More Evidence That Smokeless Tobacco Products in the U.S. Have Low TSNA Levels

New data shows that tobacco-specific nitrosamines (TSNAs) were at very low levels in almost all popular smokeless products available in the U.S. in 2006 and 2007. The findings appear in a research article in Regulatory Toxicology and Pharmacology (abstract here) authored by M.F. Borgerding and other scientists at RJ Reynolds Tobacco Company.

TSNA levels for specific brands are listed in the table below.  In reviewing the data, one should consider these points:

1.  The table lists levels in parts per million (ppm) by weight, or micrograms of TSNAs per gram of dry product.  This allows products with different moisture levels (e.g., dissolvable tobacco at 4% and moist snuff at about 50%) to be compared directly.

2.  ALL of the American products had low TSNA levels, especially when compared to products from the 1970s and 1980s (described here).  In the early 1980s, it was common to see moist snuff products with TSNA levels at 40-80 ppm; by the end of the decade, most products were under 40 ppm.  With rates declining further, to around 20 ppm in 1995, analytic reports ceased.

3.  Several Swedish snus products were analyzed; all had TSNA levels below 2 ppm. 

4.   The lowest TSNA levels were found in Ariva (0.1 ppm) and Stonewall (0.4 ppm) dissolvable tobacco pellets made by Star Scientific, Inc. (here). 

5.  Chewing tobacco products all had levels below the Gothiatek standard, which is 10 parts per million.  Gothiatek was developed by Swedish Match in the late 1990s to serve as a voluntary standard for maximum levels of some contaminants (described here).

6.  The highest TSNA levels (12-41 ppm) were found in powdered dry snuff, a form of tobacco historically favored by older Southern women, but steadily declining in popularity (evidence here).  When I worked with an investigator at the Swedish National Food Administration to analyze TSNAs in American products in 2003, we found very high levels in two powdered dry snuff brands ( abstract here).

How do smokeless tobacco TSNA levels compare with those in cigarettes?  The Reynolds scientists did not test cigarettes, but I did.  Camel and Marlboro cigarettes had TSNA levels around 7 ppm in 2003, putting them in the same range as many moist snuff and chewing tobacco products.  However, TSNAs are but one of many thousands of toxins delivered in smoke, so comparing these agents in cigarettes and smokeless is almost meaningless.  

A National Cancer Institute fact sheet describes TSNAs as “the most harmful chemicals in smokeless tobacco…” (here), but this study shows that TSNAs are present in tiny concentrations.  As discussed in a previous post (here), there is virtually no evidence that current TSNA levels are associated with any measurable cancer risks.

TSNA Levels in Smokeless Tobacco Products in the U.S., 2006 and 2007
Product	Parts Per Million
Dissolvable Tobacco
Ariva	0.1
Stonewall	0.4
Chewing Tobacco
Beech Nut	2.9
Hawken	5.2
Lancaster	1.3
Levi Garrett	5.2
Red Man	1.8
Red Man Golden	1.2
Stoker Chew Apple	4.6
Taylor’s Pride	8.3
Traditional Moist Snuff
Cooper LC WG	35.7
Copenhagen	10.8
Copenhagen LC	9.7
Copenhagen Pouches	9.9
Grizzly LC WG 2006	10.1
Grizzly LC WG 2007	9.0
Husky FC	11.2
Kayak LC WG	25.5
Kodiak WG 2006	11.9
Kodiak WG 2007	13.1
Longhorn LC WG	7.6
Red Seal FC	10.0
Renegades WG	7.9
Skoal FC Original	10.0
Skoal LC Cherry	9.1
Skoal LC Mint	10.5
Skoal LC Straight	10.4
Skoal LC WG	13.9
Timberwolf LC WG	8.1
Snus and Snus-Style Snuff
Camel Frost 2006	1.8
Camel Frost 2007	2.3
Camel Original 2006	1.9
Camel Original 2007	2.5
Camel Spice 2006	1.8
Camel Spice 2007	2.1
Catch Dry Eucalyptus*	1.4
Catch Dry Licorice*	1.4
General*	0.7
General Portion*	1.6
General White Portion*	1.3
Skoal Dry	2.7
Taboka	1.6
Taboka Green	1.6
Powdered Dry Snuff
Bruton	12.2
Dental Sweet	41.0
Levi Garrett	25.8
Railroad Mills	27.2
Red Seal	18.6

*Manufactured in Sweden

LC- long cut

FC- fine cut

WG-wintergreen

 

Dual Use and Smoking Suppression

Norway has proven that the Swedish tobacco experience can be duplicated in other countries where smokeless tobacco is used (discussed earlier here and here).  Karl Erik Lund, from the Norwegian Institute for Alcohol and Drug Research, and Ann McNeill from the University of Nottingham in the UK, have profiled male dual users (of snus and cigarettes) in Norway in a new report published in Nicotine & Tobacco Research (abstract here).

Drs. Lund and McNeill use Norwegian survey data to show that dual use has been relatively stable at 4-7% over the 25-year period from 1985 to 2010, during which exclusive snus use increased from 3% to 12% and exclusive smoking dropped from about 50% to 20%.  While U.S. tobacco prohibitionists argue that dual use will be problematic if smokers are educated about safer smokeless products, dual use has not been a public health issue in Sweden or Norway.

Another finding in the Scandinavian research is that dual users smoked fewer cigarettes than exclusive smokers (57 vs. 80 per week).  I also reported this fact in my landmark Swedish study published ten years ago (abstract here), and I documented this finding among American dual users (abstract here). 

One finding not discussed by Lund and McNeill was that among all Norwegian men surveyed from 2005-2010, 5.3% were former smokers and current snus users, while only 3.3% were former snus users and current smokers.  This shows that snus was more of a gateway FROM smoking than the reverse.  This contrasts with U.S. experience, where more male smokeless users transition to smoking (documented by me here).  It appears that Norwegian men are better informed about the relative risks of  snus use and smoking, resulting in healthier decisions.

Lund and McNeill conclude: “The increase in snus use among men in Norway has not been paralleled by an increase in dual use of snus and cigarettes.  The prevalence of smoking—the far most dangerous form of nicotine uptake—is quite low among men who use snus everyday but generally quite high among men who use snus on a less-than-daily basis. Use of snus also seemed to lower cigarette consumption.  Dual use did not lessen plans to quit smoking within 6 months but increased expectancies of being smoke-free 5 years into the future.”

An Absorbing Nicotine Lesson

Nicotine uptake from snus, cigarettes and medicinal gum varies significantly, new research shows.

Helena Digard of British American Tobacco is lead author on the work, joined by colleagues from her company and from Sweden’s Lund University; their research was published in Nicotine and Tobacco Research (abstract here).

Dr. Digard provided 20 Swedish dual users of snus and cigarettes with two loose and two pouched snus products with different nicotine levels; nicotine gum; and a cigarette, over the course of six sessions.  Snus was placed in the upper lip for one hour only and not moved; the cigarette was smoked ad lib for 5 minutes or until reaching a prescribed length; the gum was chewed every 2 seconds for 30 minutes, with juices swallowed once every minute. 

The chart from the journal illustrates critical nicotine absorption data:

1.  Cigarettes produced a rapid, but transient, nicotine spike.  Peak blood nicotine levels of around 12 nanograms (ng) per milliliter (ml) were seen seven minutes after starting to smoke, followed by a steep decline.

2.  Snus produced similar nicotine levels much more slowly, but they stayed higher longer.  The products produced varying nicotine levels (~ 10-17 ng/ml) that correlated with their nicotine concentrations; the peak occurred one hour after placement.  Subsequent declines were also slower; after two hours, nicotine levels ranged from 7 to 12 ng/ml.

3.  Nicotine gum produced low blood nicotine levels much more slowly.  The peak (8 ng/ml) at 45 minutes was similar to the cigarette level that had declined by one-third. 

These findings are similar to those reported 24 years ago in the New England Journal of Medicine (reference here); they are particularly relevant for cigarette smokers making the switch to smoke-free nicotine products. 

The big lesson: Snus delivers satisfying doses of nicotine, but not as quickly as cigarettes.  However, slower nicotine delivery means slower decline – a distinct advantage.  Switchers generally use fewer pinches or pouches of smokeless tobacco compared to the number of cigarettes they smoked, as documented in my published research in the U.S. (here and here) and in Sweden (here). 

When unit consumption drops, smokers save money, further incentivizing them to stick with their switch to safer smokeless products.