Detoxification and mineral supplementation as functions of geophagy

Journal Article · Fri Feb 01 00:00:00 EST 1991 · American Journal of Clinical Nutrition; (USA)

OSTI ID:5979107

Johns, T; Duquette, M ^[1]

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1. McGill Univ., 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.

• OSTI ID: 5979107
• Journal Information: American Journal of Clinical Nutrition; (USA), Vol. 53:2; ISSN 0002-9165
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
CLAYS
DETOXIFICATION
NUTS
TANNIC ACID
ADSORPTION
BIOLOGICAL EVOLUTION
CALCIUM
CHEMICAL COMPOSITION
COPPER
DIET
IRON
MAGNESIUM
MAN
MANGANESE
MINERALS
OAKS
ZINC
ALKALINE EARTH METALS
ANIMALS
AROMATICS
CARBOXYLIC ACIDS
ELEMENTS
FOOD
FRUITS
HYDROXY COMPOUNDS
MAGNOLIOPHYTA
MAGNOLIOPSIDA
MAMMALS
METALS
ORGANIC ACIDS
ORGANIC COMPOUNDS
PHENOLS
PLANTS
POLYPHENOLS
PRIMATES
SORPTION
TRANSITION ELEMENTS
TREES
VERTEBRATES
560300* - Chemicals Metabolism & Toxicology