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Studies show that inhaling the vaporised flavoured liquids in e-cigarettes is not without potential health consequences. [Photo: Bigstock]

To vape or not to vape? The answer is not to vape

E-cigarettes appear to trigger a range of unique immune responses – on top of  the same ones triggered by regular cigarettes

Although marketed as being safer then cigarettes, increasingly evidence is suggesting this is not the case.

Immune responses are the biological reactions of cells and fluids to an outside substance the body doesn’t recognize as its own. Such immune responses play roles in disease, including lung disease spurred on by cigarette use.

Mehmet Kesimer, PhD, senior author of the study in the American Journal of Respiratory and Critical Care Medicine this is the first study monitoring the harmful effects of e-cigarettes using sputum samples from human lungs.

“There is confusion about whether e-cigarettes are ‘safer’ than cigarettes because the potential adverse effects of e-cigarettes are only beginning to be studied,” said Kesimer, who is also an associate professor of pathology and laboratory medicine at the UNC School of Medicine.

“This study looked at possible biomarkers of harm in the lungs. And our results suggest that in some ways using e-cigarettes could be just as bad as smoking cigarettes.”

A 2016 Surgeon General’s report found that e-cigarette use has increased by 900% among high school students from 2011 to 2015. Also in 2016, the Food and Drug Administration extended its regulatory oversight of tobacco products to include e-cigarettes.

In the UK figures from the Office of National Statistics suggest the number of users of e-cigarettes has nearly doubled since 2014.

Real effects on real people

The current study used human volunteers and compared sputum samples from 15 e-cigarette users, 14 current cigarette smokers and 15 non-smokers.

What the researchers found was that e-cigarette users uniquely exhibited significant increases in:

• Neutrophil granulocyte- and neutrophil-extracellular-trap (NET)-related proteins in their airways. Although neutrophils are important in fighting pathogens, left unchecked neutrophils can contribute to inflammatory lung diseases, such as COPD and cystic fibrosis.
• NETs outside the lung. NETs are associated with cell death in the epithelial and endothelium, the tissues lining blood vessels and organs. The authors write that more research is necessary to determine if this increase is associated with systemic inflammatory diseases, such as lupus, vasculitis, and psoriasis. The study also found that e-cigarettes produced some of the same negative consequences as cigarettes.

Both e-cigarette and cigarette users exhibited significant increases in:

• Biomarkers of oxidative stress and activation of innate defence mechanisms associated with lung disease. Among these biomarkers are aldehyde-detoxification and oxidative-stress-related proteins, thioredoxin (TXN) and matrix metalloproteinase-9 (MMP9).
• Mucus secretions, specifically mucin 5AC, the overproduction of which has been associated with pathologies in the lung including chronic bronchitis, bronchiectasis, asthma, and wheeze.

The picture was complicated somewhat by the fact that of the 15 e-cigarette users, five said they occasionally smoked cigarettes and 12 identified themselves as having smoked cigarettes in the past.

“Comparing the harm of e-cigarettes with cigarettes is a little like comparing apples to oranges,” Kesimer said. “Our data shows that e-cigarettes have a signature of harm in the lung that is both similar to what we see in cigarette smokers and unique in other ways. This research challenges the concept that switching to e-cigarettes is a healthier alternative.”

Genetic damage too

The bottom line is that inhaling the vapourised flavoured liquids in e-cigarettes is not without consequences. As if to underscore this, a study last year looked at the effects of vaping on genes, again using human volunteers.

When we smoke cigarettes, dozens of genes important for immune defence are altered in the epithelial cells that line the nasal mucosa. These epithelial cells are critical for normal immune defence and several of the changes seen in smokers likely increase the risk of bacterial infections, viruses, and inflammation. But Lead researcher, Ilona Jaspers, PhD, professor of pediatrics, and microbiology and immunology at the UNC School of Medicine, and her team also found that vaping alters the same genes affected during cigarette smoking and hundreds of other genes important for immune defence in the nasal, upper airway.

“We know that diseases like COPD, cancer, and emphysema usually take many years to develop in smokers,” Jaspers said. “But people have not been using e-cigarettes for very long. So we don’t know yet how the effects of e-cigarette use might manifest in 10 or 15 years. We’re at the beginning of cataloguing and observing what may or may not be happening.”

A health double whammy

While vaping is often marketed as a safe alternative to cigarettes – some even advertise organic ingredients! – in many ways it is simply a gateway. Many e-cigarettes contain nicotine, for example, and it has recently been shown that teenagers who try e-cigarettes double their risk for smoking tobacco cigarettes. The study found that students in grades seven to 12 who had tried an e-cigarette are 2.16 times more likely to be susceptible to cigarette smoking. The younger they started vaping the more, likely a switch to cigarettes was.

These potential health risk also bring up the issues of health damage from secondhand vaping. It’s not something that has benefited from much study and what study there has been has some serious problems including poor methodology and, in 34% of cases it has been found that the authors had conflicts of interest. Nevertheless studies have found harmful metals, carcinogenic tobacco-specific nitrosamines, volatile organic compounds, carcinogenic carbonyls (some in high but most in low/trace concentrations), cytotoxicity and changed gene expression. Of special concern are compounds not found in conventional cigarettes, such as propylene glycol.

A small study published last summer found that vaping indoors–even in a well-ventilated room–releases ultrafine particles and potentially carcinogenic hydrocarbons into the air. “Our data confirm that e-cigarettes are not emission-free,” the authors wrote.

Vaping is a huge industry and now much action has thus far been taken to restrict the use of e-cigarettes. However, this month the US State of New York announced that vaping will be banned in indoor public spaces including restaurants, bars and offices.  The new rule, which will come into law in 30 days, will mean that the practice will be treated the same as smoking normal cigarettes. New York city has had a similar ban in place since 2013.