Recent evidence and expert opinion suggest vaping-gateway hypothesis is weak.
By Marina Murphy
It has often been suggested that e-cigarettes act as a gateway to smoking, but the evidence is mounting that this is not the case. Researchers testing this theory are increasingly concluding that the availability of e-cigarettes should help people stop, rather than take up, smoking.
The possibility that e-cigarettes are a way out of—not a way into—smoking should come as no surprise, especially given the Swedish snus story. Sweden has the lowest smoking rates and the lowest lung cancer rates in Europe—only 8 percent of Swedish men smoke every day, compared with a 25 percent European average—and many authorities have cited the widespread availability of snus as a key factor. Snus is surely a prime example of how providing safer, socially acceptable alternatives to smoking can encourage quitting. This is why the New Nicotine Alliance in the U.K. has gone to the European Court of Justice to try to overturn the EU ban on snus (from which Sweden is exempted).
A team of U.S. researchers recently analyzed the findings of several previous studies and found the evidence suggesting a link between vaping and future smoking to be weak, at best. In another study, conducted by British American Tobacco (BAT), a computer model designed to forecast future trends in the U.K. predicts that when e-cigarettes are available, by 2050, 32 percent of current U.K. smokers, who otherwise would have continued smoking, likely would have completely switched to e-cigarettes.
Snus and the Swedes
Snus is a pouch of oral snuff that releases nicotine when tucked under the lip or cheek. Although banned since 1992 in other EU countries, the availability and acceptance of the smokeless tobacco product in Sweden has contributed to driving down Swedish smoking prevalence to the lowest levels by far in Europe.
In fact, the proportion of Swedish men aged between 30 and 44 who smoke fell to just 5 percent in 2016, partly because many have switched to snus. Overall, just 8 percent of Swedish men (and 10 percent of women) smoke daily, compared with the EU average of just over 25 percent (goo.gl/V9aGir)
According to an article in the Scandinavian Journal of Public Health, if snus were unavailable, many more people might have continued to be cigarette smokers. The authors estimate that if the Swedish smoking prevalence was extrapolated to the rest of the EU, there would be a 54 percent reduction of male mortality from lung cancer (goo.gl/p2TK4F)
Researchers in Norway, too, have shown that snus there is used to stop smoking, reduce smoking and prevent initiation. E-cigarettes, they say, could have the same effects, depending on how they are regulated (goo.gl/dp5eia)
According to another study, switching from smoking to snus may offer a reduction in health risk similar to that of cessation (goo.gl/8aizjn). E-cigarettes, like snus, may offer equally encouraging harm reduction potential. For example, Public Health England, an executive body of the U.K. Department of Health, estimates that e-cigarettes are around 95 percent safer than cigarettes, and the Royal College of Physicians in England has proposed that e-cigarettes be widely promoted as an alternative to cigarettes (goo.gl/ZQKNsZ)
The proof is in the pudding
Whether e-cigarettes have been widely promoted is questionable, but their availability is clearly having an impact. Lynn Kozlowski, professor of community health and health behavior at the University at Buffalo, wrote recently in Drug and Alcohol Dependence that research shows that, as use of e-cigarettes have shot up, overall smoking rates have decreased.
“The national trends in vaping and cigarette smoking do not support the argument that vaping is leading to smoking,” he said in an interview. “The evidence from the prospective studies [of a gateway effect] is weak at best. … There is little evidence that those who have never smoked cigarettes or never used other tobacco products and first try e-cigarettes will later move on to cigarette usage with great frequency or daily, regular smoking.” (http://goo.gl/UavqBe)
Kozlowski’s paper also highlights several shortcomings in studies that appear to show a link between e-cigarette use and subsequent smoking. For example, many studies use misleading measures for what is considered smoking. “Measures of at least one puff in the past six months can mean little more than the experimenting vaper was curious how cigarettes compared,” Kozlowski said in the interview.
Models and prediction
In a completely different kind of study, BAT scientists developed a computer-based population model to help predict the potential public health effects of new tobacco and nicotine products. The model was used to look at a number of possible scenarios for the 50 years between 2000 and 2050, comparing what might happen if e-cigarettes were available and if they were not available on the market as an alternative to cigarettes.
All types of smokers—current smokers, nonsmokers, former smokers, e-cigarette users and dual users—were taken into account, as were dynamic behaviors, such as starting to smoke, quitting and relapsing, switching to e-cigarettes, and becoming a dual user. The model also considered the potential effect of smoking normalization on starting and quitting rates, as well as factors such as gender, aging and time since quitting.
Results show the potential for an overall beneficial effect of e-cigarettes on the population, significantly reducing smoking prevalence and smoking-related deaths. When e-cigarettes are available, by 2050 the 32 percent of smokers in the U.K. that otherwise would have continued smoking likely would have completely switched to e-cigarettes, according to the BAT model (Regulatory Toxicology and Pharmacology doi: 10.1016/j.yrtph.2017.03.012).
“Our model shows that when e-cigarettes are available, the effect of ‘normalization,’ through, for example, the visibility and familiarization of e-cigarettes versus the ‘demoralization’ of cigarettes, means that fewer people start smoking and there is a higher rate of successful quit attempts—smokers quit earlier and, although many still relapse, there are significantly more former smokers,” explains BAT’s head of reduced risk substantiation, James Murphy, who was one of the researchers.
Mathematical models like this can be used to study complex and constantly changing situations—as is the case when e-cigarettes or other new products become available to the public. They help predict the future based on what’s happened in the past, and they are particularly helpful in forecasting the possible future impact of products when the long-term health effects are unknown and epidemiological data is not available. In 2012, the U.S. Food and Drug Administration, which regulates e-cigarettes in the U.S., produced draft guidance for companies developing modified risk tobacco and nicotine products that encouraged the development and use of such models to assess the impact of new products on population health.
The picture that is starting to emerge is that, similar to snus, e-cigarettes could play a positive part in tobacco-related harm reduction. Kozlowski and colleagues say that even if there is a small gateway effect, it is swamped by the overall trend toward less smoking.
“The persistent focus on the potential risks to kids has caused adults’ understanding of the risks of e-cigarettes to worsen over time,” adds Kenneth Warner, Kozlowki’s co-author. “This is likely discouraging adult smokers from using e-cigarettes as a smoking-cessation tool.”
One objective of regulation is to minimize product risks. “The public deserves accurate information on the health risks of e-cigarettes versus cigarettes,” says Kozlowski. “From the best evidence to date, e-cigarettes are much less dangerous than cigarettes. The public has become confused about this.”
While confusion reigns, it may prove hard to realize fully the significant potential public health benefits of e-cigarettes.
Legal challenges against the EU snus ban
In July 2016, Swedish Match—the main manufacturer of Swedish snus—brought a challenge in the U.K. High Court against provision in the U.K. Tobacco and Related Products Regulations 2016 that prohibits the sale or supply of “tobacco for oral use,” including snus. The key legal arguments raised by Swedish Match are that the law discriminates against snus compared with cigarettes and lower-risk nicotine products (including e-cigarettes), that the ban is disproportionate, that it violates the EU principle of subsidiarity in removing national regulatory discretion and imposing a uniform regulatory outcome regardless of the individual circumstances of member states, that it breaches the duty to give reasons for the ban, and that it is an unjustified restriction on the free movement of goods.
The New Nicotine Alliance (NNA) is acting as a third party in the public interest. The NNA argues that the ban is disproportionate and contravenes the right to a high level of health protection. Significantly, for the first time in a challenge against U.K. (and EU) tobacco legislation, the NNA argues that the ban infringes human rights. The NNA argues that the ban contravenes the EU Charter of Fundamental Rights vis-a-vis Article 1, “Human dignity”; Article 7, “Respect for private and family life”; and Article 35, “Health care.” The NNA argues that the ban is contrary to Articles 1 and 7 because it limits smokers’ choice of safer alternatives by excluding a product that is “significantly less harmful to health than cigarettes.” Article 35 stipulates that a high level of human health protection shall be ensured in the EU policies and activities. The NNA argues that the snus ban is inappropriate as it prevents smokers from having access to a safer product and is an unsuitable means for achieving a high level of health protection.
Progress
On Jan. 26, the U.K. High Court agreed that there was a case for a review of the legislation and granted the NNA permission to intervene. Because the U.K. Tobacco and Related Products Regulations 2016 implement the Tobacco Products Directive, the case was referred to the European Court of Justice (ECJ). According to Gerry Stimson, chair of the NNA, the ECJ has now sent out the case for comment to EU member states; the European Commission, Parliament and Council; and the European Free Trade Association states. These parties may comment on the case, with comments to be received by July 7. The case will be heard in Luxembourg at the end of the year or the beginning of next year.
Implications
The ECJ ruling will apply across the EU, not just in the U.K. Referrals to the ECJ are uncommon; to get this far is a significant achievement. The NNA has, for the first time in the field of challenges to tobacco control, based a challenge on rights to autonomy and the right to health. —M.M.