It has been hypothesized that a diet rich in foods that contain fiber or plant fiber can protect the human body from a variety of serious diseases that have specifically attacked western cultures. Additionally, a diet low in fiber or plant fiber can cause the occurrence of these feared western diseases.

Appendicitis, which affects about 200 out of every 100,000 people every year in the United States, is prompted by a fall in dietary fiber intake. The most common abdominal surgical emergency in the Western world, appendectomies are comparatively rare in third world countries. Although attributing all appendicitis to low fiber diets is too simplistic, the correlation is extremely clear. Fiber is the only dietary factor that can significantly speed up the transit of feces through bowel and lower pressure within the colon.

Evidence tells us that a rise in pressure in the appendix can cause it to become vulnerable to infection by bacteria. When diets were forced to revert to more whole grains, the frequency of constipation and appendicitis decreased. There is also some evidence that people who get appendicitis may be more prone to colon and breast cancers. Although most of us do not find the threat of appendicitis extremely menacing, its link to fiber is very obvious.

Breast cancer, one of the most common cancers in women, affects one in every fourteen women. Although most of us may connect the value of a high fiber diet with cancer of the colon, most of us are unaware of its role in breast cancer prevention, with several studies finding that an increase to the highest amount of dietary fiber decreases the risk of breast cancer in women. Fiber has been shown to modify the action of circulating hormones, such as estrogen, which have been linked to the stimulation of certain cancer. Eating fiber helps to rid the body of excess estrogen which can initiate the formation of breast tumors. By eating plenty of vegetable fiber, grain fiber, and fiber from fruits and berries, can lower levels of testosterone, estrone, androstenedione and free estradiol in the body.

Generally speaking, if you have less than four bowel movements per week and if those movements are unformed or difficult to pass, you should consider yourself constipated. Many health advocates define constipation as anything less than one bowel movement per day. More women suffer from constipation than do men. Constipation is more of a symptom than an actual disease, as it refers to a decrease in bowel movements or a difficulty in passing the stool. Constipation can lead to diverticular disease and hemorrhoids, as well as a variety of ailments that are linked to long transit times and poorly formed stool.

Along with the above benefits, an increase in fiber can also help with diabetes and hypoglycemia, as it slows the absorption of food in the small intestine, helping to regulate blood sugar. A sufficient amount of fiber in the diet can also protect the body from gallstones, which are caused by an elevated blood cholesterol level. Additionally, adequate fiber protects the body from hemorrhoids, irritable bowl syndrome, prostate cancer, obesity, and varicose veins. Because of all these above reasons, one can see why it is extremely important to get adequate amounts of fiber in a daily diet, which consists of 25 to 45 grams of fiber each day.