Smokeless tobacco

Scientific Name(s): Nicotiana tabacum L. Family: Solanaceae (nightshades)

Common Name(s): Smokeless tobacco , chewing tobacco , oral snuff

Clinical Overview

Uses of Smokeless tobacco

Smokeless tobacco has not been used medically. Its recreational use carries many of the risks and dangers of smoking tobacco.

Smokeless tobacco Dosing

There is no medical indication for the use of smokeless tobacco.

Contraindications

Contraindicated in pregnancy and lactation.

Pregnancy/Lactation

Avoid use. Snuff use during pregnancy adversely affects fetal growth and increases the risk of preterm delivery and preeclampsia.

Smokeless tobacco Interactions

One case report documents the potential interaction between smokeless tobacco (which contains high levels of vitamin K) and warfarin.

Smokeless tobacco Adverse Reactions

Smokeless tobacco has caused numerous oral pathologies, including discolored teeth, excessive tooth surface wear, decreased ability to taste and smell, gingival recession, advanced periodontal soft and hard tissue destruction, tooth loss, oral leukoplakia, and increased risk of cancers in the mouth and gums. The use of smokeless tobacco may cause insulin resistance and affect blood pressure. Numerous epidemiological investigations document the potential increased health risks for cardiovascular disease, cancer, oral diseases, and glucose intolerance with smokeless tobacco use.

Toxicology

The research documents potential increased health risks for cardiovascular disease, cancer, oral diseases, diabetes, and osteoporosis when using smokeless tobacco.

Botany

Smokeless tobacco (ST) products are derived from the same botanical source as smoking tobacco ( Nicotiana tabacum ). The tobacco plant may have originated between North and South America more than 7,000 years ago. ST products often are flavored with sugar or artificial sweeteners. 1

History

American Indians may have been using tobacco throughout North and South America by the time the first European explorers arrived in the late 1400s and early 1500s. Tobacco use spread to Europe, Africa, China, and Japan over the next few centuries. Snuff use (at the time, finely ground tobacco that primarily was sniffed through the nose) was introduced to North American colonists in Jamestown, VA in 1611. Tobacco chewing in America started in the early 1700s and was widely accepted by the 1850s. 1 , 2

Snuff was the most popular form of ST in Europe and America prior to the 1800s. The current practice in the United States and many other parts of the world is “snuff dipping.” With this, the user places a “quid” of powdered tobacco in the buccal area between the gum and cheek and retains the material for a period of time, usually spitting or swallowing the resultant saliva. Quids are taken as loose portions or as small prepackaged bags of tobacco. In many parts of the world, the quid is mixed with other stimulants, such as betel or areca nut. Some users chew a “chaw” of ST. 1 , 2 , 3

ST products have been used by men and women of all levels of society. Data compiled from several large-scale studies indicate that 10 to 12 million Americans use some form of ST, with users often beginning at a very early age. Responses of 3,725 high school students in the southeastern United States indicate that 20% have tried ST products at some time. Of these users, 44% reported a first use of ST before age 13. Family influences and peer pressure were major factors in initiating use. Approximately 8% of the users felt they were addicted to the substance. Another survey of children in the third through twelfth grades in a Pennsylvania school district found that experimentation with ST had begun as early as the third grade, with the prevalence of use increasing with age. Approximately half of the boys in the seventh through twelfth grades did not believe ST products were harmful. 4 , 5 , 6

Children may be influenced by role models regarding the use of ST. A survey was conducted of Major League Baseball personnel during the 1987 season to determine their use and understanding of the hazards of ST. Twenty-five of 26 teams participated. The players (46%) “dipped” or “chewed,” more than the managers (35%), or trainers (30%). Although the users recognize the harmful potential of ST, its use remains high among baseball personnel. Use generally is more prevalent among men. However, it should be noted that in 1 study the prevalence of snuff use by women in the general population of central North Carolina was 30% (compared with 1.3% of women and 2.5% of men in the general US population). Analysis of the personality characteristics of 289 college-age users of ST found them to be more reserved, less socially outgoing, less sentimental, more conforming, and more group dependent than non-ST users. 7 , 8 , 9

Chemistry

Tobacco contains more than 2,500 chemical constituents. Some of these constituents are present naturally while others are added during cultivation, harvesting, and processing. For example, chewing tobacco consists of the tobacco leaf with the stem removed, sweeteners, and flavorings (eg, honey, licorice, rum). Snuff consists of the entire tobacco leaf (dried and powdered or finely cut) and additives such as menthol, peppermint oil, camphor, attar of roses, and oil of cloves. 2 , 10

Scientific literature lists 26 carcinogenic agents in oral snuff. Of these agents, N-nitrosamines are considered the major contributors to carcinogenic activity. Volatile and nonvolatile nitrosamines include tobacco-specific N-nitrosamines (TSNAs), polynuclear aromatic hydrocarbons, and polonium-210 (210Po). The most carcinogenic TSNAs, including 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and N-nitrosonornicotine (NNN), are found in concentrations that produced cancer in laboratory animals. 2 , 10

The major chemical groups in tobacco include aliphatic and aromatic hydrocarbons, aldehydes, ketones, alcohols, phenols, ethers, alkaloids (including nicotine, nornicotine, anabasine, anatabine, and myosmine), carboxylic acids, esters, anhydrides, lactones, carbohydrates, amines, amides, imides, nitrites, N- and O-heterocyclic compounds, chlorinated organic compounds, and at least 35 metal compounds. 2 , 11

Smokeless tobacco Uses and Pharmacology

As with smoking tobacco, the pharmacologic effect of ST is related to its nicotine content. Blood nicotine levels are achieved rapidly with ST use (within 5 minutes) and can reach 40 ng/mL, comparable with peak levels found in heavy cigarette smokers (who average approximately 35 ng/mL). 12 The use of ST, therefore, carries many of the risks and dangers of smoking tobacco.

Dosage

There is no medical indication for the use of ST.

Pregnancy/Lactation

Avoid use. Snuff use during pregnancy adversely affects fetal growth and increases the risk of preterm delivery and preeclampsia. 13 , 14

Interactions

One case report documents the potential interaction between tobacco (which contains high levels of vitamin K) and warfarin. 15 , 16 The use of ST may cause insulin resistance caused by the glucose content (50 to 150 mg/g) of “candified” chewing tobacco. 17 Tobacco products may affect blood pressure because of its high sodium content. 15 , 16

Adverse Reactions

Tooth loss and periodontal softening occurs with chronic snuff use. Extracts of ST have served as a growth substrate for 3 species of oral streptococci frequently associated with human dental caries. ST use causes excessive tooth surface wear from abrasion, decreased ability to taste and smell, gingival recession, advanced periodontal soft and hard tissue destruction, tooth loss, and soft tissue erythema. A common pathologic change observed in ST users is oral leukoplakia. In a study of Navajo Indians (14 to 19 years of age), 25% of the users compared with 4% of nonusers had leukoplakia. 4 , 18 , 19 , 20

Thromboangiitis obliterans, a distinct clinical entity characterized by segmental inflammatory and proliferative lesions of small artery and vein walls, has been observed frequently in heavy cigarette smokers. At least 1 case also has been attributed to chronic snuff use. 21

Nicotine has sympathicoadrenal-activating properties and is high in sodium and licorice, thus having the potential to affect blood pressure. Most studies examine the acute vs the chronic effects of ST on blood pressure. In 1 review article, systolic blood pressure increased 10 to 20 mm Hg and diastolic blood pressure 6 to 12 mm Hg among ST users. 3 , 16

Nicotine also causes vasoconstriction and tachycardia. Novice snuff users often experience nausea and dizziness. However, ST use is not associated with any apparent excess risk for myocardial infarction and stroke. 22 , 23 , 24

Oral pathologies (eg, cancer; gum recession, inflammation, and lesions; leukoplakia; tooth erosion; tooth decay; periodontal alveolar bone loss) are some of the main disease states associated with ST use. The rate of oral cancer often is linked to the level of TSNAs in the product. In US brands, the concentrations of TSNAs range from 5.2 to 141 ppm, which is hundreds to thousands of times higher than the concentrations allowed in food products. 25

One in 20 instances of leukoplakia will undergo malignant transformation into epidermoid carcinoma. Nitrosamines found in ST have been shown to be tumorigenic in animals. 26

Increased incidences of cancers of the mouth and gums, pharynx, and salivary glands also have been reported in ST users. Case-controlled analyses of chronic female snuff users in North Carolina found an exceptionally high mortality from oropharyngeal cancers. The relative risk associated with snuff dipping among nonsmokers was 4.2%; among chronic users the risk approached 50-fold for cancers of the gum and buccal mucosa. Users of loose portion snuff exhibit increased thickening of the oral mucosa epithelium while portion bag users show variable thickened surface layers with evidence of keratinization. In an analysis of more than 2,000 patients with oropharyngeal cancers, chewing tobacco, smoking, or both accounted for 70% of the cancers of the oral cavity, 84% of the oropharynx, and 75% of the hypopharynx. 14 , 26 , 27 , 28 , 29

Approximately one-third of ST users swallow the salivary juices. Persistent hyperglycemia was observed in diabetic patients who used “candified” chewing tobacco and regularly swallowed the juice. Analysis of several brands found 50 to 150 mg glucose/g tobacco. Blood sugar levels returned to normal once snuff use was discontinued. 17

Some investigators suggest that saccharin added to flavor some snuffs may pose an increased risk of bladder cancer. 30

Toxicology

Numerous systematic reviews on epidemiological investigations on the toxicity of ST are documented in the scientific literature. The research documents potential increased health risks for cardiovascular disease, cancer, oral diseases, diabetes, and osteoporosis when using ST. 3 , 11 , 16 , 31

Bibliography

Link to Page

Print Page

Email Page

Add to List

User reviews

0 review(s) for Smokeless tobacco