Numerous studies have found a link between cigarette smoking and Crohn’s development.

“Smoking is associated with clinical recurrence of Crohn’s disease”: http://www.ncbi.nlm.nih.gov/pubmed/15599207?dopt=Abstract

“This study demonstrates an association and a temporal relationship between cigarette smoking and Crohn’s disease.”: http://www.ncbi.nlm.nih.gov/pubmed/2912028?dopt=Abstract

“Smoking is an independent risk factor for clinical, surgical, and endoscopic recurrence in Crohn’s disease.”: http://www.ncbi.nlm.nih.gov/pubmed/8119535?dopt=Abstract

“these results suggest that smoking habit may be an important determinant of the type of inflammatory bowel disease that develops in predisposed subjects.”: http://www.ncbi.nlm.nih.gov/pubmed/6435736?dopt=Abstract

And numerous other studies have found that cigarette smoking may weaken the immune response and even prevent the immune system from recognizing harmful bacteria. So, are CD sufferers who smoke further restricting their immune system from responding to and recognizing MAP?

“Nicotine, which is one of the main constituents of cigarette smoke, suppresses the immune system”: http://www.ncbi.nlm.nih.gov/pubmed/12033743

“These results were consistent with the reversal of changes in immune function associated with smoking.”: http://www.ncbi.nlm.nih.gov/pubmed/6633406

“cigarette smoke substantially changes the immune response to bacteria”: http://www.sciencedaily.com/releases/2009/04/090407074951.htm

“Cigarette smoke affects the immune system’s ability to recognize pathogens”: http://www.medinewsdirect.com/?p=372