Geophagy Flashcards
Geophagy
Practice of eating soil or soil-like substances such as clay or chalk
Pica
Eating disorder - cravings for non-nutritive items
Oldest evidence for geophagy
Calcium-rich white clay found alongside bones of Homo habilus at Kalambo Falls near boarder of Zambia and Tanzania
Pliny
Writer in ancient Rome who notes ingestion of soil on Lemmos (island of Greece)
Textbook of hippocrates links what to geophagia
Anaemia
Historical evidence of geophagy from South America
Otomacs (tribe in Venezuela) eat fine yellow-gray clay slightly baked in fire until red crust forms every day to appease hunger
Historical evidence of geophagy from Indonesia
In Java - reddish cakes called taanampo made from iron-rich clay
Historical evidence of geophagy from Africa
David Livingstones writing about slaves eating soil in Zanzibar which they brought to the “new world”
Why did slaves in America continue to practice geophagy
- perceived nutrition
- cultural reasons
- make themselves ill so they could not work
- to commit suicide in the belief that their spirit would return to their African homeland
What was so effective that some plantations had to be abandoned
Suicide by eating large amounts of soil
Some slave owners did what to prevent soil eating
Made slaves wear masks
Historical evidence of geophagy from North America
Common among poor whites in Southern USA in early 1990s
T/F: processed, cooked, and baked dirt is still sold in the rural American South
T
What did people in early America believe about eating clay
- increased sexual prowess
- helped pregnant women have an easy delivery
Kaolin
Type of clay eaten in contemporary Africa to suppress hunger
Sold in most markets in Cameroon, flavoured with spices like black pepper and cardamom
Kaolin
Consumed by pregnant or lactating women to reduce nausea and supplement mineral-deficient diet in Africa and Asia
Clay or earth
Controversy in west for eating clay
- possibly absorbs toxins in GI tract
- can contain harmful parasites and lead poisoning
Geophagy in Kenya
- 73% of children 5-18yrs old eat soil (28 g/day)
- 154 of 275 pregnant women eat soil regularly
Contemporary geophagy in Haiti
Poor people eat “dirt cookies’ to survive
Summarize reasons why people eat soil
- sense of fullness in times of famine
- digestive aid for detoxifying food
- pharmaceutical to treat nausea
- psychological reasons (help anxiety)
- intentional illness/suicide
- perceived benefit
Indegineous people in Andes ate clay dip with what, why
Potatoes, potatoes contained toxic chemicals and clay helped prevent absorption of toxins or promoted excretion
Negative effects of eating soil
- mineral nutrient deficiencies (particularly iron)
- toxicity (can contain heavy metals)
- ingestion of bacteria or geohelminths (worms)
- intestinal blockage and excessive tooth wear
Why is iron so deficient in clay eaters
only 0.5% of iron in clay can be absorbed by humans
Phosphorus role in body
Forms bones
Potassium role in body
catalyst in protein synthesis and energy release
Calcium role in body
Promotes bone growth in conjunction with Vit D
Magnesium role in body
Protein synthesis, energy release, calcification, secretion of thyroxine, contraction of nerve impulses, and metabolic rate
Copper role in body
Associate with hemoglobin and enzyme systems
Zinc role in body
Constituent and catalyst of enzymes for metabolism and sexual development
Maganese role in body
Catalyst for enzymes, helps store thiamine
Iron role in body
Hemoglobin synthesis and enzyme systems
Clays in Southern Nigeria - study results
- rich kaolinite content clays serve as antacid
- Staphylococcus aureus and micrococcus acidophilus common of all samples
- little or no nutritive value in clays
Why was clay made a popular poison antidote in ancient times
Capacity to bind some elements
