FIBER DEFICIENCY AND COLONIC DISORDERS

Transcription

1 FIBER DEFICIENCY AND COLONIC DISORDERS

2 FIBER DEFICIENCY AND COLONIC DISORDERS Edited by Richard W. Reilly and Joseph B. Kirsne.r Department of Medicine The Pritzker School of Medicine The University of Chicago PLENUM MEDICAL BOOK COMPANY New York and London

3 Main entry under title: Library of Congress Cataloging in Publication Data Fiber deficiency and colonic disorders. "Invited papers presented at a conference held in the Center for Continuing Education, University of Chicago, under the sponsorship of the Gastroenterology Section of the Department of Medicine at the university, on May 17, 1974." Includes bibliographies and index. 1. High-fiber diet-congresses. 2. Colon (Anatomy)-Diseases-Congresses. I. Reilly, Richard W. II. Kirsner, Joseph Barnett, III. Pritzker School of Medicine. Dept. of Medicine. Gastroenterology Section. [DNLM: 1. Colonic diseases-etiology Congresses. 2. Cellulose-Deficiency-Congresses. QU75 F ] RM237.6.F ' ISBN-13: e-isbn-13: DOl: / I nvited papers presented at a conference held in The Center for Continuing Education, University of Chicago, under the sponsorship of the Gastroenterology Section of the Department of Medicine at the University, on May 17, Plenum Publishing Corporation Softcover reprint of the hardcover 1 st edition West 17th Street, New York, N.Y United Kingdom edition published by Plenum Publishing Company, Ltd. Davis House (4th Floor), 8 Scrubs Lane, Harlesden, London, NW10 6SE, England Plenum Medical Book Company is an imprint of Plenum Publishing Corporation All rights reserved No part of this book may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, microfilming, recording, or otherwise, without written permission from the Publisher

4 Foreword Epidemiologists, on the basis of studies carried out chiefly in Africa, have suggested that depletion of fiber in the modern Western diet affects health adversely. D. P. Burkitt, who has been in the forefront of this investigation, has included among the "diseases of civilization" hiatus hernia, ischemic heart disease, cholelithiasis, polyps of the colon, and cancer of the colon. All of these conditions appear to have the same geographic distribution. In these areas, the diets were characterized by increased amounts of fat and meat protein, and by an apparent deficit of fiber. It is noteworthy that while an increased intake of refined sugars also has been implicated in the Western diet, the consumption of sugar and other sweetners in the United States actually has remained fairly stable since about 1925 when the use of complex carbohydrates in the form of starchy foods began to decline. The mechanism whereby deficiency of fiber in the diet contributes to the development of colonic diverticula, presumably is by facilitating the development of segmentation of the colon and pockets of intracolonic high pressure zones associated with prolonged transit time of bowel content. Preliminary therapeutic observations, furthermore, have suggested that the addition of fiber in the form of bran to the diet may promote regularity of bowel function and perhaps lessen the likelihood that new diverticula will be formed after the resection of involved colonic segments. In relation to the pathogenesis of colonic carcinoma, the feces of Western people apparently contain increased proportions of anaerobic bacteria and these anaerobes allegedly degrade cholate to deoxycholate which then may act as a cocarcinogen within the lumen of the colon. The addition of fiber to the diet presumably would decrease the prolonged transit time within the colon, inhibit this degradation of cholate, and also help to dilute an intraluminal "carcinogen." Other conceptual mechanisms attempt to explain the increased frequency of ischemic heart disease, hiatus hernia, appendicitis and inguinal hernia v

5 vi FOREWORD largely on the basis of fiber-depleted diets in Western countries, though it should be noted that no dietary allowance or dietary requirement for fiber thus far has been established. Most of these epidemiological studies have been reported in the British literature, reflecting the influence of Burkitt's observations. American physicians and scientists appear to have directed little attention to these problems, and despite a considerable literature largely within the food industry, little scientific and clinical attention has been directed to dietary fiber and to the lack of fiber in the human diet. Yet fiber is a food substance with many properties. It apparently is capable of influencing intestinal and colonic function in many important ways. What indeed is dietary fiber and what are its functions? How valid are the epidemiological observations? Do they reflect an oversimplified view of the pathogenesis of complex illnesses undoubtedly involving more than one mechanism? How can dietary fiber presumably play a central role in the development of such diverse disorders as cancer of the colon, hiatus hernia, ischemic heart disease and diverticular disease of the large bowel? In the epidemiologic comparison of many different population groups with varying economic, social, cultural and ethnic backgrounds, are there not other as important if not more significant factors in the genesis of these diseases? To provide some answers to these challenging questions, a group of scientific investigators, not all of whom were directly involved in these fields of study, met for a one-day session on May 17, The meeting was held in the Center for Continuing Education, University of Chicago, under the sponsorship of the Gastroenterology Section of the Department of Medicine at the University. To encourage free discussion, the meeting was limited to 34 participants plus a small number of invited guests, representing the American Medical Association, the Food and Drug Administration and companies in the food industry. This volume represents a full record of the invited papers and the discussions that followed their presentation. The conference was oriented to dietary fiber and its possible effects, especially upon colonic function and colonic disorders. No attempt was made to extend the discussions to ischemic heart disease or hiatus hernia. Thus, the program was divided into three main sections, followed by a General Discussion and Summary: I. Dietary fiber and interaction with bacteria and bile; II. Fiber and colonic function; III. Fiber-deficient disorders of the colon. The objectives of the meeting were: to define the limits of our knowledge of fiber; to examine certain aspects of bowel function in relation to the possible influences of dietary fiber; to challenge the epidemiological observations mentioned earlier; to review the evidence linking the lack of dietary fiber to certain colonic disease and, most importantly, to encourage new studies of dietary

6 FOREWORD vii fiber and bowel disease. As was anticipated, the conference did not provide decisive answers to these questions, although the discussions amply confirmed the importance of the problem and its broad scope. Dr. Richard W. Reilly, Professor of Medicine at the University of Chicago, planned and arranged the conference. To his organizational skill a large share of the success of the meeting may be attributed. Already a new cooperative group for the further study of these problems in the United States is in the process of organization. It seems safe to predict that there will be an increased number of studies of dietary fiber and its relation to health and disease in many important medical centers throughout the world. Contributing to these developments have been the enthusiastic cooperation of all participants of the conference, and the efficient help of Terese Denov, Conference Secretarial Coordinator, and all the section secretaries who helped with the transcribing of manuscripts and the discussions. To all of these, we wish to express our thanks and appreciation. We are also greatly indebted to Franklin C. Bing, Ph.D., Vice President of Nutrition Dynamics, Inc., for helpful criticism and editorial advice on the preparation of the volume. Joseph B. Kirsner, M.D., Ph.D. Louis Block Distinguished Service Professor of Medicine and Deputy Dean for Medical Affairs, University of Chicago

7 Contents I. Dietary Fiber and Interaction With Bacteria and Bile Dietary Fiber D. M. Hegsted The Interrelationship Between Bile Acids, Bacteria and Dietary Fiber M. A. Eastwood Bile Salts and Fiber Kenneth W. Heaton , II. Fiber and Colonic Function Absorption From the Human Colon S. F. Phillips Electromyogram of the Cat Colon and Colonic Flow James Christensen Fiber, Bulk and Colonic Activity A. M. Connell III. Fiber Deficient Disorders of the Colon Fiber Deficiency and the Irritable Colon Syndrome 93 Thomas P. A1my Diverticular Disease (Pathology) 101 A. B. Price Fiber Deficiency and Diverticular Disease of the Colon Neil S. Painter ix

8 x CONTENTS Surgical Aspects of Diverticular Disease A. N. Smith 127 Fiber Deficiency and Colonic Tumors Denis Burkitt IV. General Discussion 149 Chairmen: Joseph B. Kirsner and Richard W. Reilly V. Summary Appendix 175 Participants 179 Index 181