Chapter 10: Tobacco

Tobacco provides an interesting social dilemma.  It is a legal drug used by a significant proportion of adults; yet, at the same time, it is the leading preventable cause of death among Americans.

Tobacco was introduced into Europe and the East after Columbus's voyage to the Americas.  It was initially promoted as a medical treatment for a wide range of ailments.  As time passed, it was associated with reproductive and other problems and was eventually dropped as a medical treatment.  All tobacco products are derived from species of the Nicotiana plant. Different products have been popular at different times—first snuff, then chewing tobacco, then cigars, and finally cigarettes.

There have been many attempts at tobacco regulation over the years, dating back to King James of England in the early seventeenth century.  During the twentieth century, reports began to appear linking smoking and lung cancer, a link confirmed by the Surgeon General's report of 1964.  Eventually, tobacco ads were banned on TV and radio, and warning labels were required on all cigarette packages.  Many additional federal, state, and local regulations have been enacted in the past 30 years. In addition, lawsuits against tobacco companies have successfully obtained compensation for the costs of the health consequences of smoking.

In response to reports about the dangers of smoking, tobacco companies marketed lower tar and lower nicotine cigarettes. However, studies have found that users adjust their smoking behavior to obtain a consistent amount of nicotine, and no type of cigarette is considered safe.  Some smokers also tried switching to smokeless tobacco—which although somewhat safer than cigarettes, does carry the serious health risks of nicotine dependence, dental disease, and oral cancer. Overall, tobacco use has declined among Americans since the 1960s, but many people still smoke cigarettes or cigars or use smokeless tobacco.  Education level is strongly correlated with smoking rates—meaning the more years of education a person has, the less likely she or he is to smoke.

Adverse health effects of smoking include significantly increased risk of lung cancer, cardiovascular disease, and chronic obstructive lung diseases such as emphysema.  The risk is greatest for smokers who begin at a young age, smoke many cigarettes and continue to smoke for a long time.  Smoking is also dangerous to nonsmokers who are exposed to environmental tobacco smoke.  Passive smoking has been linked to lung cancer and other chronic diseases, and the Environmental Protection Agency classifies secondhand smoke as a known human carcinogen.  Smoking during pregnancy carries an increased risk of miscarriage, low birth weight, and sudden infant death syndrome.  There are also later effects on the physical and intellectual development of the baby.

Nicotine is the primary reinforcing substance in tobacco.  Smokers report that nicotine has both stimulant and calming effects, depending on the person and the situation.  Nicotine mimics acetylcholine and also has an indirect sympathomimetic effect.  It increases heart rate, blood pressure, and platelet adhesiveness, while at the same time decreasing the oxygen-carrying ability of blood.  All of these effects are potentially dangerous.  Most nicotine is deactivated in the liver and then excreted through the kidneys.

Nicotine is highly toxic and most beginning smokers experience symptoms of low-level nicotine poisoning, including nausea and dizziness.  At higher levels, nicotine can cause tremors, convulsions, and paralysis of breathing muscles.

Although quitting is difficult and the relapse rate high, there are more than 40 million ex-smokers in the United States. Counseling, nicotine replacement products, and certain antidepressants have all been shown to help people quit. Smokers should keep trying to quit even if they relapse, as it often takes multiple attempts.