First of all, the smoking cessation drugs currently on the market such as nicotine gum, patches, Zyban or Chantix are very safe and carry no cancer risks.
Most devastatingly, however, there are no randomized, double-blinded placebo controlled clinical trials that compare the success of quitting smoking by using smokeless tobacco versus using a placebo.
The name of this type of study design is a mouthful, but basically boils down to a totally unbiased study. Such clinical trials are the gold standard in terms of determining if a given treatment actually works.
There is only one small, "un-blinded" study without placebos or control subjects that advocates point to as evidence that smokeless tobacco works as a smoking cessation aid. Such a study design would not be accepted by any scientific association as even mediocre evidence to support the use of snus as a means of smoking cessation.
Many of the other studies that these researchers cite are surveys of people who had never used tobacco. While these studies may suggest an association between snus use and smoking cessation, in the scientific community a survey like this is a very poor method for determining a treatment's success.
Furthermore, virtually all of the harm reduction studies predate the introduction of the extremely safe and exciting new drug Chantix (varenicline), which shows the most promise of any smoking cessation drug on the market.
Nor do the harm reduction experts acknowledge that combination therapy -- using the nicotine gum or patch (or both) combined with, say, Zyban (bupropion) -- can be quite powerful and safe.
None of these pharmaceutical approaches has cancer-causing potential; smokeless tobacco on the other hand increases the risk for cancer by at least 20 percent, and also is associated with poor oral health.
It is in this context that cigarette maker Philip Morris has announced its new campaign to introduce snus. Starting in August, this company will test market Marlboro Snus in the Dallas/Fort Worth area.
According to Philip Morris' Web site, "Marlboro Snus is a smokeless tobacco pouch product designed especially for adult smokers in the U.S."
With harm reduction in mind, Philip Morris states, "We are introducing this product into the Dallas/Fort Worth area to understand adult smoker acceptance."
Of course, even Philip Morris on its Web site admits the obvious: smokeless tobacco carries risk of cancer, cardiovascular disease and other oral diseases, can cause adverse birth outcomes among pregnant women, and is not a safe alternative to smoking.
They also acknowledge that the U.S. surgeon general has determined that smokeless tobacco use is addictive.
Taken together, all of the evidence points toward this unambiguous public health message: Tobacco use in any form must stop.
With new, safe and effective smoking cessation aids on the market -- and more being currently studied -- it seems unethical to promote smokeless tobacco as a means to quit smoking. Even in the name of harm reduction.
Dr. John Spangler is director of tobacco-intervention programs and a professor of family medicine at Wake Forest University School of Medicine.