Fiber

Immune Boosting Foods Slideshow

Author: Betty Kovacs, MS, RD
Medical Editor: William C. Shiel Jr., MD, FACP, FACR

• A little fiber history
• What is fiber?
• Fiber for weight control
• Fiber for controlling diabetes
• Fiber for preventing heart disease
• Fiber for bowel disorders
• Fiber for preventing or treating constipation
• Recommendations for fiber intake
• Some helpful hints about fiber

A little fiber history

Fiber became a household word back in 1970s when Dr. Denis Burkitt, a man nicknamed the Fiber Man, and his colleagues made "the fiber hypothesis" that states that fiber can prevent certain diseases. Through their work in Africa, they discovered that diseases that were common in the Western cultures were not common there. These included heart attacks and high blood pressure (cardiovascular diseases), obesity and diabetes (metabolic disorders), intestinal problems (constipation, diverticulosis, diverticulitis, gallstones, appendicitis, hemorrhoids, polyps, and colon cancer), varicose veins and blood clots (deep vein thrombosis). The primary dietary difference was the high intake of fiber and low intake of refined carbohydrates in the African population. Burkitt also noted the emergence of these diseases in the United States and England after 1890 following the introduction of a new milling technique that removed fiber from whole grain flour to produce white flour.

While the exact mechanism by which fiber might prevent these diseases remained unknown, Burkitt made a discovery about the beneficial impact that fiber had on bowel movements and how that related to certain diseases. Burkitt noted that he was able to predict the number of a patient's hospital visits from the size and frequency of their bowel movements. Those with high intakes of fiber had more frequent and bulky stools and had less illness. Burkitt proposed that fiber's health benefits stemmed from its ability to increase stool bulk and speed up how quickly stool moves through the colon. Since these findings, controversy remains. A great deal of research has both supported and disputed what Burkitt had discovered.