People are taking up ­vaping in unprecedented numbers – about one in ten adults now puffs on e-­cigarettes, the highest rate ever, according to figures published last year.

While vapes are generally considered safer than cigarettes, and are seen as a useful tool for quitting smoking, the ­survey of more than 13,000 people for the charity Action on Smoking and Health found about 8 per cent of adult vapers have never smoked before.

And, a growing proportion of people are both smoking and vaping, the ­numbers doing so have doubled in three years, a trend that’s worrying experts.

‘There has been a rise in vaping on its own which is introducing health risks that wouldn’t have occurred otherwise,’ says Dr Gareth Nye, a senior lecturer in anatomy and physiology at the University of Chester.

The potential risks were spelt out in a US study: people who smoke and vape are four times more likely to develop lung cancer than those who just smoke, the Journal of Oncology Research and ­Therapy reported last month.

The researchers, from Ohio State ­University, speculated that this was due to the amount of chemicals in vapes that may be carcinogenic (cancer-causing) in their own right.

Another concern is that rising numbers of young people are ­vaping – 15 per cent of those aged 16 to 24 in the UK do so, up from 11.1 per cent in 2021, according to the latest Opinions and Lifestyle Survey from the Office for National Statistics.

In May, 17-year-old Kyla Blight, a student from Cumbria, who’d been vaping since she was 15, made headlines after being rushed to hospital with a collapsed lung linked to her 4,000 puffs a week on vapes (the equivalent to 400 cigarettes).

Kyla needed five-and-a-half hours of ­surgery to remove part of her lung.

The advice from The Centers for ­Disease Control and Prevention in the US is stark: ‘If you don’t vape, don’t start.’

It points out that ‘most e-cigarettes contain nicotine, which is highly ­addictive and is a health danger’ for pregnant women, foetuses, and children.

‘Aerosol from e-cigarettes can contain harmful and potentially harmful substances. These include cancer-causing chemicals and tiny particles that can be inhaled deep into lungs,’ it concluded.

Here, experts look at some of the ­potential risks that are now linked to vaping…

Lungs

Teenager Kyla Blight developed a blister, or bleb, on her lung. Usually 1-2 cm in diameter, a bleb is full of air. When Kyla’s burst, it caused a hole her lung, releasing air into her chest cavity, causing one lung to collapse.

Anything, such as smoking, that damages the alveoli – air sacs in the lungs – can cause blebs.

Vaping has also been linked to lipoid pneumonia, where the alveoli fill with dead white blood cells laden with fatty material, which in turn causes inflammation and infection in the airways.

This build-up of white blood cells is believed to be due to the glycerol, used in e-liquids to ­create thicker vapour.

Meanwhile, growing evidence suggests there may be a link between vaping and lung cancer.

A research review, published in the journal Cancers last September, concluded that vapes were ‘a highly potential risk factor for lung cancer and an area of significant concern for the future’.

Evidence is mounting that lung cancer is linked to glycerol in vapes, says Dr Nye.

‘In the past it’s been strongly suggested that vaping is not ­carcinogenic, but now the ­evidence seems to finally be coming to light that toxins in vapes may be linked to cancer,’ he says.

‘Glycerol is safe to consume. However, when heated in vapes, it can form the carcinogenic chemical formaldehyde, which is then inhaled into the lungs.’

According to the American Cancer Society: ‘Makers of e-cigarettes often claim the ingredients are safe. But aerosols that these products produce can contain addictive nicotine, flavourings and other chemicals, some known to be toxic or to cause cancer.

‘The levels of these substances appear to be lower than in cigarettes, but the amounts of nicotine and other substances in these products can vary because they are not standardised.’

Vaping has been linked to ‘various types of cancer, including head and neck cancers, lung cancer and breast cancer, as well as blood, prostate, and bladder cancers,’ says Professor Kefah Mokbel, a consultant breast surgeon at the London Breast Institute.

He points to animal and laboratory studies on cells that suggest vaping may cause DNA damage, inflammation and other signs that can precede a tumour.

In a study, published in the US ­journal Proceedings of the National Academy of Sciences, mice exposed to vaping aerosol for 54 weeks developed lung and bladder cancer far often than non-vaping counterparts.

The evidence on cancer and vaping, while based on laboratory studies, ‘is robust’, says Professor Mokbel, but more research is needed to assess the impact of e-cigarettes on cancer rates.

Heart

Once inhaled, the nicotine in e-liquid rapidly enters your bloodstream, causing the body to release adrenaline, which in turn raises your blood pressure, pulse and breathing rates.

‘Nicotine is a problem for people with heart disease,’ says Julie Ward, a senior cardiac nurse at the British Heart Foundation.

‘It raises the heart rate, ­contradicting the goal of most treatments. If you have heart ­disease and are using nicotine replacements, such as vapes, speak to your GP first.’

Chris Pepper, a consultant ­cardiologist at Leeds General Infirmary, told Good Health: ‘I always recommend that patients quit smoking and vaping for the sake of their heart health,’ adding that nicotine is associated with inflammation and ­damage to cells, known precursors to a raised risk of ­cardiovascular problems.

Separately, research presented at the American Heart Association conference last October showed that e-cigarette users regularly exposed to nicotine consistently performed worse than non-vapers on treadmill tests – with effects similar to those from cigarettes.

Gut health

The gut wall prevents harmful microbes in the digestive tract migrating into the bloodstream.

However, a study published in the journal Science in 2021 found that the chemicals in nicotine-free vape liquids could disrupt this protective barrier, leading to ‘leaky’ gut, which in turn can lead to chronic inflammation.

‘Such inflammation can contribute to a variety of diseases and conditions, including inflammatory bowel disease, dementia, certain cancers, atherosclerosis [hardening arteries], liver fibrosis [scarring], diabetes and ­arthritis,’ said Aditi Sharma, an ­immunologist at the University of California, San Francisco, who was involved in the research.

The findings were based on studies with human gut cells and then mice, with the cells exposed to vaping liquid intended to mimic the amount used by a ‘chronic’ vaper.

Aditi Sharma told Good Health: ‘We found that vaping adversely affects the gut by causing inflammation, primarily by attacking the tight junction proteins, the guards that keep the cells of gut tight and in place. This eventually causes a leaky gut, which allows easy passage of its constituents into the bloodstream. ­Vaping triggers something like a more severe form of IBS.’

Brain

Our brains appear to be highly sensitive to the effects of e-cigarette chemicals.

Vaping is linked to mental fog, according to two studies by the University of Rochester in the US in 2020. These found that both adults and children who vape were more likely to report difficulties in concentrating, remembering or making decisions than their non-vaping peers.

However, the authors pointed out that the studies only showed a link and did not prove ­causation. It could be that people who report mental fog are simply more likely to smoke or vape, possibly to self-medicate.

Immunity

Worrying findings published this year in the Journal of Allergy and Clinical Immunology found that inhaling e-cigarette smoke could damage neutrophils, one of the first immune cells to respond if bacteria or viruses enter the body.

The findings are important as previous research has shown that damage caused to neutrophils by cigarette smoking can lead to long-term lung damage.

Researchers at Birmingham University took blood samples from healthy donors who had never smoked or vaped. Their ­neutrophils were then exposed to 40 puffs of vape vapour (an amount previous studies have shown is a low daily exposure).

The neutrophils remained alive but became ‘stuck’, incapable of ­tackling threats to the body, such as E.coli bacteria.

Aaron Scott, an associate professor in respiratory science and lead author of the study, said: ‘We found that after short, low-level exposure to e-cigarette vapour, the cells remain alive but can no longer move as ­effectively and are ­unable to carry out their normal protective functions.

‘Interestingly, vapour from e-liquids which did not contain nicotine also had the same negative effects as vapour from e-liquids which did ­contain nicotine.’

Teeth and gums

The nicotine in vapes can also stain your teeth and lead to bad breath, gum disease and receding gums, suggests Mervyn Druian, a dentist at the ­London Centre for Cosmetic Dentistry.

‘Nicotine causes vasoconstriction of blood vessels in the mouth and reduces oxygenated blood reaching the gums,’ he explains. ‘Over time, this can lead to tissue receding and tooth loss.’

A recent review of studies published in the journal Medicina concluded that ‘there is ample evidence establishing a connection between vaping smoke and an increased risk of developing ­gingivitis and ­periodontal disease.

‘The use of the vape . . . can introduce bacteria that contribute to the ­development of oral diseases in our body. In addition, there are studies that suggest that quitting vaping could be associated with an improvement in oral health.’

Mervyn Druian says: ‘The mouth needs a healthy balance of bacteria – vaping can change this.’

And e-cigarette users experience similar DNA changes to specific cheek cells as smokers, according to a study led by University College London and the University of Innsbruck in Austria.

The lead author, Dr Chiara Herzog, said: ‘We cannot say that e-cigarettes cause cancer based on our study, but . . . [the changes seen] are associated with future lung cancer development in smokers.’

Skin

Smoking has been linked to ­wrinkles. While there is less data about vaping, the nicotine in vapes is the main ­concern, says Dr Justine Hextall, a consultant dermatologist in Arundel, West Sussex.

This is because it constricts blood vessels and reduces blood flow to the skin, so less oxygen and essential ­nutrients reach the cells. Nicotine also reduces collagen production, leading to decreased skin elasticity.