A growing number of anti-smoking researchers and public health advocates are adopting a tack that not long ago would have been considered heresy: suggesting that hard-core smokers who can't kick the habit would be better off switching to new smokeless tobacco products.

With slogans such as "Spit-free" and "For when you can't smoke," these products differ markedly from the messy snuff and chewing tobacco stereotypes associated with your granddaddy's spittoon or certain pro baseball players' stuffed cheeks.

They are clean, discreet, last about 30 minutes and come in mint, wintergreen and other flavors. Some go down easily, dissolving much like a breath mint, while others look like tiny tobacco-filled teabags, tucked into the side of the mouth and discarded like chewing gum.

Though no one is calling the products "safe" — any tobacco that has been cured contains some carcinogens — numerous epidemiological studies have shown that smokeless tobacco is far less likely to cause any type of cancer, including oral cancer, than cigarettes. "If someone can't quit smoking, there is no question that smokeless is much safer. It doesn't cause heart or lung disease, and if it does cause cancer, it does so at a much lower rate," said Dr. Neal Benowitz, a professor of medicine at UC San Francisco and director of its cancer center's Tobacco Control Program.

Gary Giovino, director of the Tobacco Control Research Program at the Roswell Park Cancer Institute in Buffalo, N.Y., agreed. "If everybody who smoked used these instead, there would be less disease."

Many Americans may be unaware that most scientists and researchers say that smokeless tobacco is less hazardous than cigarettes in causing deadly disease. That's not surprising. For years, some private and government medical organizations have disseminated outdated information on the subject. For instance, the Mayo Clinic in Rochester, Minn., recently acknowledged that information on its website was incorrect and would be revised.

Though some information on the Centers for Disease Control and Prevention's website was modified after one prominent researcher protested it, the agency, part of the U.S. Surgeon General's Office, takes the position that "there is no safe form of tobacco" and that there "is no significant evidence that suggests that smokeless is a safer alternative to smoking," spokeswoman Karen Hunter said.

Some tobacco researchers contend the misinformation hinders individuals from making educated decisions about whether to switch to smokeless products. "I think it's not scientific and is a deception," said Lynn Kozlowski, who heads Pennsylvania State University's biobehavioral health department. "What the studies show is that in the U.S., smokeless causes oral cancer but that cigarettes are even more likely to cause oral cancer."

With names that include Ariva and Stonewall, both made by Star Scientific Inc., and Revel, made by the U.S. Smokeless Tobacco Co., which also makes the Copenhagen and Skoal brands, the new products have been rolled out in a few U.S. cities and are also available from their manufacturers' websites. They promise to deliver the nicotine fix smokers crave and take the edge off the physiological urge to light up.

Although the nicotine in cigarettes is powerfully addictive, it is the cigarette smoke — not the nicotine — that delivers the killer punch, possibly producing as many as 60 known carcinogens and about 5,000 other chemicals. Studies show that many people still believe that it is the nicotine that is the harmful element.

Brad Rodu, an oral pathologist at the University of Alabama, said nicotine should be treated more like caffeine: as an addictive drug that can be used safely. (His "tobacco harm-reduction" research is funded by a five-year grant from U.S. Smokeless.) "We would have smokers understand the nicotine addiction can be separated from the smoking."

Sweden's experience with smokeless tobacco is one of the forces giving momentum to this harm reduction campaign in the U.S. Over the last 40 years, a large percentage of Swedish smokers — primarily men — have switched from smoking cigarettes to using a moist snuff product called "snus."

Sweden's cancer rates for men, including oral cancer, have declined and now are the lowest in Europe. In contrast, cancer rates for Swedish women — few of whom have made the switch from cigarettes to snus — remain as high as rates for most other European women.

Nevertheless, snus is outlawed by the rest of the European Union countries, while cigarettes are widely sold and remain quite popular, an irony not lost on some European healthcare providers. In a December 2002 report titled "Protecting Smokers, Saving Lives," Britain's Royal College of Physicians concluded that "the consumption of noncombustible tobacco is on the order of 10 to 1,000 times less hazardous than smoking, depending on the product."

Many public health advocates fear that providing smokers with alternative products will keep them from quitting altogether, the healthiest option. They also fear that some nonsmokers, including teenagers, might start using them and, if they do, that the nicotine will encourage them to start smoking.

Some of this concern stems from the difficulty in knowing the long-term hazards of substitute products as well as the distrust of the tobacco companies based on past claims. For example, in 1981, the U.S. Surgeon General recommended that smokers who couldn't quit would be better off switching to "low-tar" or "light" cigarettes because they were less likely to develop smoking-related illnesses. Instead, smokers were found to puff harder and inhale more deeply to compensate, thus taking in an equal amount of tar or more. Internal documents revealed that the cigarette makers knew that to be the case all along.

Kenneth Warner, director of the University of Michigan Tobacco Research Network, said he was convinced that the promise of reduced risk kept tens of thousands smoking rather than quitting — undoubtedly hastening many deaths. Nearly three years ago, the National Cancer Institute charged that light cigarettes did nothing to lower smokers' health risks.

Among the largest fears is that teenagers will get hooked on smokeless products, then switch to smoking when they realize that cigarettes deliver a faster and more powerful hit of nicotine. Greg Connolly, former director of the Massachusetts Tobacco Control Program, said kids who start on smokeless tobacco were three times more likely to go on to smoking cigarettes — and that some smokeless companies had deliberately targeted teenagers. He agreed that the newer products are less carcinogenic and probably safer to use but said the new products were not being aggressively pushed by their makers. Instead, the more carcinogenic, dirtier discount brands of smokeless products are growing in popularity. "I'd be the first to say [the new products] are safer," Connolly said. "But I don't want them to be hurting our kids. This is an industry you can't trust."

A Lethal Habit

The push for safer alternatives comes amid mounting gloom about smoking. Although cigarette smoking has declined dramatically from its peak in the 1960s, it has leveled off in the last decade. About 46 million Americans — 22% of adults, according to the CDC — still light up each day despite aggressive public education campaigns, heavy cigarette taxes to make them less affordable, significant social stigma and widespread smoking bans in public places. An estimated 10 million Americans use smokeless tobacco.

It's a very tough habit to break — tobacco researcher and former smoker Giovino calls quitting "a toothache in the soul." Although 70% of smokers say they want to quit and 34% of them attempt to do so each year, only 10% manage to stay smoke-free for a year, according to the Institute of Medicine.

"We are not promoting tobacco use," the University of Alabama's Rodu said. "But we have a reality of 46 million smokers, and they now have only one option: to quit. It's quit or die."

Several tobacco researchers maintain that smokers would be better off switching to "medicinal" nicotine products such as patches, nicotine gums and lozenges. The "pure" liquid nicotine in these has been extracted directly from the stem of the tobacco plants. But because the plant has not been cured or burned, it doesn't present the carcinogens that other tobacco products do.

Prices of these "pure" products — designed for limited rather than long-term use — are out of reach for many. At $50 and up, they can cost several times the price of a pack of cigarettes or smokeless tobacco. About 33% of those living below U.S. poverty levels smoke, compared with 22% of the general population, according to the CDC.

The patches have not proven to be very effective, Giovino said, with fewer than 10% of users successfully quitting. This is at least in part, many researchers say, because it does not deliver enough nicotine. Tobacco products are exempt from Food and Drug Administration regulation, while safer, pure medicinal products are subject to FDA scrutiny because they are considered to be drug (nicotine) delivery systems. Getting FDA approval requires time and expense, driving up prices. Products that tout themselves as smoking-cessation aids also require FDA clearance.

Hence, the new smokeless products do not market themselves as quitting aids but rather, as substitutes for situations when someone can't smoke, such as on a plane.

"A growing number of people recognize the disparity, that the conventional cigarettes are most harmful and that cleaner alternatives face a lot of hurdles and uncertainties," said Jed Rose, director of the nicotine research program at Duke University Medical Center.

Moreover, the smokeless-tobacco makers face a difficult balance in marketing the products, for if they tout them as being safer, they face scrutiny from the Federal Trade Commission and state attorneys general and would have to prove their claims based on clinical trials they now are not required to conduct.

Some anti-smoking program directors also fear that although there may be less carcinogenic risk in the new smokeless products, no one can be sure they won't pose other potential dangers because they have not been independently tested.

"It's likely they are less hazardous, though we don't know much about them because nobody has done any analyses," said Dr. Richard Hurt, professor of medicine and director of Mayo's nicotine dependency program. "What if they're found to have strychnine in them? They can put anything they want in them because they're not regulated by the FDA."

Of course, that's true with cigarettes too. And making a less hazardous cigarette has proven nearly impossible, because igniting any plant material — from wood and charcoal to tobacco — produces carcinogens. Directly inhaling the smoke into the lungs elevates the risk even more.

Not As Pleasurable

Even if a switch to smokeless varieties were encouraged, few people would expect that smokers would give up their cigarettes entirely. First, it isn't nearly as pleasurable an experience for the smoker, Duke University's Rose said. Plus, there are all sorts of behavioral and psychological cues involved, such as craving cigarettes when one has a drink or lighting up outside the office simply to get away for a few minutes.

But many potential users of the new products may have an outdated view of their dangers. It was only after Penn State's Kozlowski said he challenged claims about smokeless tobacco on the websites of the CDC and the Substance Abuse and Mental Health Services Administration that the agencies modified the information.

Yet, the Institute of Medicine has concluded that there would be at least 60% fewer deaths from the use of smokeless tobacco products than from cigarettes. Although there is a risk of oral cancer with smokeless alternatives, cigarettes are believed to cause 2.28 times more oral cancer than smokeless tobacco, pathologist Rodu concludes.

As recently as last week, Mayo Clinic's website said, "Spit tobacco has health risks just as severe or even more severe as those associated with cigarette smoking." Asked about the statement, Mayo's Hurt said the information was incorrect and would be revised.

Sweden's experience indicates that substituting smokeless tobacco can help reduce cigarette smoking. Starting in the 1960s, the popularity of loose, fine-grained smokeless tobacco started to spread beyond its largely farmhand constituency to academics and eventually the general public, as the hazards of smoking and passive smoke became known, Swedish tobacco researcher Dr. Karl Fagerstrom said.

In the 1980s, tobacco maker Swedish Match started marketing tobacco in tiny teabag-like pouches that made it far more aesthetically pleasing to use and increased its popularity. Over the years about 30% to 50% of male smokers switched from cigarettes to snus, and smoking rates dropped by about 0.7% each year, Fagerstrom said. About 15% of Swedish men now smoke, down from 36% in 1980.

Cancer rates have also declined, with no increases in other diseases or oral cancer rates. (It has been associated with increased irritation of the gums, Fagerstrom said, though it isn't clear that isn't a problem with cigarettes as well.) One reason that carcinogens are believed to be particularly low with snus: For the last 15 years, the product has been kept refrigerated from the time it leaves the factory till the time the customer gets it. That lengthens shelf life and discourages fermentation, during which the harmful nitrosamines grow. (Once purchased, it isn't necessary to keep it refrigerated; it's generally used within a week.)

Tobacco researchers in the U.S., including some who oppose encouraging smokers to shift, have cited the refrigeration as a key difference for the lower cancer rates in Sweden, because smokeless products in the U.S. are not refrigerated and can be kept on store shelves for months.

As in the U.S., the product is sold behind the counter (to prevent theft in Sweden's case) and purchasing isn't allowed by those younger than 18. Some Swedish men were able to give up smoking entirely with no problem when they switched to snus, Fagerstrom said. Others had more trouble, missing the drag and act of smoking itself. And many seem able to have an occasional cigarette, such as when they have a drink, without getting hooked on smoking again. Hence, he said, total abstinence may not be necessary for everyone to break the habit.