Of the 20 life sciences covered by Annual Reviews Inc. in its yearly critical reviews, 7 deal with environmental topics. Within these disciplines—ecology, sociology, public health, medicine, nutrition, pharmacology and toxicology, and microbiology—environmental issues are the subject of ever-increasing political debate. Although the mission of Annual Reviews Inc. is to provide current, critical discussions of scientific progress, the role that politics plays in the rate of progress achievable in most sciences, and particularly in the seven life sciences mentioned, needs to be acknowledged. Significant political factors are the sociologic climate in which a given science is pursued, the extent to which scientific policy is determined by nonscientific issues, the availability of funding, and the perception by scientists that they are working in a favored or at least an accepted branch of science. These days it is very difficult for practicing scientists to escape the impact of politics on their work.

The field of nutrition, which deals not only with scientific aspects of food but with cultural, sociological, and psychological beliefs about foods, is particularly vulnerable to these political intrusions. For example, ancient mythology about "good" and "bad" foods is scientifically untrue, apart from foods that are extensively contaminated or poisonous. There is no evidence that all foods taken in variety and moderation cannot constitute a healthful diet. And yet, for various reasons, most of them primarily emotional, foods like bran, yogurt, brown sugar, blackstrap molasses, and honey are considered "good." For equally unscientific reasons foods such as red meat, potato chips, whole milk, ice cream, eggs, butter, and animal foods in general are considered "bad." And what was "good" two generations ago may now be "bad" if it is thought to contribute to the development of cancer or coronary heart disease. The whole diet, not just part of it, determines nutritional status. Simply stated, there are good and bad diets, not good and bad foods. Nonetheless, marketers of individual foods trumpet health claims for their products with increasing frequency and stridency.

In Volume 10, the lead article "Nutrition Science from Vitamins to Molecular Biology" by Dr. Thomas Jukes of the University of California at Berkeley is an autobiographical account of Dr. Jukes' very considerable contributions not only to science but to the battle against food faddism and scientific quackery. Dr. Jukes recounts his extensive contributions to the isolation, purification, and determination of the biological activity of a variety of B-complex vitamins and to the understanding of molecular evolution. More recently, he has come to the defense of science in the public sphere by confronting creationism, food faddism, and various forms of quackery including megavitamin therapy. An enterprising virtuoso who has accepted challenges from science as well as from politics, Dr. Jukes can serve as a role model for scientists who are timid about jousting in the public arena. We scientists tend to justify by our behavior the allegation that we live in an ivory tower and that our endeavors are dissociated from the maelstrom of human affairs. For the very reason that we are so dependent upon the society in which we work, more of us must come down from our tower and do battle in the streets. We must stand up to creationists, the animal rightists, the science nay-sayers and we must convince society that science is a friend, that the Human Genome project is more important than a Stealth bomber, and that increasing the literacy of our citizens about scientific matters is one of society's most urgent tasks.

The other reviews in Volume 10 of the Annual Review of Nutrition deal with a variety of subjects involving both experimental and clinical investigations. In the field of lipids, articles review the plasma lipid transfer enzymes, lipoprotein secretion by the liver including the metabolic function of M-3 fatty acids in controlling lipoprotein synthesis, and the role of polyunsaturated fatty acids in the skin. In the vitamin field various chapters discuss vitamin E, a possible new vitamin pyrroloquinoline quinone (PQQ), folate-binding proteins, and vitamin D as an agent for cell differentiation. The reviews on minerals include studies of selenium, iron, iodine, copper, and zinc, with particular emphasis on regulation by metallothioneins. Regulation of metabolism by nutrients is discussed in reviews on the physiology of exercise, transgenic partitioning of nutrients, the study of metabolic compartments, the role of amino acid metabolism in cachexia, and the effect of gut peptides on appetite. Specialized essays consider the role of nutrients in controlling neural tube development and affecting the formation of cataracts.

Finally, thanks are due to my associates on the Editorial Committee, the consultants who aided us in assembling the list of topics and authors, and the authors who contributed excellent reviews to Volume 10. Ann McGuire and Joan Cohen in Palo Alto, California, deserve our thanks for their important work in producing this volume.

Robert E. Olson, Editor