Addicted: In the Lungs and in the Brain
Addicted: In the Lungs and in the Brain
Nicotine is an addictive substance. When nicotine enters the bloodstream, it alters both the mind and the body. Nicotine, along with the other chemicals in tobacco, produces some pleasurable effects—but there are also very serious long-term health implications to those using tobacco products and those who live or work with tobacco users.
Today adults continue to use cigarettes much more often than other forms of tobacco. According to a 1998 survey, 24 percent of American adults smoke cigarettes (26 percent of men and 22 percent of women). The figure is lowest among the most educated adults, with only 11 percent of college-educated adults smoking. It is highest (37 percent) among those who were not high-school graduates. Some types of tobacco are used almost exclusively by men—4 percent of men use cigars, 2 percent use pipes, 3 percent use chewing tobacco, and 3 percent use snuff. Less than half of 1 percent of women use tobacco in these ways.
Although tobacco users and medical professionals have known for generations that nicotine was addictive, it is only recently that studies have proved (and tobacco companies have admitted) this fact. As an addictive substance, tobacco affects people's behavior, causing them to make choices that are harmful to their health and the health of others.
In the Bloodstream
When any form of tobacco is used, nicotine is absorbed into the bloodstream. When a person places moist snuff or chew in between the cheek and gum or inhales snuff through the nose, nicotine immediately moves into the small blood vessels in the mucous membranes of the mouth and nose. These mucous membranes in the oral and nasal cavity are thin and allow nicotine and other chemicals to be quickly absorbed into the bloodstream.
Although some people use smokeless tobacco products like chew or snuff, most tobacco users inhale the tobacco smoke. As humans inhale, oxygen is drawn into the lungs. The bronchial tubes, or airways inside the lungs, look like large upside-down stalks of broccoli. The larger parts of the stalk direct the air down
into the smallest sections. Alveoli are the small sacs found at the end of these smallest branches. They cover a huge area, with more than ninety times more surface area than the skin. It is in these alveoli that fresh oxygen is supplied to the blood during inhalation and carbon dioxide is taken out of the blood during exhalation.
When a smoker takes a puff on a cigarette, a mixture of oxygen, nicotine, and carbon monoxide, among other chemicals, are brought into the arterial bloodstream through the lungs. The arterial bloodstream supplies fresh, oxygenated blood to the brain and all the body's tissues. The brain and body need oxygen to survive and function normally. But nicotine and other chemicals from tobacco replace some of the oxygen sent into the bloodstream and, once in the bloodstream, the nicotine moves very quickly to the brain. In fact, nicotine arrives in the brain eight to ten seconds after it is inhaled or ingested.
In the Brain
When the chemical-laden arterial blood flow reaches the brain, nicotine begins promoting the production of dopamine. Dopamine is a neurotransmitter, or a chemical in the brain that carries messages between nerve cells, and is part of the complex neural circuitry that helps the body perceive pleasure. Dopamine is normally released by the brain when doing something necessary for survival (like eating) or during other pleasurable events (such as giving someone a hug). So, when nicotine enters the brain and triggers dopamine production, the tobacco user perceives that his or her action was pleasurable.
Nicotine triggers dopamine production by imitating another neurotransmitter, acetylcholine. When certain receptors on dopamine-producing nerve cells are filled with acetylcholine, dopamine is produced in moderate and controlled quantities. Nicotine is similar enough to acetylcholine that it can lock into its receptors. By doing so, it fools the body into producing elevated levels of dopamine. Alcohol, heroin, and cocaine also promote dopamine production in the brain.
Nicotine also reacts in different parts of the brain to produce other chemicals. Glutamate, the neurotransmitter that enhances memory and learning, is released when nicotine is used. One effect of this enhanced memory is that the brain remembers the pleasure it experienced as a result of the dopamine and wants to experience that pleasure again.
Endorphins, which are known as the body's natural painkiller, are also released in the presence of nicotine. Runners experience a "runner's high" from the release of endorphins. This gives runners a mental advantage—they do not have to worry about small aches and pains while they complete the race. The effects of endorphins might similarly contribute to the mental edge tobacco users feel after taking nicotine into the body.
Nicotine has several other complex physiological effects. It affects central nervous system functions, thought processes, and behavior. Some people report that nicotine separates them from their emotions, and with nicotine they can think more logically and work better. This effect helps explain why some people feel better able to cope when they use tobacco. As David Sanford, a longtime smoker, puts it, "I work better when I can smoke…. Smoking definitely helps me concentrate, and it has many anti-depressant effects (it helps me cope with my multiple sclerosis)."9
Other chemicals released by nicotine's actions in the brain help the tobacco user feel alert and energized. But for all the functions that are temporarily improved, there is a very real danger of current and future health problems. The prolific writer Stephen King said, "I used to be faster than I am now; one of my books … was written in a single week…. I think it was quitting smoking that slowed medown; nicotine is a great synapse enhancer. The problem, of course, is that it's killing you at the same time it is helping you compose."10
An Addictive Substance
The perceived benefits of tobacco are one of the reasons that people become addicted to using it. It changes the way people think and process information and how they cope with the difficulties around them. However, addiction is a complex process that
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involves the chemical properties of the drug, its cost and availability, the user's specific personality traits and genetic factors, the user's peer and family influences, prevailing social attitudes, and more. All of these factors mix together to help determine whether a person who tries a drug will subsequently become addicted.
When someone is addicted to a drug, the use of that drug on a regular basis becomes compulsive. This leads to a feeling that the user of the drug cannot control the compulsion. Without the drug, users start to experience a variety of uncomfortable symptoms, including powerful cravings. To alleviate these symptoms, they continue to use the drug despite knowing about its health implications. Steven Hoadley, a longtime smoker, started smoking when he was twenty and later became addicted to alcohol, cocaine, and heroin. Eventually, because of his addictions, he found himself homeless. He says,
Tobacco was always there…. I stole my cigarettes from whatever source I could. In those days, smoke products weren't as guarded as they are today. Supermarkets and liquor stores … often kept a display rack on the counter. I would ask the clerk to get me a pint of whiskey and when he turned his back, I pilfered a pack or two.
If I was walking down a street and a car door was open and an open pack sat on the dash, they were mine. Basically, I got them however I could. They were never a priority at that time, as the other substances took precedence. But, nevertheless, I went to great lengths.
Addiction is a full time job.11
The kick that smokers experience from smoking increases each time certain portions of the brain are exposed to nicotine. Nicotine activates cells associated with memory and learning in the hippocampus, a part of the brain. Seeking this remembered "nicotine high," an addicted smoker continues to breathe poisonous and cancer-causing substances into his or her body.
Research has shown that it only takes one cigarette for the brain to recall the nicotine high. However, it still takes an effort to begin smoking cigarettes. More than other addictive drugs, nicotine can cause dizziness, nausea, and severe discomfort the first time it is used. The beginning smoker will usually cough and gasp for air as he or she is learning to smoke. A new smoker must have good motivation for continuing to try cigarettes.
Sometimes that motivation is external—beginning smokers may want to fit in with their friends, they may have heard smoking is good for stress or diet, or they may have a family member who smokes. They may also have been brainwashed by advertising into thinking that smoking is cool, sophisticated, or macho. Dr. Elizabeth Whelan, part of the American Council on Science and Health, stated that, "cigarette smoking has not only the potential to addict physiologically by means of nicotine after just a few smokes, but also the ability to compound that addiction through behavioral and psychological facets associated with the act of smoking a cigarette."12 These behavioral or psychological factors, the habitual factors that drive a smoker to continue smoking, can be very hard for smokers to overcome.
Sometimes the motivation to smoke is internal. After a smoker experiences the effects of nicotine, he or she may want to continue to experience that feeling despite the difficult side effects. Additionally, even after just a few cigarettes, the new smoker who stops suddenly may feel withdrawal symptoms such as irritability or difficulty in concentrating or thinking. These symptoms, along with a craving for more nicotine, make it very hard to stop smoking. Christina Johnson, a longtime smoker, tells of her experiences when she ran out of cigarettes while visiting a friend. She says, "I was desperate! My body ached for it…. My friend … went around gathering cigarette butts and squeezed the last little bit of tobacco from … them… until he had enough to roll me a makeshift cigarette. It was probably the worst cigarette I've ever had but, at the time, you couldn't have told me that. I sucked it down in minutes."13
Smokers, however, often believe they are not addicted. Many smokers say they like to smoke but can quit anytime. And for a very few, that may be true. Some smokers seem to be able to go for days without a cigarette, smoke a few, and then resume their smoke-free status. This is very rare though. For most people, once their brain has felt that nicotine high, they have a desire and a real need to keep on using nicotine at any cost.
Because of nicotine's addictive qualities, tobacco users take the drug again and again. The first dose of nicotine causes the user to feel instantly awake and alert; following that, there is a calm, relaxed feeling. However, the resting heart rate actually increases by two to three beats per minute after each dose of nicotine. Nicotine constricts the blood vessels, reducing the skin temperature and decreasing blood flow to the legs and feet. Thus the smaller blood vessels cause blood pressure to be increased, leading to lightheadedness and a rapid heartbeat. While these immediate effects are not harmful in themselves, repeated use causes damage to the body that takes place over the course of the tobacco user's lifetime.
Nicotine is a highly potent poison that has been used as an agricultural insecticide. Nicotine is so dangerous that 41 percent of seasonal farmworkers who harvest tobacco contract a severe case of what is known as green tobacco sickness. This occurs when tobacco field workers handle the moist tobacco leaves and absorb nicotine through the skin, causing symptoms such as nausea, vomiting, dizziness, headaches, and cramps.
In addition to nicotine, many ingredients in tobacco itself are also toxic. For example, there are at least four thousand chemicals in cigarette smoke, two thousand of which are poisonous and over forty of which are verified to be carcinogenic. Besides tar, a sticky, brown substance deposited in smokers' lungs, ingredients of cigarettes include: acetone (found in nail polish remover); ammonia (a poisonous gas); arsenic (a rat poison); carbon monoxide (a poisonous gas found in car exhaust); hydrogen cyanide (a toxic gas used as a pesticide); DDT (a banned insecticide which caused serious harm to animals and the environment when it was in use); and formaldehyde (embalming fluid).
Tobacco producers add these chemicals in order to maintain consistent levels of nicotine in the product. Manufacturers' goals in manipulating nicotine levels are to cause people to become addicted to tobacco products.
The nicotine in tobacco does not have much to do with how much nicotine was in the leaves on the original plant. In fact, on the same tobacco plant, concentrations of chemicals in the different leaves can vary widely, with the leaves toward the top of the plant having more nicotine and a higher concentration of other chemicals.
Exercise and Smoking
Some people think those smokers who exercise rigorously are working to improve their physical condition and will therefore reduce their risk of heart attack. Yet a recent study showed that smokers who exercise have a five times greater risk of heart attack than nonsmokers do.
Normally when people exercise, their bodies release epinephrine, which speeds up their heart rate. Nicotine mimics epinephrine, so a smoker's heart is constantly signaled to speed up. The extra signals that nicotine causes are essentially false alarms, and the body stops reacting to these extra signals because it is being flooded with them. So, during exercise, when the body really does need a faster heart rate, a smoker's body may not recognize it.
A person with a diminished heart response rate may not get enough of the blood needed during a vigorous workout, which could lead to a heart attack. About one-third of heavy smokers showed a diminished response rate during an exercise test. Of men with an impaired heart response rate, almost one out of five had a heart attack and one out of ten died during the eight-year study.
In addition to increased risk of heart attacks, the lung capacity of smokers is reduced. Smokers also have reduced endurance and are often short of breath. "I can't smoke more than two cigarettes a day when I run daily," says nurse-midwife Eleanor Swift in an interview with the author. "Running is not compatible with smoking." Madeleine Armstrong found that her breathing dramatically improved about six months after she quit smoking. In an interview with the author she said, "I found … that my breathing when I play sports was so much better. Before, I did not see the difference because I had been smoking for so long that I did not know I had a problem."
However, tobacco companies require a standard level of nicotine that is difficult to regulate in the natural product. So they use these chemical additives and other means to maintain the nicotine at optimal levels. Additives like ammonia increase the amount of nicotine available to the body. Other techniques include blending different tobacco leaves together, changing the cigarette or paper design, and changing the filter. The tobacco companies' goal in making a product with a standard amount of nicotine is to get the smoker hooked. Once hooked, they will likely be customers for a long time.
Although there are also some food and fragrance components in tobacco, no one has studied how all these added substances change chemically as they are burned or how these new chemicals affect the body. A natural chemical that may be safe as a food product can be carcinogenic in its combusted state.
All tobacco users send harmful chemicals through their body. Because there is not enough time for the body to repair itself between assaults, using tobacco is like contributing to death or disease in daily doses.
Manda Djinn, a singer and writer who lives in Paris, France, began her three-pack-a-day habit at the age of eleven and sang for years in smoky nightclubs. She says, "I am left with asthma and
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respiratory allergies…. I'm still singing … but smoke anywhere in my vicinity makes me short of breath, stings my eyes and irritates my nose…. We did not have the facts [years ago] about nicotine that we have today."14
Smokeless, not Harmless
Bill Tuttle, an outfielder for the Tigers, A's, and Twins baseball teams, chewed tobacco for almost forty years. In 1993, Tuttle's wife noticed a very large lump in his mouth. He went to the doctor and learned that the lump was malignant—Tuttle had cancer.
Over the course of six surgeries, Tuttle lost most of his face. The surgeons kept removing more and more bones and other tissue because the cancer continued to spread. Tuttle's jaw was eventually cut away, and the plastic surgeons had to work hard to reconstruct his face. They took part of his skull and flipped it down to create a new cheekbone. Huge pieces of skin from his chest and other areas of his body were used to cover the places where his cancerous facial skin had to be removed. He had lost his teeth earlier because of dental problems related to his chewing habit. He lost almost seventy-five pounds. Nerves had been cut in some of his many operations so he had no arm strength and could not even open a bottle.
After his cancer took so much from him, he decided to give something back to other ballplayers. Before his death in 1998, Tuttle gave talks around the country to ballplayers and the public. First the audience was shown a picture of Tuttle as a ballplayer in his prime. Then Tuttle would appear and the audience could see firsthand the effects of smokeless tobacco. Some of the ballplayers who were chewing at the start of his talk would shamefacedly stop by the end. Because he was not afraid to speak out, Tuttle helped other ballplayers and smokeless tobacco users, from Little Leaguers to major leaguers, become tobacco free.
Countless scientific studies have shown how nicotine and tobacco smoke affect human health. Nicotine and the other chemicals in tobacco damage many body systems, including the immune system. Tobacco users increase their risk of cancer, heart disease, circulatory disorders, ulcers, and stroke. Nicotine mimics epinephrine, which means a smoker's body is constantly signaled to speed up its heart. So the heart has to work harder than it should and may not respond well when an increased heart rate is needed by the body.
A smoker's lungs are damaged and lose their elasticity because of the many chemicals in cigarette smoke: tar coats the delicate lung surfaces and smoke damages the cilia (protective hairs) in the respiratory tract. Because of this, smokers have more frequent occurrences of colds and respiratory infections, bronchitis, emphysema, and asthma. Other effects that have been linked to tobacco use are rheumatoid arthritis and hearing or vision loss. Tobacco interferes with the absorption of calcium and other nutrients, so over time tobacco users have lower bone density and an increased risk of osteoporosis. Because nicotine reacts with brain chemicals, it alters the way a person thinks, in some cases causing depression, impaired thinking, and dementia.
It is estimated that smoking costs an average of eleven minutes of life for each cigarette—a pack of cigarettes will shorten a smoker's life by three hours and forty minutes. Clive Bates, director of Action on Smoking and Health (ASH) said, "As if that's not bad enough, smokers are likely to die a more painful death and spend longer being ill while they are alive."15
Even though scientists knew nicotine was toxic and addictive, it was once believed nicotine itself did not cause cancer. Recent studies have proved that wrong—nicotine does react in the body to create a cancer-causing by-product. Scientists have recently added nicotine itself to the list of known cancer-causing chemicals in tobacco.
Even smokeless tobacco has its problems. One study showed that 46 percent of baseball players who used snuff or chew had oral lesions, as compared to 1.4 percent of nonusers. Most lesions were not cancerous, but the ballplayers in this study were young and the median time they had used tobacco was only five years. It is not known how many of those lesions have changed and become cancerous in the years following the study.
Tobacco is one of the United States's top killers—it is estimated that tobacco use causes over 430,000 deaths annually. Broken down by day, more than 1,100 people die each day of smoking related causes—enough to fill three jumbo jets. Tobacco use directly causes more deaths than alcohol, homicide, AIDS, car accidents, and illegal drugs combined.
Susannah Tate quit smoking almost two decades ago, but her family has been greatly affected by tobacco use. She tells of tobacco's toll: "My older sister's lungs are so damaged she is on oxygen and has had pneumonia a number of times, and almost died. Her husband is a heavy smoker. Two of his brothers also smoke heavily. One has just been diagnosed with severe lung cancer, [and] has perhaps two months to live."16
Health Risks for Women
Many studies done in the past about the effects of tobacco use have been done on men and then generalized to women. However, more studies are being conducted on women smokers. These studies
show that women smokers have a 50 percent higher risk of heart attacks than male smokers. They are also more than twice as likely to experience depression and have a higher risk for osteoporosis and cardiovascular disease. Additionally, women smokers have a higher risk of lung cancer than men and a higher risk of cervical cancer than nonsmoking women. More studies, some on men and women and some on women alone, are being done to determine exactly how and why tobacco use causes these and other diseases.
One possibility for the differences between the sexes is that men and women have different hormones. Female hormones may affect the way tobacco products are processed in the body and blood. As an example, estrogen may promote cancer growth by promoting a binding effect between cancer-causing chemicals in tobacco and DNA in lungs. So, there are health effects from tobacco that are unique to women.
As well as harming women more than men, tobacco use during pregnancy creates additional risks for women and for their children. Nicotine and the other chemicals in tobacco and tobacco smoke can injure an unborn child in many different ways. Nicotine acts directly on the fetus's developing brain and reduces the amount of nutrients available. Instead of an unborn child receiving the rich, oxygenated blood that it needs, it receives blood full of carbon monoxide, hydrogen cyanide, and many other harmful chemicals, including nicotine.
Low birth weight is the most commonly cited problem with smoking while a woman is pregnant. Smoking during pregnancy has also been associated with miscarriages, stillbirths, longer stays in neonatal intensive care, higher incidences of sudden infant death syndrome, fussy or colicky babies, and learning disabilities. Because nicotine stimulates cells that release the neurotransmitter acetylcholine in the developing brain and nervous system, it can change the way a fetus's brain forms, permanently affecting anything from a child's personality to the ability to think. Problems with memory or thought processes (cognitive disorders) or learning disabilities may not show up until a child is in late elementary school or even adolescence. There may also be genetic cellular damage in the developing fetus that may put that child at a greater risk for cancer or other illnesses later. Many of these babies are born nicotine addicted, and after birth, when their nicotine supply is cut off, have to go through withdrawal symptoms.
Infants are not the only ones who are affected by the smoke of others. Millions of people expose families, friends, and those in their workplace to tobacco smoke on a daily basis.
Smokers inhale only a fraction of the smoke produced by a burning cigarette. The rest permeates the environment unfiltered and is breathed in passively by anyone nearby. This passive smoking is commonly referred to as environmental tobacco smoke (ETS), and has also been called secondhand smoke. The Environmental Protection Agency (EPA) classifies ETS as a class A carcinogen, the highest designation of a cancer-causing substance.
Some doctors have always recognized the risk of ETS. In fact, throughout history, physicians and scientists have reported that
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people exposed to tobacco smoke suffer more illnesses and problems than those who are in smoke-free environments. In modern medical literature, passive smoking was first mentioned in 1974. Scientists reported that children in homes where there was ETS present had more respiratory diseases.
Children who smoke passively have an increased risk of asthma, ear infections, and respiratory tract infections like pneumonia and bronchitis. They also have decreased lung function. For example, when she was fourteen, Norah Teeter, the daughter of a smoker, stopped breathing from a severe asthma attack. After being resuscitated, the doctor told her mother that her smoking was affecting her daughter's health. Norah remembers that "My doctor told my mother she should stop smoking. I was under chronic abuse from the smoke. The smoke was a constant irritant and would increase the problem with asthma."17
Asthma and respiratory disease are not the only problems that are made worse by passive smoking. Other temporary health problems include headaches and eye, nose, and throat irritation. Because chemicals are released into the air largely unfiltered during the burning process, ETS can also cause permanent damage such as lung cancer and heart disease. In fact, over three thousand deaths each year are caused by passive smoking.
In the United States, ETS is a public-health issue. Many states have enacted laws that protect nonsmokers from being exposed to ETS in the workplace, restaurants, schools, and other public places. In many areas of the country, the tide has turned so much that smoking is considered socially unacceptable.
Although tobacco has earned a negative reputation in recent years and is becoming more and more socially unacceptable, a large percentage of the population is addicted to nicotine and continues to use tobacco on a daily basis. Despite the various health implications and public awareness surrounding nicotine addiction, many new people become tobacco users every day. Unfortunately, most of these new tobacco users are teenagers.