Experts: E-cigarettes may offer public health opportunity

The use of e-cigarettes is continuing to increase steadily, with sales of the battery-powered devices expected to exceed those of regular cigarettes by 2021.

Although the dangers of combustible cigarette smoking are well documented, the long-term impact of e-cigarette smoking is much less clear. Health authorities are particularly concerned about the use of e-cigarettes among adolescents, for whom these products may serve as a gateway to nicotine addiction. Similarly, there is significant debate regarding whether e-cigarettes should be viewed as smoking cessation tools or healthier alternatives to combustible cigarettes.

In a news briefing titled “E-Cigarettes: Public Health Threat or Opportunity?” speakers at the 2015 American Association for the Advancement of Science (AAAS) meeting discussed the potential implications of the shift toward e-cigarettes.

“E-cigarettes have been increasing tremendously in popularity, both in the United States and internationally, and yet it turns out the amount of information we have about what’s in these products, how they’re used, what’s the exposure of nicotine and other components of these products is surprisingly limited,” Wilson Compton, MD of the NIH’s National Institute on Drug Abuse, said during the briefing. “Yet, they hold great promise as a way to potentially reduce exposure to the incredibly harmful constituents in combustible tobacco, by contrast, to what appears to be a relatively clean nicotine delivery system.”

Compelling opportunity

In his presentation, “E-Cigarettes: What’s the Real Medical Innovation Breakthrough?” Kevin Bridgman, MD, chief medical officer of Nicovations, a subsidiary of British American Tobacco, discussed the technology and possible public health benefits of e-cigarettes. He addressed the product profile of a desirable e-cigarette, which would include adequate nicotine delivery, qualified and quantified vapor, a toxicant load offering real benefits vs. smoking, and attractiveness to smokers. Bridgman said a desirable product would appeal to smokers emotionally, functionally, behaviorally, sensorially and financially. He discussed the anatomy of an e-cigarette, as well as the factors that affect vapor quality: formulation composition, design and operating parameters, and device materials.
He cited a study conducted on Epi-Airway, a highly differentiated in vitro human epithelial tissue culture. In the study, cigarette smoke reduced cell viability to 12% at 6 hours. E-cigarettes showed no such decrease and displayed results similar to untreated air controls.

Bridgman said e-cigarettes present a compelling public health opportunity. He emphasized the importance of rigorous electrical and vapor testing, ingredient screening, quality standards in manufacturing, and responsible marketing and packaging.
“There is growing consensus among public health professionals that e-cigarettes are significantly less risky than conventional cigarettes. However, we believe that, in order to realize their full potential, e-cigarettes should be regulated to ensure appropriate quality and safety standards, whilst also allowing sufficiently wide retail availability, appropriate lifestyle positioning and flexibility for the rapid introduction of product innovation,” Bridgman said in a press release. “This would provide greater confidence without stifling innovation while enabling these products to compete effectively with cigarettes.”

The brain on nicotine

In his presentation, titled “Understanding Nicotine Addiction and its Brain Reward Systems,” Compton discussed the central nervous system effects of nicotine and how this might influence the popularity of e-cigarettes.
“Like other substances that seem to be abused and addictive, nicotine produces an increase in dopamine in the central reward structures, and we see that as the main pathways toward the start of an addictive process,” Compton said in an audio recording of his presentation. “Whether it’s opioids, alcohol, cannabinoids or stimulants, such as cocaine, methamphetamines or nicotine, they seem to have a common pathway of increasing dopamine in the ventral tegmental nucleus accumbens reward pathways in the midbrain structures.”

This dopamine response is associated with memory formation and in changes in the pathways leading to the frontal lobe involving executive control, judgment and decision making.

“This system that’s linked through the dopamine receptors in the midbrain seems to be very important in the addictive process,” he said.

Compton discussed the implications of addiction in adolescence and the need to protect this segment of the population from nicotine and other addictions. “We see adolescents as being important for the risk of addiction,” he said. “There’s a great deal of population-level data and observational data from epidemiology showing us that adolescence is the period when almost all addictions begin, so we see that the use of substances increases markedly in youth between the ages of 12 and 18,” he said. “That is the period of first exposure to almost all substances. We don’t see 10-year-olds or 8-year-olds or 6-year olds reaching out for these substances, so that’s a clue that something’s going on. Adolescence is the period when almost all addictions begin.”

Compton added that in individuals with no exposure to substances in adolescence, the onset later in life is significantly diminished.

Compton said a larger number of teenagers in the United States are now reporting the use of e-cigarettes, adding that many of these teen e-cigarette users have no prior history of conventional cigarette or smokeless tobacco exposure.

“So, about 36% of the eighth-grade e-cigarette users, 30% of the 10th-grade users, and 21% of the 12th-grade e-cigarette users have never used traditional tobacco products,” he said. “So that’s a concern because this may be a unique and new pathway to nicotine exposure and may open up the potential for the development of addiction to nicotine.”

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Ending the epidemic

In her presentation, Deborah Arnott offered her insights as chief executive of Action on Smoking and Health (ASH), a British public health charity established by the Royal College of Physicians. ASH, which is described as “anti-smoking, not anti-smoker,” is a nongovernmental organization funded by the British Heart Foundation, Cancer Research UK, and the UK Department of Health.

In addressing the question of whether e-cigarettes could play a role in ending the epidemic of smoking, Arnott said the answer depends on the faction contemplating it. She said harm reductionists would say yes because e-cigarettes are a “disruptive technology” and an alternative to regular cigarettes. Traditionalists, whose goals are to eliminate tobacco use, addiction and the tobacco industry, would disagree because e-cigarettes essentially negate the second two objectives.

She said ASH’s position is to minimize the risk of e-cigarettes by discouraging their use by young people and discouraging their use by never smokers. At the same time, the organization believes in maximizing benefit to traditional cigarette smoking by encouraging switching, supporting quitting and discouraging relapse.

In Britain, regular e-cigarette use has tripled from 700,000 in 2012 to more than 2 million in 2014, Arnott said. Two-thirds of these are smokers and one-third are ex-smokers. For every three individuals who try e-cigarettes, only one continues to use them.

“Those who have never smoked appear to be heavily protected from e-cigarette experimentation,” Arnott said in her presentation materials.

Although experimentation with e-cigarettes among youth is on the rise, this use is almost entirely among smokers, Arnott reported.
Arnott also discussed findings of a Cochrane Review of two randomized trials, which found that about 9% of smokers who used e-cigarettes were able to stop smoking for up to a year, compared with about 4% of those who used nicotine-free placebo e-cigarettes. Moreover, this review found that in smokers who did not quit, roughly 36% of e-cigarette users were able to decrease their usage by half.

“Cochrane reviews are world renowned for their systematic analysis of the evidence, and our findings at population level are consistent with their conclusions that electronic cigarettes have the potential to help smokers quit,” Arnott said in a press release.

Arnott cautioned against regulatory practices against e-cigarettes that are based on “prejudice rather than evidence.”
“There is a danger that the precautionary principle is being used to deny smokers access to products which can save their lives,” she said in the press release. “Over 1,000 people will die worldwide from tobacco during this 90-minute session alone. E-cigarettes have the potential to dramatically reduce this deadly toll.”

References:

The following were presented at the AAAS Annual Meeting; Feb. 12-16, 2015; San Jose, California:

Arnott D. Global tobacco control: What to do about e-cigarettes?

Bridgman K. E-cigarettes: What’s the real medical innovation breakthrough?

Compton W. Understanding nicotine addiction and its brain reward system.

Disclosure: Arnott reports no relevant financial disclosures. Bridgman is chief medical officer at Nicovations Ltd.