The health impact of smokeless tobacco products: a systematic review.

INTRODUCTION: The objective was to systematically review studies on health outcomes from smokeless tobacco (SLT) products. METHODS: We analysed published literature on the health outcomes from SLT use between 01/01/2015 to 01/02/2020, following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol using PubMed, Embase, Scopus, and Google Scholar. RESULTS: Of 53 studies included, six were global, 32 from Asia, Middle East and Africa (AMEA), nine from USA and six from Europe. 'Poor'-rated studies predominated (23;43%), in particular, for global (4;66%) and AMEA (16;50%). Health outcomes differed between SLT-products and regions; those in AMEA were associated with higher mortality (overall, cancer, Coronary heart disease (CHD), respiratory but not cardiovascular disease (CVD)), and morbidity (CVD, oral and head and neck cancers), with odds ratios up to 38.7. European studies showed no excess mortality (overall, CVD, from cancers) or morbidity (ischemic heart disease (IHD), stroke, oral, head and neck, pancreatic or colon cancers) from several meta-analyses; single studies reported elevated risk of rectal cancer and respiratory disorders. Pooled study data showed protection against developing Parkinson's disease. US studies showed mixed results for mortality (raised overall, CHD, cancer and smoking-related cancer mortality; no excess risk of respiratory or CVD mortality). Morbidity outcomes were also mixed, with some evidence of increased IHD, stroke and cancer risk (oral, head and neck). No studies reported on switching from cigarettes to SLT-products. CONCLUSION: Our review demonstrates stark differences between different SLT-products in different regions, ranging from zero harm from European snus to greatly increased health risks in AMEA. The literature on the safety profile for SLT-products for harm reduction is incomplete and potentially misinforming policy and regulation.

Role of snus in initiation and cessation of tobacco smoking in Sweden.

OBJECTIVE: To examine patterns of smoking and snus use and identify individual pathways of Swedish tobacco users in order to clarify whether snus use is associated with increased or decreased smoking. METHODS: Retrospective analysis of data from a cross-sectional survey completed by 6752 adult Swedes in 2001-2 focusing on identifying tobacco use history by survey items on current and prior tobacco use and smoking initiation and cessation procedures. RESULTS: 15% of the men and 19% of the women completing the survey were daily smokers. 21% of the men and 2% of the women were daily snus users. Almost all (91%) male daily smoking began before the age of 23 years, whereas initiation of daily snus use continued throughout the age range (33% of initiation after age 22). 20% of male primary snus users started daily smoking compared to 47% of non-primary snus users. Thus, the odds of initiating daily smoking were significantly lower for men who had started using snus than for those who had not (odds ratio (OR) 0.28, 95% confidence interval (CI) 0.22 to 0.36). Among male primary smokers, 28% started secondary daily snus use and 73% did not. 88% of those secondary snus users had ceased daily smoking completely by the time of the survey as compared with 56% of those primary daily smokers who never became daily snus users (OR 5.7, 95% CI 4.9 to 8.1). Among men who made attempts to quit smoking, snus was the most commonly used cessation aid, being used by 24% on their latest quit attempt. Of those men who had used one single cessation aid 58% had used snus, as compared with 38% for all nicotine replacement therapy products together. Among men who used snus as a single aid, 66% succeeded in quitting completely, as compared with 47% of those using nicotine gum (OR 2.2, 95% CI 1.3 to 3.7) or 32% for those using the nicotine patch (OR 4.2, 95% CI 2.1 to 8.6). Women using snus as an aid were also significantly more likely to quit smoking successfully than those using nicotine patches or gum. CONCLUSION: Use of snus in Sweden is associated with a reduced risk of becoming a daily smoker and an increased likelihood of stopping smoking.

Effect of smokeless tobacco (snus) on smoking and public health in Sweden.

OBJECTIVE: To review the evidence on the effects of moist smokeless tobacco (snus) on smoking and ill health in Sweden. METHOD: Narrative review of published papers and other data sources (for example, conference abstracts and internet based information) on snus use, use of other tobacco products, and changes in health status in Sweden. RESULTS: Snus is manufactured and stored in a manner that causes it to deliver lower concentrations of some harmful chemicals than other tobacco products, although it can deliver high doses of nicotine. It is dependence forming, but does not appear to cause cancer or respiratory diseases. It may cause a slight increase in cardiovascular risks and is likely to be harmful to the unborn fetus, although these risks are lower than those caused by smoking. There has been a larger drop in male daily smoking (from 40% in 1976 to 15% in 2002) than female daily smoking (34% in 1976 to 20% in 2002) in Sweden, with a substantial proportion (around 30%) of male ex-smokers using snus when quitting smoking. Over the same time period, rates of lung cancer and myocardial infarction have dropped significantly faster among Swedish men than women and remain at low levels as compared with other developed countries with a long history of tobacco use. CONCLUSIONS: Snus availability in Sweden appears to have contributed to the unusually low rates of smoking among Swedish men by helping them transfer to a notably less harmful form of nicotine dependence.

European Union policy on smokeless tobacco: a statement in favour of evidence based regulation for public health.

RATIONALE: This statement is an updated version of one released by the same authors in February 2003. The statement was produced to follow up the Royal College of Physicians (RCP) Tobacco Advisory Group report "Protecting smokers, saving lives: the case for a tobacco and nicotine regulatory authority", which argued for an evidence based regulatory approach to smokeless tobacco and harm reduction and posed a series of questions that regulators must address in relation to smokeless tobacco. The purpose of this statement is to provide arguments of fact and principle to follow the RCP's report and to outline the public health case for changing existing European Union (EU) regulation in this area. A review of regulation in relation to harm reduction and regulation of tobacco products other than cigarettes is required in Article 11 of EU directive 2001/37/EC, and this is a contribution towards forming a consensus in the European public health community about what policy the EU should adopt in the light of this review, or following ongoing legal action that may potentially strike out the existing regulation altogether. PUBLIC HEALTH CASE: We believe that the partial ban applied to some forms of smokeless tobacco in the EU should be replaced by regulation of the toxicity of all smokeless tobacco. We hold this view for public health reasons: smokeless tobacco is substantially less harmful than smoking and evidence from Sweden suggests it is used as a substitute for smoking and for smoking cessation. To the extent there is a "gateway" it appears not to lead to smoking, but away from it and is an important reason why Sweden has the lowest rates of tobacco related disease in Europe. We think it is wrong to deny other Europeans this option for risk reduction and that the current ban violates rights of smokers to control their own risks. For smokers that are addicted to nicotine and cannot or will not stop, it is important that they can take advantage of much less hazardous forms of nicotine and tobacco-the alternative being to "quit or die". and many die. While nicotine replacement therapies (NRT) may have a role in harm reduction, tobacco based harm reduction options may reach more smokers and in a different, market based, way. Chewing tobacco is not banned or regulated in the EU but is often highly toxic, and our proposal could remove more products from the market than it permitted. REGULATORY OPTIONS: We believe that the EU policy on smokeless tobacco should adapt to new scientific knowledge and that the European Commission should bring forward proposals to amend or replace Article 8 of directive 2001/37/EC with a new regulatory framework. Canada has developed testing regimens for tobacco constituents and these could be readily adapted to the European situation. A review of EU policy in this area is required no later than December 2004, and we believe the Commission should expedite the part of its review that deals with harm reduction and regulation of tobacco products other than cigarettes so as to reconsider its policy on smokeless tobacco. We held this view before Swedish Match brought its legal proceedings to challenge EU legislation and we will continue to hold these views if its action fails.

Trends in urinary bladder cancer incidence in Sweden 1960-93 with special reference to histopathology, time period, birth cohort, and smoking.

This study investigates the incidence trends of urinary bladder cancer in Sweden from 1960 through 1993 (a total of 46,211 cases). Age-standardized incidence rates increased among men from 14.6 per 10(5) in 1960 to 33.5 in 1993 and among women from 4.8 to 8.8, corresponding to an average annual increase of 2.4 percent (95 percent confidence interval [CI]) = 2.0-2.7 percent) and 1.1 percent (CI = 0.9-1.4 percent), respectively. The largest increase occurred in the oldest age-groups. The proportion of patients with transitional cell carcinoma increased in men from 66.0 percent in 1960-64 to 93.6 percent in 1990-93 and in women from 61.0 percent to 89.4 percent. The proportion of patients with papillomas decreased, whereas those with adenocarcinoma and squamous cell carcinoma were stable. Regression modeling (based on the period 1960-89) showed a strong linear effect due to either period and/or cohort. Among men, additional non-linear effects by both period and cohort were obtained. The cohort effects were more important. Cohort data on having smoked daily showed considerable similarities with the estimated cohort-effects. Our findings suggest that the increase of tobacco smoking in successive generations can explain the increase in incidence rates of bladder cancer in Sweden, whereas improved diagnostic activities and registration are less likely to explain fully the changes in incidence rates.

Nicotine dependence versus smoking prevalence: comparisons among countries and categories of smokers.

OBJECTIVES: To collect available international data on nicotine dependence as defined by the Fagerström Test of Nicotine Dependence, and to compare levels of dependence among countries and categories of smokers. DATA SOURCES: Published and unpublished studies known to the authors and a search of EMBASE from 1985-1995. STUDY SELECTION: Studies included were those based on a nationally representative sample of a country's population, or a sample of smokers seeking cessation assistance. DATA SYNTHESIS: Smokers who seek help in stopping smoking are much more dependent than the average smoker. Men consistently score higher on dependence than women. Ex-smokers appear to have lower dependence than current smokers. A country with low smoking prevalence, the United States, seems to have smokers with higher dependence scores than countries where smoking is more prevalent (such as Austria and Poland). CONCLUSIONS: Successful tobacco control may result in a higher dependence among the remaining smokers (due to selective quitting by low-dependent smokers). The remaining highly dependent smokers may need more intensive treatment.

Smoking recidivism among an age cohort of men in Zutphen (The Netherlands): 1960-1985.

Current smoking decreased and former smoking increased among a cohort of originally middle-aged men in Zutphen during the period 1960-1985. Cohort analyses revealed two distinct advantages in comparison with the usual cross-sectional analyses: inconsistent answers on never smoking could be eliminated, and former smokers resuming their habit could be traced. Recidivism of smoking increased strongly during the period 1977-1985. If recidivism of smoking affected younger cohorts as well, it could develop into an important health problem.

Implications of the tobacco dependence syndrome for smoking control programmes.

Motivational and psychosocial treatments for tobacco dependence, while valuable, are not sufficient to solve nicotine-related problems, which usually require a pharmacological approach. There is also a need for training programmes for health workers and major educational campaigns on the nature of tobacco dependence to be directed at opinion leaders, teachers and the public at large.

Moist snuff in Sweden--tradition and evolution.

Snuff-dipping was already widespread in Sweden in the 19th century. After the 1920s snuff sales went down, but Sweden still kept its position as world leader in per capita consumption of moist snuff. Following a major advertising campaign snuff consumption began rising again in the late 1960s. The Swedish Tobacco Company claims that Swedish snuff is a 'less harmful' alternative to cigarettes. Swedish epidemiological studies indicate that there is a cancer risk from snuff-dipping, but it is low compared with smoking. Accordingly, the STC claims to "do a good job replacing cigarettes with snuff". However, an analysis of the trends in tobacco usage patterns in Sweden during the last few decades does not support this claim. The marketing of moist snuff has not primarily attracted older smokers who would seek help in order to stop smoking, but young people. The use of snuff is no prerequisite and no guarantee for a decrease of smoking. On the contrary, taking up snuff must be seen as an introduction to the tobacco habit and possibly a first step towards taking up cigarettes.

Worldwide changes and trends in cigarette brands and consumption.

When looking at the above review of changes and trends in cigarette consumption some summary conclusions can be drawn: a continued growth in cigarette consumption will mainly take place in developing countries; price increases may have complex and unexpected effects, such as changing the brand structure of the market rather than reducing its size on a long-term basis; future studies of cigarette consumption trends will have to give increased attention to generic and hand-rolled cigarettes; in the future it will be irrelevant to look at the distinction between filter cigarettes and nonfilter ones; the important distinction will be between different types of filter cigarettes; an increasing taste consciousness among large groups of smokers will most probably constitute an additional obstacle to low-tar cigarettes ever becoming a viable vehicle for the limitation of smoking-related health risks.

Passive smoking in aircraft--a current WHO project.

Only few measurements of levels of pollution by tobacco smoke in aircraft have been made. The results suggest that levels are quite moderate, but studies of actual reactions by passengers and cabin crew indicate rather strong, objective effects. These consist of irritation of the mucous membranes of eye, nose and throat as well as perception of bad odours. Evidently, environmental tobacco smoke causes distress in aircraft already at lower concentrations than under ground conditions, probably because of special climatic conditions such as ultra-low air humidity, elevated levels of ozone, subnormal air pressure and, eventually, disturbance of the concentration of light air ions. None of these abnormalities can easily be eliminated. Ventilation, however effective in terms of rate of air changes, can not effectively curb local peak concentrations, and, close to a smoker the concentration of smoke may be 100 times as high as the room average. Therefore, aircraft must provide separate smoking resp non-smoking areas. Area division along an aisle is unacceptable since the ventilation system makes the aisle and adjacent seats on both sides be located in one whirl of common air. WHO will try to stimulate improvements of airline practices and aircraft design.