An interpretative review of smokeless tobacco research in the United States: Part II

Breaking the Barriers: Strategies for a Comprehensive U.S. Tobacco Control Program

Given the health and social consequences of tobacco, a policy analysis strategy consisting of three approaches; legal, market, and health education is presented. A unifying feature of the strategy recommendations is that each addresses both prevention of the initiation of tobacco habits and encouragement of cessation. Overall, the strategies focus exclusively on policy alternative initiatives oriented toward reducing the toll of smoking within the United States. The manuscript addresses the conflict that public policy must resolve between the long-term negative health effects and the short-term positive economic interests of tobacco. The critical idea is that policy makers must think beyond local efforts and recognize that they can be a part of a larger network movement working in different ways, yet cooperating for better effectiveness and support to decrease and ultimately stop the use of tobacco products.

Systematic review of the relation between smokeless tobacco and cancer of the pancreas in Europe and North America

Background

Recent reviews claiming smokeless tobacco increases pancreatic cancer risk appear not to have considered all available epidemiological evidence; nor were meta-analyses included. We present a systematic review of studies from North America and Europe, since data are lacking from other continents. Risk is also difficult to quantify elsewhere due to the various products, compositions and usage practices involved.

Methods

Epidemiological studies were identified that related pancreatic cancer to use of snuff, chewing tobacco or unspecified smokeless tobacco. Study details and effect estimates (relative risks or odds ratios) were extracted, and combined by meta-analyses.

Results

Nine North American and two Scandinavian studies were identified. Reporting was limited in four studies, so only seven were included in meta-analyses, some providing results for never smokers, some for the overall population of smokers and non-smokers, and some for both.

Giving preference to study-specific estimates for the overall population, if available, and for never smokers otherwise, the random-effects estimate for ever smokeless tobacco use was 1.03 (95% confidence interval 0.71–1.49) based on heterogeneous estimates from seven studies. The estimate varied little by continent, study type, or type of smokeless tobacco.

Giving preference to estimates for never smokers, if available, and overall population estimates otherwise, the estimate was 1.14 (0.67–1.93), again based on heterogeneous estimates. Estimates varied (p = 0.014) between cohort studies (1.75, 1.20–2.54) and case-control studies (0.84, 0.36–1.97). The value for cohort studies derived mainly from one study, which reported an increase for never smokers (2.0, 1.2–3.3), but not overall (0.9, 0.7–1.2). This study also contributed to increases seen for snuff use and for European studies, significant only in fixed-effect analyses.

The studies have various weaknesses, including few exposed cases, reliance in cohort studies on exposure recorded at baseline, poor control groups in some case-control studies, and lack of a dose-response. Publication bias, with some negative studies not being presented, is also possible.

Conclusion

At most, the data suggest a possible effect of smokeless tobacco on pancreatic cancer risk. More evidence is needed. If any risk exists, it is highly likely to be less than that from smoking.

Systematic review of the relation between smokeless tobacco and non-neoplastic oral diseases in Europe and the United States

Background

How smokeless tobacco contributes to non-neoplastic oral diseases is unclear. It certainly increases risk of oral mucosal lesions, but reviewers disagree as to other conditions. In some areas, especially South-East Asia, risk is difficult to quantify due to the many products, compositions (including non-tobacco ingredients), and usage practices involved. This review considers studies from Europe (in practice mainly Scandinavia) and from the USA.

Methods

Experimental and epidemiological studies published in 1963–2007 were identified that related risk of oral lesions to smokeless tobacco use. Data were assessed separately for oral mucosal lesions, periodontal and gingival diseases, dental caries and tooth loss, and oral pain.

Results

Oral mucosal lesions: Thirty-three epidemiological studies consistently show a strong dose-related effect of current snuff on oral mucosal lesion prevalence. In Scandinavia, users have a near 100% prevalence of a characteristic "snuff-induced lesion", but prevalence of the varied lesions reported in the USA is lower. Associations with chewing tobacco are weaker. The lack of clear association with former use suggests reversibility following cessation, consistent with experimental studies showing rapid lesion regression on quitting.

Periodontal and gingival diseases: Two of four studies report a significant association of snuff with attachment loss and four out of eight with gingival recession. Snuff is not clearly related to gingivitis or periodontal diseases. Limited evidence suggests chewing tobacco is unrelated to periodontal or gingival diseases.

Tooth loss: Swedish studies show no association with snuff, but one US study reported an association with snuff, and another with chewing tobacco.

Dental caries: Evidence from nine studies suggests a possible relationship with use of smokeless tobacco, particularly chewing tobacco, and the risk of dental caries.

Oral pain: Limited evidence precludes any clear conclusion.

Conclusion

This review confirms the strong association of current use of smokeless tobacco, particularly snuff, with prevalence of oral mucosal lesions. It provides suggestive evidence of an association of snuff use with gingival recession and attachment loss, and of chewing tobacco with dental caries. While smokeless tobacco clearly increases risk of oral mucosal lesions, interpretation for other endpoints is limited by study weaknesses, including poor confounding control.

Smokeless tobacco and cigarettes: differential attitudes and behavioral intentions of young adolescents toward a hypothetical new peer

Examined adolescents' perceptions of cigarette smokers and smokeless tobacco users. Participants were 562 middle school students in rural Florida who viewed 1 of 6 videotapes of a hypothetical peer (i.e., actor) who would soon be attending their school. The videotapes differed only as a function of sex (boy or girl) and tobacco condition (no tobacco, cigarette, smokeless tobacco). After viewing the videotape, participants completed 2 measures designed to assess attitudes and behavioral intentions toward the peer. Results indicated that (a) the actor in the no-tobacco condition was rated more favorably than actors in the other two conditions, although the actor in the smokeless-tobacco condition was rated more favorably than the actor in the cigarette condition; (b) girls viewed the actor in smokeless-tobacco condition more favorably than did boys; (c) compared to nonsmokers, adolescents with a cigarette use history provided more favorable ratings for the actor in the cigarette condition. Taken together, results suggest that different types of tobacco use may have a different impact on social image within the young adolescent population.

Smokeless tobacco, reaction time, and strength in athletes

PURPOSE

This study investigated the effects of smokeless tobacco on reaction time and strength in a group of Division III athletes.

METHODS

Athletes were tested for simple and choice reaction time, maximum voluntary force, and maximum rate of force generation of the knee extensors on a KinCom dynamometer at 250 degrees.s-1. Smokeless tobacco-using athletes (N = 20) were tested while both using and after abstaining from smokeless tobacco. Another group of athletes (N = 20) who did not use smokeless tobacco served as a control group.

RESULTS

Simple and complex reaction times were not affected by smokeless tobacco use or abstention. In the simple reaction time test, maximum voluntary knee extensor force was higher in the smokeless tobacco-using group while abstaining (P < 0.05). Maximum rate of force generation in the simple reaction time test was not statistically different between the conditions. In the choice reaction test, both strength parameters (maximum force and maximum rate of force generation) were higher in the user group while abstaining (P < 0.05) compared with the using condition. The strength parameter measurements in the control group were not statistically different from the tobacco-using group, while either using or abstaining.

CONCLUSIONS

We conclude that smokeless tobacco use has no effect on reaction time but may detrimentally influence maximum voluntary force and maximum rate of force generation.

Snuffing it out: a smokeless tobacco intervention with athletes at a small private college

This study assessed attitude, knowledge, and use of smokeless tobacco (moist snuff, dry snuff, or chewing tobacco) among male varsity athletes at a small private college. Forty-three athletes were surveyed and 17 (40%) were found to be current users. Of these users, 27% reported dipping more than once a day, everyday; 25% of all users had noticed physical changes, such as white spots, inside their mouths. The wide acceptance of using smokeless tobacco was clear from the finding that 49% of those surveyed believed that athletes should be allowed to use "chew" during practice. These athletes also showed limited knowledge of the nicotine content and physiological effects of smokeless tobacco. As a result of the study, the authors developed a two-part intervention that included an educational presentation and oral screening by a local dentist and an administrative directive enforcing the National Collegiate Athletic Association's policy on smokeless tobacco use. A follow-up survey indicated the intervention had had some positive effects on the athletes' attitudes toward and knowledge about using smokeless tobacco. The survey also showed an increase from 4 to 7 in the number of former users who said they had stopped using smokeless tobacco.

An evaluation of a tobacco use education-prevention program: a pilot study

This study was designed to implement a psychosocial approach to primary prevention of cigarette and smokeless tobacco use among seventh-grade students. The prevention program was presented by peer leaders who were older high school students. Program intervention addressed parental, peer, and media influences on tobacco use, and taught refusal skills for resisting social pressures to smoke or chew tobacco. Program effectiveness was examined in terms of three variables: knowledge (basic knowledge about tobacco facts), refusal skills (degree of self-reported assertiveness in refusing to use tobacco), and attitude (positive and negative attitudes toward tobacco). These variables were assessed at pre- and posttests, and 1-month follow-up to program termination. It was found that students who received the intervention reported increased knowledge and improved resistance skills regarding the use of tobacco, as compared to a control group. Attitudes toward tobacco were initially negative and did not change over the course of the intervention in either group. In addition, 1-year follow-up was conducted on the intervention group, indicating that treatment gains were maintained.

The smokeless tobacco 'time bomb'

All healthcare professionals need to become aware of the extent and seriousness of smokeless tobacco use. In this article, the authors briefly review the current status of smokeless tobacco and describe its usage patterns and practices, pharmacologic (addictive) aspects, and associated health problems. They also suggest ways that primary care physicians can discover or prevent smokeless tobacco use in their patients.