Tobacco Additives ebooksclub.org Tobacco or Health Physiological and Social Damages Caused by Tobacco Smoking Second Edition

Principles Substance Effects Additives฀with฀a฀ pharma-cologi- cal฀effect Free฀nicotine฀base Ammonium Ammonium฀technology฀increases฀release฀in฀ smoke฀ [110] Dissociation฀of฀increasing฀nicotine฀effect฀and฀ tar฀yield฀reduction฀ [14] Additives฀that฀ enhance฀the฀ effect฀of฀ nicotine Acetaldehyde฀produced฀by฀ the฀burning฀of฀sugars Laevulinic฀acid฀degradation฀ product฀of฀starch,฀cane฀ sugar฀and฀cellulose Cocoa฀and฀theobromine Glycyrrhizin฀an฀ingredient฀of฀ liquorice Pyridine฀from฀tobacco Increases฀the฀addictive฀effects฀of฀nicotine฀ [110,฀ 111] ,฀optimised฀sugar฀content฀of฀the฀ cigarette฀provides฀the฀basis฀for฀optimal฀ formation฀of฀acetaldehyde฀and฀thus฀for฀an฀ optimal฀nicotineacetaldehyde฀ratio฀ [110] Nicotine฀laevulinate฀removes฀the฀harshness฀ from฀the฀tobacco฀lavour฀while฀preserving฀ the฀aroma,฀the฀salt฀also฀intensiies฀binding฀ to฀the฀high-afinity฀nicotine฀receptors฀by฀ about฀30฀ [112] Cocoa฀contains฀alkaloids฀which฀modify฀the฀ effects฀of฀nicotine:฀one฀such฀alkaloid฀is฀ theobromine฀1,฀which฀has฀bronchodila- tor฀activity฀and฀thus฀improves฀absorption฀ on฀inhalation฀ [113] Possesses฀bronchodilator฀activity,฀to฀date฀this฀ effect฀is฀suspected฀during฀smoking Acts฀like฀nicotine฀but฀is฀less฀reliable.฀Has฀a฀ central฀calming฀action.฀Like฀nicotine,฀ pyri฀dine฀is฀formed฀on฀pyrolysis.฀Both฀ sub฀stances฀have฀CNS-antagonist฀activity฀ [114] Flavour฀modiiers฀ required฀to฀ improve฀the฀ taste฀of฀ nicotine Sugar Liquorice Chocolate Cocoa฀butter Improves฀lavour,฀particularly฀due฀to฀the฀ sugar-ammonium฀reaction฀ [115] ฀by฀giving฀ smoke฀a฀mild฀and฀natural฀lavour Added฀to฀sugar฀to฀improve฀the฀lavour฀of฀the฀ smoke฀more฀mellow,฀woody฀ [116] Harsh฀tobacco฀lavour฀is฀rounded฀off฀by฀traces฀ of฀chocolate Makes฀tobacco฀smoke฀less฀harsh฀ [117] Additional฀toxins Coumarins Acetaldehyde Powerful฀aromatic฀agents,฀but฀hepatotoxic,฀ use฀now฀mostly฀abandoned Mutagenic,฀embryotoxic,฀causes฀tumours฀in฀ the฀respiratory฀tract Additional฀toxins Furfural฀acetate Maltol Eugenol Mutagenic,฀has฀a฀synergistic฀carcinogenic฀ effect฀in฀conjunction฀with฀benzo[a]pyrene Mutagenic฀only฀in฀vitro As฀a฀phenol,฀its฀carcinogenic฀activity฀is฀ uncertain฀ [118] ;฀tests฀required Substances฀that฀ alter฀ side-stream฀ smoke Sodium฀acetate Calcium฀hydroxide Used฀in฀cigarette฀paper฀instead฀of฀tripotassium฀ citrate,฀hence฀less฀visible฀side-stream฀ smoke฀through฀the฀paper฀ [119] Less฀irritating฀for฀non-smokers฀after฀ impregnation฀of฀cigarette฀paper฀ [120] ,฀ milder฀aroma Table 3.7 ฀฀฀Select฀list฀of฀tobacco฀constituents฀used฀in฀cigarette฀production฀and฀their฀effects฀on฀the฀ smoker฀ [80] synthetic฀substances฀ [87,฀88] .฀Cigarette฀additives฀have฀also฀been฀found฀to฀reduce฀the฀per- ception฀of฀environmental฀tobacco฀smoke฀ETS;฀ [87] . Legislators฀and฀consumers฀falsely฀assume฀that฀additives฀make฀it฀easier฀for฀the฀consumer฀ to฀accept฀cigarettes฀with฀a฀low฀tar฀yield฀and฀that฀the฀health฀risks฀are,฀thus,฀also฀reduced.฀ These฀cigarettes฀have฀perforated฀ilters฀in฀order฀to฀dilute฀the฀inhaled฀air.฀However,฀smokers฀ very฀quickly฀learn฀to฀cover฀these฀perforations฀with฀their฀hands฀in฀order฀either฀to฀regulate฀ nicotine฀delivery฀or฀to฀achieve฀deeper฀inhalation. The฀modern฀US฀cigarette฀contains฀10฀additives฀calculated฀with฀reference฀to฀weight,฀ mostly฀in฀the฀form฀of฀sugar,฀aromatic฀agents฀and฀moistening฀agents.฀They฀contain฀further฀ additives฀that฀modify฀the฀effects฀of฀nicotine฀and฀make฀the฀inhaled฀mainstream฀and฀evap- orating฀side-stream฀smoke฀appear฀more฀pleasant฀and฀less฀annoying.฀In฀this฀context,฀it฀is฀ important฀to฀remember฀that฀side-stream฀smoke฀sometimes฀contains฀higher฀levels฀of฀toxic฀ substances฀ than฀ mainstream฀ smoke;฀ CO฀ levels฀ in฀ side-stream฀ smoke,฀ for฀ example,฀ are฀ 4–14฀times฀higher฀than฀those฀in฀mainstream฀smoke฀see฀Fig.฀ 3.2 .

3.5 Cigarettes with Reduced Tar Yield

If฀cigarettes฀are฀labelled฀“Light”฀and฀“Ultralight”,฀smokers฀imagine฀that฀there฀are฀a฀number฀ of฀advantages:฀reduced฀tar฀and฀nicotine฀yields,฀lesser฀risk฀to฀health฀and฀milder฀lavour.฀A฀ considerable฀proportion฀of฀smokers฀believe฀that฀lower-tar฀cigarettes฀are฀less฀dangerous฀than฀ regular฀ cigarettes.฀ According฀ to฀ the฀ representative฀ judgement฀ of฀ smokers฀ of฀ ultralight฀ 45.7,฀light฀32.2฀and฀regular฀cigarettes฀22,฀ultralight฀cigarettes฀reduce฀the฀risk฀of฀ cancer฀ [88] .฀In฀a฀survey฀of฀12,371฀Canadians,฀the฀label฀“Light”฀was฀associated฀with฀“less฀tar”฀ 20.1,฀ “less฀ nicotine”฀ 36.2,฀ “greater฀ safety”฀ or฀ “induces฀ less฀ dependence”฀ 3.2,฀ “milder฀taste”฀6.7฀and฀“nothing”฀or฀“marketing฀trick”฀14.1.฀The฀term฀did฀not฀convey฀ anything฀at฀all฀to฀a฀large฀proportion฀of฀survey฀respondents฀ [89] .฀For฀the฀most฀part,฀smokers฀ are฀unaware฀of฀the฀tar฀and฀nicotine฀yields฀of฀the฀cigarettes฀they฀smoke฀and฀believe฀that฀they฀ are฀reducing฀the฀risk฀to฀their฀health฀by฀smoking฀light฀40฀and฀ultralight฀cigarettes฀60฀ [87,฀89] .฀In฀the฀context฀of฀other฀surveys,฀lower฀scores฀were฀reported฀for฀these฀questions฀see฀ also฀ [88] .฀According฀to฀the฀Canadian฀survey,฀in฀fact,฀more฀smokers฀complained฀of฀health฀ problems฀emphysema,฀asthma,฀lung฀cancer,฀stroke฀after฀switching฀from฀regular฀to฀light฀ cigarettes฀compared฀with฀smokers฀who฀stayed฀with฀regular฀cigarettes฀2.13฀vs.฀1.94฀ [89] . Smokers฀frequently฀ignore฀the฀existence฀of฀cigarettes฀with฀a฀reduced฀tar฀yield,฀despite฀ the฀declaration฀on฀the฀packs.฀Consumers฀interpret฀these฀igures฀as฀a฀relection฀of฀varying฀ levels฀of฀damage฀to฀health.฀Table฀ 3.5 ฀presents฀details฀of฀the฀tar฀and฀nicotine฀yields฀of฀dif- ferent฀cigarette฀brands.฀Various฀studies฀indicate฀that฀there฀are฀no฀reliable฀data฀to฀show฀that฀ switching฀from฀regular฀to฀light฀cigarettes฀reduces฀cigarette฀consumption฀or฀the฀desire฀to฀ smoke฀ [89] .฀Also,฀switching฀from฀regular฀to฀light฀cigarettes฀as฀a฀deliberate฀interim฀strategy฀ does฀not฀ultimately฀improve฀success฀rates฀for฀smoking฀cessation. From฀the฀lawsuits฀against฀the฀tobacco฀industry฀in฀the฀USA,฀it฀has฀emerged฀that฀the฀ tobacco฀companies฀knew฀for฀decades฀about฀the฀discrepant฀and฀distorted฀results฀obtained฀ with฀smoking฀machines฀based฀on฀criteria฀deined฀by฀the฀ISO฀International฀Organization฀ for฀ Standardization,฀ founded฀ in฀ 1946฀ to฀ promote฀ worldwide฀ trade฀ and฀ collaboration.฀ Agencies฀in฀the฀USA฀including฀the฀Federal฀Trade฀Commission,฀the฀FDA฀and฀the฀National฀ Cancer฀Institute฀are฀now฀working฀towards฀a฀useful฀solution฀to฀the฀problem.฀The฀European฀ Commission฀is฀also฀preparing฀proposals฀for฀the฀correct฀measurement฀of฀tar฀and฀nicotine฀ yields฀in฀cigarettes. A฀few฀smokers฀may฀actually฀beneit฀minimally฀from฀low-tar฀cigarettes,฀but฀the฀health฀ consequences฀in฀a฀positive฀sense฀have฀not฀yet฀been฀demonstrated.฀However,฀it฀has฀been฀ shown฀that฀deeper฀inhalation฀is฀associated฀with฀an฀increase฀in฀adenocarcinomas,฀a฀type฀of฀ cancer฀rarely฀seen฀in฀the฀past฀and฀affecting฀the฀deep฀sections฀of฀lung฀tissue.฀One฀study฀ published฀in฀1997฀presented฀summary฀data฀on฀smokers฀who฀had฀smoked฀light฀and฀ultra- light฀cigarettes฀over฀the฀period฀from฀1959฀to฀1991฀and฀who฀were฀found฀to฀have฀an฀increased฀ incidence฀of฀adenocarcinomas;฀these฀tumours฀were฀found฀to฀occur฀17฀times฀more฀com- monly฀in฀women฀and฀10฀times฀more฀commonly฀in฀men฀ [90,฀91] . In฀2003,฀Kabat฀published฀a฀review฀on฀50฀years’฀experience฀of฀reduced-tar฀cigarettes฀and฀ posed฀the฀question฀about฀the฀known฀health฀effects฀ [92] .฀It฀was฀stated฀that฀since฀1950s,฀ciga- rettes฀sold฀in฀the฀United฀States฀have฀undergone฀a฀progressive฀modiication,฀including฀the฀ addition฀of฀ilters฀and฀a฀reduction฀in฀the฀average฀machine-measured฀tar฀and฀nicotine฀yield฀ per฀cigarette฀by฀over฀60.฀These฀and฀other฀temporal฀changes฀in฀manufactured฀cigarettes,฀ coupled฀with฀the฀complexity฀of฀smoking฀behaviour,฀make฀it฀dificult฀to฀assess฀the฀impact฀ of฀the฀newer฀cigarettes฀on฀health.฀Some฀researchers฀have฀suggested฀that฀the฀newer฀prod- ucts,฀marketed฀as฀being฀less฀harmful,฀may฀in฀fact฀provide฀no฀beneit฀compared฀to฀the฀older,฀ higher฀tar฀cigarettes.฀Kabat฀critically฀evaluated฀the฀available฀epidemiologic฀evidence฀on฀ the฀health฀effects฀of฀low-tar฀cigarettes.฀After฀identifying฀important฀methodological฀prob- lems฀ confronting฀ research฀ in฀ this฀ area,฀ studies฀ of฀ lung฀ cancer,฀ coronary฀ heart฀ disease,฀ chronic฀obstructive฀pulmonary฀disease฀and฀total฀mortality฀were฀examined฀in฀terms฀of฀their฀ strengths฀and฀weaknesses฀and฀their฀results.฀Thirty-ive฀studies฀of฀lung฀cancer฀were฀found฀ to฀be฀suggestive฀that฀smokers฀of฀low฀tar฀cigarettes฀have฀a฀lower฀risk฀by฀20–30฀com- pared฀to฀smokers฀of฀higher฀tar฀cigarettes.฀Only฀a฀minority฀of฀studies฀of฀heart฀disease฀pro- vided฀evidence฀of฀a฀reduction฀in฀risk,฀on฀the฀order฀of฀10.฀Studies฀concerning฀chronic฀ obstructive฀ pulmonary฀ disease฀ COPD฀ were฀ inconsistent,฀ but฀ the฀ majority฀ suggest฀ decreased฀risk฀in฀smokers฀of฀lower฀tar฀cigarettes.฀Finally,฀studies฀that฀included฀total฀mor- tality฀indicated฀with฀a฀high฀degree฀of฀consistency฀that฀the฀total฀death฀rate฀is฀reduced฀in฀ smokers฀of฀lower฀tar฀cigarettes,฀on฀the฀order฀of฀10–20฀ [92] . However,฀there฀are฀also฀studies฀that฀indicate฀that฀there฀are฀no฀major฀changes฀and฀addi- tional฀analyses฀of฀existing฀data฀sets฀could฀further฀clarify฀the฀impact฀of฀low-tar฀cigarettes.฀ In฀this฀respect,฀a฀further฀analysis฀by฀Thun฀and฀Burns฀also฀examined฀the฀epidemiological฀ evidence฀relevant฀to฀the฀health฀consequences฀of฀“reduced฀yield”฀cigarettes฀ [93] .฀They฀con- clude฀that฀some฀epidemiological฀studies฀have฀found฀attenuated฀risk฀of฀lung฀cancer,฀but฀not฀ other฀diseases,฀among฀people฀who฀smoke฀“reduced฀yield”฀cigarettes฀compared฀to฀smokers฀ of฀uniltered,฀high฀yield฀products.฀These฀studies฀probably฀overestimated฀the฀magnitude฀of฀ any฀association฀with฀lung฀cancer฀by฀overadjusting฀for฀the฀number฀of฀cigarettes฀smoked฀per฀ day฀one฀aspect฀of฀compensatory฀smoking฀and฀by฀not฀fully฀considering฀other฀differences฀ between฀smokers฀of฀“high฀yield”฀and฀“low฀yield”฀cigarettes.฀Selected฀cohort฀studies฀in฀the฀ USA฀and฀UK฀were฀found฀that฀showed฀that฀lung฀cancer฀risk฀continued฀to฀increase฀among฀ older฀smokers฀from฀the฀1950s฀to฀the฀1980s,฀despite฀the฀widespread฀adoption฀of฀lower฀yield฀