|
|
||||||||
American Journal of Clinical Nutrition, Vol 53, 448-456, Copyright © 1991 by The American Society for Clinical Nutrition, Inc
ORIGINAL RESEARCH COMMUNICATIONS |
T Johns and M Duquette
School of Dietetics and Human Nutrition, Macdonald College, McGill University, Quebec, Canada.
Clays employed historically in the consumption of astringent acorns plus seven edible clays from Africa were examined in relation to the functional significance of human geophagy. On the basis of sorptive maxima for tannic acid ranging from 5.6 to 23.7 mg/g, we conclude that adsorption of tannic acid in traditional acorn preparation methods in California and Sardinia helped make these nuts palatable. Calcium available in solution at pH 2.0 and 0.1 mol NaCl/L was 2.10 and 0.71 mg/g for the Sardinian and Californian clays, respectively. The African clays released calcium, copper, iron, magnesium, manganese, or zinc in amounts of nutritional significance from some clays but not from others. A clay recovered from an archaeological site occupied by Homo erectus and early H. sapiens was indistinguishable mineralogically, in detoxification capacity and in available minerals, from clays used in Africa today. We suggest that the physiological significance of geophagy made it important in the evolution of human dietary behavior.
This article has been cited by other articles:
![]() |
S. Krief, R. W. Wrangham, and D. Lestel Diversity of items of low nutritional value ingested by chimpanzees from Kanyawara, Kibale National Park, Uganda: an example of the etho-ethnology of chimpanzees Social Science Information, June 1, 2006; 45(2): 227 - 263. [Abstract] [PDF] |
||||
![]() |
N. J. Dominy, E. Davoust, and M. Minekus Adaptive function of soil consumption: an in vitro study modeling the human stomach and small intestine J. Exp. Biol., January 15, 2004; 207(2): 319 - 324. [Abstract] [Full Text] [PDF] |
||||
![]() |
M J Dreyer, P G Chaushev, and R F Gledhill Biochemical investigations in geophagia J R Soc Med, January 1, 2004; 97(1): 48 - 48. [Full Text] [PDF] |
||||
![]() |
A.R.P. Walker, B.F. Walker, F.I. Sookaria, R.J. Cannan, and R.J. Cannan Pica The Journal of the Royal Society for the Promotion of Health, October 1, 1997; 117(5): 280 - 284. [Abstract] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |