点击显示 收起
Department of Morphological Sciences, The Bruce Rappaport Faculty of Medicine, Technion–Israel Institute of Technology, Haifa, Israel
Division of Pulmonary-Critical Medicine, Department of Internal Medicine, University of California, Davis
by Lester Packer and Carol Colman, 1999, 256 pages, hardcover, $24.95. John Wiley and Sons, Inc, New York.
The role of free radicals and antioxidants in biomedical problems is of great current interest to both the biomedical community and the public. The US population consumes an estimated $15 billion worth of dietary supplements (including antioxidant micronutrients) annually, fueled by hot consumer interest in alternate health remedies and fortified by unbridled corporate marketing strategies that are relatively unmonitored by the governmental regulatory policies that monitor the safety and efficacy of drugs. In The Antioxidant Miracle, the authors articulate their understanding of this field to the public from the perspective of a basic scientist who has made monumental contributions to the field and is a true believer in the concept that antioxidants are beneficial to human health.
The book has 4 multichapter parts and several appendixes. The introduction describes the main theme of the book, which is the advantage of antioxidant supplementation to health. In part 1, the authors lay the basic principles and introduce the mechanisms of action of the various antioxidants. The major idea revolves around the concept of the "antioxidant network," namely, that antioxidants work in concert by recycling each other. Five main players in the network are introduced: vitamins E and C, coenzyme Q10, glutathione, and lipoic acid. The major features that make them such efficient antioxidants are described in simple lay language. However, it should be emphasized that much of the evidence for the existence of the antioxidant network concept comes from in vitro studies and there is scarce evidence for its validity in vivo. Nonetheless, this concept is a revolutionary idea that largely originated at Packer's laboratory.
Part 1 also covers topics like the nature of free radicals and their involvement in various diseases such as cancer, heart disease, and stroke and in diseases characterized by inflammatory immune system activation. The role of free radicals in disease processes has been relatively overlooked in modern medicine. It has only been in the past 20–25 y that an explosion of information in this field has led to an understanding that radicals do play a role in numerous cellular regulatory processes. It is through these mechanisms that antioxidants can intervene.
Part 2 is devoted to more extensive descriptions of the 5 members of the antioxidant network. In this section, the involvement of this network in providing protection against stroke, heart disease, and cataract are described, including the positive effects of lipoic acid in curtailing biomolecular damage caused by radiation and cigarette smoke. Part 2 also discusses the roles of vitamins E and C in the chemoprevention of cancer, neurodegenerative and cardiovascular diseases, and the common cold. Finally, somewhat less elaborate discussions are devoted to the functions of cytochrome Q10 and glutathione in modulating disease processes.
Part 3 describes what Packer calls the "network boosters," which include antioxidants such as the flavenoids, carotenoids, and selenium, of which the latter is not by itself an antioxidant but is an essential component of several antioxidant enzymes. Although there is test tube evidence that flavenoids and carotenoids can recycle vitamin C, they are not essential ingredients of any cells and therefore are not considered major components of the antioxidant network system. The sections on flavonoids and the "controversial" carotenoids are particularly illuminating. The authors do an excellent job of presenting the controversy around the unequivocal epidemiologic evidence that people who eat foods rich in carotenoids are less likely to die of cancer and the almost equally unequivocal results of studies that showed almost 30% higher mortality from lung cancer in smokers taking ß-carotene supplements.
In part 4 a detailed and elaborate discussion is devoted to what is called the "Packer plan." This involves a strategy for deploying antioxidants in combating disease and improving health and longevity. In this last section, practical recipes and specific dosages are enumerated for each of the recommended antioxidant supplements. Their food sources and various maladies that can somewhat speculatively be ameliorated by eating particular supplements are detailed. Special sections in this part of the book are devoted to antioxidant supplements recommended for persons at special risk, such as smokers, those individuals at high risk of developing cancer and cardiovascular diseases, and the aged.
Finally, in the appendix, graphs and tables are presented that bring quantitative aspects to the major ideas of the book. Quantified aspects of poor and good plasma antioxidant profiles are depicted. Graphic description of the network concept and how vitamin E is transported in the body are also illustrated. It is curious that the supporting figures and tables were left the appendix because it would have been more useful to incorporate them throughout the book to break up the long and sometimes repetitive text. Fourteen pages of authoritative references and an 8-page index complete the work.
The Antioxidant Miracle is smooth and easy to read. It is intended for an educated lay public and, thus, the scientific language is minimized. It provides a relatively up-to-date, reasonably factual account of most current areas in free radical research as they relate to nutritional considerations. The many facts are intertwined with somewhat optimistic interpretations and oversimplifications of the biological intricacies of complex disease processes. It does clearly provide a useful tool for educating a relatively uninformed public. On the surface, it provides an integrated holistic version of the virtues of a healthy diet supplemented with selected antioxidant supplements, in keeping with Packer's own values, beliefs, philosophical orientation, and interpretations of his own and others' research activities. This is in contrast with the food faddists of yore, and there is basic science underpinning the claims made. Unfortunately, the promises made are really hypotheses and it is now up to more hands-on health-care practitioners and clinical researchers, including nutritional epidemiologists, to step up to the plate with well-designed, rigorous clinical studies to evaluate the role of antioxidants in human health and disease.