Effects of cigarette smoke on the immune system.

Although the health risks of tobacco smoking are well documented, there is increasing evidence that smokers have a lower incidence of some inflammatory and neurodegenerative diseases. Many of the adverse and beneficial effects of smoking might result from the ability of cigarette smoke to suppress the immune system. Nicotine, which is one of the main constituents of cigarette smoke, suppresses the immune system but might have therapeutic potential as a neuroprotective and anti-inflammatory agent.