Maintaining Nicotine Dependence Nicotine and Dependence

3.3.4 Marketing of Cigarettes with a “Reduced” Health Risk

By฀even฀discussing฀technical฀aspects฀of฀cigarette฀production,฀the฀tobacco฀industry฀used฀ every฀endeavour฀to฀make฀the฀purchaser฀believe฀that฀the฀modern฀cigarette฀represented฀less฀ of฀a฀health฀risk฀than฀cigarettes฀in฀the฀past.฀Thus,฀it฀pointed฀to฀the฀installation฀of฀the฀cigarette฀ ilter฀ [53] ฀and฀has฀repeatedly฀cited฀the฀minimal฀health฀risk฀associated฀with฀this฀product.฀For฀ the฀consumer,฀however,฀the฀tobacco฀industry฀has฀never฀communicated฀clearly฀where฀the฀ health฀risk฀actually฀lies.฀At฀most฀it฀is฀stated฀that฀the฀newer฀“low-nicotine฀and฀low-tar”฀ciga- rettes฀light฀and฀ultralight฀cigarettes฀are฀“healthier”฀than฀regular฀cigarettes฀e.g.฀Viceroy,฀ Marlboro,฀Winston฀ [54] ฀Tables฀ 3.4 – 3.6 .฀With฀the฀cigarette฀industry฀making฀such฀claims,฀ light฀and฀ultralight฀cigarettes฀are฀smoked฀more฀frequently฀than฀“orthodox”฀brands฀ [41] .฀ The฀actual฀concentrations฀of฀toxic฀substances฀CO,฀benzo[a]pyrene฀have฀since฀been฀pub- lished฀Tables฀ 3.5 ฀and฀ 3.6 .

3.3.5 Compensatory Behaviour by Smokers

The฀tobacco฀industry฀realised฀relatively฀soon฀that฀light฀cigarettes฀are฀smoked฀differently฀ from฀regular฀cigarettes,฀a฀fact฀that฀was฀also฀evident฀from฀a฀comparison฀of฀human฀smoking฀ behaviour฀patterns฀with฀those฀of฀a฀smoking฀machine฀ [55] .฀The฀dependent฀smoker฀immedi- ately฀detects฀the฀modiied฀release฀pattern฀of฀nicotine฀from฀the฀new฀cigarettes.฀Cigarettes฀ with฀a฀reduced฀nicotine฀yield฀are฀inhaled฀more฀deeply฀to฀obtain฀the฀same฀nicotine฀dose.฀In฀ many฀cases,฀especially฀in฀situations฀of฀stress฀or฀altered฀psychological฀mood,฀either฀stronger฀ Table 3.6 ฀฀฀A฀comparison฀of฀smoke฀data฀for฀two฀low-yield฀US฀ilter฀cigarettes฀smoked฀according฀to฀ the฀FTC฀method฀and฀by฀smokers฀ [109] Parameters FTC฀machine฀ smoking Cigarette฀smokers FTC฀0.6–0.8฀nicotine FTC฀0.9–1.2฀nicotine Puff Volume฀ml 35.0 48.6฀45.2–52.3 a 44.1฀40.8–46.8 b Interval฀s 58.0 21.3฀19.0–23.8 a 18.5฀16.5–20.6 b Duration฀s 2.0 1.5฀1.4–1.7 a 1.5฀1.4–1.6 b Nicotine฀ mgcigarette 0.7฀0.6–0.8 1.74฀1.54–1.98 c 2.39฀2.20–2.60 d 0.1฀1.09–1.13 Tar฀mgcigarette 8.5฀7.7–9.5 22.3฀18.8–26.5 e 29.0฀25.8–32.5 f 15.4฀14.2–14.9 CO฀mgcigarette 9.7฀9.0–10.4 17.3฀15.0–20.1 g 22.5฀20.3–25.0 h 14.6฀14.2–14.9 BaP฀ngcigarette 10฀8.2–12.3 17.9฀15.3–20.9 i 21.4฀19.2–23.7฀ j 14฀10.1–19.4 NNK฀ngcigarette 112.9฀96.6–113.0 186.5฀158.3–219.7 i 250.9฀222.7–282.7฀ j 146.2฀132.5–165.5 Test฀groups:฀ a 56,฀ b 71,฀ c 30,฀ d 42,฀ e 18,฀ f 19,฀ g 15,฀ h 16,฀ i 6฀and฀ j 3฀smokers cigarettes฀ are฀ used฀ or฀ two฀ or฀ more฀ cigarettes฀ are฀ smoked฀ in฀ rapid฀ succession฀ [56] .฀ Observations฀of฀this฀kind฀were฀made฀with฀the฀Marlboro฀Light฀brand฀ [57] .฀In฀fact,฀observa- tions฀and฀indings฀obtained฀with฀light฀cigarettes฀have฀often฀been฀the฀subject฀of฀publications฀ [25,฀54,฀58,฀59] .฀The฀health-related฀consequences฀of฀long-term฀use฀of฀these฀cigarettes฀can- not฀ yet฀ be฀ foreseen,฀ especially฀ because฀ they฀ are฀ smoked฀ with฀ greater฀ intensity,฀ deeper฀ inhalation฀and฀larger฀inhaled฀and฀exhaled฀volumes฀ [60] .฀Many฀smokers฀were฀previously฀ unaware฀that฀light฀cigarettes฀have฀or฀had฀vents฀in฀the฀ilter฀to฀improve฀ventilation฀e.g.฀the฀ Winston฀“Reds”฀brand฀ [61–64] .฀The฀tobacco฀industry฀argued฀unoficially฀that฀as฀the฀ciga- rette฀increasingly฀burns฀down,฀the฀holes฀become฀blocked฀and฀hence,฀the฀release฀of฀nicotine฀ is฀increased฀ [65] . Cigarettes฀with฀selective฀reductions฀in฀nicotine฀delivery฀have฀been฀considered฀as฀poten- tial฀tools฀to฀prevent฀or฀treat฀nicotine฀dependence฀or฀reduce฀harm฀by฀virtue฀of฀reduced฀nico- tine฀and฀nitrosamine฀delivery.฀An฀important฀question฀is฀whether฀individuals฀smoke฀these฀ products฀more฀intensively,฀as฀has฀been฀shown฀to฀occur฀with฀ventilated-ilter฀cigarettes.฀To฀ investigate฀this฀issue,฀we฀compared฀conventional฀highly฀ventilated฀ilter฀cigarettes,฀having฀ very฀low฀tar฀and฀nicotine฀yields฀when฀smoked฀by฀Federal฀Trade฀Commission฀method฀1฀mg฀ tar,฀2฀mg฀carbon฀monoxide฀[CO],฀2฀mg฀nicotine,฀with฀low฀nicotine฀content฀cigarettes,฀ manufactured฀from฀a฀genetically฀modiied฀strain฀of฀tobacco,฀which฀had฀higher฀tar฀but฀lower฀ nicotine฀yield฀14฀mg฀tar,฀13฀mg฀CO,฀02฀mg฀nicotine.฀A฀total฀of฀16฀cigarette฀smokers฀par- ticipated฀in฀two฀8-h฀sessions฀order฀counterbalanced฀during฀which฀they฀smoked฀each฀type฀ of฀cigarette฀ad฀libitum.฀Expired-air฀CO,฀plasma฀nicotine฀and฀smoking฀topography฀measures฀ were฀collected.฀Subjects฀showed฀signiicant฀increases฀in฀smoking฀when฀using฀the฀highly฀ ventilated฀ilter฀cigarettes฀and฀puff฀volume฀was฀signiicantly฀greater฀than฀with฀the฀low฀nico- tine฀content฀cigarettes.฀Subjects฀achieved฀an฀expired-air฀CO฀level฀of฀as฀high฀as฀74฀with฀ the฀low฀nicotine฀content฀cigarettes;฀the฀latter฀produced฀CO฀levels฀similar฀to฀those฀measured฀ at฀baseline฀when฀subjects฀smoked฀their฀habitual฀brands฀of฀cigarettes.฀Plasma฀nicotine฀levels฀ obtained฀ when฀ subjects฀ smoked฀ the฀ highly฀ ventilated฀ ilter฀ cigarettes฀ also฀ were฀ signii- cantly฀higher฀than฀when฀they฀smoked฀the฀low฀nicotine฀content฀cigarettes.฀These฀results฀ indicate฀that฀the฀delivery฀of฀substantial฀amount฀of฀smoke,฀with฀selective฀reductions฀in฀nico- tine฀yield,฀appears฀to฀prevent฀compensatory฀smoking฀behaviour.฀Further฀studies฀should฀ determine฀whether฀similar฀results฀are฀obtained฀in฀naturalistic฀environments฀ [66] .

3.3.6 Optimising Nicotine Release

According฀to฀the฀tobacco฀industry,฀one฀of฀its฀crucial฀research฀objectives฀was฀to฀increase฀the฀ availability฀of฀nicotine฀released฀from฀tobacco฀to฀smokers฀as฀the฀free฀base:฀the฀pH฀of฀tobacco฀ has฀an฀important฀function฀in฀this฀context.฀Depending฀on฀pH,฀nicotine฀is฀present฀in฀the฀form฀ of฀a฀diprotonated฀or฀monoprotonated฀salt฀and฀as฀the฀free฀base฀ [67] .฀The฀former฀is฀the฀bound฀ form฀pK 1 ฀=฀3.02฀and฀the฀latter฀is฀the฀freely฀available฀form฀pK 1 ฀=฀8.02.฀The฀free฀form฀ penetrates฀biological฀membranes฀very฀rapidly฀and฀extensively,฀whereas฀the฀penetration฀of฀ the฀ bound฀ form฀ is฀ very฀ much฀ slower฀ and฀ less฀ quantitative.฀ Because฀ the฀ nicotine฀ base฀ reaches฀the฀brain฀far฀more฀rapidly,฀the฀tobacco฀industry฀became฀aware฀of฀this฀property฀of฀ free฀ nicotine฀ at฀ a฀ very฀ early฀ stage฀ [68] .฀ The฀ higher฀ the฀ pH,฀ the฀ greater฀ the฀ amount฀ of฀ extractable฀nicotine฀ [69] .฀The฀pH฀of฀cigarette฀smoke฀is฀between฀6.5฀and฀7.0,฀a฀range฀in฀