Health effects associated with smokeless tobacco: a systematic review

Abstract

Background: It is believed that health risks associated with smokeless tobacco (ST) use are lower than those with cigarette smoking. A systematic review was therefore carried out to summarise these risks. Methods: Several electronic databases were searched, supplemented by screening reference lists, smoking related websites, and contacting experts. Analytical observational studies of ST use (cohorts, case-control, cross sectional studies) with a sample size of >500 were included if they reported on one or more of the following outcomes (all cause mortality, oral and pharyngeal cancers, other cancers, cardiovascular diseases, dental diseases, pregnancy outcomes, surgical outcomes). Data extraction covered control of confounding, selection of cases and controls, sample size, clear definitions and measurements of the health outcome, and ST use. Selection, extraction and quality assessments were carried out by one or two independent reviewers. Results: A narrative review was carried out. Many of the studies lacked sufficient power to estimate precise risks, mainly due to the small number of ST users. Studies were often not designed to investigate ST use, and many also had major methodological limitations including poor control for cigarette smoking and imprecise measurements of exposure. Studies in India showed a substantial risk of oral or oropharyngeal cancers associated with chewing betel quid and tobacco. Studies from other regions and of other cancer types were not consistent. Few studies have adequately considered the non-cancer health effects of ST use. Conclusions: Chewing betel quid and tobacco is associated with a substantial risk of oral cancers in India. Most recent studies from the US and Scandinavia are not statistically significant, but moderate positive associations cannot be ruled out due to lack of power. Further rigorous studies with adequate sample sizes are required, especially for cardiovascular disease.

Awareness of mouth cancer in Great Britain

“…4 Use of oral tobacco (chewing tobacco and tobacco mixtures such as paan) has also been linked to oral cancers. 5 Little is known about awareness of mouth cancer in the UK population. The most recent study involved focus groups in northern England and reported low levels of awareness in a group of older male drinkers and smokers.…”

A Cross-Country Comparison of Knowledge, Attitudes and Practices about Tobacco Use: Findings from the Global Adult Tobacco Survey

“…Both smoked and smokeless, forms of tobacco are associated with increased risk of chronic and terminal diseases (Critchley et al, 2003;Gupta et al, 2003;Nair et al, 2004;Krishna et al, 2013). These diseases include destructive periodontitis (Cutress, 2003;Gupta et al, 2003;; oral and oropharyngeal cancers (Johnson et al, 2011;Radoi et al;2013); oral potentially malignant disorders, notably leukoplakia, erythroplakia, and oral submucous fibrosis (Warnakulasuriya et al, 2007) and cardiovascular disorders including stroke .…”

Use of Smoke-less Tobacco Amongst the Staff of Tertiary Care Hospitals in the Largest City of Pakistan

“…Different product types have differing disease profiles, depending on ingredients and manufacturing techniques, but all SLT products are potentially addictive, some delivering even higher doses of nicotine than cigarettes. In addition, chewing tobacco and snuff contain 28 carcinogens which are significantly associated with various types of cancers mainly including of oral cavity, upper gastro-intestinal track and of the head and neck (Critchley & Unal, 2003;Khawaja, et al, 2006).…”