Smokeless Tobacco - An Overview

Smoking, especially cigarette smoking, is the most common form of tobacco consumption world-wide. It is generally accepted that smoking carries health risks for smokers. The combustion and pyrolysis products of tobacco generated during smoking are considered to be responsible for the harmful effects. Smokeless tobacco, another wide-spread form of tobacco use, is not subjected to burning and produces no combustion or pyrolysis products. Therefore, there is an increasingly intense debate about the potential role of smokeless tobacco in reducing the harm of tobacco use.

An overview is presented on the different types of smokeless tobaccos consumed around the world. Commercial products differ widely in composition and patterns of use. The smokeless tobaccos of the Western world (Europe and North America) need to be clearly distinguished from those popular in Asia, Africa and South America. The modern smokeless tobaccos used in Europe and North America are reviewed regarding their chemical composition and toxicological properties. Agents of concern found in smokeless tobacco, especially the tobacco specific N-nitrosamines, are dealt with in particular.

The epidemiological evidence is summarized concerning a wide range of health outcomes. Published reviews and studies are presented and interpreted regarding non-neoplastic oral diseases, various forms of cancer, circulatory diseases, several other diseases and pregnancy outcome. While many of the epidemiological studies have weaknesses and data are often inconsistent it is quite obvious that smokeless tobacco use is much less risky for consumers than smoking. In fact, for modern forms of European moist snuff such as Swedish snus, which is subject to strict quality standards, there is evidence for - if any - only very limited serious health risk.

The ongoing public discussion centers around the influence smokeless tobacco may have on smoking rates (initiation or cessation) and the occurrence of tobacco specific diseases - with Sweden being a revealing example. There is an interesting controversy regarding product and marketing regulations for smokeless tobaccos in the European Union.