(Inspired by Double AA) Based on the Premise (which I may be wrong on) that there are pieces of the actual Tobacco leaves or whatever else is smoked in the inhaled part of the smoke hence there would seem to be ingestion of Tobbaco in the smoking processes. Why is there no Bracha on Smoking?
Original source: http://revach.net/article.php?id=3388 My edited and shortened version
Tasting something and then spitting it out without digesting does not require a bracha (Shulchan Aruch 210:2). This happens when tasting something to see if spices are needed .
The Magen Avraham (210:9) questions whether a bracha is required when smoking.It is similar to tasting and then spitting out which does not require a bracha being that the smoke is never digested or it should be no different than smelling which does require a bracha rishona. Even more so here since some people actually swallow the tobacco.
The Minhag Yisroel Torah (210) brings down from the K'sav Sofer that R' Mordechai Banet, prior to smoking a cigarette, would make a shehakol on another food item with the intent to include the cigarette as well. Should the cigarette require a bracha, the shehakol (an all encompassing bracha) would include it. However the Minhag Yisrael Torah writes that the minhag b'zman hazeh is not to make a bracha prior to smoking.
It seems to me that, regardless of whether bits of tobacco find their way to the stomach, this is obviously not eating in any meaningful sense, and thus would not be subject to a food berachah.