Most smokers know smoking is bad for them, but many of them don't know exactly what it is about their habit that's so dangerous. A recent survey of smokers enrolled in a quitting program showed many think nicotine causes cancer. Many also smoke so-called "light" cigarettes because they think it will reduce the health risks.

But those beliefs are wrong, said Virginia Reichert, NP, director of the Center for Tobacco Control at North Shore-Long Island Jewish Health System in New York and the researcher who conducted the survey. Nicotine alone isn't known to cause cancer, she explained, and many studies have shown that "light" cigarettes aren't any safer than regular ones.

The survey included 1,139 smokers in Reichert's cessation program. She presented the findings at a recent meeting of the American College of Chest Physicians.

RESOURCES: Great American Smokeout Reasons to Quit Quitlines and Other Support

In recent years, some very preliminary studies done in the lab have suggested that nicotine may aid the growth of cancer cells that have already formed. But these early studies havenÂ’t shown nicotine to be nearly as dangerous in this regard as are some of the other components in tobacco smoke. Tobacco smoke contains over 4,000 chemicals, more than 60 of which are known to be cancer-causing.

"We thought some people would believe nicotine causes cancer, but we were very surprised to see how many people believe that," Reichert said. Just how many were misinformed? Nearly 72% of women and almost 60% of men in Reichert's survey thought nicotine caused cancer.

The main problem with nicotine is that it's highly addictive -- itÂ’s what keeps smokers coming back for more.

About 72% of women and 63% of men in the survey said they smoke "light" cigarettes because they think "lights" are less harmful. ("Light" cigarettes are also referred to as "reduced yield" because they yield lower levels of tar and nicotine when connected to a standard smoking machine -- though smokers may not get less of these substances when they smoke these cigarettes.)

"People think 'light' cigarettes are better for them, but they aren't," Reichert said. "People who smoke 'lights' usually smoke more of them to get the nicotine they need, and they suck harder on the cigarette to get the nicotine they need."

All that means even smokers of "light" cigarettes take in large amounts of the many chemicals in cigarettes that are known to cause cancer. Aside from cancer, smoking can also cause heart disease, stroke, lung diseases like emphysema, asthma, and bronchitis, and a host of other health problems.

Reichert's findings echo those of a separate study published in 2004 that showed smokers are confused about the effects of nicotine. That study also found that many smokers are wary of nicotine replacement products -- the very tools that could help them kick the habit.

Researchers from the Roswell Park Cancer Institute surveyed 1,046 adult smokers about their beliefs about nicotine and nicotine replacement products like the patch, gum, inhaler, and nasal spray. They published their findings in Nicotine and Tobacco Research. As in Reichert's study, most smokers thought nicotine causes cancer, and around half believed less nicotine made cigarettes less harmful.

Those mistaken ideas may help explain why so many people in the study expressed concerns about nicotine replacement products, the Roswell Park researchers said. For instance, many people thought nicotine patches were more likely or as likely to cause a heart attack as smoking -- when in reality they're less likely to. Many also worried about becoming addicted to nicotine replacement products.

Yet numerous studies have shown that these products are safe and effective in helping smokers quit. In fact, using medications like nicotine replacement or bupropion (an antidepressant marketed under the name Zyban for smoking cessation) can double a smoker's chances of successfully quitting. Counseling, quitlines, and support groups can also be very helpful.

"That myth that you should just be able to do it Â… that's just not true," Reichert said. "It's very, very difficult. It's important that smokers get the right information and get referred to a program that can give them the help they need."

Citations: "A Study of Gender Discrepancies Amongst Smokers Regarding Perceptions of Cigarette Use." Presented at CHEST 2005, the annual meeting of the American College of Chest Physicians. First author: Virginia Reichert, NP, North Shore-Long Island Jewish Health System.

"Stop-smoking medications: Who uses them, who misuses them, and who is misinformed about them?" Published in the Dec. 2004 issue of Nicotine and Tobacco Research (Vol. 6, Supplement 3: S303-S310). First author: Maansi Bansal, MS, Roswell Park Cancer Institute.