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.
1 comment:
This is a fascinating post. It is unfortunate that politicized outcomes and preferred results have so tainted the outcome of what should be objective science. Thank you for your dogged adherence to the truth. - JVC
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