WHEN a friend pulled out a cigarette and lighted it in front of me recently, I was surprised. Although we had spent a considerable amount of time together, I had never seen him smoke.
But I was more taken aback by how he downplayed the habit. He didn't think that his smoking posed a problem. He insisted that he wasn't addicted to cigarettes, that he could give them up if he wanted.
"In their own minds, they're not really smokers," says Dr. Joseph DiFranza, professor of family medicine at University of Massachusetts Medical School. They say they could take cigarettes or leave them. Recent research tells a different story.
The notion that light smokers can become dependent on nicotine is a relatively new one. Until recently, it was assumed that only heavy or moderately heavy smokers could become nicotine dependent. Traditional definitions of dependency also require that smokers meet a number of clear-cut criteria. They must, for example, suffer from nicotine withdrawal or demand increasingly larger amounts of nicotine.
Now some experts argue that dependence begins when smoking can no longer be given up freely. They suggest that it should be viewed simply as a loss of autonomy or free will. "The real meaning of addiction is that you've lost some control," says DiFranza.
He and his colleagues have developed a questionnaire to assess this loss of control over tobacco. Light smokers who have any one of the symptoms described in the questionnaire are more likely to have difficulty quitting smoking in the future, he has found. In one study, smokers who developed one or more of the symptoms were 29 times more likely to fail at their first attempt at quitting.
When dependence is defined this way, it doesn't take many cigarettes for some smokers to qualify. "Symptoms of dependence are quite common among light smokers," DiFranza says. "If they go a few days without a cigarette, they experience the same symptoms that heavy smokers suffer from if they don't smoke for a few hours." They might develop cravings for cigarettes and become irritable.
It doesn't take long to become "hooked" either. Symptoms of dependence typically begin within a few months — if not weeks — of the onset of smoking, even light smoking. "Dependence can sometimes begin to develop after just a few cigarettes," says DiFranza.
In fact, because nicotine dependence can develop even when smoking occurs only sporadically, there doesn't appear to be any safe level of smoking.
It's not just nicotine dependence that light smokers need to worry about. They appear to be at risk for many — if not all — of the serious health consequences associated with heavier smoking. "Down to one cigarette a day, you can still see an elevated risk of lung cancer," DiFranza says.
The good news for light smokers is that quitting may not be as difficult as it is for people who smoke heavily. A recent study found that light smokers appear to have fewer symptoms of dependency than heavy smokers and seem to retain somewhat more control over nicotine.
Unfortunately, my friend's window of opportunity for quitting may have already closed. When I spoke to him recently, he assured me that I shouldn't worry about his occasional smoking because job stress had driven him to start smoking a lot.
Dr. Valerie Ulene is a board-certified specialist in preventive medicine practicing in Los Angeles. She can be reached at email@example.com. The MD appears the first Monday of the month.
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A few questions on dependence
Smokers who answer "yes" to even one of the following questions have become dependent on nicotine, say researchers at University of Massachusetts Medical School.
Have you ever tried to quit, but couldn't?
Do you smoke now because it is really hard to quit?
Have you ever felt as if you were addicted to tobacco?
Do you ever have strong cravings to smoke?
Have you ever felt you really needed a cigarette?
Is it hard to keep from smoking in places where you are not supposed to?
If you've tried to stop smoking (or when you haven't used tobacco for a while):
Did you find it hard to concentrate because you couldn't smoke?
Did you feel more irritable because you couldn't smoke?
Did you feel a strong need or urge to smoke?
Did you feel nervous, restless or anxious because you couldn't smoke?