>>11639188 (pb)
https://boltonsmokersclub.wordpress.com/2015/03/02/nicotine-and-niacin-nicotinic-acid/
Good discussion on this subject. I think smoking and the possible benefits of it have something to do with what the smoke does to macrophages.
On a side note, if you research the formation of the US NIH and the influence of the wife of a prominent advertiser named Mary Lasker you will find some very, very spoopy connections between eugenics, the anti-smoking efforts of recent decades, advertising/marketing, NIH funding and the Lasker Foundation/Lasker Prize.
http://www.smokershistory.com/laskersy.htm