The CCFA looks even deeper into Crohn's, pointing out that genetics, race, and ethnicity play a huge role in increasing the risk of developing the disease. American Jews of European descent develop the disease 4-5 times more than the general population (CCFA.org), and Crohn's is widely thought of as a disease affecting mostly white people. With that being said, it is noteworthy to mention that the rate of occurrence with African Americans is steadily increasing.
Crohn's disease is more common in women. Smokers are more likely to develop Crohn's than non-smokers. Although it occurs at any age, the greatest risk for developing it lies in the age range of 15-35. Environment also plays a huge role, with Crohn's occurring more in urban areas than in rural ones. Also, people in northern climates tend to develop the disease more often than those in southern climates.
As research continues to pour in via studies concerning IBD, and specifically Crohn's, more concrete information will be available. The disease is yet to be fully understood, so hopefully as time passes, the statistics reported by both the CCFA and CDC will decrease across the board.
References:
About the Epidemiology of IBD. (n.d.). Retrieved April 7, 2015, from http://www.ccfa.org/resources/epidemiology.html
Epidemiology of the IBD. (2015, March 31). Retrieved April 7, 2015, from http://www.cdc.gov/ibd/ibd-epidemiology.htm