In this instalment of our Harm Reduction Heroes series, Snusforumet talks to Arielle Selya, the American scientist who set out to investigate whether vaping leads young people to smoking – only to find the data pointing in another direction.

Arielle Selya didn’t set out to become a tobacco harm reduction advocate.

Quite the opposite.

When e-cigarettes began attracting serious attention in the United States around 2014, Selya was a young academic specialising in adolescent smoking and nicotine dependence. 

Like many researchers around her, she found the emerging “gateway” theory entirely plausible: young people would start vaping, become dependent on nicotine and eventually graduate to cigarettes.

So she decided to test it.

“I really bought into the e-cigarette story,” she tells Snusforumet. 

“It was completely plausible to me that e-cigarettes were a gateway.”

Then she looked at the data.

And the data refused to cooperate.

From physics to faces to public health

Selya’s route into tobacco research was anything but conventional. 

She studied physics before earning a PhD in neuroscience at Rutgers, where she researched how the brain recognises faces. 

The work gave her a strong quantitative background – and an early introduction to scientific fields divided into competing camps. But she increasingly wanted to work on problems with a more immediate effect on people’s lives.

A postdoctoral position offered her a route into public health. Around 2010, she began working on adolescent smoking, addiction, and nicotine dependence.

Then vaping arrived.

The study that changed her thinking

By the time Selya was a junior faculty member at the University of North Dakota, concern about e-cigarettes and young people was gathering momentum.

And she thought she’d identified a useful way to test the gateway hypothesis.

Rather than simply asking whether young people who vaped were subsequently more likely to smoke – an association that could have many explanations – she wanted to test a specific mechanism.

Did vaping create nicotine dependence, which then drove people towards cigarettes?

Her 2018 paper found no statistically significant association between e-cigarette use and later cigarette smoking. Cigarette smoking, by contrast, was associated with later e-cigarette use. 

“What I found was the complete opposite from what I expected,” she says. It was the first serious crack in the prevailing narrative.

One of the paper’s reviewers was British harm reduction advocate Clive Bates. 

It was her first encounter with Bates. In his review, he suggested researchers should consider not only a gateway into smoking, but an off-ramp away from it.

“He really put the idea about tobacco harm reduction in my head,” she says.

When the population data told the same story

Yet Selya remained cautious.

Because the cohort had originally been recruited around early smoking experimentation, there were questions over whether it provided a clean test of the gateway hypothesis. So she tried another approach.

Selya then turned to nearly two decades of US youth smoking data. If vaping were driving substantial numbers of young people into smoking, cigarette use should have exceeded previous trends. 

Instead, smoking declined faster than expected – a pattern more consistent with diversion away from cigarettes than a population-level gateway into them.

By then, Selya says, the accumulation of findings had changed her mind about the gateway theory.

“I was convinced at this point,” she recalls.

The cost of asking the wrong questions

Selya says she soon discovered that challenging conventional tobacco-control thinking could carry professional consequences.

Grant reviewers, she recalls, appeared to interpret even neutral investigation of harm reduction as her endorsing or promoting youth vaping.

One response to a grant proposal effectively asked whether, by considering reduced-risk products, she was suggesting that they should be recommended to children.

“No, I’m not saying that,” she recalls thinking.

Selya later joined Pinney Associates, a consultancy that advises JUUL Labs and other nicotine and tobacco companies on tobacco harm reduction, where she is now a Senior Scientist. She also consults as a scientific advisor to the Global Forum on Nicotine (GFN).

While she agrees industry-funded research deserves scrutiny, Selya adds that funding incentives across tobacco control should also be examined consistently. 

“Everybody has incentives,” she says.

Moreover, the population modelling that helped change her views on the gateway theory was publicly funded and completed before she joined Pinney.

The new battleground: dual use

The argument over vaping has evolved since those early gateway debates.

Selya says that at scientific conferences she now encounters far greater acceptance of the idea that switching from cigarettes to e-cigarettes reduces risk.

The resistance, she believes, has shifted towards dual use – people simultaneously smoking and using a lower-risk nicotine product.

Critics often treat dual use as evidence that alternative products have failed and are increasing overall health risk. Selya thinks that can miss what happens to individuals over time.

“Maybe dual users were even worse off to begin with,” she says. 

“And maybe they reduced their cigarette consumption after they started.”

Her concern is that studies sometimes compare dual users with very different groups of smokers without asking what happened to the same people after they began vaping. 

A smoker who becomes a dual user but sharply reduces cigarette consumption may still be moving along a harm reduction pathway, she argues.

Evidence that’s becoming harder to dismiss

Selya is encouraged that the wider evidence on vaping and smoking cessation has strengthened.

Cochrane’s latest review found “high-certainty evidence” that nicotine e-cigarettes increase quit rates compared with traditional nicotine replacement therapy.

Selya remains frustrated that so many papers still describe the evidence as “mixed” despite convincing evidence to the contrary.

“That drives me crazy,” she says.

She also sees attitudes towards nicotine pouches as potentially less entrenched than those surrounding vaping, partly because there is no inhalation involved.

The important distinction, in her view, is the one harm reduction has always made: different behaviours can carry very different levels of risk.

‘If something doesn’t work, do something different’

That philosophy extends to regulation.

Selya believes it’s important to prevent youth access to nicotine products. What she questions is the leap from that legitimate concern to prohibition for everyone.

Her preferred model of public health is more straightforward: give people accurate information and allow adults to make informed choices.

“I’ve always thought that public health’s job should be to educate people and then let them make their own decisions,” she says.

She worries that policymakers can become trapped in an escalating cycle: higher taxes, more restrictions, flavour bans and finally prohibition, even when earlier interventions fail to produce the intended results.

“If you have a hammer, everything looks like a nail,” she says.

Harm reduction, after all, is hardly a radical principle elsewhere in public health. Seatbelts do not eliminate car crashes. Condoms do not eliminate sex. Needle exchanges do not eliminate drug use.

For Selya, tobacco remains the strange exception.

And perhaps that explains why her journey matters.

She did not arrive at tobacco harm reduction through ideology. She arrived there by trying to prove the opposite.

But the data kept pointing somewhere else.

Eventually, she followed it.