Dietary fiber in human nutrition

Abstract

In recent years there has been a reawakening of interest in the effect of plant fibers on human nutrition. This has been spurred by the epidemiological work of Burkitt, Painter, Walker, and Trowell and by some laboratory and clinical studies performed by Eastwood, Kritchevsky, and other investigators. “Fiber” is the collective term used to identify the various polysaccharides and lignin fractions of foods that are not hydrolyzed by the enzymes of the digestive system (but that are, or might be, hydrolyzed by intestinal microorganisms). To some investigators, “fiber” means all these polymers plus the other components of the cell wall (cutins, minerals, etc.) intimately involved in the fiber function. The combination of epidemiological studies and laboratory research has lead to various hypotheses that have linked “low fiber diets” in Western countries to various chronic diseases. Some of the diseases mentioned are major chronic afflictions of the developed nations (e.g., colon cancer and CHD), and the possible interrelation of fiber in the diet with the etiology of these syndromes has stirred a great deal of interest.