Unlike most drugs, the undesirable health effects of nicotine are only long-term. Even so, the complete cost of nicotine addiction to users and to the community is vast!
Statistics from the Centers for Disease Control and Prevention indicate that tobacco use remains the foremost preventable cause of premature death in the United States, causing approximately 440,000 premature fatalities each year and resulting in an annual cost of more than $75 billion in direct medical costs as a result of smoking.
Over the past forty years, cigarette smoking has caused an estimated 12 million deaths, including 4.1 million fatalities from malignant tumors, 5.5 million fatalities from vascular disease, 2.1 million deaths from lung disease, and 94,000 infant deaths associated with pregnant mothers smoking during gestation.
Second-hand smoke, also identified as environmental tobacco smoke, is a mixture of the smoke given off by the burning end of tobacco products (side stream smoke) and the ordinary smoke breathed out by smokers. It is a complex mixture which contains many chemicals (including formaldehyde, cyanide, carbon monoxide, ammonia, nicotine and other poisons), many of which are known to be carcinogenic.
Non-smokers exposed to secondhand smoke at home or work increase their risk of contracting cardio-vascular disease by 25 to 30 percent and lung cancer by 20 to 30 percent. Moreover, secondhand smoke causes respiratory problems in non-smokers such as coughing, mucus, and reduced lung function.
Children exposed to secondhand smoke are at an increased risk for sudden infant death syndrome, severe lung illness, ear complications, and more serious asthma. Since 1964, 28 Surgeon General’s reports on smoking and health have determined that tobacco use is the single most preventable cause of disease, incapacity, and death in the United States.
In 1988, the Surgeon General resolved that cigarettes and other forms of tobacco, such as cigars, pipe tobacco, and chewing tobacco, are addictive and that nicotine is the drug in tobacco that causes addiction.
Nicotine gives an almost immediate “kick” because it causes a discharge of epinephrine from the adrenal cortex. This stirs up the central nervous system and endocrine glands, which causes a sudden discharge of blood sugar. Stimulation is then followed by depression and lethargy, leading the user to seek more nicotine.
Nicotine is absorbed instantly from tobacco smoke in the lungs, and it does not matter whether the tobacco smoke is from cigarettes, cigars, or pipes. Nicotine also is absorbed easily when tobacco is chewed. With regular use of tobacco, levels of nicotine accumulate in the body during the day and persist overnight. Thus, daily smokers or chewers are exposed to the effects of nicotine for 24 hours each day.
Addiction to nicotine end results in withdrawal problems when a person attempts to stop smoking. For example, a study found that when chronic smokers were deprived of cigarettes for 24 hours, they had increased annoyance, hostility, and aggression, and loss of social cooperation. Persons suffering from withdrawal also take longer to reclaim emotional stability following stress. During times of abstinence and/or cravings, smokers have shown deficiencies across a wide array of psychomotor and cognitive functions, such as language comprehension.
Adult females who smoke generally have early menopause. Pregnant women who smoke cigarettes run an increased risk of giving birth to stillborn or premature babies or infants with low natal mass. Children of females who smoked while expecting have an increased risk for developing conduct disorders. National research of mothers and daughters have also found that maternal smoking during pregnancy increased the likelihood that feminine children would smoke and would persist in smoking.
In addition to nicotine, cigarette and cigar smoke is primarily composed of a dozen gases (mostly carbon monoxide) and tar. The tar in a cigarette, which varies from approximately 15 mg for a standard cigarette to 7 mg in a low-tar cigarette, exposes the user to an increased risk of lung cancer, emphysema, and bronchial problems. The carbon monoxide in tobacco smoke increases the chance of heart disease. The Environmental Protection Agency has concluded that secondhand smoke causes lung cancer in adults and seriously raises the risk of respiratory illness in children, along with sudden infant death.
Research has shown that nicotine, like cocaine, heroin, and marijuana, elevates the amount of the neurotransmitter dopamine, which affects the brain pathways that control reward and gratification. Scientists have pinpointed a distinct molecule - the beta 2 (b2) sub-unit of the nicotine cholinergic receptor - as a critical component in nicotine addiction. Mice that lack this subunit fail to self-administer nicotine, implying that without the b2 subunit, the mice do not experience the positive reinforcing properties of nicotine. This finding isolates a potential site for targeting the growth of nicotine addiction treatment.
Other investigations found that individuals have greater opposition to nicotine addiction if they have a genetic irregularity that decreases the function of the enzyme CYP2A6. The decrease in CYP2A6 slows the breakdown of nicotine and protects users against nicotine addiction. Understanding the role of this enzyme in nicotine addiction gives a new target for contracting more effectual treatment to help folks stop smoking. Medications may be developed that can reduce the function of CYP2A6, thus providing a new approach to preventing and treating nicotine addiction. Another study found vast changes in the brain’s pleasure circuits during withdrawal from chronic tobacco use. These changes are comparable in size and length to similar changes documented during withdrawal from other addictive drugs such as cocaine, opiates, amphetamines, and liquor.
Scientists found major decreases in the responsiveness of the intelligence of laboratory rats to congenial stimulus after nicotine administration was abruptly stopped. These changes lasted several days and may relate to the anxiety and melancholy experienced by humans for several days after quitting smoking “cold turkey.”
The end results of this research may help in the evolution of better treatments for the withdrawal symptoms that may stand in the way of individuals’ efforts to quit.
