Book Review

Natural Antioxidants in Human Health and Disease

N Engl J Med 1995; 332:688March 9, 1995

Article

Natural Antioxidants in Human Health and Disease
Edited by Balz Frei. 588 pp. San Diego, Calif., Academic Press, 1994. $99. ISBN: 0-12-266975-4

The first 128 pages of this book contain four chapters that clearly summarize the basics of free-radical chemistry, the generation of free radicals in biologic tissues, and the nature of antioxidant defense systems in mammals. The balance of the book (16 chapters) deals with current knowledge relating antioxidants (mainly natural antioxidants) to cancer, cardiovascular disease, immunity and infection, cataracts, and neurologic disorders.

The reviews of basic studies — of cell-culture, animal, and epidemiologic studies — make a persuasive case for a connection between free radicals and diseases. However, a pattern quickly emerges in the chapters dealing with disease. Despite the strength of the basic studies and epidemiologic correlational studies, each chapter concludes with much the same message: “We cannot decide whether antioxidant supplements will influence this disease process unless and until we launch large, double-blind, randomized clinical intervention trials.” This conclusion may be frustrating and unsatisfying, but it is what seems to emerge, despite the strength of some of the epidemiologic evidence and, in some instances, the convincing interventional data in animal models of disease. As Bruce Ames points out in a nice foreword, epidemiologic studies repeatedly demonstrate strong negative correlations between the intake of fruits and vegetables and the risks of various degenerative diseases. Such correlations have been recorded with respect to many of the diseases discussed in this book. However, as several contributors point out, it by no means follows that the correlation relates exclusively or even partly to the antioxidants contained in those fruits and vegetables. There could be confounding of several kinds. For example, a high intake of fruits and vegetables generally correlates with a low intake of fats. It may also correlate with geographic locale and economic status. Still, the combination of strong epidemiologic correlations plus the strong conceptual basis for predicting protection by antioxidants makes one hopeful that preventive measures may someday be proved to work — or, they may not. The contributors of the chapters on specific categories of disease generally make well-balanced presentations that stress the strengths of the evidence from cell-culture and animal studies while maintaining appropriate restraint in the interpretation of epidemiologic studies. All of us await the results of clinical trials.

The editor, Balz Frei, has chosen highly qualified contributors. This book should be useful for scientists, physicians, and nutritionists seeking to improve their understanding of the basic science of antioxidants. Unfortunately, the editor's hope that the book will also be accessible to “lay persons interested in the potential health benefits of natural antioxidants” will probably not be realized. For the most part, this book is written rather rigorously and does not slow down for newcomers. For those reasonably familiar with the context, it should be a useful review of current knowledge and likely future directions.

Daniel Steinberg, M.D., Ph.D.
University of California, San Diego, La Jolla, CA 92093