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Abstract
Background Sales of smokeless tobacco products have increased in the USA. More than one in eight males in the 12th grade are current users of smokeless tobacco. Surveillance data examining nicotine levels of smokeless tobacco subsequent to 2006 have not been reported in the literature.
Methods Data on nicotine levels and design features (eg, pH, moisture content, leaf cut and flavour) of smokeless tobacco products sold in Massachusetts were obtained from manufacturers between 2003 and 2012. Design features, levels and temporal trends in unionised (free) nicotine and nicotine content of smokeless tobacco products were analysed overall and by manufacturer and product type.
Results The annual total number of moist snuff products increased from 99 in 2003 to 127 in 2012. The annual total number of reported snus products increased from 4 in 2003 to the highest level of 62 in 2011, before decreasing to 26 in 2012. Overall, mean unionised (free) nicotine remained relatively stable (β=0.018 (95% CI −0.014 to 0.050) mg/g dry weight/year) from 2003 to 2012. However, both levels and temporal trends of mean free nicotine varied significantly among manufacturers (p<0.001). Since 2003, the free nicotine content of snus has increased at an overall rate of 0.192 (95% CI 0.138 to 0.246) mg/g dry weight/year, but varied by manufacturer (p<0.001).
Conclusions The number of smokeless tobacco products increased in the Massachusetts market. Further, mean unionised (free) nicotine levels in smokeless tobacco products of several manufacturers continued to rise despite decreasing levels from other manufacturers. The current success in tobacco control is very likely undermined without government surveillance, regulation and widespread public disclosure of nicotine levels in these products.
- Nicotine
- Surveillance and monitoring
- Public policy
- Non-cigarette tobacco products
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Introduction
With the decline of cigarette sales, sales of smokeless tobacco products have increased. Nielson convenience store sales data show “sales of moist snuff products (including snus) increased by 65.6% between 2005 and 2011”.1 As sales have increased, the number of teenage males using smokeless tobacco in the USA raises concern. According to the 2012 Monitoring the Future survey, more than one in eight males in 12th grade are current users of smokeless tobacco (use in past 30 days).2 Additionally, as restrictions on smoking increase, there is concern for overall increased smokeless tobacco use. Smokeless tobacco and snus products are often marketed toward smokers for use when smoking is prohibited. Both products offer a non-combustible alternative to cigarettes. Moist snuff is fermented ground tobacco traditionally sold loose in cans but offered in pouches (a small tea-like bag containing tobacco). Snus is made with air-cured tobacco, water, salt and flavourings. It is steam-heated finely ground moist snuff commonly packaged in pouches. Both are used by placing a pinch or pouch between the lip or cheek and gum.3
The increase in smokeless tobacco sales corresponds with the increase in the number of moist snuff products available and the marketing efforts of tobacco companies. From 1998 to 2008, the total advertising and marketing expenditures of the top five smokeless tobacco companies in the USA increased by 276%, from $145 million to $547 million.4 Tobacco companies persist in advertising smokeless products in magazines that appeal to youth, including Sports Illustrated and Rolling Stone.5
As with cigarettes, nicotine is the addictive ingredient in smokeless tobacco, but little information is available about nicotine content and other characteristics of smokeless tobacco products in the US market. The amount of nicotine and how it is delivered is associated with a product's addictive potential.6 Studies have shown that the amount of unionised (free) nicotine in smokeless tobacco is determined by the nicotine contained naturally in the tobacco leaf as well as modifiable design features of the products.7 ,8 The importance of free nicotine in the unionised form is that the unionised nicotine more freely permeates membranes, including the buccal mucosa and the blood–brain barrier. The alkalinic property of smokeless tobacco facilitates the absorption of nicotine in the mouth.9 Further, the absorption of nicotine per dose is greater with the use of chewing tobacco or snuff compared with that of smoking cigarettes.9 Benowitz et al10 concluded “because of prolonged absorption, overall nicotine exposure was twice as large after single exposures to smokeless tobacco compared with cigarette smoking”. The authors state further that “the average intake of nicotine in our subjects chewing 7.9 gm tobacco was 4.5 mg, an intake equivalent to that of four cigarettes smoked in the typical day”.10
The Commonwealth of Massachusetts General Law c. 94, §307B requires smokeless tobacco product manufacturers to submit an annual report to the Massachusetts Department of Public Health (MDPH) to disclose characteristics of their products marketed to Massachusetts residents.11 An article published in 2008, using the aforementioned annual report data, examined the levels of unionised (free) nicotine and marketing of moist snuff from 2000 to 2006, concluding that unionised (free) nicotine may be a contributing factor to the increase in youth and adult moist snuff use.12 Given the importance of conducting regular surveillance on unionised (free) nicotine, nicotine content, and design features of smokeless tobacco products, this study expands upon the aforementioned study by Alpert et al. This study includes more recent years (through 2012) from the annual report data and provides analysis of snus data alongside moist snuff data analysis. This study examines a 10-year period (2003–2012) to be consistent with previously published research examining long-term trends.
Methods
Since December 1997, each smokeless tobacco product manufacturer with sales in Massachusetts has been required by law to submit to the MDPH an annual report with the total unionised (free) nicotine content in milligrams per gram of tobacco; nicotine content in milligrams per gram of tobacco (total nicotine); pH of tobacco; and moisture content as a percent of weight of tobacco for each brand, sub-brand or generic unbranded smokeless tobacco product. The submitted information was captured and stored in a MDPH database system for surveillance and analysis.
For the purpose of this study, information submitted over the past 10 years (2003–2012) was analysed. Moist snuff products were grouped for each manufacturer by brand (eg, Marlboro), sub-brand (eg, Snus Classic), cut (fine cut, long cut or pouch) and flavour (natural/straight, cool-flavoured, fruit-flavoured or other). Wintergreen, mint and ice flavours were included in the ‘cool’ moist snuff group. Fruit flavours constituted a third group, while coffee, vanilla and butternut were grouped into a fourth category of ‘other’ flavours. Snus products were coded at the brand and sub-brand level by manufacturer.
Key product attributes analysed included mean unionised (free) nicotine (mg/g), total nicotine (mg/g), pH and per cent moisture content. Averages of these attributes were computed for each year by sub-brand and brand for all moist snuff and snus products, and by cut and flavour for moist snuff. Product attributes were compared among manufactures, cut and flavour group for moist snuff and among manufacturers for snus. Given the large number of snus brands from Swedish Match North America (SMNA) and the small market share, averages were calculated both with SMNA included and with SMNA removed from the analysis. Temporal trends in mean unionised (free) nicotine, nicotine content, pH and moisture content were analysed using multilevel linear mixed effects models including calendar year as a fixed effect. The models accounted for the nested structure of sub-brand grouped within brand within manufacturer. Market category and design features were controlled for given previous research documenting the correlation between these variables and the level of unionised (free) nicotine available for the user.12 Multivariate analysis was then performed controlling for all market category and design features. All statistical computations were carried out using Stata MP V.12.0 (StataCorp, College Station, Texas, USA).
Results
Moist snuff: brands, design features and temporal trends
Summary statistics of moist snuff brands and products are shown in table 1. A total of 136 distinct moist snuff products belonging to 38 brand families were documented between 2003 and 2012. The annual total number of moist snuff products reported increased from 99 in 2003 to 127 in 2012. US Tobacco Company had the largest number of products recorded for a given year (52 in 2012).
Number of reported moist snuff products and mean (SE) of unionised nicotine, nicotine content, pH and moisture content by year from 2003 to 2012
Table 3 summarises mean unionised (free) nicotine in smokeless products by manufacturer and market category (flavour and cut). For moist snuff, SMNA and Conwood products have the highest mean unionised (free) nicotine level, nicotine concentration and mean pH (table 3). Unionised (free) nicotine levels were positively associated with nicotine content and pH (p<0.001) as would be expected from the Henderson–Hasselbalch equation.13 Yearly data and trends for nicotine content, pH and moisture content are included in the tables for reference. On average, straight-flavoured or natural-flavoured moist snuff had significantly more unionised (free) nicotine than fruit-flavoured moist snuff (p<0.001). Fine-cut and long-cut moist snuff had more unionised (free) nicotine than pouches (p<0.001).
Temporal trend analysis of all moist snuff products found that mean unionised (free) nicotine remained relatively stable (β=0.018 (95% CI −0.014 to 0.050) mg/g dry weight/year) from 2003 to 2012 (table 4 and figure 1). When a multivariate regression analysis was conducted, controlling for market category (cut, flavour) and design features (content, pH, moisture content), unionised (free) nicotine continued to remain stable (β=−0.013 (95% CI −0.030 to 0.005) mg/g dry weight/year) over the same time period (p=0.157). The temporal trend, however, varied significantly among manufacturers (p<0.001). The unionised (free) nicotine of US Tobacco Company products, the largest moist snuff manufacturer, increased at an annual rate of 0.098 mg/g dry weight/year (p<0.001). National Tobacco Company/RBJ Sales Inc. products increased at a higher rate of 0.578 mg/g dry weight/year from 2003 to 2012 (p<0.001). In contrast, Swisher products decreased at a rate of −0.095 mg/g dry weight/year (p<0.006), SMNA products decreased at a rate of −0.001 mg/g dry weight/year (p=0.979) and Conwood Company products decreased at a rate of −0.244 (p<0.001). At the brand level, most brands followed the same temporal pattern as their manufacturer.
Mean unionised (free) nicotine of moist snuff and snus by product type.
A significant increase in mean unionised (free) nicotine was seen for cool-flavoured products 0.097 (95% CI 0.051 to 0.143; p<0.001) and pouch products 0.31 (95% CI 0.224 to 0.396; p<0.001) while a significant decrease was found for straight-flavoured products −0.089 (95% CI −0.139 to −0.04; p<0.001) and fine-cut products −0.097 (95% CI −0.155 to −0.038; p=0.001). No significant change was noted for fruit-flavoured products or long-cut products.
Snus: brands, design features and temporal trends
Between 2003 and 2012, 113 distinct snus products were documented (table 2). The annual total number of snus products reported ranged from 4 in 2003 to a maximum of 62 in 2011, before decreasing to 26 products in 2012. Snus products were manufactured predominately by SMNA, which had 90 products within 17 brands throughout the time period. For non-SMNA snus products, US Tobacco Company had nine products within two brands (Revel and Skoal), RJ Reynolds had five products within one brand (Camel), and Philip Morris had nine products sampled within one brand (Marlboro).
Number of reported snus products and mean (SE) of unionised nicotine, nicotine content, pH and moisture content by year from 2003 to 2012
Design features for Snus are summarised in table 3. SMNA had significantly higher unionised (free) nicotine, higher pH ratings and more moisture content than the other three companies. Philip Morris snus brands had the highest mean nicotine content 13.63 mg/g.
Mean (SE) of unionised nicotine, total nicotine content, pH and moisture content of moist snuff and snus products sold in Massachusetts (2003–2012), overall and by manufacturer and market category*
Since 2003, the unionised (free) nicotine content of snus has increased at an overall rate of 0.192 mg/g dry weight/year (p<0.001) (table 4). This increase was not consistent among manufacturers, however, with US Tobacco Company displaying a decrease in free nicotine of −0.399 (p=0.002) and Philip Morris demonstrating a decrease of −0.261 (p=0.079) mg/g dry weight/year. The overall increase can be attributed mainly to the increase of 0.227 (p<0.001) for SMNA snus products and an increase of 0.53 (p<0.005) for RJ Reynolds snus products. Data analysis of the remaining manufacturers (without SMNA) shows a significant decreasing trend −0.134 (95% CI −0.225 to −0.044) noting that no snus products were available for testing prior to 2009 for RJ Reynolds and Philip Morris (figure 1). For all snus products, yearly data and trends for nicotine content, pH and moisture content are included in the tables for reference.
Temporal trends of total unionised nicotine, nicotine content and pH in moist snuff and snus products sold in Massachusetts between 2003 and 2012
Discussion
To our knowledge, this is the first report in the literature to document the substantial growth in the number of smokeless tobacco products. The number of moist snuff products has continued to grow, and the number of snus products increased exponentially from 2003 until 2011, before decreasing dramatically in 2012. The tobacco control community knows little about the marketing that is associated with this rapid escalation and contraction of smokeless products. One might infer that each of these products targets a particular market segment; yet little is known about the consumer response to this array of new products and why so many smokeless tobacco products would be abruptly removed from the Massachusetts market.
Data from Massachusetts tobacco surveillance programme demonstrate that the amount of unionised (free) nicotine in moist snuff and snus products vary considerably among manufacturers as well as over time. The aggregate trends in unionised (free) nicotine levels are perplexing. Variations among manufacturers are not easily explained nor are inconsistencies in nicotine content and unionised (free) nicotine. Nicotine content can be affected by variations in agricultural conditions resulting in unionised (free) nicotine fluctuations. Additionally, as indicated in previous research, nicotine content, pH and moisture content are attributes that can be influenced, if not controlled, during the manufacturing process.12 Inconsistencies in the Massachusetts data raise questions regarding potential manipulation of these attributes and concern regarding the role other factors, such as constituents, may play in determining the amount of unionised (free) nicotine for a given product. Closer attention, continued surveillance and public reporting must be undertaken to apprise the user of the characteristics associated with each of these products. Future reports also must incorporate information at the manufacturer and brand/product levels.
Another important trend is the rapid increase in unionised (free) nicotine levels in snus products. While the mean total nicotine in snus products has been less than that of moist snuff products since 2003 (figure 1), mean free nicotine of snus products surpassed that of moist snuff products beginning in 2006. Much of the increase in mean unionised (free) nicotine can be attributed to the high values for SMNA snus products. As of 2011, SMNA had only a small percentage of market share (less than 1%),1 but the exceptionally high level of unionised (free) nicotine in SMNA products should be monitored as snus products assume a higher percentage of smokeless tobacco sales and more products are introduced by other companies.
Data reported to the MDPH suggest that the number of fruit-flavoured moist snuff products have started to decline after a sharp increase in 2005 and 2007. These fruit-flavoured products have lower levels of unionised (free) nicotine and a lower pH, data that would be consistent with targeting these products for youth initiation. Again, continued surveillance of the design features and how these products are marketed, who is purchasing them and the corresponding sales volume should be initiated.
Considering the potential risk for nicotine addiction associated with use of smokeless tobacco products and the aggressive marketing of these products to youth as well as current smokers, it is critical to continue and expand surveillance on smokeless products at the state and national levels. It is imperative that the government mandate testing, regulation and widespread public disclosure of the levels of nicotine contained in these products and delivered by these products when used as intended. Additionally, there needs to be communication strategies that will effectively inform the consumers about the potential harm of using these products. There are many questions that remain. What is causing the variations and discrepancies in the surveillance data? What do these aberrations mean to the user? What are the health implications for using a product with varying amounts of nicotine? Without the necessary research and surveillance efforts, the success of tobacco control, understanding and preventing the use of smokeless tobacco products, will be undermined.
What this paper adds
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The number of moist snuff products sold in Massachusetts increased from 99 in 2003 to 127 products in 2012; the number of snus brands increased from 4 in 2003 to 26 in 2012.
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The amount of unionised (free) nicotine in snuff and snus brands varies among manufacturers, consistent with the argument that unionised (free) nicotine levels are controlled in the manufacturing process.
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The increase in unionised (free) nicotine in snus products has surpassed that of moist snuff products beginning in 2006. Much of this increase is due to high values for Swedish Match North America. Snus products merit continued surveillance.
Footnotes
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Contributors All authors contributed to the conception and design of the study. DC, TL and LK contributed to the acquisition of the data. LC, KK and WL contributed to the analysis of the data. DC, LK, KK, TL, MP and RH contributed to the drafting of the article, and all authors revised the article for publication.
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Funding This research was provided by a grant from the Center for Disease Control and Prevention (grant number 5U58DP002004).
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Competing interests None.
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Provenance and peer review Not commissioned; externally peer reviewed.