Vitamin A in Health and Disease PDF
Preview Vitamin A in Health and Disease
Vitamin • tn Health and Disease Vitamin • tn Health and Disease ANITOXIDANTS IN HEALTH AND DISEASE Series Editors LESTER PACKER, PH.D. University of California Berkeley, California JDRGEN FuCHS, PH.D, M.D. Johann Wolfgang Goethe University Frankfurt, Germany 1 . Vitamin A in Health and Disease, edited by Rune 8/omhoff Related Volumes Vitamin E in Health and Disease, edited by Lester Packer and Jiirgen Fuchs Vitamin • tn Health and Disease edited by Rune Blomhoff Institute for Nutrition Research University of Oslo Oslo, Norway Marcel Dekker, Inc. New Vork•Basei•Hong Kong Library of Congress Cataloging-in-Publication Data Vitamin A in health and disease I edited by Rune Blomhoff. p. em. -(Antioxidants in health and disease ; 1) Includes bibliographical references and index. ISBN 0-8247-9120-7 (alk. paper) 1. Vitamin A-Physiological effect. 2. Vitamin A in human nutrition. I. Blomhoff, Rune. II. Series. [DNLM: 1. Vitamin A-physiology. QU 167 V8375 1994] QP772.V5V56 1994 612.3 '99-dc20 DNLM/DLC for Library of Congress 93-46009 CIP The publisher offers discounts on this book when ordered in bulk quantities. For more information, write to Special Sales/Professional Marketing at the address below. This book is printed on acid-free paper. Copyiight © 1994 by Marcel Dekker, Inc. All Rights Reserved. Neither this book nor any part may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, microfilming, and record ing, or by any information storage and retrieval system, without permission in writing from the publisher. Marcel Dekker, Inc. 270 Madison Avenue, New York, New York 10016 Current printing (last digit): 10 9 8 7 6 5 4 3 2 1 PRINTED IN TIJE UNITED STATES OF AMERICA To Maia and Henrik! Series Introduction In June of 1992, 17 international researchers in the field of free radical and antioxidant biology and preventive medicine met at the village of Saas Fee, Switzerland, and drew up the Saas Fee Declaration to recognize the importance of prevention in medicine and health. Since then, hundreds of researchers from around the world have signed the declaration: Saas Fee Declaration On the significance of antioxidants in preventive medicine. 1. The intensive research on free radicals of the past 15 years by scientists world-wide has led to the statement in 1992 that anti oxidant nutrients may have major significance in the prevention of a number of diseases. These include cardiovascular and cerebro vascular disease, some forms of cancer and several other dis orders, many of which may be age-related. 2. There is now general agreement that there is a need for further work at the fundamental scientific level, as well as in large scale randomized trials and in clinical medicine, which can be expected to lead to more precise information being made available. 3. The major objective of this work is the prevention of disease. This may be achieved by use of antioxidants which are natural physio logical substances. The strategy should be to achieve optimal v vi Series Introduction intakes of these antioxidant nutrients as part of preventive medicine. 4. It is quite clear that many environmental sources of free radicals exist, such as ozone, sunlight, and other forms of radiation, smog, dust, and other atmospheric pollutants. The optimal intake of antioxidant provides a preventive measure against these hazards. 5. There is a great need for improvement in public awareness of the potential preventive benefits of antioxidant nutrient intake. There is overwhelming evidence that the antioxidant nutrients such as vitamin E, vitamin C, carotenoids, alpha-lipoic acid and others are safe even at very high levels of intake. 6. Moreover, there is now substantial agreement that governmental agencies, health professionals and the media should promote information transfer to the general public, particularly when evidence exists that benefits for human health and public expen diture are overwhelming. This declaration arose from the overwhelming evidence now available indicat ing that antioxidants play a critical role in wellness, health maintenance, and the prevention of chronic and degenerative diseases. Antioxidants neutralize free radicals that are generated during normal metabolism and during exposure to environmental insult. Free radicals play a role in most major health problems of the industrialized world, including cardiovascular disease, cancer, and aging. Some antioxidants are quite familiar as vitamins or vitamin-forming com pounds: vitamin E, vitamin C, and the carotenoids, including beta-carotene. These antioxidants must be constantly replenished through the diet. Others, such as ubiquinols and the thiol antioxidants, including glutathione and lipoic acid, are manufactured by the body, but the levels of many of these can be bolstered through dietary supplementation. Until recently, it was thought that each anti oxidant played its role in isolation from the others. But work in several laboratories indicates that there is a dynamic interplay among the systems. For example, when vitamin E neutralizes a free radical in a membrane, it becomes itself a relatively harmless free radical, which decomposes. However, vitamin C can regenerate vitamin E from the vitamin E radical, in effect "recycling" vitamin E. Vitamin C becomes a radical in the process, but it, too, can be recycled by interacting with other antioxidant systems. It has been shown that these inter actions occur in the test tube, and nutritional supplementation studies support this idea for the whole organism. Thus, there is emerging a picture of a com plex interplay among the defense systems, with the various antioxidant cycles acting to prevent cell damage and disease. Our knowledge is far from complete but these findings already have implications in terms of recommendations for supplementation. Series Introduction vii Hence, it seems particularly appropriate to present this series at the present time. Never has the demand for knowledge about antioxidants been greater, and never has their potential for treating disease and improving health been clearer. The series highlights natural antioxidants and artificial antioxidants which mimic natural systems. The last decade has been marked by enormous breakthroughs in the under standing of the molecular mechanisms underlying the functions of vitamin A and retinoids in the body. At the same time, we have greatly increased our knowledge about the therapeutic effects of these substances in several diseases. Recent progress on metabolism and nutrition, functions in embryonic development, dif ferentiation and reproduction, as well as epidemiological aspects related to vitamin A are reviewed in this book by Rune Blomhoff. Because of its wide range, the book may serve as a source of up-to-date information and as a reference for scientists in several disciplines, including nutritionists, biochemists, molecular biologists and clinicians, and those entering the field of vitamin A and retinoids. Lester Packer Jiirgen Fuchs
The list of books you might like
