Volume 8 of the Annual Review of Nutrition presents another rich mixture of reviews in the fields of experimental, clinical, and public health nutrition. The divisions among these branches of nutrition are becoming blurred as given problems in nutrition are increasingly approached from all sides. The human animal, furthermore, is accessible and numerous enough to investigate across the range of disciplines from cell and molecular biology to epidemiology. In fact we are hearing more, these days, not only of genetics but of genetic epidemiology as a field for the elucidation of risk factors in the nutrition-related chronic diseases.

Inclusion of data from both clinical and experimental nutrition is obvious in many of the reviews contributed this year. This integration of approaches to clarify nutritional problems in biology is most welcome. The discussion of regulation in the broad context of genetics, metabolism, and nutrition is another theme exemplified in this volume, particularly in the essays on insulin receptors, cachectin, heredity and body fat, and inborn errors of pterin metabolism.

Reviews on the vitamins include updates on thiamin, riboflavin, biotin, pantothenic acid, vitamin D, vitamin E, and vitamin K as it pertains to the synthesis of bone matrix proteins. The inorganic nutrients reviewed include phosphorus, magnesium, copper, molybdenum, and chromium.

The importance of n-3 fatty acids and the role of dietary lipids and alcohol in cancer risk are discussed, as is the absorption of intact proteins by the gastrointestinal tract. Chapters on fiber, lactation, fetal nutrition, lymphocytes, and olfaction complete the list.

Drs. Austin and Overholt devote then: prefatory chapter to the very timely subject of "Nutrition Policy: Building the Bridge Between Science and Politics." They discuss the barriers as well as the symbioses between scientists and politicians in developing nutrition policy. They stress the need for all students of nutrition to learn something about the political process because of the enormous challenges that the world will face in the twenty-first century. Judicious scientific input will be required to solve the Third World's problems of undernutrition that prevail in stark contrast to the Western World's problems of overnutrition.

The everlasting conflict between the drive to specialize and the need to generalize plagues nutrition scientists as never before. Nutrition science needs both emphases in order to serve humanity. Let's hope that the legitimate need for specialization in the most fundamental aspects of biology in order to understand nutritional disease does not totally overwhelm the social and ecological need to optimize food intake in the various human societies that inhabit this planet.

I would, again, like to thank my associates on the Editorial Committee, the consultants who aided us in assembling the list of topics and authors, and the authors who contributed the excellent reviews that appear in Volume 8. Ms. Margot Platt, in Palo Alto, California, deserves our continuing thanks for her important work in producing this volume.

Robert E. Olson, Editor