Is vaping safe? What the latest research says about the cigarette substitute

Jack Rear
41 million people around the world are vaping – but we don't yet know the long-term health consequences - Bloomberg News

There’s currently a low-level battle raging in the medical community. On one side, we have Public Health England (PHE), which , since 2015, has been encouraging smokers to take up vaping as an aid to quitting. And in the other corner is the World Health Organisation (WHO), which is damning of the practise. 

In its strongest denunciation of e-cigarettes so far, WHO recently posted a series of tweets outlining the latest science around vaping. The organisation described e-cigs as “harmful to health” and “not safe”, pointing to studies that show: exposure to nicotine can damage the developing brain of vapers under the age of 20; that e-cigarettes increase the risk of heart disease and lung disorders; that vaping can damage foetuses if used during pregnancy; and that vaping can cause second-hand damage to non-vapers, just as second-hand smoke can cause harm to non-smokers. 

The organisation went on to criticise claims that e-cigarettes can help smokers quit, saying there is not enough evidence. That contradicts advice from Public Health England, which tells smokers to make the switch. PHE says e-cigs are 95 per cent safer than traditional cigarettes, and argues that vaping has helped people give up smoking. 

NHS data bears out PHE’s point, showing that 48pc of users are vaping as a precursor to giving up smoking, while 30pc say they do so because they believe there are less health risks associated with the practice compared to smoking. However, WHO says there’s not enough evidence to suggest that vaping helps people quit smoking and says there are “other proven, safer and licensed products”, such as nicotine gym and patches.

Part of the problem here is that vaping is still a relatively new phenomenon, so science is scrambling to keep up with the growth in e-cigs. The evidence for or against vaping, as a trawl through the papers published so far demonstrates, is cloudy at best...

What is vaping?

Vaping is the practice of smoking electronic cigarettes (known as e-cigarettes). The products work by heating a liquid solution (often referred to as an e-liquid) to form a vapour which the user inhales.

Ordinarily, that solution is made up of nicotine, flavourings, and a liquid called propylene glycol and/or glycerine, which acts as a solvent but also helps to thicken the vapour produced by the device.

E-cigarettes do contain the addictive element of a cigarette (nicotine) without containing tar or producing carbon monoxide, which are heavily linked to lung disease and cancer. Thus e-cigarettes allow smokers to get their nicotine fix while avoiding some cancer-causing side-products.

It is worth noting, however, that while nicotine does not cause cancer, it has been linked to various other health effects. It can cause birth defects, according to a 2015 study, and as WHO mentions, it can be harmful for developing brains. High doses of nicotine can cause nicotine poisoning which results in vomiting, nausea, and even death. 

Is vaping safe?

It is certainly true that e-cigarettes do not contain tar and do not burn to produce carbon monoxide. This mitigates the risk of contracting cancer or other lung-related conditions such as emphysema.

As it stands, most of the fatalities and medical emergencies associated with e-cigarettes come from the risk of them overheating or exploding and causing burns and other injuries. This is often caused by malfunctioning lithium-ion batteries within poor quality e-cigarette products. PHE is clear that the UK has some of the tightest regulations on e-cigarettes, so most users would not face these problems if purchasing a device from a reputable brand.

However, in September 2019, British factory worker, Terry Miller, from Tyne and Wear, was named as the first e-cigarette user in the world believed to have developed a fatal disease due to his vaping habit, which he'd picked up eight months earlier. 

The 57-year-old died in 2010 after developing lipoid pneumonia. Doctors said oil from vaping fluid was found in his lungs. It is unclear as to whether this was an isolated incident or indicative of a wider problem.

Immune system damage and lung disease

According to a 2018 study from the University Of Birmingham, vaping damages immune cells in the lungs, preventing them from being able to clear harmful bacteria. The study suggests that the vapour from an e-cigarette leaves the user’s lungs in a similar condition to a cigarette smoker’s.

The scientists behind the study took samples of lung cells from eight non-smokers with no history of lung disease. These samples were exposed to varying levels of e-liquid and condensed vapour and it was discovered that the vapour boosts production of inflammatory chemicals in the lungs while also disabling cells which are designed to flush harmful particles out of the lungs.

It also found that the vapour can trigger chronic obstructive pulmonary disease (COPD). This is an overarching term for diseases including severe bronchitis, asthma and emphysema.

Cancer and heart disease

Also in 2018, the New York Society Of Medicine announced their opinion that vaping is significantly less harmful than smoking, but shared research which suggests that some of the same diseases and illnesses could affect vapers as smokers.

After exposing cell samples to the vapour from e-cigarettes for ten years, the scientists looked for DNA mutations in cells from animals and humans.

They found that e-cigarette vapour damages DNA and prevents the genetic code from repairing itself. This is because the nicotine in e-liquids break down into nitrosamines which are carcinogenic (cancer causing) chemicals. In short, this means that there is a possibility that vaping could contribute to lung and bladder cancer. 

Another, recent review found that e-cigarettes may damage the heart. The researchers looked at 38 studies into vaping's impact on heart health and found evidence it increased heart rate, blood pressure and arterial stiffness, in almost three quarters of the tests. It led to the authors of the study demanding PHE change its advice on vaping. 

In the UK, people aged 25-34 or 35-49 are most likely to vape Credit: Jason Lee/Reuters

Addictive to children

One of the major areas of concern is around children and young people vaping. While the consensus is that vaping is a positive decision for those who want to give up smoking traditional cigarettes, there is a growing trend for young, non-smoking people to take up vaping as a lifestyle choice.

A 2015 study from Liverpool John Moores University found that one in five teenagers aged between 14 and 17 had tried e-cigarettes. Of those, 40pc had either never smoked before or had tried it and didn’t like it.

The worry is that e-cigarettes are acting as a gateway drug of sorts. Young people get addicted to the nicotine in e-cigarettes, and then go on to take up smoking as a result. Getting addicted at that earlier age can also lead young people to become more likely to take risks and abuse other substances, according to the John Moores University study.

On the other hand, a 2017 survey from PHE found that only 3pc of young people aged between 11 and 16 vaped regularly. Of those, the vast majority were already smoking anyway. Of those who’d never smoked, between 0.1pc and 0.5pc had taken up vaping, said the survey’s authors.

However, as WHO and various other bodies have discussed, nicotine can be harmful to developing brains, damaging the parts of the brain responsible for impulse control, attention, cognition and mood.

'Popcorn lung'

The chemical diacetyl, which is often used in food production as a butter substitute, was the centre of controversy after it was found in around 75pc of all flavoured e-liquids. It is thought to cause inflammation, scarring and constriction of the tiny airways in the lung known as bronchioles, reducing air flow when inhaled.

Several factories which used the chemical to make microwave popcorn were investigated by the United States National Institute for Occupational Safety and Health, which found that workers developed bronchiolitis obliterans after inhaling diacetyl for a long time. Researchers then looked into other places the chemical was used and found that the vast majority of e-liquid producers put it into their solutions.

Diacetyl was subsequently banned for use in e-liquids by the UK government in 2017. It remains in use in other countries around the world.

Second-hand vaping

According to a report from the World Health Organisation in 2014, second-hand vaping might have harmful effects just like second-hand smoking. The report says: “The fact that (e-cigarettes) exhaled aerosol contains on average lower levels of toxicants than the emissions from combusted tobacco does not mean that these levels are acceptable to involuntarily exposed bystanders.”

"In fact, exhaled aerosol is likely to increase, above background levels, the risk of disease to bystanders, especially in the case of some (e-cigarettes) that produce toxicant levels in the range of that produced by some cigarettes."

Still better than cigarettes?

PHE’s position on vaping is based on a joint report published in 2015 by King’s College London and Queen Mary London, which argued that vaping is around 95pc less dangerous than smoking. Their research admitted that there were potential dangers around vaping, particularly with regards to the chemicals used to flavour the e-liquid. However, the group argued that in comparison to the risks around smoking, e-cigarettes caused “a fraction of the harm”.

The report estimated that if every smoker in Britain switched to vaping, around 75,000 lives would be saved every single year. In addition, the report suggested that e-cigarettes, once regulated, should be offered by the NHS to anyone looking to give up smoking.

There is still much we don’t know

In 2016, researchers from Imperial College London shared a report which suggested that it could be ten or twenty years before the full effects of of e-cigarettes become apparent.

The report did openly state that the likelihood of vaping being worse for people than smoking was highly unlikely, although it warned that those who took up the practise were “taking a bet”. They were particularly concerned about the rise in people who had never smoked before but had taken up vaping.