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Regular vaping by young adult Australians is rare

Posted on December 22, 2018


There is very little information on how many young adults vape in Australia. However, two recent studies have confirmed that regular vaping in this group is rare, especially among those who have never smoked.

Study 1

A study by Melka et al published today in the American Journal of Preventative Medicine surveyed nearly 9,000 young women with an average age of 22 years.

The study found that only 1.6% of the women who had never smoked (142 in total) had tried vaping (even a puff) in the last 12 months

Although  the frequency of vaping was not measured, the number of regular vapers who had never-smoked is likely to be very small indeed. Based on other studies, probably no more than 0.5%.

Many studies have shown that use by young non-smokers is mostly experimental, often just once or twice. Many do not use nicotine. Occasional use of vaping is of negligible importance to public health.

Regular vaping exposes users to higher risk, but is still far less harmful than smoking.

Of course some of the young never-smokers who vaped regularly may otherwise have smoked. Vaping may be diverting them from a much more harmful and addictive habit.

The vast bulk of vaping was by young women who were already smoking. 60% of smokers had tried vaping and 14% of ex-smokers. Many of these young people would be using vaping as a quitting aid, a positive step towards better health.

Anti-vaping advocates have tried to spin these results to suggest that youth vaping is a big problem for young people in Australia.

However, the figures speak for themselves.

Study 2

Another recent Australian study by Jongenelis et al of 1,116 18-25 year-old men and women found that 9% (104 people) had used an e-cigarette in the last 30 days. Most users were smokers and regular use by never-smokers was rare. Only 6 never-smokers vaped regularly (weekly or more).

These results are similar to overseas studies of adolescents, which have found that among those who have never smoked, regular use of vaping products is rare. In the United Kingdom, 0.1-0.5% of never smoking youth vape regularly (10 days or more per month. In the United States, only 0.3% of never-smokers vape regularly (>20 days per month).

Is nicotine harmful to the developing brain?

Young people should not vape, but the reality is that many will try it. Kids experiment, mostly only for a short time. Some but not all use nicotine. As the brain is developing, some have raised concerns that nicotine may harm the developing brain.

Nicotine is active in the brain. It has known pharmacological effects and can change brain circuitry. However, although other chemicals in inhaled smoke are toxic, there is no scientific evidence that nicotine harms the developing brain in humans. There have been rodent studies showing harmful effects, but the relevance of these to humans is unclear.

If nicotine was harmful to the adolescent brain, where are all the brain damaged adults from the millions of people who started as teens and smoked for decades?

It is also theorised that nicotine may sensitise the brain to other drugs and increase the risk of substance abuse. However, there is no evidence to support this theory in humans.

We need more research to fully understand the impact of vaping and the overall effect on the health of young people.

However, one thing we know for sure is that adolescent rats should definitely not smoke.

Posted by Colin Mendelsohn, colin@athra.org.au


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4 Replies to “Regular vaping by young adult Australians is rare”

Simon Chapman

Colin, who is suggesting that "brain damage" might occur from nicotine exposure in adolescents? There are many other possible cognitive consequences of nicotine exposure. This Swedish twin registry with 21,589 subjects (https://www.ncbi.nlm.nih.gov/pubmed/19931961) shows an inverse association between smoking and IQ. The intriguing question is whether lower IQ is associated with (predicts) smoking or whether nicotine exposure might lower IQ. Animal studies show brain effects from nicotine, and I'm sure you don't subscribe to the ignorant dismissal you often hear that animal studies hold no relevance for humans.

This 2015 Lancet meta-analysis (https://www.thelancet.com/journals/lanpsy/article/PIIS2215-0366(15)00152-2/fulltext) concluded "Daily tobacco use is associated with increased risk of psychosis and an earlier age at onset of psychotic illness. The possibility of a causal link between tobacco use and psychosis merits further examination." The discussion has much to say about nicotine as the likely candidate.

This paper (https://www.ncbi.nlm.nih.gov/pubmed/27216261) found "A higher maternal cotinine level, measured as a continuous variable, was associated with an increased odds of schizophrenia [in offsping] (odds ratio=3.41, 95% confidence interval, 1.86–6.24). Categorically defined heavy maternal nicotine exposure was related to a 38% increased odds of schizophrenia. These findings were not accounted for by maternal age, maternal or parental psychiatric disorders, socioeconomic status, and other covariates. There was no clear evidence that weight for gestational age mediated the associations."

I realise that you appear to regard nicotine as having an almost vitamin-like halo around it, but your statement above that "there is no scientific evidence that nicotine harms the developing brain in humans." is frankly irresponsible.

Colin

Simon,

There are two fundamental flaws in your 'evidence'
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Firstly, the studies you refer to show an 'association' between smoking and low IQ, psychosis and schizophrenia. People who smoke are more likely to have those problems and smoking may be a contributing factor. However, as you know, studies of this kind are not able to show that smoking causes those problems.
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Secondly, tobacco smoke has over 7,000 toxic chemicals. There is no evidence in the studies you quoted that nicotine is the chemical associated with those effects.
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You say that there are many other cognitive consequences of nicotine exposure. On this point you are correct. Nicotine is well known to have many beneficial effects. A meta-analysis of 41 placebo controlled trials found significant positive effects of nicotine on motor abilities, attention, and memory. (Heishman S. Psychopharm 2010) Other studies show it improves concentration and alleviates stress.
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Nicotine has other beneficial effects. It is neuroprotective and helps to prevent Parkinson's disease (Nicholatos JW. Acta Neuropathol Commun 2018). Furthermore in schizophrenia, nicotine normalises brain function, improves cognition, sensory gating, attention and working memory. (Beck AK. Schiz Research 2018)
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You say that 'Animal studies show brain effects from nicotine'. While animal studies can be useful at times, their value in predicting what happens in human is very limited and wrong in the great majority of cases. (Shanks N. Philos Ethics Humanit Med 2009; Akhtar A. Camb Q Health Ethics 2015).

Simon Chapman

Thank you for explaining the difference between association and causation, Colin.

However, it seems that you may have a different standard for judging the status of evidence where the findings might be positive for nicotine than when they might be negative, as when you refer me to the Parkinsons paper. Some might call this confirmation bias. You note that animal studies can be useful "at times". In this instance, I note that you are dismissive of them when they provide evidence that is inconvenient to the mission to rehabilitate nicotine. You'd be aware that animal studies have long been used in drug safety and efficacy development. One of the most basic tests in toxicology, the LD 50 test, provides a standard for showing what dose of a drug, pathogen etc will kill 50% of animals exposed to it. Here's quite a lot more for you to read and (I predict) dismiss, about nicotine disruption of the adolescent brain. https://www.sciencedirect.com/science/article/pii/S1878929311000570

The weight of this evidence is such that I could not imagine any research ethics committee allowing any longitudinal RCTs examining dosing of adolescents with nicotine.

You say "There is no evidence in the studies you quoted that nicotine is the chemical associated with those effects." Perhaps you did not read the Lancet systematic review right through? The authors went to that question directly and extensively.

You are doubtless aware that the tobacco industry carefully monitored and funded studies research "supporting the idea that individuals with schizophrenia were less susceptible to the harms of tobacco and that they needed tobacco as self-medication. The tobacco industry promoted smoking in psychiatric settings by providing cigarettes and supporting efforts to block hospital smoking bans." https://www.ncbi.nlm.nih.gov/pubmed/17984298

Colin

The evidence for the neuroprotective effects of nicotine in Parkinsons disease in humans is modest but positive, unlike in animal models where 'nicotine alone has slight or no motor effects' (Thiriez C. Expert Rev Clin Pharmacol 2011). Perhaps you were looking at the animal studies again?
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For example, these reviews found benefits of nicotine in PD in humans:
– 'Altogether, these findings suggest that nicotine and nAChR drugs represent promising therapeutic agents for the management of Parkinson’s disease' (Quik M. Movement Disorders 2012).
– 'In vivo these effects resulted in improvements in mood, motor skills and memory in subjects suffering from PD pathology'. (Barreto GE. Frontiers in Aging Neuroscience 2015)
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I am not suggesting that animal studies do not have their uses, but there is no experimental or epidemiological evidence in humans supporting your claims of significant neurological harm. Theoretical arguments are insufficient.
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In any case, the question is not whether nicotine is toxic or not. It is whether the overall population effect of nicotine vaping is positive. All good quality modelling studies which make realistic assumptions indicate a positive effect from vaping in saving lives and preventing illness. Even your favourite, the NASEM report says 'The modelling results suggest that, under likely scenarios, the use of e-cigarettes in the population will result in a net public health benefit.' (Presentation 23 Jan 2018. Slide 40)
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The Lancet review on smoking and psychosis (Gurillo P. Lancet Psych 2015) refers to theoretical mechanisms for a causative link between nicotine and psychosis, but is clearly insufficient evidence to claim causation.
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Your point about the tobacco industry is of course irrelevant. While you remain preoccupied with destroying Big Tobacco (which has been an abject failure), harm reductionists remain focussed on saving the lives of smokers.

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