Clearing the air
E-cigarettes containing nicotine are becoming increasingly popular in Australia, despite restrictions that prohibit the domestic marketing of the product and sale of the liquid nicotine required to vape them.
The health debate around vaping is polarising, and muddying the waters further is the disparate findings from e-cigarette research, some of which says nicotine e-cigarettes are as carcinogenic as tobacco, while other papers claim nicotine is safe and vaping is the ultimate solution to smoking cessation.
Medical Forum canvassed a variety of opinions and attempted to follow the current evidence trail to address three questions:
- Are e-cigarettes effective smoking cessation or harm reduction devices?
- What harm is causal to e-cigarette usage?
- Are young people starting to vape in lieu of tobacco smoking?
Reducing tobacco harm
A/Prof Colin Mendelsohn of the University of New South Wales and chair of the Australian Tobacco Harm Reduction Association (ATHRA) sees vaping as a legitimate form of tobacco harm reduction and especially helpful to assist smokers who can’t quit via traditional nicotine replacement therapies.
“There is a huge reduction in risk and if the alternative is for the person to continue smoking, then vaping is a no brainer,” he said.
Australia has some of the strictest laws for e-cigarettes in OECD countries and Colin believes this is based on a misconception.
“People attribute a lot of health concerns to nicotine, for which there is no evidence. There is no evidence it causes cancer, or lung disease, it has only a minor role in cardiovascular disease and there are some other minor effects,” he said.
“It’s the drug people are addicted to but because they have always associated it with smoking, they think nicotine, and not tobacco, is the problem. People use nicotine as the argument against vaping without any evidence.”
Furthermore, he suggests that vaping is relatively harmless compared with tobacco smoking.
“There are no serious known health effects from vaping. No one has died from vaping; it has been available since 2003. Sure, we might find out one day there might be problems but from what we know of the chemistry and the science so far, the risk is small.”
Colin’s message to GPs is to focus on the best outcome for a patient who can’t or won’t quit smoking.
“If you have a patient in front of you, your responsibility is to deliver the best care for that patient. If the patient is going to smoke anyway and the risk of vaping is 5% that of smoking, how can you ethically justify not recommending vaping to the smoker.”
Colin believes the reluctance of the Australian government and the medical establishment to embrace e-cigarettes comes down to an inherent conservative culture.
“We have no tolerance for people using nicotine or anything that looks like a cigarette, or people being addicted to any drug. There is significant political risk to take on the legalisation of e-cigarettes and not a lot to gain – I think there is still a lot of money being made from tobacco taxes.”
“If we look at the evidence dispassionately, the smoking rates in Australia have not fallen in six years and in other countries they are falling faster than ever and the only difference is vaping.”
Not approaching e-cigarettes as a harm reduction method, he says, is doing a disservice to those who can’t quit.
“We are failing these people. We are not giving them a valid treatment option that is working overseas and could save lives.”
Colin cites literature from the UK which supports the claims that e-cigarettes are effective smoking cessation devices.
“E-cigarettes are twice as effective as our currently best available treatment,” Colin said. “What that shows is a causal relationship between e-cigarettes and quitting.”
With regards to young people taking up vaping, Colin does not think it’s the issue it is made out to be.
“There is a moral panic in the US that is not evidence based. Yes, vaping has increased in the past 12 months among young people, but the smoking rate is falling faster than ever. We think that what is happening over there are kids being diverted from smoking to vaping.”
A/Prof Mendelsohn’s research: https://www.ncbi.nlm.nih.gov/pubmed/29623987
E-cigarettes as cessation devices
Medical Forum spoke with addictive behaviour and smoking cessation researcher Prof Peter Hajek, from the Wolfson Institute of Preventive Medicine and the London School of Medicine. He has found e-cigarettes, at a population level, helpful to tobacco smokers to quit and particularly so for highly dependent smokers.
Yet, are e-cigarettes more effective than other nicotine replacement therapies?
“They are more effective than nicotine replacement medications, but they have not yet been compared with varenicline, which is the most effective drug treatment for smokers,” Peter said.
Peter sees vaping as a better alternative because it “represents a dramatic reduction in health risks and there are also signs that many smokers who quit with e-cigarettes stop vaping eventually as well.”
“If e-cigarettes prove to be effective cessation devices, there will be huge benefits to public health. We are now much closer to the goal of eradicating smoking-related disease and death than ever before.”
“Most smokers do not have a death wish and if a safer alternative to cigarettes is available, they will, of course, switch to it.”
Prof Hajek’s research: https://www.nejm.org/doi/full/10.1056/NEJMoa1808779
When it comes to vaping and young people, the dilemma is whether it prevents them from smoking or starts them smoking.
Curtin University’s Dr Michelle Jongenelis is a behavioural and physical health promotion researcher and has published a number of papers on user behaviour and e-cigarettes. In one of her studies, Michelle and her colleagues look at the susceptibility and inclinations of young adults aged 18-25 years to vape and smoke.
The findings, which correlate with studies in the US and UK, suggest young adults who had used e-cigarettes were significantly more susceptible to tobacco smoking than young adults who had not vaped.
“Young adults and adolescents who have never smoked and begin using e-cigarettes are more likely to go on to smoke tobacco cigarettes – establishing a gateway hypothesis,” Michelle said.
Her research also indicated that young people were taking up vaping instead of smoking, so a gateway was being provided for non-smoking young adults and adolescents.
“It’s a whole new cohort being attracted to these devices and who could end up smoking later on.”
The Australian debate around e-cigarettes is vastly different to that in the US, which has little in the way of barriers to access. Companies such as Juul, which had nearly a 40% stake in the US e-cigarette market in 2017, can market their products freely and consequently the North America e-cigarette market is the biggest in the world.
It comes as no surprise then that most of the current academic literature is from the US and it reports a spike in e-cigarette use among adolescents.
“And, for the first time in recent years, there has been a corresponding increase in tobacco cigarette use, which had been declining. This increase is being attributed to the growing use of e-cigarettes,” she said.
Michelle’s research found that few people aged between 18 and 25 took up smoking.
“Most who are going to smoke will start before they are 18 with 80% of young adults saying they never intended to smoke, but this cohort was at risk, due to e-cigs,” she said.
Given her research and knowledge of overseas literature, Michelle said the evidence at this time did not support the use of e-cigarettes as a smoking cessation method and recommended GPs to follow the recommendations of the NHMRC and the WHO.
Dr Jongenelis’s research: https://www.sciencedirect.com/science/article/abs/pii/S0955395919301720
What about nicotine?
Nicotine itself is a contentious topic among researchers. Medical Forum spoke with Dr Moon-shong Tang, a professor at the New York University School of Medicine and a DNA researcher. Moon-shong’s published paper suggests a correlation between e-cigarette usage and DNA harm.
“The question is whether nicotine is carcinogenic in humans? Can inhaled nicotine be nitrosated in human organs? To address this question, we first must determine if nicotine can cause DNA damage, mutations and tumorigenic transformation in human cells,” he said.
“Our results show that nicotine can cause all these carcinogenic effects. We then tested whether e-cigarette smoke can cause similar effects in mice. We found DNA damage in lung, bladder and heart in mice exposed to e-cigarette vapour for 12 weeks, which is equivalent to a human smoking e-cigarettes for several years.”
These results were not what Moon-shong and his colleagues expected.
“We are very surprised by our findings. Nicotine has been studied for decades. How could nicotine’s effect on DNA, its ability to repair and mutagenesis escape the attention of scientific community? It’s a puzzling question.”
Moon-shong fears that e-cigarettes could be a public health issue in years to come.
“It takes about two decades for tobacco smokers to develop cancer. So, I expect human cancer caused by e-cigarettes may be unravelled in decades to come. Scientists and health policy makers must think carefully before making recommendations,” he said.
This evidence is counter to how Professor Peter Hajek views nicotine, referencing data from Swedish research on snus which largely replaced smoking. “Snus is oral tobacco that delivers nicotine but, outside pregnancy, carries very few, if any, health risks. The key point is that the snus experience suggests that nicotine on its own carries limited health risks, not much different from the risks of caffeine.”
Dr Tang’s research: https://www.ncbi.nlm.nih.gov/pubmed/29378943
Name your flavour?
Another unknown with e-cigarettes is the flavourings, which are largely unregulated. Medical Forum spoke with A/Prof Jessica Fetterman from Boston University School of Medicine and a tobacco and e-cigarette researcher.
Jessica found a relationship between e-cigarette flavourings and endothelial cell dysfunction.
“Five flavouring additives – vanillin (vanilla), menthol (mint), cinnamaldehyde (cinnamon), eugenol (clove), and acetylpyridine (burnt flavouring) – all impaired the ability of the endothelial cells to produce nitric oxide. The inability of these cells to make nitric oxide is one of the early changes we see in the development of heart disease,” she said.
“We already know that some of the additives such as cinnamaldehyde and diacetyl cause respiratory symptoms and, if inhaled at high enough doses, pulmonary diseases. The vast majority of e-cigarette liquids contain nicotine and we’ve found that the newer pod-style e-cigarettes further enhance the absorption of nicotine, which raises serious concerns for heart health.”
With regards to long-term users, Michelle believes e-cigarettes may increase the risk of heart disease later in life.
“The levels of carcinogens appear to be lower in e-cigarettes but many other chemicals in the liquids are known to have significant cardiovascular toxicity. While it is likely to be some time before we know the long-term effects of e-cigarette use, the early studies are indicating that they are not a reduced-harm product when it comes to heart health.”
A/Prof Fetterman’s research: https://www.ncbi.nlm.nih.gov/pubmed/29903732
Harm to the lungs
Medical Forum spoke with A/Prof Dongmei Li from the University of Rochester School of Medicine and Dentistry and Center for Research on Flavored Tobacco Products. She said there was evidence at a population level of potential harm of vaping on lung tissue.
“We identified a cohort of e-cigarette users who had never smoked tobacco reporting wheezing and related respiratory symptoms,” she said.
These symptoms were worse for current vapers who were smokers, but not isolated to them.
A/Prof Li’s research: https://tobaccocontrol.bmj.com/content/early/2019/02/13/tobaccocontrol-2018-054694
Conflicting findings, similar outcomes
We found a vast gap between the evidence, depending on which data set we drew on, with some academics finding e-cigarettes to be damaging and others finding nicotine to be harmful. In fact, depending on who you ask, we could be facing a public health dilemma in decades.
While others believe nicotine is safe and vaping presents a low health risk (some say 95% less harmful), especially in comparison to cigarettes.
But does this address the potential harm of that 5%?
What we heard repeatedly was: “it is better to not vape, if you can help it, as the evidence is not clear.” However, the reality is that upwards of three million Australians are smokers and this figure has stagnated over the past few years, so the question really comes down to this: Is it better to vape than smoke?
The science jury is still out. What we do know is nicotine is extremely addictive and tobacco smoking is a major public health issue. So, if vaping is useful for smoking cessation, then it may well be a “no brainer” like Colin Mendelsohn says.
But when it comes to a new generation of long-term vapers, the evidence might be many years away.
E-cigs blamed for respiratory death
Since we went to press, the first death believed to be caused by e-cigarette usage has been reported in the United States. The patient died from an, as yet, unknown respiratory disease. The Center for Disease Control (CDC) has identified another 215 potential cases of where e-cigarettes are considered causal to pulmonary illnesses.
What we know:
- Research is indicating that e-cigarettes do cause harm
- There are 215 identified cases of severe lung diseases so far in 25 US states in which e-cigarettes are a contributing factor
- There has been one reported death linked to e-cigarettes
What we don’t know:
- No one product or device has been identified
- If the e-cigarette users were prior smokers
- Whether THC or nicotine e-cigarettes are to blame