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 Like many people, Daniel believes nicotine gum is far less harmful
for him than smoking. Doctors worldwide agree. By giving up
cigarettes, they say, Daniel has removed at least 90 percent of the
health risks of his habit.
Even so, the possibility that people can be addicted to nicotine,
but not die from it, is at the heart of a growing debate in the
scientific community. Scientists don’t doubt nicotine is addictive,
but some wonder if a daily dose could be as benign as the caffeine
many of us get from a morning coffee.
It’s a debate that has been aggravated by the rising popularity of
electronic cigarettes - tobacco-free gadgets people use to inhale
nicotine-laced vapor, which have helped some people quit smoking.
The idea of nicotine as relatively benign goes against the negative
image of the drug that built up over the decades when smoking rose
to become an undisputed health threat.
Psychologists and tobacco-addiction specialists, including some in
world-leading laboratories in Britain, think it's now time to
distinguish clearly between nicotine and smoking. The evidence shows
smoking is the killer, not nicotine, they say.
"We need to de-demonize nicotine," said Ann McNeill, a professor of
tobacco addiction and the Institute of Psychiatry, Psychology &
Neuroscience at King's College London, who has spent her career
researching ways to help people quit smoking.
She wants people to understand the risks are nuanced – that
potential harms lie on a curve with smoking at one end, and nicotine
at the other. People who don't see that may hesitate to seek help
stopping smoking, or try to restrain their intake of nicotine
replacement therapy (NRT). That can make it harder to quit.
Some studies show nicotine, like caffeine, can even have positive
effects. It's a stimulant, which raises the heart rate and increases
the speed of sensory information processing, easing tension and
sharpening the mind.
All this raises other questions: Could nicotine prime the brains of
young people to seek harder stuff? Or, in an aging society, could
its stimulant properties benefit people whose brains are slowing,
warding off cognitive decline into Alzheimer’s and delaying the
progression of Parkinson’s disease?
So far the answers aren’t clear. And the divide is as political and
emotional as it is scientific.
RELATIVE HARMS
McNeill says her work is, in part, to honor the legacy of her former
mentor at King's, British psychiatrist Mike Russell. About 40 years
ago, Russell was one of the first scientists to suggest that people
"smoke for the nicotine, but die from the tar" – an idea that helped
lay the ground for the NRT business of gums, patches, vaporizers and
now e-cigarettes.
Some scientists note Russell’s insight has been misused by the
tobacco industry. For decades, companies’ false promises of “light”
cigarettes helped lure more smokers, says Mike Daube, professor of
health policy at Curtin University in Australia. “We have seen more
than six decades of tobacco industry distraction products,
promotions and deceptions,” he says. “They reveled in advertising
that implied both reduced risks and even health benefits.”
Smoking kills half of all those who do it - plus 600,000 people a
year who don't, via second-hand smoke - making it the world's
biggest preventable killer, with a predicted death toll of a billion
by the end of the century, according to the World Health
Organization.
Few doubt that nicotine is addictive. How quickly it hooks people is
closely linked to the speed at which it is delivered to the brain,
says McNeill. The patch is very slow; gum is slightly quicker. But
there is no evidence as yet that significant numbers of people are
addicted to either. Daniel, who works long hours in London's
financial district, says he chews less on weekends when he's
relaxing, doing sport and hanging out with his kids.
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One reason smoking is so addictive is that it's a highly efficient
nicotine delivery system, McNeill says. “Smoking a tobacco cigarette
is one of the best ways of getting nicotine to the brain - it's
faster even than intravenous injection." Also, tobacco companies
used various chemicals to make the nicotine in cigarettes even more
potent.
Pure nicotine can be lethal in sufficient quantities. There is some
evidence it may lead to changes in adolescent brain development,
especially to the part responsible for intelligence, language and
memory.
Stanton Glantz, a professor of tobacco at the University of
California, San Francisco, says the younger kids are when they start
using nicotine, the more heavily addicted they get. "This is likely
because their brains are still developing," he said.
Countering that, others say studies have focused on animals and that
in any case, nicotine should not be available to under-18s. Michael
Siegel, a tobacco control expert and professor at Boston University,
says that in the few studies so far, such effects have been seen
only in smokers, not smoke-free nicotine users.
Elsewhere, studies have looked at nicotine's potential to prevent
Alzheimer's disease, and to delay the onset of Parkinson's.
A study in the journal Brain and Cognition in 2000 found that
“nicotinic stimulation may have promise for improving both cognitive
and motor aspects of Parkinson's disease.” Another, in Behavioral
Brain Research, suggested “there is considerable potential for
therapeutic applications in the near future.” Other work has looked
at the stimulant's potential for easing symptoms of attention
deficit hyperactivity disorder (ADHD).
In Sweden, many people get their nicotine from sucking smoke-free
tobacco called "snus." Research there has put rates of lung cancer,
heart disease and other smoking-related illness among the lowest in
Europe.
“FUNCTIONAL ADDICTION”
Even so, the idea of "safe nicotine" has not caught on.
Marcus Munafo, a biological psychologist at Britain's Bristol
University, says public health campaigns of the 1970s and 1980s
bound nicotine, addiction and cigarettes tightly together to hammer
home smoking's harms. Those associations may blur the potential for
cleaner nicotine to lure smokers away from cigarettes.
Munafo is questioning the notion that a nicotine addiction is, in
itself, bad. At a "smoking laboratory" in Munafo’s department,
people who are still hooked on cigarettes smoke under controlled
conditions. At the moment, researchers are studying genetic
differences in how deeply people inhale, as part of a project
analyzing people’s needs and responses to nicotine.
"Should we really be that bothered about addiction in and of itself,
if it doesn't come with any other substantial harms?” said Munafo.
“It's at least a discussion we need to have."
(Edited by Sara Ledwith)
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