Nicotine Levels in American Smokeless Tobacco Products
Posted Nov 07 2012 3:58pm
Nicotine levels in smokeless tobacco products available in the U.S. in 2006 and 2007 were analyzed by scientists at RJ Reynolds Tobacco Company (abstract here ). I previously discussed other analyses reported by the scientists, on tobacco-specific nitrosamine levels ( here ) and trace metals ( here ).
Nicotine is tobacco’s primary attraction for humans; it provides many positive effects on human behavior (reviewed here ). It is widely known that nicotine can be consumed by inhaling the smoke of burning tobacco, or by using smokeless tobacco, with differences in the efficiency and rate of absorption ( here ).
When using smokeless tobacco, nicotine is absorbed across the lining of the mouth. Many factors affect this, including the physical characteristics of the product (chewing tobacco, fine cut moist snuff, powdered snuff, pouch, etc.), and how it is held in or moved around the mouth. An important factor is the product’s pH – its acidity or alkalinity. Nicotine cannot be absorbed efficiently in an acidic environment like that of the stomach; that’s the reason tobacco isn’t consumed like tea or coffee.
The amount of nicotine readily available to the smokeless user can be calculated by measuring the product’s pH. A higher pH yields more available, or “free” nicotine. Of course, one of the roles of saliva is to buffer alkaline and acidic foods to a neutral pH, so even acidic smokeless products provide some nicotine as saliva works to neutralize their acidity.
The table reflects levels of nicotine and free nicotine in smokeless tobacco products in 2006 and 2007. Because nicotine levels were not calculated on dry weight, dry products are not entirely comparable to products with higher moisture content. Differences can also be seen within categories.
In general, chewing tobacco and dry snuff had low levels of free nicotine, while levels in moist snuff products were considerably higher.
What does this mean for the smoker who switches to smoke-free products? There are no simple answers. Inhaling smoke provides a bolus, or spike, of nicotine within seconds of the first puff, but the small amount is metabolized quickly. Some smokeless products are capable of delivering a similar peak level, but at a slower pace, and research shows that with smokeless products, the falloff from peak levels is much slower.
The broad range of free nicotine levels among these products is good news for smokers. They should look for a smokeless substitute that satisfies them.
Nicotine (mg/g) and Free Nicotine (mg/g) Levels in Smokeless Tobacco Products in the U.S., 2006 and 2007