Lack of fruits/vegetables and specifically the subsequent association with lack of fiber intake is often blamed on the increasing prevalence of crohn’s disease. Especially after a study a few years ago came out suggesting lack of fiber intake was associated with later development of crohn’s disease. In Japan this theory is also popular, supposed Western diets are the cause of the increase in crohn’s disease by some.
I have posted 2 large-scale studies in the past that debunked this theory…
Daily consumption of fruit/vegetables in OECD countries and crohn’s disease prevalence.