotine from those of other components of cigarettes.”

People using patches, sprays or gum tend to only use them for the duration of time they are trying to quit, quickly ceasing once they believe they are free of tobacco’s clutches. 

For vapers, it’s a completely different proposition.

Vaping works because it mimics many of the actions of smoking, and allows adults to use their device until their brain registers an appropriate level of nicotine in the bloodstream (called self-titration). People can adjust how frequently they use their device by altering the nicotine strength of the eliquid or the amount of vapour they inhale to their lungs – hence higher nicotine strength eliquids or direct-to-lung vaping can result in fewer puffs.

Due to the similarity of smoking to vaping, the convenience of the alternative means quitters continue to use their devices for a long period after they’d have stopped using patches, sprays or gum.

Dr Khouja says: “We used genetics to try to distinguish the health effects of nicotine from those of other substances in cigarette smoke. We found that nicotine does not cause the adverse health conditions seen in people who smoke: poor lung function, COPD, lung cancer, and coronary heart disease. However, it does increase heart rate.”

To assist people in understanding the Mendelian Randomisation process the team employed, she recommends a 2-minute primer on YouTube for interested readers.

“Mendelian randomisation studies the association between genes and exposures (e.g., nicotine use) and outcomes (e.g., cancer) to understand whether a causal relationship exists and to account for confounding. Confounding occurs when other factors apart from the exposure being studied (e.g., nicotine exposure) influence the outcome. Confounding factors can make it difficult to determine a true causal relationship,” Dr Khouja continues.

“Our genes are randomly inherited from our parents and do not change even if we are exposed to confounding factors. Researchers use genetics in place of the exposure in MR and argue that any differences in health outcomes are related to the specific factor they are studying. Using an extension of MR, multivariate MR, we can look at two exposures with common genetic causes at the same time and account further for confounding. This allows us to understand if they both have an effect, or if only one of the factors is truly causing the outcome.”

And what did they ultimately discover? 

The study’s authors concluded: “We find that nicotine does not appear to be an independent cause of poor lung function, lung cancer, COPD, or coronary heart disease but does increase heart rate. These results support previous evidence that nicotine itself does not directly cause adverse health outcomes.”

This is great news for those who have worried relatives using safer nicotine products such as vapes.