Geophagia
Geophagia (/ˌdʒiːəˈfeɪdʒ(i)ə/), also known as geophagy (/dʒiˈɒfədʒi/),[1] is the intentional[2] practice of consuming earth or soil-like substances such as clay, chalk, or termite mounds.
[3] Geophagy in non-human primates is primarily used for protection from parasites, to provide mineral supplements and to help metabolize toxic compounds from leaves.
Galen, the Greek philosopher and physician, was the first to record the use of clay by sick or injured animals in the second century AD.
[8] In vitro and in vivo tests of these soils and many others from southeastern Peru indicate that they also release nutritionally important quantities of minerals such as calcium and sodium.
[14] Researchers Lee et al. show that parrot geophagy in South America is positively correlated to a significant degree with distance from the ocean.
[4] Studies have shown many benefits of geophagy such as protection from parasites (4.9%), mineral supplements (19.5%), and helping to metabolize toxic compounds from leaves (12.2%) nonexclusive.
[4] From soil analysis, it has been seen that one of the main compounds in the earth consumed by these primates is clay minerals that contains kaolinite, which is commonly used in medications for diarrheal and intestinal problems.
[21] In other cases, geophagy is used by the Ring-Tailed Lemurs as a preventive and therapeutic behaviour for parasite control and intestinal infection.
[22] The study was done at the salt licks in Veun Sai-Siem Pang Conservation Area, a site that is visited by various species of nonhuman primates.
[16] Slaves who practised geophagia were nicknamed "clay-eaters" because they were known to consume clay, as well as spices, ash, chalk, grass, plaster, paint, and starch.
[26] In Africa, kaolinite, sometimes known as kalaba (in Gabon[27] and Cameroon),[28] calaba, and calabachop (in Equatorial Guinea), is eaten for pleasure or to suppress hunger.
[29] Consumption is greatest among women, especially to cure nausea during pregnancy, in spite of the possible dangerous levels of arsenic and lead to the unborn child.
[30][31] Another example of geophagia was reported in Mangaung, Free State Province in South Africa, where the practice was geochemically investigated.
[26] Clay minerals have been reported to have beneficial microbiological effects, such as protecting the stomach against toxins, parasites, and pathogens.
To the extent that these cravings, and subsequent mineral consumption (as well as in the case of cravings for ice, or other cold neck vasoconstricting food which aid in increasing brain oxygen levels by restricting neck veins) are therapeutically effective decreasing infant mortality, those genetic predispositions and the associated environmental triggers, are likely to be found in the infant as well.
Likewise, multigenerationally impoverished villages or other homogenous socioeconomic closed genetic communities are more likely to have rewarded gene expression of soil or clay consumption cravings, by increasing the likelihood of survival through multiple pregnancies for both sexes.
