Cigarette additives may produce important changes to the effects of tobacco, altering dependence, toxicity, or use behaviours. Changes to the physiological properties of nicotine could also radically alter the character of tobacco dependence. Additives that enhance the body’s interaction with nicotine or other constituents may increase their addictive or toxicological effects. The addition of bronchodilators to cigarettes may have similar effects by allowing deeper inhalation and deposition of smoke constituents in areas of the respiratory tract where they are more likely to be absorbed. The perception of smoother smoke may facilitate increased or deeper inhalation of tobacco smoke by removing physical barriers. Similarly, reduced irritation may encourage or support increased frequency of use. Candy-like flavours, such as cherry, may also be used to target youth and women.
Tobacco manufacturers emphasize in public statements that the majority of additives have been shown to be safe when eaten in foods.
However, cigarette additives compounds are significantly more toxic when inhaled or absorbed directly into the bloodstream rather than ingested.
In the digestive system, additives and other complex molecules are broken down by enzymes into simpler chemical structures and/or transformed into other compounds. These processes render most substances less toxic to the body. In contrast, tobacco additives escape the metabolic pathways that would help make them less toxic. Although a number of cigarette additives are present in commercial products only in small concentrations, it does not follow that these can be considered harmless