Politics and prejudices aside, evidence is piling up to show that nicotine- is habit-forming, especially when delivered via cigarette smoke. As a drug-like agent, nicotine works directly on the brain, creating physical and psychological needs that millions of people worldwide find hard to resist. Even the stark reality of cancer and heart disease does not deter some from smoking. Exactly how nicotine spurs dependence is not well understood, since pinning down what nicotine does in the body has been difficult and controversial.
Efforts to separate nicotine’s impact on the body from the ffects of thousands of other chemicals in tobacco have not been entirely successful. One reason is that nicotine alone causes a wide variety of effects in the body, doing different things in different people, at different times. (http://www. ahcpr. gov/) In some smokers, for example, nicotine seems to work as a stimulant, making them feel sharper mentally, helping them focus on a task, helping get things done. In others, it acts as a depressant, slowing people down, helping them relax, so people use it for a variety of reasons.
In fact, recent evidence even suggests icotine can be helpful in two severe brain disorders, Parkinson’s disease and Alzheimer’s disease. Nicotine is made naturally in plant tissues, especially tobacco leaves, where it acts as an insect repellent. Pure nicotine is a colorless-to-amber oil that is found in smaller amounts in cauliflower, eggplant, tomatoes, green peppers and potatoes. Nicotine is a natural alkaloid, a nitrogen-containing organic chemical called beta-pyridyl-alpha-N-methylpyrrolidine. Only a few natural liquid alkaloids are known, and they seem to play similarly powerful roles in the human body.
Nicotine’s biochemical relatives include cocaine, morphine, quinine and atropine. But the question now is whether nicotine is an addictive substance like cocaine and heroin. Reports of the U. S. Surgeon General’s office released since 1988 say nicotine is considered a strongly addictive drug. “The nicotine delivered by tobacco products is highly addictive,” Dr. David A. Kessler, commissioner of the Food and Drug Administration, said recently in testimony before the House subcommittee on health and the environment.
The addictive properties of nicotine re so strong, in fact, Kessler said, that: “After surgery for lung cancer, almost half of smokers resume smoking. Among smokers who suffer a heart attack, thirty-eight percent resume smoking while they are still in the hospital. Even when a smoker has his or her larynx removed, forty percent try smoking again. ” Such claims that nicotine is addictive are strongly disputed by the tobacco industry, which emphasizes the ways smokers differ from heroin addicts. “We believe that addiction requires professional help” to break drug habits, said Thomas Lauria, a spokesman for the
Tobacco Institute, in Washington. But people can often quit smoking cigarettes on their own, without professional help, he said. (Nordenberg, 1997) Also, Lauria said, unlike liquor, cocaine and heroin, “cigarettes are not intoxicating,” and smoking doesn’t normally break up families, ruin careers or lead to crime. “We believe,” he said, “that in order to include smoking as an `addiction,’ you have to redefine the term and water down its meaning, to the point where you could say coffee is addictive.
“I admit that cigarettes are ddicting, but the question is whether nicotine [alone] is sufficient” to cause addiction, said neuroscientist Jed Rose, a co-inventor of the nicotine patch. “Or, are there other aspects of cigarettes that interact with nicotine” to cause addiction? Rose, at Duke University, thinks that “the underlying chemistry of nicotine is clearly important in maintaining the dependence” on smoking. “But it’s more than just getting nicotine into the bloodstream. It’s how it’s administered in the smoke that becomes critically important for the smoker. “