Snus and Moist Snuff May Be Protective Against Dental Cavities

One of the longstanding federal warnings on smokeless tobacco is: “This product can cause gum disease and tooth loss.”  This warning has no scientific basis.

I previously discussed a study from Sweden concluding that snus use was not associated with gum disease (here).  A 2012 study by the same research group concluded that “snus use does not increase the risk of dental caries [cavities].” (here)

The latter study was based on 1,500 residents of Jönköping, Sweden, who underwent detailed dental health exams in 1983, 1993 and 2003. Lead author Anders Hugoson and colleagues employed teams of dentists who observed the number of teeth, saliva factors, oral hygiene and cavities.  A key indicator of cavities is the number of tooth surfaces that are decayed or already filled with silver or other material (abbreviated DFS).  A lower DFS means healthier teeth.

The study’s snus users in 1983 had an average 20 DFS, a statistically significant half of the 41 DFS in smokers and nonusers of tobacco.  In 1993, snus users had 22 DFS, compared with 37 in smokers and 36 in nonusers, also significant.  By 2003, the margin was narrower and not significant, but the 19 DFS among snus users was still lower than among nonusers (28) and smokers (29).

The results of this research were similar to an American study published in 1999 (abstract here).  It showed that while American chewing tobacco, which is coated with a sugar solution, is associated with cavities, users of moist snuff, with no added sugar, had lower cavity scores than nonusers of tobacco. 

Both of the above studies, however, were less than forthright in their portrayal of smokeless tobacco. It is the norm in epidemiologic research for risks among exposed groups to be compared with risks among a referent, nonexposed group.  In the Swedish studies, the protective effect of snus was masked by making snus users the “referent group” for some of the statistical analyses.  The American study was similarly flawed, as chewing tobacco users were the referent group, thus masking the protective effect of moist snuff. 

The authors of the American research, Drs. Scott Tomar and Deborah Winn, are outspoken tobacco opponents.  I have previously discussed Dr. Winn’s oral cancer misinformation campaign here, here  and here.

Why might snus and moist snuff be protective for cavities?  Neither product has any added sugar, and both probably stimulate saliva production, which is generally protective against cavities.  In addition, smokeless products tend to have an alkaline pH, which Dr. Hugoson writes “may favour the remineralization of the tooth surfaces and the inhibition of the [cavity-forming] acid [bacteria].”    

 Unbiased scientific research and reporting is the best prescription for healthy teeth and healthy lives.

What’s the Takeaway from Snus?

A new study from British American Tobacco scientists answers that fascinating question, providing valuable information for consumers and regulators. 

Snus contains nicotine and other constituents that make tobacco satisfying, but it also contains contaminants, albeit in vanishingly small amounts.  It is useful to know how much of these constituents users extract and consume during typical use.

Dr. Helena Digard and colleagues published their research in Chemistry Central Journal (abstract here).  They recruited 21 male snus users in Sweden to use four 1-gram pouched snus products for one hour.  They then compared constituent levels in the used pouches with levels in unused pouches from the same package. 

The researchers found that the percentage extraction of constituents from snus was fairly consistent, even though they were present in concentrations that differed by almost a million-fold.  For example, users extracted about one-quarter of the available salt (sodium and chloride), which was present in milligram quantities in the snus pouches.  Also present in milligram quantities was propylene glycol, the solvent used in many e-cigarettes, of which about 30% was extracted; a third of the available nicotine was consumed.

Several constituents, including ammonium (28% extracted), nitrate (27%), and flavorings (19-30%), were present in microgram quantities (one thousand times smaller than milligrams).  Tobacco-specific nitrosamines were present in nanogram quantities (one millionth of a milligram); about 36% were extracted.

This study’s results were reasonably consistent with those from research published in 2012 by John Caraway and P.X. Chen of Reynolds American (abstract here), although the latter work showed somewhat lower extraction of TSNAs and slightly higher extraction of nicotine.  As Nigard et al. acknowledged, there is wide variation in the percentage of extraction among different snus users and even by a single user on different occasions.

The American Cancer Society’s Anti-Tobacco Campaign Ignores Its Own Research

The American Cancer Society continues to misinform smokers about vastly safer options.  With chapters in nearly every county across the nation, the ACS is a powerful tobacco harm reduction opponent.

Since it cannot argue against tobacco harm reduction on the facts, the ACS resorts to false and deceptive claims.  For example, last week the House Consumer Protection Committee of the Illinois General Assembly scheduled a hearing on tobacco harm reduction.  Heather Eagleton, Illinois Director of Public Policy and Government Relations for the ACS Cancer Action Network, issued a press release replete with false statements; it was reported in a popular capitol blog that previewed the event (here).

False Statement 1.  “This is a new twist on the old tobacco marketing campaigns of the 1960s, 1970s, and 1980s that falsely promised health benefits to be derived from filtered, ‘light’, and ‘less tar’ tobacco product alternatives that were ‘more safe’ versus ‘less safe.’ These ‘harm reduction’ messages were false then and are false now.”

Ms. Eagleton is apparently unaware that the ACS was responsible for some of the “false promises.”  In 1976 (here)  and in 1979 (here), the organization documented and promoted the health advantages of light cigarettes compared with full-flavor brands.  The ACS president said in the latter year that “findings of the new study suggest a way for smokers to reduce their lung cancer risk by switching to low tar-nicotine cigarettes if they find it impossible to quit entirely.”

False Statement 2.  “There is research, however, to show these products cause cancer of the mouth, pancreas and esophagus, as well as other serious health conditions.”

This is a completely false assertion by Ms. Eagleton.  It ignores the 2009 results of the most comprehensive analysis of relevant research (discussed here).  More importantly, Ms. Eagleton ignores research from her own organization.  In 2005, ACS investigators published results from the first and second Cancer Prevention Studies (abstract here), two of the largest studies of smokeless tobacco use and deaths in the U.S.  Here are the ACS-reported noteworthy risks for smokeless tobacco users:

Relative Risks (95% Confidence Interval) of Death From Selected Diseases Among Smokeless Tobacco Users in the American Cancer Society’s Cancer Prevention Studies (CPS)
Disease	CPS-I	CPS-II
All Cancers	1.07 (0.95 – 1.20)	1.19 (1.02 – 1.40)
−Oropharynx	2.02 (0.53 – 7.74)	0.90 (0.12 – 6.71)
−Digestive system	1.26 (1.05 – 1.52)	1.04 (0.77 – 1.38)
−Lung	1.08 (0.64 – 1.83)	2.00 (1.23 – 3.24)
−Urinary system	0.97 (0.77 – 1.22)	1.15 (0.85 – 1.56)
−Other cancers	0.90 (0.71 – 1.14)	1.49 (1.04 – 2.14)
Cardiovascular diseases	1.18 (1.11 – 1.26)	1.23 (1.09 – 1.39)
Respiratory diseases	1.28 (1.03 – 1.59)	1.11 (0.84 – 1.45)
Emphysema	1.86 (1.12 – 3.06)	1.28 (0.71 – 2.32)

First, note that the excess risk for oral cancer among smokeless tobacco users in both ACS studies was ZERO.  In fact, there was only one death from oropharyngeal cancer among smokeless users in CPS-II, compared with 45 deaths among nonusers of tobacco.  ACS staff certainly would have spotlighted increases in cancers of the pancreas or esophagus; this report never mentions these cancers, which is virtual confirmation that risks weren’t increased.

There are some elevated risks in this table.  For example, smokeless users in CPS-I had slightly increased deaths from digestive system cancers, and CPS-II smokeless users had small increases for other cancers and cardiovascular diseases.  The reasons for these findings are obvious: CPS-I smokeless users had significant elevation in emphysema, and CPS-II users had a two-fold elevation in lung cancer, both of which are caused by smoking.  So, while the ACS tried to study exclusive smokeless users, the subjects were also smoking.

In summary, the ACS harm reduction messages were false then and are false now. The organization continues to deny almost 60 million American tobacco users truthful information about smokeless tobacco and e-cigarettes.  Tobacco users, and their families and friends are responsible for at a portion of the nearly $900 million the ACS collects in contributions annually (here).  They, and the public at large, deserve more honest and forthright public health messaging from such an influential organization.

Dual Use, Double Standard

Tobacco harm reduction opponents have myriad rationales for withholding from smokers vital information about safer products.  One common objection is that smokers will become dual users (of both cigarettes and smoke-free substitutes), and never achieve abstinence. 

While scientific evidence (here) rebuts such dual use allegations, tobacco opponents are not dissuaded.  They further claim that safer tobacco products simply aren’t necessary, given the availability of nicotine medicines; those, however, work for only seven percent of smokers (here and here). 

Interestingly, nicotine medicines are used concurrently by a small percentage of smokers.  A 2003 study reported that 10% of smokers in the GlaxoSmithKline “Committed Quitters” program were dual users at 12 weeks after enrollment, and 2% were dual users at 24 weeks (here).

There are several differences between smoke-free tobacco products (like snus and e-cigarettes) and over-the-counter pharmaceutical nicotine products:

• Smoke-free tobacco is affordable; pharmaceutical nicotine is expensive
• Smoke-free tobacco is perceived as recreational; pharmaceutical nicotine is seen as medicine
• Smoke-free tobacco delivers nicotine/tobacco satisfaction; pharmaceutical nicotine does not

Smoke-free tobacco and pharmaceutical nicotine are identical in one respect: They are both candidates for dual use with cigarettes.  Criticizing the former while giving a pass to the latter is an unacceptable double standard.