How harmful is vaping?

Evidence shows that regular vaping can lead to an accelerated loss of lung function. Photo / Getty Images

Everyone agrees vaping is not harmless, but how harmful is not yet fully clear.

Stuart Jones, a Middlemore Hospital respiratory physician and member of the Asthma and Respiratory Foundation’s scientific advisory board, says the majority of early studies were funded and conducted by e-cigarette companies themselves without independent testing.

“In the past, Big Tobacco has proven to be untrustworthy, so I don’t trust a word they say until it can be independently verified.”

Jones says there is now clear evidence that e-cigarettes cause inflammation and damage to the airways.

“Vape exposure can cause more acute inflammation of the airways than traditional cigarettes do. There is evidence that regular vaping can lead to an accelerated loss of lung function, with drops of as much as 5% over two years reported in one follow-up study, five times the standard rate of decline.

“We know that e-cigarettes have less known carcinogens, so will possibly cause less cancer, but we don’t actually know for sure. Through the heating involved in the vaping process, we are creating hundreds of thousands of new chemicals that we’ve never inhaled into our airways before.’’

A foundation report cites studies warning that nicotine exposure during adolescence has a harmful effect on brain maturation, including cognitive functioning. A 2012 Dutch study linked nicotine exposure from cigarette smoking by adolescents to cognitive impairment in later life and attention deficits.

The foundation’s report says vaping has been consistently associated with depression, attention deficit hyperactivity disorder (ADHD) and conduct disorder in adolescents.

A US study found vaping menthol and mint flavours exposed users to high levels of the carcinogen pulegone. And when cinnamon flavour is heated, it creates a unique aldehyde – cinnamaldehyde –that can make users more vulnerable to respiratory infection.

Jones, backed by the College of GPs, also points to an analysis of studies by the Australian National University last year, which found vaping can cause seizures, nicotine toxicity, nicotine addiction and be a “gateway” to tobacco smoking. Accidental or intentional exposure to nicotine vape liquids can lead to poisoning.

In one study, he says, 25% of mice exposed to the nicotine-containing vape for five days a week over 12 months developed adenocarcinoma of the lung, a form of lung cancer.

He was at a Thoracic Society meeting a month ago where a study was presented in which human respiratory cells exposed to vape over five days showed extensive damage to respiratory airway cells. “After five days, those cells didn’t regenerate, they didn’t repair themselves.’’