Volume 19, Issue 18 p. 2497-2506
Research Article

Nitrogen balance and δ15N: why you're not what you eat during nutritional stress

Benjamin T. Fuller

Corresponding Author

Benjamin T. Fuller

Research Laboratory for Archaeology and the History of Art, University of Oxford, 6 Keble Road, Oxford OX1 3QJ, UK

Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK

P.O. Box 707, Auburn, CA 95604, USA.Search for more papers by this author
James L. Fuller

James L. Fuller

Sutter Auburn Faith Hospital, 11815 Education Street, Auburn, CA 95602, USA

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Nancy E. Sage

Nancy E. Sage

Sutter Auburn Faith Hospital, 11815 Education Street, Auburn, CA 95602, USA

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David A. Harris

David A. Harris

Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK

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Tamsin C. O'Connell

Tamsin C. O'Connell

Department of Archaeology, University of Cambridge, Downing Street, Cambridge CB2 3DZ, UK

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Robert E. M. Hedges

Robert E. M. Hedges

Research Laboratory for Archaeology and the History of Art, University of Oxford, 6 Keble Road, Oxford OX1 3QJ, UK

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First published: 16 August 2005
Citations: 386

Abstract

While past experiments on animals, birds, fish, and insects have shown changes in stable isotope ratios due to nutritional stress, there has been little research on this topic in humans. To address this issue, a small pilot study was conducted. Hair samples from eight pregnant women who experienced nutritional stress associated with the nausea and vomiting of morning sickness (hyperemesis gravidarum) were measured for carbon (δ13C) and nitrogen (δ15N) stable isotope ratios. The δ13C results showed no change during morning sickness or pregnancy when compared with pre-pregnancy values. In contrast, the δ15N values generally increased during periods of weight loss and/or restricted weight gain associated with morning sickness. With weight gain and recovery from nutritional stress, the hair δ15N values displayed a decreasing trend over the course of gestation towards birth. This study illustrates how δ15N values are not only affected by diet, but also by the nitrogen balance of an individual. Potential applications of this research include the development of diagnostic techniques for tracking eating disorders, disease states, and nitrogen balance in archaeological, medical, and forensic cases. Copyright © 2005 John Wiley & Sons, Ltd.