Evidence-Based Approach to Fiber Supplements and Clinically Meaningful Health Benefits, Part 2: What to Look for and How to Recommend an Effective Fiber Therapy.
Dietary fiber that is intrinsic and intact in fiber-rich foods (eg, fruits, vegetables, legumes, whole grains) is widely recognized to have beneficial effects on health when consumed at recommended levels (25 g/d for adult women, 38 g/d for adult men). Most (90%) of the US population does not consume this level of dietary fiber, averaging only 15 g/d. In an attempt to bridge this "fiber gap," many consumers are turning to fiber supplements, which are typically isolated from a single source. Fiber supplements cannot be presumed to provide the health benefits that are associated with dietary fiber from whole foods. Of the fiber supplements on the market today, only a minority possess the physical characteristics that underlie the mechanisms driving clinically meaningful health benefits. In this 2-part series, the first part (previous issue) described the 4 main characteristics of fiber supplements that drive clinical efficacy (solubility, degree/rate of fermentation, viscosity, and gel formation), the 4 clinically meaningful designations that identify which health benefits are associated with specific fibers, and the gel-dependent mechanisms in the small bowel that drive specific health benefits (eg, cholesterol lowering, improved glycemic control). The second part (current issue) of this 2-part series will focus on the effects of fiber supplements in the large bowel, including the 2 mechanisms by which fiber prevents/relieves constipation (insoluble mechanical irritant and soluble gel-dependent water-holding capacity), the gel-dependent mechanism for attenuating diarrhea and normalizing stool form in irritable bowel syndrome, and the combined large bowel/small bowel fiber effects for weight loss/maintenance. The second part will also discuss how processing for marketed products can attenuate efficacy, why fiber supplements can cause gastrointestinal symptoms, and how to avoid symptoms for better long-term compliance.
is a clinical scientist, Procter & Gamble, Mason, Ohio, where he has worked for 18 years. After serving in the US Army (509th Airborne, 221st Military Police), Dr McRorie completed an associate of arts degree in nursing and worked 14 years as an emergency department/intensive care unit RN at teaching hospitals that included Johns Hopkins Hospital in Baltimore and Children's Hospital National Medical Center in Washington, DC. He went on to complete a bachelor of science degree at the University of Maryland, followed by a dual PhD in neuroscience and physiology at Michigan State University, where he was also a physiology instructor for the medical school. Dr McRorie was previously the director of clinical affairs at Ethicon Endo-Surgery, a Johnson & Johnson company. His research interests include neurogastroenterology and motility, gastroesophageal reflux disease, and the physical effects of fiber supplements on metabolic syndrome, cholesterol lowering, improved glycemic control, constipation, diarrhea, and irritable bowel syndrome. He is a fellow of the American College of Gastroenterology, the American Gastroenterological Association and the American College of Nutrition, and a member of the American Diabetes Association.
Pub Type(s)Journal Article