Unlike most drugs, the undesirable health effects of nicotine are only long-term. Even so, the overall cost of nicotine addiction to smokers and to the community is huge!
Statistics from the Centers for Disease Control and Prevention indicate that tobacco use remains the most prominent preventable cause of premature death in the United States, causing approximately 440,000 premature deaths each year and resulting in an annual cost of more than $75 billion in immediate medical costs as a result of smoking.
Over the past forty years, cigarette smoking has caused a projected 12 million deaths, including 4.1 million deaths from cancer, 5.5 million fatalities from cardiovascular disease, 2.1 million deaths from respiratory disease, and 94,000 infant deaths related to pregnant women smoking during pregnancy.
Second-hand smoke, also referred to as environmental tobacco smoke, is a mixture of the smoke given off by the burning end of tobacco products (side stream smoke) and the mainstream smoke exhaled 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, serious respiratory infections, ear problems, and more serious asthma. Since 1964, 28 Surgeon General’s reports on smoking and health have resolved that tobacco use is the single most unnecessary cause of disease, disability, and death in the United States.
In 1988, the Surgeon General concluded that cigarettes and other types of tobacco, such as cigars, pipe tobacco, and chewing tobacco, are addictive and that nicotine is the drug in tobacco that causes addiction.
Nicotine provides an almost immediate “kick” because it causes a discharge of epinephrine from the adrenal cortex. This stimulates the central nervous system and endocrine glands, which causes a sudden discharge of blood sugar. Stimulation is then followed by depression and exhaustion, leading the user to seek more nicotine.
Nicotine is absorbed quickly 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 immediately when tobacco is chewed. With regular use of tobacco, levels of nicotine accumulate in the body during the day and persist during sleep. Thus, daily smokers or chewers are exposed to the effects of nicotine for 24 hours each day.
Addiction to nicotine end results in withdrawal symptoms when a person attempts to stop smoking. For example, a study found that when chronic smokers were dispossessed of cigarettes for 24 hours, they had increased annoyance, hostility, and aggression, and loss of social collaboration. Persons suffering from withdrawal also take longer to recoup psychological equilibrium following anxiety. During periods of abstinence and/or craving, smokers have shown impairment across a wide range of psychomotor and cognitive functions, such as linguistic comprehension.
Adult females who smoke generally have earlier menopause. Pregnant females who smoke cigarettes run an increased risk of having stillborn or premature babies or infants with low birth weight. Children of women who smoked while expecting have an increased risk for contracting conduct problems. National research of pregnant mothers and daughters have also found that maternal smoking during the perinatal period increased the chance that female children would smoke and would persist in smoking.
In addition to nicotine, cigarette and cigar smoke is primarily composed of a dozen gases (largely carbon monoxide) and tar. The tar in a cigarette, which varies from around 15 mg for a normal strength cigarette to 7 mg in a low-tar cigarette, exposes the user to an increased risk of lung cancer, emphysema, and bronchial disorders. The carbon monoxide in tobacco smoke increases the likelihood of heart disease. The Environmental Protection Agency has resolved that secondhand smoke causes lung cancer in adults and seriously raises the risk of respiratory problems in children, along with sudden infant death.
Research has shown that nicotine, like cocaine, heroin, and marijuana, elevates the level of the neurotransmitter dopamine, which affects the cerebral pathways that regulate reward and gratification. Scientists have isolated a particular 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, suggesting that without the b2 subunit, the mice do not undergo the positive reinforcing properties of nicotine. This finding identifies a likely site for targeting the growth of nicotine addiction medications.
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 large decreases in the responsiveness of the intelligence of laboratory rats to gratifying motivation 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 results of this research may help in the development of better treatments for the withdrawal problems that may stand in the way of smokers’ efforts to quit.