In the mid-1800s the vast majority of tobacco factories produced
chewing tobacco rather than tobacco for smoking. It was not until the
early 1900s that smoking began to replace chewing, at first in the form of
cigars, which provided a transitional opportunity to both chew (the cigar
is often left in the mouth, allowing nicotine to be absorbed orally) and
smoke at the same time.
HOW NICOTINE MOVES THROUGH THE BODY
The speed and efficiency with which nicotine enters the blood and is
transferred to the brain depends very much on how it is administered.
If a person takes nicotine by mouth in the form of snuff (smokeless
tobacco), the absorption of nicotine may be more complete than it is with
smoking, but the dose is delivered over a much longer period of time. For
example, the typical dose of nicotine from a cigarette is about one milligram.
However, a plug of snuff maintained in the mouth continuously for thirty
minutes delivers a dose in the three- to five-milligram range. The mucous
membranes of the mouth are a good site for absorption because a lot of blood
flows nearby, but the process is still much slower there than it is in the lungs. So,
while snuff delivers a larger total dose over time than a cigarette does, they both
result in about the same peak concentration of nicotine in the blood. Nicotine gum
delivers less nicotine than snuff. Even if it is chewed for thirty minutes continuously,
nicotine gum generally delivers only about 1.5 milligrams of nicotine. As this is being
written, tobacco companies are continuing to develop and test-market tobacco-free
oral nicotine delivery devices. As smoking has diminished across several decades
in the United States, tobacco companies have done research that indicates that about
30 percent of adult smokers are interested in smokeless products, but many of them
are not comfortable with chewing tobacco or snuff, so the companies are designing
more creative tobacco-free nicotine products that can deliver nicotine orally. Regardless
of the specific oral delivery system, if the nicotine is getting absorbed from inside the
mouth, its route into the body will be the same. Cigars present an interesting case in
nicotine absorption, because generally the smoker doesn’t inhale. Although some of the
smoke still makes it to the lungs, most of it comes into contact with membranes in the
mouth and upper airways, across which nicotine can be absorbed. How much nicotine
gets absorbed through the direct contact of the cigar tobacco with the mouth depends
largely on the style of smoking. Those folks who stick a cigar in their mouth and leave it
there until the end looks like the end of a dipstick from an old lawn mower engine will
absorb much more nicotine through the mouth than those who hold the cigar in their hand
and puff intermittently.
Once nicotine is absorbed, how is it distributed? Again, this depends on
how it is taken. With snuff the distribution is slower, but the peak nicotine
concentrations are quite similar to those obtained after smoking a cigarette.
HEALTH RISKS OF SMOKELESS TOBACCO
Most experts agree that smokeless tobacco is far less harmful than smoking cigarettes,
while allowing that the chewing of tobacco and snuff represent significant
health risks in their own right. In addition to the nicotine they deliver, their prolonged
use can increase the likelihood of cancers of the mouth and esophagus. Many users
develop thickening lesions in the mouth that may develop into cancer of those tissues.
Smokeless tobacco also causes gum disease, which can result in inflamed and
receding gums and can expose the teeth to disease. In addition, because smokeless
tobacco products generally contain very high amounts of sugar, they also promote the
development of dental cavities. In short, smokeless tobacco is not a safe substitute for
smoking. It is also not a good “performance enhancing” drug for athletes, though a
staggering number use it that way. Many young people believe that the nicotine in
smokeless tobacco products increases their physical reaction times and the power of
their movements in various sports like baseball, track and field, and football. This is
actually not true. There is no evidence of significant gains in reaction time, and there
are studies that indicate that nicotine actually decreases the speed and force of leg
movements during reaction-time studies. Its negative effects on heart function also
argue against the use of nicotine during athletic activities.
Before leaving the topic of the behavioral and environmental cues that
perpetuate smoking and challenge those who try to quit, it’s important to
discuss e-cigarettes, which were initially developed as an aid for people
trying to quit smoking. As we mentioned, these are devices that deliver
nicotine to the lungs without burning tobacco. In fact, they contain no
tobacco at all. They look like cigarettes, right down to the red LED that
turns on and looks like a glowing cigarette ember when the user draws air
into it (although at least one brand comes in a slick-looking black color
with a blue LED). A sensor turns the device on when a drop in internal
pressure is created by the user taking a drag. Powered by a rechargeable
battery, an atomizer converts liquid nicotine (mixed with other chemicals
and flavorings) into a warm mist, allowing it to be drawn into the lungs.
The user then exhales a mist that looks a lot like smoke but is odorless.
Clearly, e-cigarettes allow the smoker to engage in most of the behavioral
aspects of smoking and may thereby turn out to be a very good quitting
aid, though their usefulness has yet to be thoroughly studied. But even if
they did not help anyone quit and just resulted in smokers switching over
to e-cigarettes, they would still have some value as a “harm reduction”
option for smokers. Essentially they amount to a nicotine delivery system
that mimics the actions associated with smoking without delivering any
known cancer-causing agents to the user. However, e-cigarettes should not
be viewed as risk-free. After all, users may remain addicted to nicotine even
though they eliminate their exposure to carcinogens. It’s analogous to switching
heroin addicts to methadone—the user may remain addicted, but to a less
dangerous compound. We will know more as research studies address this issue.
Meanwhile, e-cigarettes are gaining popularity rapidly in the United States among
both adults and teens.
The use of e-cigarettes—which deliver nicotine but contain no tobacco—
involves many of the same habits associated with smoking and delivers nicotine
to the lungs like cigarettes do. So the experience is very much like actual smoking—
without the smoke. Adding these habits to nicotine delivery makes it hard to determine
what role the nicotine alone plays in the reported calming effect.
*Excerpted from Buzzed: The Straight Facts about the Most Used and Abused Drugs from Alcohol to Ecstasy, Fully Revised and Updated Fourth Edition by Cynthia Kuhn, PhD, Scott Swartzwelder, PhD and Wilkie Wilson, PhD. Copyright 2014, 2008, 2003, 1998 by Cynthia Kuhn, Scott Swartzwelder and Wilkie Wilson. With permission of the publisher, W.W. Norton & Company, Inc. All rights reserved
FURTHER INFORMATION ON E-CIGARETTES
An Essay by Jed E. Rose, PhD
Originally Appeared in the April 11th Edition of the Wall Street Journal
The emergence of e‐cigarettes over the last 10 years has stirred an intense debate
as to the promise vs. perils of this new technology. In evaluating the potential public
health impact of e‐cigarettes, we must bear in mind the staggering toll of death and
disease caused by cigarette smoking throughout the world. In the U.S. alone, 540,000
premature deaths are attributed to smoking each year (http://www.nejm.org/doi/full/10.1056/NEJMsa1407211?rss=searchAndBrowse). In this context, we should not discourage
promising new approaches that might change this unacceptable status quo. As with any
new potentially therapeutic approach, we must evaluate e‐cigarettes based on information
currently available, while recognizing that an exhaustive analysis of all of the potential
long‐term effects will require many years of study. In the meantime, we cannot afford to
delay providing smokers with alternatives that may help them relinquish use of combustible
cigarettes, with their demonstrated harm.
The U.S. Surgeon General and other experts have linked the vast majority of smoking‐related
disease to the combustion products of smoke, not to the nicotine per se (http://www.nejm.org/doi/full/10.1056/NEJMp1314942). Nicotine is a powerfully addictive substance, but it is not the cause of cancer, lung disease or vascular disease seen in smokers. While quitting all nicotine containing products may be an ideal goal, smokers who try to stop on their own have less than a 5% chance of long‐term success, and only about a 10% chance with the assistance of a medical provider (http://tobaccocontrol.bmj.com/content/21/2/110.full.pdf+html). In this setting, the ability to switch from using cigarettes to e‐cigarettes
that contain nicotine but do not burn offers enormous promise as a means to save lives and reduce harm.
Highly credible organizations have concluded that e‐cigarettes are helpful in reducing or eliminating combustible tobacco use (http://onlinelibrary.wiley.com/doi/10.1111/add.12659/epdf). In fact, recently the British government’s drug regulatory authority, the MHRA, approved an e‐cigarette as a quit‐smoking medicine (http://www.telegraph.co.uk/news/health/news/12079130/Ecigarettes‐
win‐first‐approval‐as‐a‐medicine‐opening‐way‐for‐prescription‐by‐the‐NHS.html). This position is also supported by common sense when one considers that every other form of nicotine replacement studied to date has demonstrable efficacy in helping people stop smoking, including nicotine patch, gum, lozenge, nasal spray and inhaler. Compared to these FDA‐approved forms of nicotine replacement, e‐cigarettes can more effectively satisfy a smoker’s craving by delivering nicotine as rapidly as does a cigarette, while also replacing the habitual aspects of smoking, which research has shown to be
critically important to smokers. Given these findings, it is not surprising that many smokers are able to switch from cigarettes to e‐cigarettes. As e‐cigarette technology improves, these devices will almost certainly become more effective tools to aid smokers in breaking their addiction to combustible cigarettes.
Expert panels have also concluded that e‐cigarettes are associated with a profound reduction of overall health risks ‐‐ 95% or more, compared to combustible cigarettes
alth_England_FINAL.pdf). Although no substance is “absolutely safe,” available current evidence overwhelmingly supports the view that e‐cigarettes are reasonably safe, far less risky than cigarettes, and clearly help some smokers to quit. In the U.S., appropriate regulation by the FDA is needed to ensure that e‐cigarettes will adhere to accepted safety standards.
Despite expert consensus, some researchers have focused their attention primarily on exaggerated health concerns. These reports have a sensational quality and often gain wide coverage by the press. For example, some early reports suggested that e‐cigarettes produce formaldehyde, a toxic substance found in cigarette smoke (http://www.nejm.org/doi/full/10.1056/NEJMc1413069). More recent research, however, has shown that under normal operating conditions, e‐cigarettes release far less formaldehyde than cigarettes (http://www.sciencedirect.com/science/article/pii/S1438463916000158). Moreover, because there are numerous carcinogens in cigarette smoke, the formaldehyde component of cigarette smoke has been estimated to raise smokers’ risk of cancer by less than 1 part in 1000. Thus the overall cancer risk presented by formaldehyde in e‐cigarette vapor is likely to be insignificant. In contrast, cigarette smoking with its many carcinogens presents a significant risk of cancer, including a 1
in 6 chance of developing lung cancer (http://www.nature.com/nrc/journal/v9/n9/full/nrc2703.html). Other researchers have pointed to the rising use of e‐cigarettes among adolescents and the correlation between adolescent e‐cigarette use and subsequent smoking. This is an indisputably important area of inquiry, but again the concerns have been exaggerated. While there is experimentation with e‐cigarettes among youth, there is no evidence that youth are becoming addicted to e‐cigarettes in large numbers or that adolescents who experiment with e‐cigarettes and later use combustible
cigarettes would not have used combustible cigarettes anyway, due to predisposing genetic and environmental factors. Another report examining population data suggested that e‐cigarettes may not be effective for smokers who want to quit (http://www.thelancet.com/journals/lanres/article/PIIS2213‐2600%2815%2900521‐4/fulltext). This report gained wide press coverage but
was flawed because smokers who turn to e‐cigarettes may be a self‐selected group that finds quitting smoking especially difficult. The gold standard scientific method for assessing efficacy is the randomized clinical trial, and two trials to date have shown e‐cigarettes can help smokers quit (http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD010216.pub2/full).
Having worked my entire career to develop effective smoking cessation treatments, including the nicotine patch, I have realized that current approaches are ineffective for the vast majority of smokers. Alternative approaches that promote cessation and harm reduction are urgently needed. The World Health Organization predicts 1 billion deaths will be attributable to smoking during the 21st century (http://www.who.int/tobacco/mpower/mpower_report_full_2008.pdf); e‐cigarettes
have an unparalleled potential to reduce the health impact of smoking by allowing smokers to replace the habit and nicotine of smoking, without the toxic effects of combustion. Therefore, smokers who are unable to quit should not be discouraged from using e‐cigarettes instead of smoking.
Author disclosure. I have devoted my career over the past 35 years to the development of more effective smoking cessation treatments. I have contributed to the development of the nicotine skin patch, provided data supporting the rationale underlying the development of varenicline, and developed personalized, adaptive smoking cessation treatment algorithms. The worldwide annual death toll from smoking and the limited long-term success rates of abstinence-oriented cessation treatments has convinced me that harm reduction has an important role in reducing the adverse public health impact of smoking. In recent years, I have also contributed to the invention of novel approaches to nicotine inhalation for tobacco harm reduction or cessation. Along with the U.S. Food and Drug Administration and proponents of the Family Smoking Reduction and Tobacco Control Act, I have accepted that the tobacco industry has a valid and major role in developing reduced risk tobacco products. I have accepted research funding from the tobacco industry, under conditions that provide transparency and oversight to ensure research integrity, and currently serve as a paid consultant to Philip Morris International, specifically to support development of reduced risk products. I am listed as an inventor on a nicotine inhalation technology sold to that company, but have no financial interest in the future sale of products.