Since the 1980s, tobacco companies have
investigated and brought to market cigarettes
that heat, but not burn, tobacco, or have
modifi ed the tobacco blend to reduce specifi c
toxic and/or carcinogenic compounds in the
smoke. Cigarette smoke, which contains about
150 toxicants, causes a host of fatal health
problems, including cardiovascular disease,
chronic obstructive pulmonary disease, stroke
and cancer. Nevertheless, at least a fi fth of
people over 16 in Britain and nearly a third of 20
to 24-year-olds still smoke.
Now, British American Tobacco (BAT) is
conducting its fi rst clinical trial-type study of
novel cigarettes that have been designed to
produce less toxicants in their smoke, compared
with conventional cigarettes. While it is only a
fi rst step towards genuinely safer cigarettes, new
legislation in the US could encourage further
innovation in this controversial area.
The idea behind BAT's study is to fi nd the right
combination of technologies and biomarkers in
the body to ultimately develop and sell less toxic
cigarettes.
BAT's prototype products comprise three
different technologies (see Box), which, when
measured in the lab by a smoking machine,
are claimed to reduce many of the toxicants
in cigarette smoke by between 50 and 90%,
compared with conventional cigarettes. To test
whether this is actually the case when people
– not machines – smoke, the study involves
switching smokers of regular cigarettes to similar
strength novel cigarettes, measuring biomarkers
in their saliva and urine and comparing the
levels to those in smokers who weren't switched
and to non-smokers. If smoking the novel
cigarettes reduces the smokers' exposure to
various toxicants, the levels of the excreted
biomarkers should be reduced in those smoking the novel cigarettes (www.controlled-trials.com/
ISRCTN72157335).
But can smoking be made genuinely safer?
Robert West, Cancer Research UK-funded director
of tobacco studies at the UCL Health Behaviour
Research Centre, says: 'In my opinion the
tobacco industry seem perfectly happy to market
and aggressively promote addictive products
that they know kill millions of people. Research
into how their products might kill slightly fewer
millions seems to be rather missing the point.’
Others disagree. ‘There is a clear sense
within the scientific community, beyond those
that would take the “abstinence is the only
good approach to smoking”, that the smoke
from a cigarette, or cigarette-like product, can
be made less toxic, and from that it could be
argued that the negative biological impacts
of smoking could be reduced,’ says consultant
Roger Jenkins, a consultant and former chemist
at Oak Ridge National Laboratory in the US, who
has conducted research on tobacco smoke and
secondhand smoke exposure for the tobacco
industry and the Center for Indoor Air Research.
‘We have to move beyond demonising tobacco
companies to making it clear that we expect them to
raise the sense of urgency in developing genuinely
less harmful products,’ says Mallen Baker, a
consultant on corporate social responsibility.
‘Governments should either ban tobacco outright,
or make it possible and even necessary that reduced
harm products be developed that are accepted in
the marketplace.’
In June 2009, US president Barack Obama
signed historic legislation – The Family Smoking
Prevention and Tobacco Control Act – giving
the US Food and Drug Administration authority
to regulate tobacco products, which, like new
drugs, will now have to undergo rigorous
scientific review to support any health claims.
‘The US legislation is right to focus on the
composition of the products. We need tobacco
companies to have clear signals and incentives
to innovate to produce reduced harm products,’
says Baker.
David O' Reilly, BAT's head of public health
and scientific affairs, says that the effect on
innovation will depend on what the regulations
are. ‘Blanket bans on additives and ingredients
could stifl e innovation. Scientifically-based
frameworks could help promote safer products,’
he says.
Meanwhile, as far as it goes, BAT's study
would provide very useful information concerning
the utility of ‘potentially reduced exposure
products’, says Jenkins. But, although such
studies are an important first step, they cannot
determine whether smoking a lower toxicant
product would lead to a potentially improved
health outcome, he points out.
The current study builds on previous work
in which four of the chemicals in tobacco
smoke were correlated with biomarkers in the
body: nicotine with metabolites of nicotine
such as cotinine; 4-(methylnitrosamino)-1-(3-
pyridyl)-1-utanone (NNK) with the biomarker 4-(methylnitrosoamino)-1-butanol (NNAL);
acrolein with 3-hydroxypropyl mercapturicacid
(HPMA); and pyrene with 1-hydroxypyrene
(OHP). The current study, which started in April
2009, will measure these plus another 13 smoke
toxicants.
BAT has shown that it is possible to
measure the corresponding biomarkers of these
toxicants, but there is no evidence yet that
its products will reduce people's exposure to
those toxicants.
Some toxicants in tobacco smoke are also
found elsewhere: People can be exposed to
benzene, for example, at petrol stations, or
polyaromatic hydrocarbons in barbecued food,
and volatile nitrosamines from cooking bacon. To
control the conditions and minimise the effects
of metabolism and environment on biomarker
expression, the study participants – 250 smokers
and 50 non-smokers – will be confined to the
clinic and eat and drink similar things.
BAT's study measures biomarkers of exposure,
which help to assess the levels of toxicant inside
a person. But it is biomarkers of harm that
are needed to tell what biological effect those
toxicants are having over time. However, there
are few, if any, agreed-upon by the scientific
community. Finding those is a big part of BAT's
research programme, says Proctor.
What BAT's study does show, however,
is a more transparent model of tobaccoproduct
development. While other tobacco
scientists including Gerhart Scherer, and
tobacco companies such as RJ Reynolds, have
conducted similar studies on reduced exposure
products, BAT is registering its study online and
publishing results in a peer-reviewed journal.
‘The company made a commitment to openness
and transparency many years ago … before the
FDA legislation had even been conceived,’ says
O'Reilly.
‘If the [US] government supports BAT’s
commitment to openness, then other companies
may be pressured to follow suit,’ says Baker.
A big problem, however, is smokers'
acceptance of new products. BAT's novel
cigarettes contain similar amounts of nicotine as
normal cigarettes but, regardless of their relative
safety, smokers might not like them. The general
diluter in the tobacco, for example, produces
drops of glycerol in the smoke, which also
dilutes the taste, says Proctor. A lack of taste
could make smokers over smoke or draw harder
– as was the problem with the introduction of
low-tar cigarettes.
‘Getting consumers to give up something
that they perceive to taste better even though
there are much more healthy alternatives [like
diet drinks, for example] is not an easy thing to
do,’ says Jenkins. ‘Put simply, if the smoke does
not taste good to the smoking community, they
simply will not adopt the new product.’
BAT's trial results are expected in early
2010.
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