Fiber intake in North America is only one-fifth what it was a hundred years ago. The backlash of our so-called modern diet is now being seen. Current research shows that many serious diseases common in North America are virtually non-existent in places like rural Africa where high fiber intake is routine. For example, diverticular diseases is unheard of among populations that eat high-fiber diets. In North America, diverticular diseases effects about one in 10 persons over 40 and about half the population over age 65.
Colon cancer is one of the greatest cancer killers of non-smokers.
Research indicates high-fat diets promote the development of this disease while high dietary fiber intake inhibits it. Some dietary fiber is actually broken down by bacteria living in the digestive tract. Researcher believe these healthy bacteria bind cancer causing agents and render them harmless. It is thought a diet high in fiber encourages the proliferation of these anti-cancer bacteria which in turn reduces the risk of cancer. Other researchers believe that fiber's bulk dilutes cancer causing substances and sweeps them from the digestive tract, giving them less time to do their deadly work.