The Wall Street Journal “Numbers Guy” blog said that while smokeless tobacco products remain far less popular than cigarettes in the United States, a collection of products that deliver nicotine without smoke—including dip, chew, snuff and newer items that look more like chewing gum—have sparked a heated debate about health risks.
Opponents of these products have presented numbers that suggest smokeless tobacco is an enormous public-health threat akin to cigarettes, while supporters, including some scientists, suggest smokeless items could offer a solution to smoking’s toll on public health. Both claims are based on misinterpretations of the data, said the report.
Critics of smokeless tobacco have spoken out recently about elevated risks of oral cancer and dangers these items pose to children who accidentally ingest them. All of these risks appear to be overblown, said the blog, particularly compared with smoking, which is far more likely to kill than smokeless alternatives.
But researchers who recommend these products as alternatives for smokers seeking to quit also are relying on hazy figures, the report added. Much of their evidence comes from Sweden, where use of smokeless products has risen in recent decades as smoking, and lung-cancer rates, have fallen. Many scientists who study tobacco use remain unpersuaded that the drop in cancer rates stemmed from the increase in use of smokeless products.
In pressing the case for more stringent regulation of smokeless tobacco, a National Cancer Institute physician last week testified before Congress that smokeless-tobacco products can multiply users’ risk of oral cancer by up to 50 times. The American Cancer Society followed up with a similar statement. But as Brad Rodu, professor of oncology at the University of Louisville whose research is funded by the tobacco industry, pointed out in a blog post this week, the risk figure is based on a survey of individuals who had used a form of tobacco called dry snuff, which is inhaled through the nose—a product that now is little used.
Peter Shields, deputy director of the Lombardi Comprehensive Cancer Center at Georgetown University, looked at several studies on smokeless tobacco risk and concluded that smokeless tobacco raises the risk of oral cancer by three to 10 times compared with nontobacco users, rather than 50 times, the Journal blog said.
Dr. Thomas Glynn, director of cancer science and trends for the American Cancer Society, said this week that his organization will no longer use the statistic citing a 50-fold increase in risk.
Several recent studies focused on other risks. This week, a study published online by the journal Pediatrics reported that chewable tobacco products were the second-most-common tobacco product accidentally ingested by children, as reported to poison-control centers nationwide. The study echoed fears among health advocates that newer smokeless items including strips and lozenges could be mistaken by children as candy.
But the study didn’t note that smokeless products—categorized as chewing tobacco—caused just three major incidents, which are defined as life-threatening, disabling or disfiguring, and no deaths from 2005 to 2008, said the Journal.
Add up all the risks of smokeless tobacco, say supporters of its role in smoking prevention, and using smokeless products raises the risk of premature death by only 2% of the amount that taking up smoking does, according to the report, citing Joel Nitzkin, chair of the tobacco control task force of the American Association of Public Health Physicians.
Some scientists agree, said the blog. “If nicotine could be provided in a form that is acceptable and effective as a cigarette substitute, millions of lives could be saved,” reported the U.K.’s Royal College of Physicians’ tobacco advisory group in 2007.
If researchers could be assured smokers really would quit, they would get behind it. “If we can get everybody to switch to smokeless, great,” Gregory Connolly, a professor at Harvard University’s school of public health, told the newspaper. “That would be wonderful.”
But he and others doubt that will happen. They point to surveys showing that smoking rates are higher among smokeless-tobacco users than among the rest of the population.
Much of the available data on smokeless tobacco comes from Sweden. There, men gradually have cut down on smoking and increased their use of snus, a form of moist snuff that doesn’t require spitting, in a shift that began in the 1970s. Lung-cancer deaths among Swedish men peaked in 1978; since then, the death rate has declined to the lowest in the European Union.
This is the major basis for claims that smokeless tobacco can have a massive public-health benefit. But even believers acknowledge they are making some assumptions beyond what can be proven. “I would be just as interested as you in any study that directly shows that snus use is a cause of decline in smoking rates,” Lars Ramstrom, director of the Institute for Tobacco Studies in Stockholm, told the paper. “But I do not have a real hope of ever finding such a study.”
The experience of another effort to induce American smokers to switch clouds the picture for Terry Pechacek, associate director for science in the Centers for Disease Control & Prevention’s office on smoking and health. He recalled that many smokers switched to low-tar cigarettes beginning in the 1960s, under the mistaken belief they were safer. “We need to be careful not to repeat this experience,” he told the Journal. Public-health officials, he added, are reluctant to advocate any form of tobacco use.