Crohn's disease

A common health problem
Initially recognised as a rare disorder, Crohn's disease became a more common health problem in the industrialised world during the 1970s. During the 1980s the number of patients seemed to stabilise. However, most recent reports indicate an increase in numbers of newly diagnosed cases of Crohn's disease, especially among children and teenagers.

Inheritance and environment
Clearly, both Crohn's disease and Ulcerative colitis have multifactor origin. Twin studies from Sweden, Denmark and UK have demonstrated that genetic factors explain approximately 20-50% of Crohn's disease cases. This would suggest then, that at least 50% of cases are caused by alternative factors, not relating to genetic inheritance. The most obvious environmental risk factor is cigarette smoking, with a two-fold lifetime risk for smokers to develop Crohn's disease as compared to non-smokers. Furthermore, smokers tend to have a more severe course of the disease than non-smokers and also less benefit from medication.

Surprisingly enough, no clear link has been established between special diets and the risk of either Crohn's disease, or Ulcerative colitis. However refined sugar, margarine, baker’s yeast and cola drinks have been listed as presumptive environmental risk factors.