13 January 2019
By Javaid Ahmad Khan, Professor, Section of Pulmonology and Critical Care Medicine and Ayesha Butt, Medical Student, The Aga Khan University, Karachi, Pakistan
Smokeless tobacco (SLT) is a mammoth public health issue, the risks and perils of which have been condoned over the years, despite its many hazards and rampant widespread use. More than 300 million adults in 70 countries use smokeless tobacco. 89 per cent of these users are in South-East Asia. Low- and middle-income countries are home to more than 250 million adult SLT users and in a few countries like India and Bangladesh, SLT use is very high and surpasses the prevalence of smoking. A major cause of concern is the fact that while smoking rates are falling, unfortunately the use of SLT continues to increase. In countries like UAE, SLT use is very common because of the largely immigrant population. The plethora of various different SLT products available, their greater social acceptability and perception of being minimally harmful and lack of regulation of SLT, add to the complexity and gravity of the issue.
SLT is associated with the development of a myriad of cancers in the human body, including cancers of mouth, nasal cavity, lungs, trachea, pancreas, liver and oesophagus. Tobacco-specific nitrosamines, which form during the growing, curing, fermenting, and ageing of tobacco, are one of the major culprits in this regard. Additional substances found in SLT with carcinogenic potential include: radioactive element (polonium-210) found in tobacco fertiliser, polynuclear aromatic hydrocarbons formed when tobacco is cured with heat and deleterious metals (arsenic, beryllium, cadmium, chromium, cobalt, lead, nickel, mercury). Studies have shown that more than 50 per cent of oral cancers in India and Sudan are attributable to smokeless tobacco products, whereas about 4 per cent of oral cancers in American men and 20 per cent of oesophageal and pancreatic cancers in Swedish men can be linked to SLT use. Epidemiological data from the U.S. and Asia show a raised risk of oral cancer (overall relative risk 2.6 [95 per cent CI 1.3-5.2]). Risks of oesophageal cancer (1.6 [1.1-2.3]) and pancreatic cancer (1.6 [1.1-2.2]) have also increased, as shown in northern European studies.
One-third of all cancers in Bangladesh, India, Pakistan and Sri Lanka are associated with SLT use. Nine case-control studies from India and one from Pakistan on cancers of the oral cavity, have demonstrated relative risks of oral cancer for men who were current chewers of paan with tobacco compared to non-chewers varied from 1.8 (95 per cent CI: 1.2–2.7) to 5.8(95 per cent CI: 3.6–9.5) compared to 30.4 (95 per cent CI: 12.6–73.4) to 45.9 (95 per cent CI: 25.0–84.1) in women. In addition, a study from Pakistan showed that the risk in people who had ever been chewers of paan with tobacco developing oral cancer was 8.4 times (95 per cent CI: 2.3–30.6). In an analysis of three case-control studies from India on oesophageal cancer, significant odds ratios for tobacco chewers varied from 2.1 to 3.2.
Oral mucosal lesions, leukoplakia and periodontal disease are corollaries of SLT use, as are fatal ischaemic heart disease, type 2 diabetes and fatal stroke. 75 per cent of the paan masala chewers were found to develop oral submucus fibrosis within 4.5 years and quid chewers in about 9.5 years. A study showed that chewing of betel quid with tobacco for 15–30 minutes leads to significant increments in heart rate and blood pressure. As they contain nicotine, it is unsurprising that SLT products also induce dependence, tolerance and withdrawal symptoms upon cessation of use, much like cigarettes.
SLT products also lead to stillbirth, pre-term birth and low birth weight. A nearly threefold increase in stillbirths and a 100–400 g decrease in birth weight, in offspring of women who used SLT during pregnancy was noted in studies from India.
In South East Asia, SLT use is more widespread than cigarette smoking and is increasing with time. The Global Youth Tobacco Survey (GYTS) delineated an increase in the prevalence of current SLT use among 13–15-year-olds in Bhutan (from 7.4 per cent in 2004 to 21.6 per cent in 2013), Nepal (from 6.1 per cent in 2007 to 16.2 per cent in 2011), Myanmar (6.5 per cent to 9.8 per cent from 2004– 2011). GATS-2010 in India revealed that 35 per cent of adults in India used tobacco. Among them, 21 per cent adults used only SLT, 9 per cent only used smoking tobacco and 5 per cent used smoking tobacco as well as SLT. 33 per cent men and 18 per cent women consumed SLT compared to 24 per cent men and 3 per cent women who smoke cigarettes. Generally, the prevalence of SLT use was higher in rural areas than in urban areas. Similarly, SLT use was more pronounced among the low socioeconomic strata and less educated adults. The majority of immigrant workers in the Middle East are from India, Pakistan, Bangladesh, Sri Lanka and Nepal, where SLT use is very common.
An important facet in the SLT issue is the fact that while public health and medical professionals have campaigned vehemently against smoking for decades, SLT tends to be ignored. This is exhibited in GATS 2010 in India, by the fact that only 34 per cent of SLT users were asked about SLT use by a healthcare professional in the 12 months prior to survey and only 27 per cent received advice to quit, in contrast to 54 per cent of smokers who were asked in the same period if they smoked and 46 per cent were advised cessation.
In the developed world, SLT product innovations such as portion pouches, dissolvable tobacco, unique flavourings, and varying nicotine levels have been introduced by manufacturers in a bid to attract more customers. They have also marketed new SLT products to smokers as alternatives to cigarettes in circumstances which do not permit smoking. These marketing ploys may adversely impact public health by promoting tobacco use, even in those who have not used it previously and discouraging cessation. In 2016, US$759.3 million was spent on advertising and promotion of smokeless tobacco products compared to US$684.9 million in 2015.
Types of smokeless tobacco include chewing tobacco (loose leaf, plug, or twist and may come in flavours), snuff (moist, dry, or in packets) and dissolvables (lozenges, sticks, strips, orbs). Smokeless tobacco products that contain areca nut are commonly used in countries in South Asia, and in migrant populations from these countries. Various forms of SLT are used in South Asia. Unprocessed tobacco is the cheapest form used. Kaddipudi are cheap ‘powdered sticks’ of raw tobacco stalks and petioles, used in Karnataka. A commercial mixture of tobacco, lime and spices is zarda. It is typically flavoured with cardamom and saffron and often chewed in betel quid, and is popular in north India, Pakistan and Bangladesh. Pattiwala is sun-dried, flaked tobacco with or without lime, used mainly in Maharashtra and several north Indian states. Mawa, popular among teenagers especially in Gujarat, contains thin shavings of areca nut with some sun-dried tobacco and slaked lime. Gutka, a dry preparation commercialised since 1975, containing areca nut, slaked lime, catechu, condiments and powdered tobacco, was originally available custom-mixed from paan vendors. For the last couple of decades, gutka has been available under several brand names.
A similarly packaged mixture without tobacco, often with an identical brand name, is called paan masala. These products have become very popular especially among teenagers and young adults in many states of India and in Pakistan. Naswar or Niswar, used widely in Afghanistan and Pakistan, is a mixture of powdered tobacco, slaked lime, and indigo and can be homemade or available commercially. In Pakistan, naswar is tobacco flavoured with cardamom and menthol. Nass, a mixture used in Pakistan, Iran and the Central Asian Republics contains local tobacco, sometimes partially cured, ash, cotton or sesame oil and in some areas, lime. It is placed under the tongue or in the lower labial groove.
The Way Forward
As part of an interventional study in India, brief advice on tobacco cessation was offered to tuberculosis patients, in the Revised National TB Control Program (RNTCP), who were also tobacco (including SLT) users. Brief advice on tobacco cessation takes less than three minutes and consists of five A’s: asking if the patient uses tobacco in any form; advice on quitting tobacco; assessing readiness to quit tobacco use; assisting with counselling and appropriate treatment; and arranging for follow up. After six months had elapsed, 67.3 per cent of patients had quit tobacco. In a similar initiative in Bangladesh, people were advised to quit tobacco during hypertension screening visits. Consequently, the prevalence of SLT astoundingly dropped from 33.2 per cent to 0.4 per cent. This demonstrates the utility of simple, cost effective interventions, which can be integrated into existing health infrastructures and frameworks.
Another educational intervention, in Karnataka, India, was carried out by specially trained primary health centre (PHC) workers, who used films, exhibits and pictures to delineate the injurious effects of tobacco. The quit rates in men and women in the intervention cohort were 26.5 per cent and 36.7 per cent, respectively, compared to 1.1 per cent and 1.5 per cent in a control cohort.
Educating school children about the perils of tobacco proved to be an effective measure in Goa, India, when students in 46 villages were trained to communicate anti-tobacco information to their parents and to the community. 1.5 years later, 8.9 per cent men and 11 per cent women had quit tobacco use.
Mass media interventions are also extremely effective methods of disseminating health education and dissuading people from using SLT. In 1990, educational information about the use of tobacco was broadcast on All India Radio. Consequently, in Karnataka, nearly 6 per cent of tobacco users reported quitting the habit, as did 4.3 per cent in Goa. In addition, about one-third of tobacco users intended to quit and another third had reduced their consumption.
An approach called CATCH has been propagated to deal with SLT.
Initiatives at an international level should also be undertaken. Addressing Smokeless Tobacco and building Research Capacity in South Asia (ASTRA), an international group, comprising experts from six UK universities and five institutions from Bangladesh, Pakistan and India, aims to carry out policy research and develop interventions to address the problems caused by the use of smokeless tobacco in South Asia. ASTRA will evaluate how effectively are the policies recommended by the Framework Convention on Tobacco Control (WHO-FCTC) being applied for ST in low- and middle-income countries (LMICs). The group will also train research teams in these countries to carry out impactful SLT research.
Smokeless tobacco use is a colossal public health issue particularly in South Asia. However, it remains largely ignored despite its many deleterious ramifications and high prevalence. Lack of awareness among the general public about SLT being harmful and the normalisation of its use – as a habit in prevalence since ages in this region, further complicate the problem. However, it is of paramount importance that efforts are made on national, institutional, community and individual levels to discourage SLT use and help people quit.
References available on request.