Smoking is one of the worst habits you can take up since it's linked to all sorts of health risks such as lung cancer, emphysema, and cardiovascular disease. That's a pretty convincing list to make anyone quit (or never start), but a recent study suggests one surprisingly good thing could come out of smoking — prevention of certain types of allergies.
Smoking cigarettes decreases the body's allergic response by obstructing the activity of mast cells (cells that contain histamine). This study was performed on mouse mast cells, but researches think the same antiallergy effect will hold true for people too. That's not to say you should take up smoking to cure your springtime sniffles and sneezing, but it could help explain why smokers are less susceptible to allergy symptoms.